Proceedings
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1. 4R Nutrient Management for Corn Production on Upper Midwest SoilsCorn (Zea mays L.) demand for nitrogen (N) is often met using inorganic fertilizer on Upper Midwest soils. While applying the right rate of fertilizer N normally has the greatest impact on yield and N use efficiency (NUE), selection of the right fertilizer source, placement, and application timing can fine-tune rate recommendations, improve NUE by matching soil N availability to corn demand, and minimize loss to the environment. Given the diversity of corn production environments, th... J. Spackman, F. Fernandez, K. Fabrizzi |
2. A 2020 Vision on Nutrient Use DecisionsMany farmers this fall are facing significant financial stress due to several factors including low crop prices and weather-induced crop losses. Crop prices are currently much lower than they were in the first half of this decade but we have been here before … time tested principles continue to apply. Past studies of the characteristics of the most profitable farmers show that they tend to have higher yields, lower costs, and are more rapid adopters of technology than their less profit... P.E. Fixen |
3. A Nitrogen Soil Test for CornIn the past decade, many states have started including a soil test when making N recommendations. In order for a soil N test to be useful, it must provide information that is not known or incorporated when making N recommendations without a test. If a test does not provide explainable, qunlltifiable infarmation. the tcs: !cses its usefghess. In Minnesota, a falllspring preplant N test has been used in the western tier of counties, which have lower rainfall than the rest of the state, for many ye... |
4. Alfalfa Responses to PotassiumThe potassium requirement of alfalfa is greater than that for any other nutrient. Potassium influences several systems within alfalfa plants including enzyme activity, carbohydrate production and transport, stornatal activity, photosynthesis through chlorophyll content and C02 exchange rate, and nitrogen fixation. Excellent reviews on the role of K in physiological processes are provided in the most recent potassium monograph (Munson, 1985). Potassium also markedly influences alfalfa agronomical... |
5. An Overview of the Thompson/Baker Farming Systems StudyThere is a general lack of quantitative information, collected from field-scale studies, that can be used to assess long-term effects of alternative farming systems. The objective of an on-going study in central Iowa is to quantitatively evaluate several chemical, physical, biological, and economic parameters on the Richard Thompson (alternative) and Eugene Baker (conventional) farms. This project was initiated in 1989 on adjacent 32-ha tracts of land, that have Clarion loam, Nicollet loam, Cani... |
6. Assessing the Source of Groundwater Nitrates- And You Thought Good Wine Took TimeControversy continues with elevated groundwater nitrate concentrations being attributed to N fertilizer use. Current research defining best management practices in farming system K management seldom addresses the influence these practices have on groundwater. Why? The results of this Missouri research show that the influence of management on groundwater nitrates may last for decades. The study provides support for time requirements when assessing farming system impact on groundwater quality. ... |
7. Can nitrogen application rate and timing management contribute to yield benefit in dryland winter wheat?Nitrogen (N) is a key component that affects grain yield and protein content in wheat. Optimizing fertilizer N application rate and time may contribute to an increased yield along with an adequate protein level. To evaluate the effects of different rates and application timing of N on grain yield and quality, a field study was carried out at four different locations across Nebraska (Mead, Grant, Sidney, and Scottsbluff) in 2018/19. At all locations, the experimental layout was split-plot rand... D. Ghimire, B. Maharjan |
8. Certified Crop Adviser (CCA) ProgramThe Certified Crop Adviser (CCA) Program is being developed under the auspices of the American Society of Agronomy (ASA). The ad hoc steering committee is comprised of industry and university agronomists, state dealer associations, independent crop consultants, several organizations (including T.F.1, P.P.I., ARA, TVA) and ASA staff. This is a broad group representing wide geographic parts of the U.S., and has also included USDA officials, representing SCS and Extension. The purpose of the CCA pr... |
9. Changes in Iowa's Soil Test P and K Interpretations and RecommendationsResearch results from long-term and short-term experimentation in Iowa have been consistent in the response or lack of response of Iowa field crops to applications of fertilizer phosphorus (P) and potassium (K) at various soil test levels for P and K. Analyses of the research data have established critical soil test values for P and K and the most economic soil test range for P and K to maintain (Mallarino, Webb, and Blackmer, 1991a and 1991 b; Mallarino and Blackmer, 1992 and 1994; Webb, Mallar... |
