Proceedings
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1. A Comparison of Producer Adoption of Precision Agricultural Practices in Denmark, The United Kingdom, and Nebraska in the United StatesWhile a lot of research and commercial development has taken place in precision agriculture in recent years there is little information available about the experience and opinions of the producers who are trying to make it pay its way in the field. Information about producer experiences in precision agriculture would be useful in guiding hture research and development in both the public and private sectors. Important questions could include: - what types of precision agriculture practices are pr... |
2. A Weighted Classified Method for Nitrogen Zone DelineationEven though zone management in precision agriculture is a relatively new science. extensive research has been conducted on the best predictors for determining optimal nitrogen management zones in site-specific farming (Bausch et al., 2002; Fleming and Buchleiter, 2002; Franzen and Nanna, 2002, Hendrickson and Han, 2000; Lund et al.. 2002: Stenger et a].. 2002). Different techniques. varying from cluster analysis (Jaynes et al.. 2003; Kitchen et al., 2002: Ralston et al.. 2002) to neural networks... |
3. Adapt-N: A Computational Tool for Precise N Management in CornCurrent approaches to estimation of optimum N fertilizer rates are based on mass balances, average expected economic return based on field experiments, soil N tests, an d crop leaf or canopy sensing. However, denitrification and leaching losses of nitrogen may occur from dynamic and complex interactions among weather, soil hydrology, crop water and N uptake, and management practices , and result in high variability in annual crop N needs in maize ( Zea mays L.) production. W eather impacts the ... |
4. Adjusting N Recommendations Based on a Previously Grown CropNitrogen recommendations in North Dakota are based on a yield goal multiplied from some empirically derived factor in a linear formula. There are a three adjustments to the N recommendations that result form these formulas (Franzen and Cihacek, 1996). They are the soil test nitrate-N to some depth, a sampling date adjustment ifthe sampling was conducted in the fall prior to September 15, and a previous crop credit. Two of these three adjustments are based on some knowledge regarding mineralizati... |
5. An Overview of On-Farm Nitrogen Rate ResearchBecause crop advisors, farmers, and some in the fertilizer industry questioned the University's N recommendations as being too low and raised concerns that the N calibration research had been done primarily in small plots on University Experiment Station land. numerous N calibration studies for corn after soybeans were conducted on farmers' fields in southern Minnesota and northeastern Iowa from 1989 through 2002 to validate present N recommendations. On-farm replicated trials were conducted by ... |
6. Assessing Nitrogen Management and Claypan Soil Variability Effects on Switchgrass using Reflectance SensingThe topsoil depth or depth to the claypan (DTC) can be highly variable across the landscape for some Midwest soils. This makes managing crops on these soils difficult because their productivity can be highly variable. In some ar eas of the landscape there can be no topsoil and leave the claypan exposed (e.g., side-slope) while in other areas it can be buried (e.g., toe-slope) (Kitchen et al., 1999). Due to the high variability of theses soils, switchgrass (Panicum virgatum L.) is a potential pro... |
7. Assessing Spatial and Temporal Nutrient Dynamics with a Proposed Nutrient Buffering IndexContinued adoption of precision agriculture will lead to the accumulation of spatially and temporally dense soil fertility and yield data. Current soil fertility recommendation strategies use regional estimates of soil buffering properties to adjust application rates. A site specific nutrient buffering index (BI) is presented that uses accumulated yield maps and soil test data to locally estimate soil buffering properties relative to fertilizer additions and crop removal. BI is a quantity-inten... |
8. Biochar: Waste, or Product?Nutrient losses following summer and fall manure applications result in economic and water quality problems. We tested the potential of biochar (BC) and ammonium thiosulphate (ATS) as manure additives to retain nutrients by reduci ng nitrate pool size and runoff of N and P. To determine appropriate rates to use in field expe riments, the compounds were initially added at different rates to liquid swine manure (LSM) then the slurry mixed with soil and incubated. The selected rates, based on N tra... |
9. Building a Corn Nitrogen Rate Database for Minnesota's Irrigated Sandy SoilsA study was conducted to determine the optimum N rate to apply for corn grown on irrigated sandy soils in Minnesota. Sandy soils in Minnesota vary in the texture of the surface fron silt loam to sand. Since 2006, 11 sites had 8 to 9 N fertikizer rates applied. The optimum N rate for the sandy sites with a silt loam surface texture ranged from 168 kg N/ha to 200 kg N/ha while the sandy surfaced soils optimum N rate ranged from 250 kg Nha to 280 kg N/ha. The silt loam surface soil sites optimum N ... |
10. Can Unmanned Aerial System-Mounted Passive Sensors Be Used To Recommend Sidedress Nitrogen Rates In Corn? A Comparison Between Active and Passive SensorsThe objectives of this research were to (i) assess the correlation between active and passive crop canopy sensors’ vegetation indices at different corn growth stages, (ii) assess sidedress variable rate nitrogen (N) recommendation accuracy of active and passive sensors compared to the agronomic optimum N rate (AONR) and (iii) assess sidedress VR N rate recommendation correlation between active and passive sensors. Two experiments were conducted, one near Central City, Nebraska on a Novi... L. Bastos, R. Ferguson |
11. Chemistry of Soil Phosphorus - Agronomic and Environmental ImplicationsTo be available for uptake by crop plants or to stimulate algal growth in a eutrophic environment, P must in a dissolved form. Therefore, in the absence of soil erosion, chemical processes that can transfer phosphate ions from the soil solution to the solid phase can limit P bioavailability and mobility. These processes include exchange, adsorption, and precipitation reactions. This presentation focuses on how local fluctuations in soil water content, solution pH, redox potential, and dissolv... M. Thompson |
12. Comparative N and Dry Matter Dynamics in Corn Ears, Stems, and Leaves During the Critical Period After Early and Late-split Sidedress NThere is currently great interest in the possible agronomic and environmental benefits of split N applications that include a late vegetative sidedress timing. The objective of this study was to determine the impact of N rate and timing of N application on the accumulation of N and dry matter in the ears, stems, and leaves of corn during the critical period (encompassing the period two weeks before to two weeks after silking) in order to understand the differing sensitivity to N stress in the... S. Mueller, T. Vyn |
13. Comparison of Nitrogen Management Zone Delineation MethodsAn alternative to dense grid soil sampling for delineating residual soil N levels or N availability is a zone sampling approach. The zone approach assumes that soil N patterns are logically linked to some inherent causal effect, either natural or man-made. A number of delineation methods have been examined. including apparent soil EC (Kitchen et al.. 1999). yield mapping (Taylor and Whitney. 2001: Diker et al.. 2002), topography (Franzen et al.. 1998), aerial imagery (Williams et al., 2002 Srip... |
14. Corn and Soybean Response to Potassium Fertilization and PlacementI\ncreased adoption of conservation tillage, evidence of large within-field nutrient variability, and an apparent increase in the Frequency of crop potassium (K) deficiency symptoms in Iowa and other states have prompted questions about the effectiveness of current soil-test K interpretations and fertilizer recommendations. These questions relate to fertilizer placement and management of within-field nutrient variability. Broadcast placements are less costly than banded placements but they seem ... |
15. Corn Nitrogen Calibration in South DakotaSouth Dakota (SD) corn nitrogen (N) rate recommendations were last established in 1991 and based on the coefficient of 1.2 lbs N/bu of the yield goal. The South Dakota corn N rate calculator subtracts the pre-plant soil test NO3-N (0-2ft) and legume credits and adds 30 lbs N/a for recently established no-till. Much improved corn genetics, shifting farming practices, and climate changes warrant re-calibration of corn N rate recommendations. During 2013-2105, N rate studies were conducted at 20... A. Bly, S. Berg |
16. Corn Nitrogen Response Across Environments and Crop RotationRecent research on corn has tended to show variability in N response. Brown et al. (1993) reported that economically optimal N rates among 77 sites in Illinois ranged from zero to more than 200 lb N per acre. Results from other studies show similar variability in time and space. Even with such variability, results over environments have been combined and used to develop an N fertilizer rate guideline in Illinois based on anticipated corn yield (Hoeft and Peck, 2002). This guideline suggests pro... |
17. Corn Plant Uniformity Following Shallow NH3 Placement in Precision-Guided, Pre-Plant Nitrogen ApplicationsCorn (Zea mays L.) production relies extensively on different types of N fertilizers, and anhydrous ammonia (NH 3) continues to be a dominant N s ource in much of the Corn Belt. Timing and placement of NH 3 fertilizer can affect plant-to-plant uniformity and yield of corn, and especially so when high N rates are applied and there is little time between spring pre-plant NH 3 application and planting. The effects of shallow pre-plant NH3 placement on corn plant-to- plant uniformity were investig ... |
18. Corn Residue Harvesting Effects on Yield Response to N FertilizationProducers have many choices of diverse tillage practices for their corn (Zea mays L.) production systems. However, no-till has become an important soil management practice to help reduce water and wind erosion, as well as nutrient runoff, while conserving soil moisture for crop use. No-till systems also help farmers by saving labor and time, as well as reducing farm costs due to less equipment and fuel consumption. Nevertheless, no-till production is typically more successful and has higher crop... |
19. Deep Tillage in a Corn-Soybean Production SystemMany crop producers in the Midwestern United States are currently using deep tillage, accomplished with equipment designed to run at depths of 30 to 40 cm, even though the effects of this practice are not well characterized. We assessed the effects of deep tillage, no tillage, and chisel plowing in the fall, with and without secondary tillage in the spring, on penetrometer resistance, plant stand, and yield of corn and soybean grown in rotation. In the spring, averaged across two years and six ... |
20. Deep Zone Tillage in Southeast Minnesota1 Deep Zone Tillage In SE MN (Rawson) i - --4 I Continuous corn y~eld as affected by trllage system at Rochester, 1997-00 (4-yr avg) LSD (0 10) = 3 bu - 170 IW 9 3 I 163 160 No-hll Rawson Stnp-UI Chtsel + . tillage system at Rochester, 1997-2000. LSD (0 10) = NS Rawson Stnptll Onepass Corn following soybean treatments Tillage for ' Tn # Soybean Corn 1 No-till No-till 2 Chisel + 3 No-till Ripstrip 4 Chisel + 5 No-bll Fall striptill 6 Chisel + 7 No-till One-pass 8 Chisel + 9 Chisel + Ch~sel 34kMj ... |
21. Detecting Spatially Variable Corn Nitrogen Needs Using Green Reflectance from 35MM PhotographsRising fertilizer costs and environmental concerns are reasons producers are looking to decrease nitrogen (N) fertilizer rates. This study investigated the use of relative green reflectance fiom 35 rnrn aerial photographs to detect spatially variable corn [Zea mays L.] N needs for developing variable rate fertilizer maps. Photographs were taken at three different growth stages (V7, V11, R3) at altitudes from 3,000 to 5,500 fi for two Missouri fields representing alluvial and deep loess soil type... |
22. Diagnosis of Nitrogen Deficiency in Maize and the influence of Hybrid and Plant DensityThe precise diagnosis of maize N status has proven to be a difficult task because of annual 1 variation in internal N-use efficiency (kg grain kg- N uptake) and temporal change in N concentration in plant tissue. Analysis of leaf N concentration (g N leaf) has not been a consistently successful N diagnostic because of temporal and hybrid differences in specific leaf weight (SLW=g leaf me2 leaf). An alternative N diagnostic; specific leaf nitrogen (g N m-2 leaf), is unrelated to leaf mass. Maximu... |
23. Do Phosphorus TMDLs Interfere with Crop Nutrient RecommendationsHistorically, phosphorus (P) fertilizer recommendations for crops have been based on the crop grown, soil P test levels, locally correlated and calibrated yield responses, efficient use of P fertilizer, and fertilizer and crop price ratios. With the implementation of TMDLs and the need for reduced P loading in surface waters, P fertilizer applications must also safeguard water quality. In order to understand the challenges that this presents and the possible changes in P fertilizer recommendatio... |
24. Do Soil Tests Predict Yield Response to Phosphorus in Modern Corn and Soybean Production?Modern corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] production systems produce higher yields, and consequently, may remove more nutrients than fertilizer rates based upon existing soil test recommendations for these yields. With greater emphasis on soil test levels for nutrient stewardship strategies, soil tests need to also predict critical levels in which fertilized nutrient responses are likely. Current soil test recommendations for Illinois have negl... T. Beyrer, F. Below |
25. Effect of Changing the Rotation Sequence in a Long Term Tillage and Fertility StudyA continuous experiment was conducted fiom 1970 to 1999 to determine the long term effects of fertilizer application and tillage practices on soil acidity, organic matter and nutrient changes, and crop responses. Four tillage treatments were evaluated: continuous conventional: alternate till (two years no-till: one year conventional); continuous chisel till; and continuous no-till. Five fertilizer treatments were also evaluated (Ib ac-' N-P205-K20): check, 0-0-0; 175-0-0 broadcast; 160-0-0 broad... |
26. Effect of Late-Applied N on Corn Dry Matter, N Content, and YieldNitrogen management of corn (Zea mays L.) may be improved by delaying N application until just prior to the rapid growth phase (approximately V6-V8). This timing is commonly referred to as 'sidedress'.� Some farmers do not sidedress because they are concerned inclement weather may delay N application beyond V8, requiring high clearance equipment to apply N and possibly reducing grain yield. However, few studies have investigated the effects of late-applied N in rain-fed production environment... |
27. Effects of Applied Soil Micronutrients on Corn and Soybean Yields in Eastern South Dakota EnvironmentsMicronutrients although taken up by plants in small quantities, their deficiencies can have significant detrimental effects on grain yield. As growers aim for maximum corn and soybean yields, availability of micronutrients in agricultural market both as individual source or combined with other secondary nutrients have also increased. However, effects of micronutrients on corn and soybean grain yields are not well documented for South Dakota (SD) soils, and growers seem to be concerned if appl... D. Karki, A. Bly, S. Berg |
28. Effects of Chloride From Poultry Litter and Muriate of Potash on Cured Tobacco Leaf QualityPoultry litter is growing more popular as a soil amendment in western Kentucky. due to recent poultry industry expansion. There is concern among the tobacco industry that chloride levels in poultry litter may have detrimental effects on cured leaf quality. A three year study is being conducted at the University of Kentucky to compare availability of chloride fiom poultry litter and muriate of potash and its effect on cured leaf quality. A randomized complete block design structure was chosen, wi... |
29. Enhanced Efficiency Phosphorus Application for a Corn-Soybean RotationPhosphorus (P) is an essential plant nutrient that is taken up by plants as inorganic ions (H 2PO4- and HPO 4 -2) found in soil solution. With higher fer tilizer costs, farmers are evaluating application rates and considering enhanced effi ciency phosphorus applications or treatments. AVAIL®(Specialty Fertilizer Products, Leawood, KS), NutriLife Max® (Advanced Microbial Solutions, Pilot Point, TX), and P ₂O ₅ Max (Rosen's Inc., Fairmont, MN) are three products that are intended to enhance ... |
30. Enhancing Soil Nitrogen Availability in Corn-Based Cropping SystemsThe development of sustainable N management systems requires a better understanding of the contribution of on-farm resources to the active N pool size and its mineralization. This study explores the effect of substrate diversity and living corn roots on improving N supply through mineralization. A "diverse system", consisting of a corn (Zea mays L.)-corn-soybean (Glycine mar L.)-wheat (Triticum aesiiwrm L.) rotation with cover crops and fertilized with composted manure was compared with a corn m... |
31. Evaluation of Algorithm Thresholds for Crop Canopy Sensor-Based In-Season Nitrogen Application in CornNitrogen fertilizer is frequently the most lim iting nutrient in corn production. Typically most nitrogen is applied before plan ting. Since nitrogen can leave th e soil system fairly easily, the result can be an inefficient use of nitrogen fe rtilizer. Previous research has shown increased efficiency with no reduction in yield by applying nitrogen later in the season when the crop is actively growing, with rates regul ated spatially through the use of active crop canopy sensors. This study eva... |
32. Evaluation of Banded Fertilizer for Soybean ProductionResponse of the soybean crop to phosphate and potash fertilizer when soil test levels indicate the need for additional P andlor K is well documented. The value of the additional bushels exceeds the cost of the fertilizer. In general, phosphate and potash fertilizer, when needed, can either be broadcast and incorporated before planting or applied in a band at the time of planting. The banded application is Frequently preferred for a variety of reasons. This is especially true when the soybean cro... |