10. Corn Nitrogen Tests in MissouriExperiments were carried out in farmer fields starting in 1995 with the objective of evaluating or developing field-specific tests to optimize N fertilizer rates for corn. Because some of the soil nitrate tests seem to work differently when manure or alfalfa is in the cropping system, most farms had pairs of experiments, one with an organic N source and the other with none. Descriptions of the experimental locations are given below. Location 1 2 Year 1995 1995 1995 1995 1995 PROCEDURES Countv Ca... |
11. Correlation and Calibratin of the SMP Lime Requirement Test with Direct Titration of Soil AcidityThe SMP Buffer method (Shoemaker, et al, 1961) of routinely determining lime requirement on soil samples has been used at the University of Kentucky Soil Testing Laboratory (UKSTL) since the mid-1960's. Initial correlation and calibration for Kentucky soils was a result of incubating several soil samples over a period of time after mixing different rates of lime with them (D.E. Peaslee, 1975, personal communication). During the ensuing years, county agricultural extension agents have raised many... |
12. Cover Crops Influence Soil Health and Nutrient Cycling in a Multi-Location Study in South DakotaSoil without living roots potentially loses mobile nutrients and retains excess water. Unprotected soil degradation and erosion enable the loss of carbon and nutrient rich top soil. Cover crops provide armor for the soil protecting from carbon and nutrient loss. Cover crop blends may influence soil health parameters and nutrient cycling. This multi-locational study depicts the influence of cover crop species blends with varying grass and broadleaf concentrations on established soil-health ind... D. Sanyal, J. Wolthuizen, D. Karki, J. Clark, A. Bly |
13. Do cover crops improve soil health and enhance nutrient availability to cash crops?Bare soils are prone to erosion and lose soluble nutrients. Cover crops provide protection to the soil against erosion and nutrient loss. We hypothesized that the cover crops should uptake available nutrients from the soils in the fall when there is no cash crop, assimilate the nutrients in their tissues, and in the following spring, should release the nutrients back to the soil during the next cash crop growing season. In our study, we are quantifying the nutrients taken up by the cover crop... D. Sanyal, A. Rahhal, H. Bielenberg, J. Wolthuizen, J. Clark, A. Bly |
14. Does cover crop composition improve soil health and enhance nutrient availability to cash crops?Crop and livestock producers in South Dakota are showing greater interest in cover crops for the multidimensional benefits it can provide towards enhanced nutrient availability to the cash crops and livestock nutrition. Growers use different blends of grasses and broad leaves, mostly legumes and brassicas, as cover crops. We hypothesized that carbon and nitrogen ratio and fiber composition in those cover crop residues regulate the nutrient release, thus influence the processes regarding nutri... D. Sanyal, A. Rahhal, H. Bielenberg, J. Clark, J. Wolthuizen, A. Bly |
15. Does Maize Need Pre-Plant N if Sub-Drip Fertigation Can be Used To Provide Season Long N?Multiple nitrogen (N) applications are becoming more common as a way to assure adequate N availability for optimum growth and yield of maize (Zea mays L.), while minimizing the potential for negative environmental consequences associated with N loss. Unclear, however, is how much N needs to be applied at planting in order to get the full value of in-season applications. Our objectives were to determine the amount of preplant N needed to maximize maize yield, when additional N is prov... B. Wiegmann, F. Below |
16. Does Starter Fertilizer Benefit Late Planted Corn?Starter fertilizers are used by producers to help overcome wet and cool soils often encountered with early planted corn. Early planted corn in no-tilled fields and limited drainage typically have the greatest chance of response from starter fertilizers. Starter fertilizers can range from a mixture of UAN, ammonium polyphosphate (APP), and other fertilizers to low salt (LS) formulations containing N, P, K and various micronutrients. Some that promote LS starter fertilizer products claim that U... E. Ritchey, H. York |
17. Economic Optimum Rates of N for Corn Production in IowaProper nitronen (N) fertilizer is essential if crop producers are to maximize profits and minimize environmental contamination. A study to determine 'economic optimum N fertilizer rates was conducted in Iowa from-1987 to 1991. The results show that Iowa crop producers over-applied N during those years primarily due to not considering residual N in the soil. This was especially true following the drought year of 1988.... |
18. Effect of N Fertilization on Accumulation and Release of Readily-Mineralized Organic NIncreased nitrogen (N) fertilizer use has generated concern about groundwater contamination by nitrate (NO,?. The objective of this work was to determine how previous N management and cropping system affect fertilizer N use efficiency. Research plots from a long-term N rate study on a silt loam soil were used to evaluate the impact of long term N rates on immobilization and mineralization of fertilizer N. Labeled '5~~,15~~, was applied at rates of 0, 60, 120, 180, and 240 lblacre to subplots of ... |