33. Evaluation of Four Iron Sources for the Control of Iron Deficiency Chlorosis in SoybeanIron deficiency chlorosis (IDC) is a destructive disorder of soybeans grown on calcareous soils in the North Central region. Certain chelates are effective at preventing IDC, but the quality of commercial-grade materials varies. The objective of this greenhouse study was to compare the ability of four commercial iron fertilizers to prevent IDC in soybeans. The four sources were a high-quality FeEDDHA product (FeEDDHA-1), an FeEDDHA product of lower quality (FeEDDHA-2), FeEDDHSA, and FeHBED. T... H. Ohm, R. Goos |
34. Evaluation of Novel Soybean Inputs to Enhance YieldThe U.S. Average soybean yield was 43.5 bushes/acre in 2010 (www.nass.usda.gov), with reports of much higher yields in some areas. With large yield differences among years and locations, as well as some high-profile marketing and publicity campaigns promoting 'high yield' management, producers are interested in any inputs or management practices that might improve yields. High soybean prices at present and interest in finding ways to increase yield have led to emergence of a number of new produc... |
35. Evaluation of Polyhalite as a Source of Potassium and Sulfur for a Corn-Soybean Rotation in MinnesotaPolyhalite contains K, S, Mg, and Ca which could be used as a source of nutrients for crops in Minnesota. The objective of this research was to determine if polyhalite can utilized within for a two-year corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation. Field studies were established at two locations in Minnesota with the soil test K of <120 ppm (0-6 inch sample extracted with 1M NH4OAC) and where a response to S was expected. Treatments were polyhali... A. Sutradhar, D. Kaiser, C. Rosen |
36. Evaluation of Starter Fertilizer Formulations and Placements for Conservation Tillage Production SystemsWith the interest in and importance of the use of starter fertilizers in conservation tillage production systems, research was continued to evaluate higher rates of N in starter fertilizers and different starter fertilizer placements. The use of starter fertilizer containing N, P and K significantly increased corn yields compared to a N only program, even though soil P and K levels were high. Increasing N rates in direct seed placed starter did not increase yields and significantly reduced plant... |
37. Evaluation of the Amino Sugar-N Based Soil test in Iowa Corn ProductionAn important improvement in estimating economic N applications for corn production would be to predict the soil N supply capacity each year. The objective of this research is to evaluate the adaptability and potential calibration of the amino sugar-N based Illinois N Soil Test in corn production fields across diverse Iowa soils. Nitrogen rate trials were conducted at multiple sites over several years, many on producer fields. Soil samples were collected at 0-6 and 0-12 inch depths in the fall an... |
38. Fall Nitrogen for Winter Wheat Production?Fall nitrogen (N) applications are typically not recommended in Kentucky unless previous corn yields exceed 30 bu/A more than expected or when wheat is planted later than optimal in combination with a wet fall. In 2016, much of Kentucky experienced this combination of yield and environmental conditions. A study was initiated to test the need for fall applied N and how much fall N may be needed. Wheat was planted at recommended (normal) dates and then at dates that would be considered later th... E. Ritchey, J. Grove |
39. Fertilizer Management for Strip-till and No-till Corn ProductionStrip-tillage for corn production can be advantageous over no-till. particularly in areas with heavy soils and high rainfall during spring months. Under these conditions in no-till systems. planting delays andlor slow. uneven emergence are common. Strip-tillage creates a narrow tilled area for the seedbed while maintaining the inter-row residue cover, allowing for erosion protection associated with no-till. yet providing an area in the rowr where the soil will dry out and warm up earlier in the ... |
40. Field Estimate of Dairy Manure Nitrogen Availability to PotatoesWithin Wisconsin, there is a distinct movement toward dairy herd expansion and consolidation of small farms. With the increase in manure production, these large dairies are considering various land and manure management arrangements with non-livestock farmers, such as potato producers. The purpose of this study is to evaluate several potato production issues resulting from such partnerships including the availability of dairy manure nutrients to potatoes. Nitrogen and phosphorus availability wer... |
41. Field Scale Variability of Corn Yield response Functions to Fertilizer Nitrogen ApplicationVariable rate nitrogen (N) application assumes that corn response to N fertilizer varies within a field. However, this hypothesis has not been formally tested yet. Field variation of corn response to N fertilizer and economically optimum N fertilizer rates (EON) were assessed in on- farm experiments throughout central Illinois. Fields (16 to 32 ha.) were subdivided into 13 to 20 areas. Five nitrogen rates were randomized within these areas in 28 kg N increments (2 rates) and decrements (2 rates)... |
42. How Does Your Garden Grow? Fertilizer- Friend or FoeGeo-spatial technologies are becoming common place in commercial agriculture and hands-on exercises using these concepts and technologies klfill many state K-12 education standards. The activity topics covered crop nutrients (nitrogen, phosphorus and potassium), global positioning systems (GPS), geographic information systems (GIs), types of agricultural field equipment, soil types and crop identification. Students developed and implemented plant growth experiments to test nutrient application h... |
43. Identification of Reasons for High Temporal Soil-Test Potassium VariationExtensive research has focused on potassium (K) fertlization and soil K testing during several decades in the Corn Belt. IN Iowa, more t han 200 conventional or on-farm strip trials were conducted since the iddle 1990s until the early 2000s. Results of this research were used to update Iowa State University (ISU) K recommendations in 1999 and in 2002. In spite of increasd knowledge about soil-test K calibration, K fertilizer placement meethods, and needed K fertilizer rates, this research demons... |
44. Illinois Nitrogen Soil Test for Sugar Beets and Corn in MichiganIn Michigan the presidedress nitrate test (PSNT) (Magdoff et al.. 1984) is used to adjust nitrogen (N) recommendations for corn and sometimes sugar beet. Many growers do not use the PSNT because the presidedress soil sampling time does not conveniently fit into their operation. Preplant nitrate tests do not provide a good estimate of plant available N because of the relatively wet weather conditions during Michigan springs. .Another drawback to the PSNT is that it tends to recommend N on soils w... |
45. Impact of Liquid Hog Manure and Inorganic Phosphorus (P) Fertilizer Additions on Soil Test P and P Uptake by RyegrassOntario recently introduced a phosphorus (P) index to assess the relative risk of surface water contamination resulting from P application to cropland, and to suggest possible management strategies and application restrictions to reduce this risk. The index incorporates various soiVsite characteristics (soil test P level, erosionlmnoff potential etc.) as well as management practices (rate and method of P application). Within the development of the P index, questions were raised regarding the rel... |
46. Impact of Nitrogen Application Timing on Corn ProductionWater quality issues have renewed interest in timing of nitrogen (N) application as a means to improve use efficiency in corn and reduce losses. Improved economic return is also desired as N fertilization is one of the most costly inputs to corn production. Time of fertilizer application is a component of the site-specific 4R nutrient management stewardship programs. In Iowa, the Nutrient Reduction Strategy has a 7% (37% std. dev.) nitrate-N reduction with a 0% (3% std. dev.) corn yield chang... J. Sawyer, D. Barker, J. Lundvall |
47. Impacts of Management, Moisture, and Phosphorus Form on Phosphorus Loss PotentialPhosphorus (P) is considered one of the major nutrients contributing to degradation of water quality in the United States. Our objectives were to examine P loss potential associated with: 1) high moisture conditions. 2) application (surface and incorporated) of manure from animals fed different diets and 3) sorption dynamics of inorganic and organic P compounds. The study of high moisture conditions evaluated the effects of near surface moisture conditions (wet and saturated), time (up to 28 day... |
48. In-Furrow Starter and Broadcast Phosphorus and Potassium Fertilization for CornIncreasing awareness of potential impacts of farming on the environment has renewed interest in further study of fertilizer management strategies that reduce nutrient inputs. Fertilizer recommendations for phosphorus (P) and potassium (K) usually are based on soil-test values and nutrient removal with crop harvest. Many Midwest fmers follow these recommendations. but many others apply removal-based P and K fertilizer rates even in high-testing soils. The typical farmer applies P and K fertilizer... |
49. In-Season Nitrogen Fertilization of SoybeanNitrogen (N) fertilization is not a traditional nutrient management practice for soybean production in Iowa. Soybean is a legume plant and is assumed to adequately obtain needed N through symbiotic fixation. However, there has been interest over the years in using N fertilization to increase yield and grain protein due to the recognition of the large N requirement associated with high yields. Depending on the soil residual inorganic N level and soil N mineralization characteristics, approximatel... |
50. In-Season Soil Nitrogen as a Predictor of Corn Grain YieldCorn (Zea mays L.) grain yield is closely linked to plant available soil nitrogen (N). Our objectives were to (i) examine the influence of N rate, source, and time of application on N use efficiency with relation to grain yield and total plant N uptake, and (ii) evaluate in-season soil N testing as a tool to determine N rate needs and predict grain yield. During the 2014-2015 growing seasons, 12 fields across Minnesota varying in soil and climate conditions received 1) pre-plant urea (0 to 20... J. Spackman, F. Fernandez |
51. Independence of Crop Yield and Nitrogen Rate Across SitesHistorically soil fertility specialists in the North Central States of the USA have constructed nitrogen (N) rate recommendations based on ‘yield goals’ or ‘expected yield’. Within the past ten years, there has been a general realization by soil fertility researchers that within a site or field there is a relationship between N rate and yield; however, because of soil and weather differences between sites there is no relationship in N rate studies with a large number o... D. Franzen, L. Sharma, H. Bu, E. Schultz, J. Breker, A. Denton |
52. Influence of Source and Particle Size on Agricultural Limestone Efficiency at Increasing Soil pHExcessive soil acidity is known to have potential negative impacts on crop production. The chemical and physical characteristics of a liming material determine its capacity to neutralize soil acidity. The calcium carbonate (CaCO3) equivalent (CCE) and estimates of particle size impact on the efficiency at increase soil pH are considered when assessing a material’s liming value. The reaction of limestone particles within the soil depends largely on the soil pH and the material surface ar... J. Jones, A. Mallarino |
53. Interrelationship of the Nitrogen Cycle and Carbon Sequestration- Greenhouse Gas Mitigation in Row CropsAgiculture's contribution to global warming is principally through its historical release of carbon in soil and vegetation to the atmosphere and through its contemporary release of nitrous oxide and methane. The sequestration of soil carbon in soils now depleted in soil organic matter is a well-known strategy for mitigating the buildup of COz in the atmosphere. Less well- recognized are other mitigation potentials such as better management of nitrogen fertility. A full-cost accounting of the eff... |
54. iPhone Apps: Corn Nitrogen Fertilizer Rate Calculator and Nitrogen Fertilizer Price Comparison CalculatorAs communications technology advances, there is a need for Extension to deliver information and decision- making tools that leverage these new technologies to engage existing and new clientele groups in new wa ys. Smart technologies allow ac cess to pertinent information on-the- go and out in the field, right when it's needed. ... |
55. Irigated Soybean Response to Nitroen Applied During Early Pod FormationHigh yield soybean ( Glycine max L.) has a high rate of N uptake during grain fill with maybe 2/3 of the N derived from the atmosphere. The rema ining needs to come from the soil. Previous research has found that the probability of response to N applied at early pod development (R3) for yield trials, including 44 with mean yield >60 bu/A, we re conducted in Nebraska to determine effect on soybean yield of applying N and S to the soil at R3. With 27 lb/A N applied and >60 bu/A yield, mean yield ... |
56. Is There a Role for Gypsum in Midwest AgricultureFor the past two years, there has been an increased interest in gypsum throughout the Midwest. It's reasonable to ask if this interest is a consequence of improved crop production or the follow-up of increasted sales activity. For many years, gypsum has been used to improve crop production in some parts of the United states. In most of these situations it was used to supply sulfur (S). In some cases, gypsum has been used to supply calcium, an important nutrient for profitable peanut production T... |
57. Long-Term Measurement of Nitrate Leaching Below Corn Agreosystems and a Restored PrairieMany studies have evaluated nitrogen leachmg from tile drained agricultural soils, but less research has been performed on many well drained soils also common throughout the Midwest. This study measured nitrate leaching fiom chisel-plow (CP) and no-tillage 0 agroecosystems in order to determine the effects of common agricultural practices on the quality of water that drains past the root zone of crops. In an effort to obtain background levels of nitrate leaching from a natural ecosystem, measure... |
58. Long-Term Nitrogen Fertilization Effects on Corn Yields and Soil PropertiesA long-term experiment (1 958-2002) provides information about the sustainability of long-term nitrogen (N) fertilizer use and continuous corn production in the northern Corn Belt. The experiment includes three N rates (none, medium, and high) applied annually in a randomized complete block design with four replications. Nitrogen rates in the medium and high categories increased over time and are currently 125 and 250 lb Nlacre. Lime treatments were imposed on the long-term N rates in 1985 using... |
59. Managing Riparian Buffers to Improve Soil Structural PropertiesFifty-five percent of Kentucky's stream impairments have been attributed to agriculture. Riparian buffer management may improve buffer effectiveness and reduce agricultural contaminants impairing water quality. Three mowing regimes and one native grass establishment regime were imposed in the riparian buffer zone surrounding a tributary of Cane Run Creek in Fayette County KY. Treatment plots measured 10m x 15m, with 10 replications of each treatment. One year after treatment, root biomass, soil ... |
60. Managing Urea Fertilizer for Optimal N Use and Productivity of CornCorn (Zea mays L.) yield is usually limited by nitrogen (N) availability more than any other nutrient in agricultural soils. Urea is the primary source of inorganic nitrogen fertilizer used worldwide, either as a crystalline solid containing 46% N, or a urea-ammonium nitrate solution (UAN, 28-32%). A major caveat, however, to urea as an N fertilizer is its susceptibility to loss through volatilization when applied to the soil surface. Many products are marketed as nitrogen stabi... B. Bernhard, F. Below |
61. Manganese Fertilizer Antagonism of Glyphosphate EfficacyMichigan soybean producers have observed antagonism of glyphosate efficacy in tank mixtures with foliar manganese (Mn) fertilizers. The objectives of this study were to (1) evaluate four Mn fertilizer formulations for their effect on glyphosate activity. (2) evaluate the effect of Mn fertilizer application timing on glyphosate activity, (3) evaluate the efficacy of three adjuvants in overcoming the Mn fertilizer antagonism of glyphosate. (4) determine the spray solution ratio of h4n2' and glyph... |
62. Manitoba Corn Meets 4-R Nitrogen Management (Year 2): Effects on Crop Performance and the EnvironmentReplicated corn trials to evaluate previous research on fertilizer technologies were conducted in 2015 under farm conditions at three sites Manitoba as well as in Quebec. Sites were located northwest of Elm Creek, MB on a loamy fine sand, near Carman, MB on a loamy very fine sand and at Culross, MB (southeast of Elm Creek) on a Red River clay. Treatments in the Manitoba trials included: a zero N Check; three rates of urea/ESN (50% each by weight) broadcast/incorporated prior to plan... C. Cavers, S. Sager, G. Parent |
63. Manure and Tillage Effects on Phosphorus in RunoffPhosphorus (P) loss in runoff from cropland is an environmental concern because this P often promotes weed and algae growth in lakes, rivers, and streams. Water bodies with a large supply of nutrients (well nourished) are termed eutrophic. Eutrophic conditions can result in excessive algae and plant growth and when these weeds and algae die and decompose, dissolved oxygen levels in the water is depleted resulting in odors, fish kills, and a general degradation of the aesthetic and recreational v... |
64. Micronutrients as Starter and Foliar Application for Corn and SoybeanCorn and soybean production under high yield environments can benefit from the combined use of starter and foliar fertilization, including macro and micronutrients. The objective of this study was to evaluate corn and soybean response to starter fertilizers in combination with foliar application of macro and micronutrients to maximize yield s. Experiments were conducted in 2010 and 2011 at two locations for corn and soybean under irrigation. Starter and foliar fertilizer treatments were applied ... |
65. Mine the Data Not the Soil: Big Data Considerations for Soil FertilityFarm data has become a current topic in agriculture as well as other industries and is known as ‘big data’. Debate regarding the ownership of the data and who should receive value from the use of that data are hotly debated. This paper dispels many of the myths of big data in agriculture and offers insights into best management practices with respect to using data isolated to a given farm as well as within a larger community. A substantial portion of this paper was adapted from Gr... T. Griffin |
66. Mitigating Phosphorus Movement from Agricultural FieldsAgriculture is often cited as the primary factor for the high P loads polluting Lake Erie and Ohio�۪s watersheds, but the contributions of agriculture as a system, a combination of tillage, best management practice (BMP) and fertilizer source rather than an industry is unknown. This study supplied either commercial fertilizer or poultry litter to tilled or no-till production systems with their corresponding BMPs of incorporation and cover crops, respectively, to determine the P lost via surf... |
67. N-Fertilizer Recovery Efficiency by Corn Using Controlled Release UreaLimited research has been conducted on the use of 15N-labeled controlled release urea fertilizers under field conditions for corn production. The objectives of this study were to: 1) evaluate the fate of N derived from a blend of two enhanced efficiency N fertilizers in corn plants throughout the growing season; and 2) to determine the N recovery efficiency of the two N sources from a blended application. A field study was conducted during the 2015-2016 growing season at Iracemápo... H. Gonzalez, D. Ruiz diaz, C. Filho, P. Trivelin |
68. Nitrate Concentrations and Flux in Drainage Water- Impacts of Tile Spacing and Precipitation Events and Implications for TMDLSIn the humid region of the eastern cornbelt efforts to optimize productivity of poorly drained soils has led to increased spatial intensity of agricultural tile drains. This intensification in installation of drainage tile is often a primary management consideration when field cultivation is being minimized or eliminated entirely. The objective of this study was to quantify the effects of tile spacing on the concentration and flux of nitrate in tile effluent. Continuous corn was grown on a well-... |
69. Nitrate-N Loss Reduction: Scale of In-Field and Edge-of-Field Practice Implementation to Reach Water Quality GoalsStates in the Mississippi River Basin have developed state level nutrient reduction strategies in response to the 2008 Hypoxia Action Plan. The Iowa Nutrient Reduction Strategy was released in 2013 and the Nonpoint Source Nutrient Reduction Strategy Science Assessment reviews potential practice performance in reducing downstream nutrient loss and the scale of implementation that would be necessary to reach the Hypoxia Action Plan goal of a 45% reduction in riverine Nitrogen and Phosphorus. To... M. Helmers |
70. Nitrogen Fertilizer Additives, Which Ones Work?Nitrogen fertilizer additives were evaluated in nine different studies. In the first study, Nutrisphere had no effect on urea hydrolysis when applied with a urea solution. In a second study, Nutrisphere had no effect on nitrification when applied with a urea solution. In a third study with urea granules, Nutrisphere had little effect on ammonia volatilization. In a fourth study with urea granules, Nutrisphere had no effect on nitrification. In a fifth study, Nutrisphere was found to be less effe... |
71. Nitrogen Fertilizer Management for Wheat Under Dual Purpose Grazing and Grain ProductionDual purpose winter wheat is a common system used in many regions of the Southern Great Plains. The objective of this study was to i.) evaluate the interaction of wheat grazing management and soil and fertilizer nitrogen requirements with emphasis on dual purpose wheat. This study was established at three locations during the 2015-2016 growing season. Experimental design was a randomized split block design with 16 treatments including simulated grazing and grain only treatments and varying ra... T. Gardner, D. Ruiz diaz, C. Edwards |
72. Nitrogen Fertilizer on Soybeans: Are We Making Progress?The recent drop in the price of soybeans has dampened enthusiasm for applying inputs of uncertain value to crops, but application of fertilizer N during the season is often reported by soybean yield contest winners as a way to increase yields, and some producers have adopted this as a practice. As soybean yields have increased, the amount of N required by the crop has increased. Soybean seed with 36 percent protein is about 5.75% N, and a bushel of soybean grain contains about 3 lb.... E. Nafziger, J. Vonk |
73. Nitrogen Management: Unraveling the Effect of Timing and FormImprovement of nitrogen use efficiency by co rn production would decrease the potential for nitrogen loss into the environment. A study ha s been conducted in Ames, Iowa on 16 different forms and rates of nitrogen in both a continuous corn and corn-soybean production systems. There were differences among treatments; howeve r, the most consistent treatment was the SuperU applied as a 150 lb A -1 preplant or as 50 lb A-1 preplant and 100 lb A-1 sidedress and UAN with Agrotain adde d to both the 5... |
74. Nutrient Deficiency Diagnostic Training with Field and Hydroponically Grown CropsThe Manitoba Crop Diagnostic School was initiated in 1995 and annually provides training for 350 - 400 field agronomists over a two week period in mid July. Symptons of nutrient deficiencies, other than Nitrogen (N), have proven difficult to demonstrate on the fertile high organic matter loam texturd soiles of the Carman Researh Station. The following techniques have been developed to demonstrate many of the macro and micronutient deficiencies which may occur in prairie crops.... |
75. Nutrient Management Implications of Relay Cropping on the EnvironmentResidual nitrogen (nitrate-N) remaining in the root zone after seed corn production is frequently greater than under commercial corn production. This nitrate is subject to leaching into the shallow ground water of the Platte River Valley in South-Central Nebraska. as noted by elevated nitrate-N concentrations under seed cornfields compared to other fields. Hard-red winter wheat was planted into seed corn residue in early October of 2001 as a cover crop to scavenge residual- N from the root zone ... |
76. Nutrient Management Practices for Water QualityField to Market®: The Alliance for Sustainable Agriculture Field to Market® is a diverse alliance working to create opportunities across the agricultural supply chain for continuous improvements in productivity, environmental quality, and human well-being. The group provides collaborative leadership that is engaged in industry-wide dialogue, grounded in science, and open to the full range of technology choices. ... A. Herges |
77. Nutrient Management Studies in Bio-Fuel Cropping SystemsResearch was conducted to determine the effect of nutrient management practices on bio-fuel crop production, and to evaluate long term effects of bio-fuel crop production on selected chemical, physical and microbiologi cal properties. Experimental plots for research on bio-fuel crops production were established in 2008 at two sites in Missouri. The experimental design was an 8x3 factorial laid out in a sp lit plot design. The main plots were eight bio-fuel cropping systems including: 1) continu... |
78. Phosphorus and Potassium Removal and Leaching from Residue in Corn and SoybeanResearch is continually being conducted to adjust and update recomm endations for phosphorus (P) and potassium (K), and to be tter understand relationships betw een nutrient application, grain yield, nutrient removal with harvest, and soil-test values. Studies in Iowa and other states of the north central region have been used to develop guidelines about P and K removal rates in corn and soybean for use together with soil testing information to manage P and K. There is very large temporal varia... |
79. Phosphorus and Potassium Response In No-Till Corn and Soybean ProductionCurrent UWEX fertilizer recommendations and plant analysis interpretation guidelines were developed prior to the release of GMO corn. There is some concern amongst University soil fertility specialists and industry agronomists that corn and soybean response to P and K fertilizer applications may be different with modern corn hybrids and soybean varieties. In addition, in the UW recommendation system, an estimate of the amount of nutrients removed in the harvested portion of the crop is used t... C. Laboski, T. Andraski |
80. Phosphorus Distribution After Long-Term P Fertilizer Placement Under Strip-TillageLong-term phosphorus fertilizer placement under strip-tillage tillage can affect the vertical and horizontal distribution of soil test P (STP). The objective of this study was to evaluate the effect of P fertilizer placement on STP distribution under strip-till. A study was established in Scandia, Kansas in 2006 under a corn- soybean rotation. Treatments included a (1) control (No P); and P applied at 80 lb P2O5 ac-1 as (2) broadcast, (3) deep band, (4) broadcast with starter 2x2, a... C. Edwards, D. Ruiz diaz |
81. Post-Harvest Soil Nitrate Following Corn Production in Eight Midwestern StatesApplying nitrogen (N) at economically optimal rates (EONR) and at times of rapid crop uptake are practices that are thought to minimize the amount of residual soil nitrate (RSN) in the profile that may be susceptible to loss. The objective of this study was to evaluate the effects of rate (0 to 280 lb N/a in 40 lb increments) and timing (pre-plant (PP) or PP plus V9 sidedress (PP+SD)) of N application on corn grain yield and RSN in the top 3 feet of soil relative to the calculated EONR. Thirt... C. Bandura, C. Laboski, J. Camberato, P. Carter, R. Ferguson, F. Fernandez, D. Franzen, N. Kitchen, E. Nafziger, J. Sawyer, J. Shanahan |
82. Potassium Effects on Yield, Grain Quality, Lodging, and Stalk Strength in RiceMissouri has a long history of rice production, going back to 1910 when the crop was first grown in the northeast region of the state. From this 40-acre start, rice acreage has increased steadily over the years to over 180,000 acres currently. The statewide average yield was 110 bu/A in 1997 and increased to over 156 bu/A in 2015. Traditionally, nitrogen (N) management has been given top priority by farmers. But with increased yields and rotations with soybeans, K fertility is increasingly be... D. Dunn, G. Stevens |
83. Potassium Recalibration for Corn in North Dakota and Sampling TimePotassium (K) fertilizer recommendations for corn (Zea mays, L.) are commonly guided by yield response calibrations to soil K levels; however, sample drying and time of soil sampling have been shown to affect the amount of extractable K. Potassium rate trials were established at 13 locations in southeastern North Dakota during 2015 with objectives to evaluate soil K testing methods and their relationship with corn yield response to K fertilization and to assess temporal soil K variat... J. Breker, D. Franzen |
84. Prediction of Corn and Soybean Grain Yield Response to P in Minnesota Using the Haney H3A and Mehlich-III TestsMinnesota soils are highly variable in P availability due to the wide range of chemical properties. Currently, two soil tests are used to measure soil P in Minnesota, the Bray-P1 for pH<7.4 and the Olsen P for pH>7.4. The purpose of this study was to correlate crop response in corn and soybean rotations to the Bray-P1, Olsen, Mehlich-III, and Haney H3A extractions and to determine critical concentrations for each extraction method. Soil P tests were also correlated with one another to d... D. Kaiser, L. Leverich, J. Vetsch, J. Strock |
85. Previous Management Impacts on Soil Phosphorus LevelsThe Homestead Acts of the early 19th century across many areas of the United States resulted in the formation of 65 ha (160 acre) farms. The areas where livestock were concentrated on these farms consisted of a small portion of the 65 ha. As farms have become larger, many of the original farm building sites have been abandoned. These abandoned farmsteads still affect management decisions today. The objectives of this study are to show the visual and statistical relationships between both existi... |
86. Project Sense: Sensors for the Efficient Use of Nitrogen and Stewardship of the Environment. An On-Farm Research Effort to Increase Adoption of Sensor Based N ManagementLow nitrogen use efficiency (NUE) has been attributed to several factors including asynchrony between nitrogen (N) fertilizer application, crop demand, and spatial variability (Shanahan et al., 2008). Sidedress applied N synchronizes crop uptake demand for N, but does not address the spatial and temporal variability that exists in a field year to year. Active crop canopy sensors provide an ability to monitor and respond to spatial and temporal N variability for a given field. A three-year pro... B. Krienke, R. Ferguson, J. Luck, L. Thompson, J. Parrish, N. Mueller, T. Mieno, J. Crowther, T. Shaver, T. Ingram, D. Krull, K. Glewen |
87. Providing Flexibility in P and K RecommendationsHistorically, land grant Universities have generally provided a single rate recommendation for nutrients such as phosphorus (P) and potassium (K). Depending on the particular University in question, these nutrient rate recommendations are generally based on two widely recognized approaches to managing soil and fertilizer P and K - the nutrient sufficiency approach and the build-maintenance approach. The goal of a nutrient sufficiency based soil fertility program is to apply just enough P andior ... |
88. Relationship between Nitrogen Rate and Weed Removal Timing on Corn YieldWeeds actively compete for nitrogen in corn grain production systems. Field studies were conducted in 2009 and 2010 at the Michigan State University Crop and Soil s Research Farm in East Lansing , MI to evaluate the effect of N application rate and weed removal timing on grain yield . Treatments included four preplant incorporated rates of urea (0, 67, 134, and 202 kg N ha - 1 ) and four weed removal timings (5, 10, 15, and 20 cm) based on average weed canopy height. An additional season- long w... |
89. Relationship Between Response Indices Measured In-Season and at Harvest in Winter WheatCurrent methods for making nitrogen recommendations in winter wheat (Triticum aestivurn L.) do not adjust for in-season temporal variability of plant available non-fertilizer nitrogen (N) sources. The purpose of this study was to compare the use of different nitrogen response indices determined in-season @INDVI and RIPLANTHEIGkm) to the nitrogen response index measured at harvest (RIHARvEST). In addition, this study evaluated the use of the in-season response indices for determining topdress nit... |
90. Residual Effects of Nitrogen Fertilization on Soil Nitrogen Pools and Corn GrowthNitrogen (N) fertilization of corn (Zea mays L.) may increase, decrease, or not affect the N supplying capacity of the soil. Six field-scale corn N rate trials were established in corn-soybean rotations in diverse soil types across Indiana. Six N rates ranging from about 25 to 270 lb N ac-1 were replicated 4 to 6 times at each site and re-applied to the same plots for each of four corn crops. In the fifth corn season, 2015, half of the replications at each location were sup... M. Moser, R. Nielsen, J. Camberato |
91. Respiration as a Measure of Soil Health: Challenges and OpportunitiesIn recent years, respiration has become a commonly-used soil health metric. It has been used as a standalone predictor of soil N supplying capacity and in conjunction with other metrics to assess overall soil health. However, the sources of variation underlying respiration itself have not been thoroughly assessed. We show that across growing regions in California, respiration was unable to accurately predict soil N supply. The R2 values were much higher in fields that had received a rece... J. Wade, S. Culman, T. Hurriso, W. Horwath, R. Miller |
92. Response of Continuous Corn to Varying Rates and Placements of Starter FertilizerPrevious research has shown that starter fertilizer, a small amount of fertilizer placed with or near the seed at planting, often accelerates early season growth and increases biomass production, but does not always increase grain yield in corn (Zea mays L.). Our objective was to evaluate the effects of starter fertilizer on crop growth and development, as well as grain yield and moisture in continuous corn cropping systems. Treatments consisted of no fertilizer applied at planting (Cont... C. Hornaday, J. Camberato, R. Nielsen |
93. Response of Corn Grown in Two Crop Rotations to Different N Rates and NitrapyrinNitrogen fertilization of corn is necessary to obtain adequate yields. Loss of soil-applied N1-L'-N fertilizers due to nitrification can decrease corn yield significantly. Nitrate contamination of ground or surface water supplies should also be considered. Use of nitrapyrin may help address these issues, though in fine textured soils response to its use is difficult to predict. A 10-year study was done to determine the effects of annual application of ammonia with nitrapyrin upon the yield of co... |
94. Savi Determination in Carrots- Comparing Constant and Dynamic Soil Adjustment FactorsReliable interpretation of reflectance measurements of vegetation in incomplete canopies is confounded by the influence of soil background. Qi et al. (2000) developed a fi-actional coverage uc) model from the NDVI of target vegetation and soil. Spectral data from a two year (2001, 2002) carrot study was used to determine if the fractional coverage (fc) model could be used to estimate the observed fractional coverage of the developing carrot canopy. Reflectance measurements and matching digital ... |
95. Site-Specific Management of Iron Deficiency in CornThe addition of FeS04mH20 in the seed row increases corn (Zea mays L.) yield in areas with Fe deficiency-induced chlorosis. Our objectives were to determine the correct application rate of FeS04.H20 for irrigated corn, identi9 the spatial distribution of Fe deficiency, and alleviate deficiency symptoms with targeted FeS04.H20 applications. Eleven site-years were selected for small-plot studies in western Kansas. At these fields, soil CaC03 content in chlorotic or problematic deficient areas of t... |
96. Site-Specific Manure Application Effects on Corn Yield and N StatusManure, a renewable resource, is an excellent source of nutrients that can be substituted for synthetic types of fertilizers. The organic matter in manure can enhance the physical and chemical properties of soils, especially infertile soils, as these soils typically contain low levels of organic matter and nutrients, and have low water holding capacities. The objective of this study was to evaluate the ability of manure application for improving crop yield and N status in less productive areas ... |
97. Site-Specific Nitrogen Management for Reducing Soil Residual NitrateSite-specific N management has potential for increasing the efficiency of N fertilizer use, and thereby reducing environmental impact. Field studies were conducted in 2000 and 2001 to evaluate the potential for site-specific N management to reduce residual soil nitrate in Missouri cornfields. Field-size side-by-side fertilizer N treatment strips were applied in cooperating farmers' fields. The site-specific crop N requirement (optimal N rate) was determined for sub- blocks that contained a full... |
98. Slow-Release Fertilizer Effect on Groundwater Nitrogen Concentration in Sandy Soils under Potato ProductionCurrent nitrogen (N) fertilizer management practices for potato farming have led to elevated levels of N in the local groundwater. Slow-release fertilizer, specifically Environmentally Smart Nitrogen® (ESN®) polymer coated urea (PCU ) may reduce the amount of N leaching to groundwater; however no field scale studies have been performed in Wisconsin to validate these assertions. Field experiments were conducted at the Hancock Agricultural Research Station using Russet Burbank potato, planted i... |
99. Soil Carbon Sequestration in Agriculture- Research Efforts in the Central U.S.Since the late 1800's fossil fuel use, expansion of cultivated agriculture, and forest clearing have led to an increase in atmospheric C02 from 260 pprn to current levels >370 ppm (IPPC, 1995). Most of the recent increase in COz has been attributed to combustion of fossil fuels for energy and transportation. This increase in atmospheric COz potentially impacts climate, as it is a greenhouse gas. It has been estimated that 20-40% of targeted emission reductions in the U.S. can be met by carbon se... |
100. Soil Health: Approaches in Fertility ManagementInconsistent grain yield and in some cases variable yield response to fertilizer inputs suggest improving fertility management strategies with greater emphasis towards resilient cropping systems may also improve nutrient efficiency. The soil microbiome may affect nutrient mineralization, nutrient movement to roots, disease incidence, and other specialized relationships (e.g., nodule formation in soybean (Glycine max L.)). Although within-field grain yield variability has correla... K. Steinke |
101. Soil Test Phosphorus and Potassium as Affected by Site Specific Soil Fertility ManagementThe overall objective of this field scaled study was to provide an in-field evaluation of common site specific fertilizer strategies used in corn 1 soybean production. While a team of researchers are working on several specific objectives, this work specifically focuses on three of them. First, to evaluate the variability in soil tests for making site specific phosphate (P) and potassium (K) application. Second, to measure the change in this variability over time as affected by fertilizer manage... |
102. Soybean Yield Response to P Fertilizer Placement as Affected by Soil Parameters: A ReviewIn the last decades, several studies were conducted to evaluate more efficient P fertilizer management with emphasis on placement. Many of these studies report contrasting results, suggesting that a general recommendation may not be appropriate and specific factors of soils, crops, and weather should be considered. A literature search was completed using Google Scholar, and published papers that met our selection criteria included 62 experiments, with 95 site-years. Approximately 9.8% of the ... F. Hansel, D. Ruiz diaz, L. Rosso |
103. Spatial Response of Corn to Banded Zinc Sulfate Fertilizer in IowaThe solubility of zinc (Zn) decreases as pH increases. There are soil associations that contain high pH spots within fields where the surrounding soils' pHs are slightly acid. It is reasonable to expect that Zn availability, due to a difference in solubility, is different in the two areas. The objectives of this study were to find corn (Zea nlnys L.) grain yield responses to Zn fertilizers within fields and to define the soil characteristics in responsive areas. The study was conducted at twelve... |
104. Starter Fertilizer for Corn on Lakebed SoilsMany producers use starter fertilizers because cold and wet conditions may occur zfter planting. In addition, startzr fertilizers may improve the efficiency of nutrient uptake by the crop in a sidedress system. Historically, producers in Northwest Ohio consider phosphorus the most important component of a starter fertilizer, even though research has shown that nitrogen provides most of the yield benefit. However, many fields in Northwest Ohio have more than adequate levels of phosphorus for cor... |
105. Starter Fertilizer for Row Crop Production Under No-till Conditions in Eastern NebraskaStarter fertilizer application often results in increased corn and sorghum yield under no-till conditions, probably due to lower soil temperatures as compared to tilled soil. Five dryland and 5 irrigated corn trials. and 12 dryland grain sorghum trials were established after soybean in 2002 and 2003 on rolling land in eastern Nebraska with different soil types and topographic positions. Three placement positions were compared: in the seed furrow. over the row. and 2" to the side and 2" deep (2x2... |
106. Starter Fertilizer Slows the Movement of Corn Roots Across the RowApplications of starter fertilizer may alter the root morphology of young developing plants by causing lateral roots to proliferate when the root system enters the highly concentrated fertilizer band. This may affect the timing of root movement across the row when starter fertilizer is used. The timing of root movement across the row was determined by placing 20 12-inch-long perforated cylinders vertically in the soil at the V2 leaf stage. The cylinders were placed approximately every 15&rdqu... J. Lee, J. Camberato, R. Nielsen |
107. Survey of the Tissue Nutrient Status of Winter Wheat in KentuckyA field survey conducted in western Kentucky (KY) was initiated to determine if University of Kentucky soil fertility recommen dations for winter wheat production was adequate. Twenty- nine fields in 15 western KY counties were iden tified by county extension agents for sampling. Soil and tissue samples were collected for anal ysis in a 150 foot by 150 foot sampling area. Approximately 100 flag leaf samp les were collected, air-dried, ground, and analyzed for N, P, K, Mg, Ca, S, B, Zn, Mn, Fe, ... |
108. Switchgrass Response to Nitrogen: Trade-offs between Quantity and QualityIn 2009 and 2010, a study was conducted at four loca tions in southwest Wisconsin to determine optimal nitrogen (N) fertilizer rates and harvest timings for switchgrass quantity and quality. The study was conducted as a randomized complete bloc k, split plot design with five main plot treatments (0, 56, 112, 168, and 224 kg ha -1 of N) and three split plot treatments (mid-fall, late- fall, and early spring harvest). Dry matter (D M) yields increased between 2009 and 2010 and were most often max... |
109. The Anaerobic Potentially Mineralizable Nitrogen Test as a Tool for Nitrogen Management in the MidwestThe anaerobic potentially mineralizable nitrogen (PMNan) test is a tool that can improve estimations of mineralizable nitrogen (N) and enhance nitrogen use efficiency. This tool may also help improve predictions of N uptake, grain yield, and the economic optimum nitrogen rate (EONR) of corn (Zea mays L.). A 32 site-year study across eight US Midwestern states was conducted to 1) compare the effect of incubation length (7-, 14-, 28-d), soil sampling timing, N fertilizer rate, and thei... J. Clark, K. Sloan veum, F. Fernandez, J. Camberato, P. Carter, R. Ferguson, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, J. Sawyer, J. Shanahan |
110. The Analysis of Nitrogen and Plant Population InteractionsNitrogen and plant population are significant factors for corn production. Accurate nitrogen fertilizer and seeding rate recommendations are essential for optimizing profitability for the fmer and minimizing nitrogen losses. Research and development of yield response curves provide important information that can be used to understand the relationships between these inputs (nitrogen fertilizer and corn seeds) and output (grain yield). Over the varying levels of inputs. yield response functions ca... |
111. The Effect of Tillage and Lime Rate on Soil Acidity and Grain Yields of a Corn-Soybean RotationModern tillage systems, such as reduced tillage and no-tillage systems, provide shallow incorporation of surface applied materials at best. Because of concern of over-liming the surface few inches of agricultural soils, producers either reduce lime rates (and apply more often) or perform some sort of soil inversion to mix the lime deeper into the soil profile. The objectives ofthis field study were to evaluate the effects of tillage, lime rate and time of limestone application on corn and soybea... |
112. The Future of the U.S. Nitrogen Industry-SlidesThe Future of the U. S. Nitrogen lndustry David Asbridge November ZOO3 Nitrogen Situation U.S. Ammonia - Cost & Margins $ Per Ton 1 U.S. Fertilizer Consumption Index of U.S. Nitrogen Prices January 2002 = 1.0 January 2002 - October 2003 -% 1997-2003 Nitrogen Market Driving Factors Record increase in world nitrogen capacity World Ammonia Capacity vs Consumption 1997-2002 Nitrogen Market ( Driving Factors I 1997-2002 Nitrogen Market Driving Factors + Record increase in world nitrogen capacity + Ch... |
113. The Illinois Nitrogen Soil TestNitrogen fertilizer recommendations for corn production are often estimated on the basis of a realistic yield goal, with adjustments to allow for N credits fiom other sources, such as legumes or manure. A yield-based recommendation may have merit on a long-term basis. but under- or over- fertilization is apt to occur in any given growing season since soil N availability is not taken into account. Insufficient application of N can have serious economic consequences for the farmer, whereas excessi... |
114. The Importance of Soil Microorganisms in Aggregate StabilityAggregate stability is a soil quality factor. Water stability of aggregates is related to microbial activity. This paper reviews microbial inputs to aggregate stability. Soil fungi have long hair-like projections, hyphae that can physically entangle soil particles and exude glues. Microbial glues are discussed with special emphasis on arbuscular mycorrhizal (AM) fungi and the glue-like compound, glomalin. produced on hyphae of this group of fungi. Influences of management practices on AM fungi a... |
115. Tillage and Nitrogen Responses to Residue Removal in Continuous CornWith the growing interest in harvesting corn stal k residue for use as biofuel comes the need to examine how residue removal might affect yield a nd N needs of the subsequent corn crop. We are conducted an experiment over the past five years ( 2006 to 2010) at four Illinois locations (three in Mollisols and one in Alfisol) in which all, part, or none of the corn residue is removed, followed by tilled and no-till split within each residue treatment, a nd with N rates split within each residue-til... |
116. Tillage, Crop Rotation, and Cover Crop Impact on Corn Nitrogen Requirements in Southeastern South DakotaNitrogen is the lifeline of corn production. There is uncertainty whether nitrogen (N) requirements are the same for corn raised under long term no-till versus conventional till production systems. The objective of this study was to evaluate N fertilizer requirements for long term no-till soils in southeastern South Dakota, while considering effects from cover crops and crop rotation. This was a two year study at the SDSU Southeast Research Farm near Beresford, SD on long term no-till plots e... S. Berg, P. Sexton, R. Gelderman, A. Bly, C. Derdall |
117. Timing of Spring N Application to Soft Red Winter WheatHistorically, in the northern Corn Belt, the majority of the N for winter wheat is applied as a single application when fields become green and initiate spring growth (Greenup). Time between initial spring greenup and early stem elongation (Feekes GS 6) is relatively short (four to six weeks). During this time, the potential for N loss is generally low because soil and air temperatures are cold enough to minimize volatilization and nitrification. Producers attempt to apply N at greenup because f... |
118. Topsoil Thickness Effects on Phosphorus and Potassium Dynamics on Claypan SoilsDue to variable depth to claypan (DTC) across landscapes, nutrient supply from subsoils, and crop removal, precise P and K fertilizer management on claypan soil fields can be difficult. Therefore, a study was performed to determine if DTC derived from soil apparent electrical conductivity (ECa) could be used to improve P and K management for corn (Zea mays L.) and soybean (Glycine max [L.]). Research was conducted on a claypan soil at the University of Missouri&rsq... L. Conway, M. Yost, N. Kitchen, N. Kitchen, K. Sudduth |
119. Urea Application Timing Influence on No-till CornFertilizer N for no-till corn in South Dakota is often limited to surface applications of urea. Surface applied urea can volatilize. A study was conducted in 1998, 1999, 2000 and 2002 (four site years) on no-till corn comparing surface broadcast urea timing. Nitrogen rates (50 and 100 Ibs Nla) were applied in the fall. winter. early spring, planting. and V-6 stage. Ear leaf samples were analyzed for N concentration in 1999 and 2000 and grain yield was measured each year. Precipitation was measur... |
120. Using Historical Yield Patterns in Fields as a Management Tool to Variably Apply NitrgenIn whole field studies in southem Illinois a uniform rate of N application was compared with variably applied rates of N based upon historical crop yields for each field. The fields used were partitioned in "low". "medium", and "high" zones of productivity depending upon the normalized yield of the preceding 5 to 10 years of crops grown. Two formulas were used to variably apply nitrogen. One formula (VRN-One) calculated a N rate that favored more fertilizer in "high" productivity regions and les... |
121. Utilizing Inhibitor Technology to reduce Ammonia Volatilization Losses from Urea Sources Applied to Conservation TillageA severe limitation to urea fertilizers and the ureacomponent in livestock wastes is the high potential for volatile loss of nitrogen (N) as ammonia. Losses are especially severe when the urea-containing materials are surface applied with no or only limited subsequent incorporation. Extensive losses are also observed when urea is applied to warm soils that are moist and undergoing rapid drylng. Soil pH, the presence of an active microbial population, and soil texture are also known to impact vo... |
122. Validating Potassium Fertilizer Guidelines in Alfalfa-corn RotationsIn 2008 to 2010, on-farm research was conducted on 10 fields with medium soil test K (STK) to validate Minnesota K fertilizer guidelines by determining the effect of K fertilizer applications on alfalfa yield and quality in its last production year, and estimating the carryover of excess fertilizer K to first-year corn. We were surprised to find that no K fertilizer was needed to maximize alfalfa yield or overall forage feed value and quality. Luxury consumption of K occurred because as K applic... |
123. Variability of Soil Test Potassium in Space and TimePotassium soil test may be highly variable within fields. In the western part of the North Central Region, where the history of K fert ilization is marked by low rates of K fertilizer and fields where K has never been applie d, natural variability of K is governed by clay content and landscape position. In areas where K fertilization has been high, man-made variability is more common. Man-made variability may be experienced as differences in historic rates within fields merged over years of own... |
124. Variation in Internal N Efficiency of Corn and Impact on Yield-Goal Based N RecommendationsInternal N efficiency (IE) is defined as bushels per acre (GY) produced per pound of N per acre (PMN) in the plant at physiological maturity (R6). Internal N efficiency defines the required amount of plant N content at R6 in a yield-goal based N rate recommendations (currently used in 30 U.S. states) and several commercial N recommendation models. Commonly IE is assumed to be constant at an approximate value of 0.8 bu lb-N-1 in yield-goal based recommendations. Our research objective was... M. Shafer, J. Camberato, P. Carter, R. Ferguson, F. Fernandez, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, R. Nielsen, J. Sawyer, J. Shanahan |
125. Vegetative Assessment of Phosphorus and Nitrogen Status in Maize Using Remote SensingAssess spatial variability of soil P and N is not only costly but also a time consuming processes. Remote sensing measurements of canopy spectral reflectance can provide a rapid and non- destructive method for assessing plant-canopy nutrient status. The main objective of this research was to detect P and N stress during the early corn growth by selecting specific wavelengths, or combinations of them, using narrow band field sensors. In 2001, two corn experiments were planted over an old manure e... |
126. What Can Long Term Experiments Provide for Improving Phosphorus and Potassium Management?Agricultural research utilizes both short-term and long-term experiments. Short-term experiments provide useful information on how a system is affected at the time of management changes, and evaluate short-term responses by the soil or crop. Agricultural systems are complex systems with multiple components that operate on different time scales of response, however. Therefore, the initial response of either the whole system or individual components may not necessarily indicate the direction or... A. Mallarino |
127. Winter Annual Weeds Affect Nitrogen Availability for No-Till CornWinter annual weeds effects on nitrogen availability have not been adequately studied. The objective of this study was to determine winter annual weed s effects on nitrogen availability for rainfed no -till corn (Zea mays L.) following soybeans ( Glycine max L. Merr.). Field research was conducted in 2010-2011 at 14 sites with heavy winter annual weed pressure in eastern Kansas. A two -factor factorial arrangement in a randomized complete block design with three replications included t hree her... |
128. Winter Wheat Growth and Grain Yield Response to Individual Agronomic InputsProducers’ interested in optimizing wheat (Triticum aestivum L.) growth and yields have adopted intensive (i.e. high-input) wheat management systems in Michigan. Additional research is required to evaluate growth, grain yield, and profitability of multiple and individual agronomic inputs. An omission field trial was initiated in Lansing, MI during 2015 to evaluate the response of soft red winter wheat to six agronomic inputs in enhanced (high-input) and traditional (low-input) ... D. Quinn, K. Steinke |
129. Yield Goal Versus Delta Yield to Predict Nitrogen Need in CornFertilizer nitrogen (N) needs of corn can vary widely both among and within fields. Many states use a yield goal to identi@ differences in fertilizer N need combined with an N credit system to adjust for N provided by the soil from sources such as soil organic matter, residual inorganic N and crop residues. Some have questioned yield-goal derived fertilizer N recommendations because of its poor correlation with fertilizer N need, leading some states to eliminate yield goal from their N recommend... |