19. Effect of Rotation on Corn Yield and Economic Returns Under Composted Manure or Fertilizer ManagementThe benefits of growing corn in rotation with other crops as opposed to continuous corn have been mentioned in numerous research and technical publications. The benefits of adding to the crop mix include improved soil structure (Raimbault and Vyn, 1991) and soil nutrient availability (Copeland and Crookston, 1992). especially from rotations that include legumes such as soybeans or legume cover crops. Other benefits include better weed (Bhowmik and Dow, 1982). insect (Benson, 1985) and disease co... |
20. Effect of Subsoil Tillage on Crops Grown in No-Till and Reduced Till ManagementsThree different subsoil tillage experiments were conducted in southern Illinois on soils with root-limiting claypans that restrict crop growth. In the first experiment conducted at the SIU Belleville Research Center, subsoiling to 16 inches depth was compared to no subsoiling in a field that had been in long term, continuous no-till corn production. After 4 years of study, only small corn and soybean yield increases have observed with the tillage (2.0 bu/ac for corn and 1.0 bu/ac for soybeans) .... |
21. Effects of Residue Density Levels on the Response of No-till Corn to N Fertilizers and InhibitorsExperiments were conducted from 1989-91 at tho southern Illinois locatio~ls (~elle\?ille and Car*bcrndale) to evaluate the effect of residue levels un the perfor-mance of N fertilizers, urease inhibitors, and placenient on the response of no-till conl. Levels of 0, 50, 100, and 200 percent of existing (pre-plant) amounts were established in the crop residues of previous corn. Kitrogen fertilizers were urea-ammonium nitrate (UAN) solution (dribble, injection. and split-applied) and urea (broadcas... |
22. Efficacy of Variable-Rate Application Technology for Phosphorus, Potassium, and Lime ManagementVariable-rate (VR) application technology may improve P and K fertilizer and lime use efficiency, increase crop yield and the profitability of crop production, and reduce within-field soil-test variability. On-farm research assessed the potential of VR P or K fertilization and liming for corn and soybean in Iowa. Replicated strip-trials evaluated one to three cycles of the two-year rotation. Treatments for areas 10-30 acres in size were a non-fertilized or unlimed control, VR based on dense g... A.P. Mallarino |
23. Evaluating Relationships between Soil Respiration and Nitrogen Use Efficiency in CornAvailable nitrogen (N) often limits the agricultural production of corn (Zea mays) and the N fertilizer use efficiency is of primary concern for producers in Kansas and the Midwest. This study was carried out to understand the agronomic value of commercially available soil health tests (e.g. 24 hr CO2 burst) and their relationship to components of nitrogen use efficiency (NUE) in corn. Relationships between N response and soil CO2 evolution were investigated across multiple sites and manageme... D. Ruiz diaz, B. Rutter |
24. Evaluation of Soil Test Methods and Crop Response to Phosphorus Fertilization in KansasWheat (Triticum aestivum) is typically considered the most responsive crop to phosphorus (P) fertilization in Kansas. This study was conducted to evaluate wheat response to P fertilization using modern genotypes and soil test calibration/interpretation for Kansas soils. The study was conducted during the 2018-2019 growing season with eleven locations in Kansas. Randomized complete block design was used for four differe... C. Weber, D.A. Ruiz diaz |
25. Evaluation of Sulfur Fertilizers In Corn ProductionSulfur deficiencies and corn yield increases from S fertilization have been documented in Iowa since the mid-2000’s. Therefore, S fertilization management is an important component of high yield corn production. Many S fertilizers are available for use in correcting deficiencies. However, specific product evaluations have not been widely conducted in Iowa. In addition, a new S fertilizer has recently become available in the Midwest U.S., the mineral polyhalite. The research objectives w... J. Sawyer, M. Castellano, A. Sassman, J. Lundvall |
26. Evaluation of Three N Recommendation Systems for Corn Yield and Residual Soil NitrateProper N application rates are required for continued economic and environmental viability of U.S. agriculture. Application at rates below that required for economic optimum will place U.S. farmers at a competitive disadvantage in the world market. On the other hand, excessive rates of N fertilizers may result in contamination of ground water. ... |
27. Four R Nitrogen management for cotton. MU-FDRC research update.Cotton is a much different crop than corn. In addition to the dicot vs. monocot difference, cotton is a perennial plant cultivated as an annual crop. A cotton crop must be “encouraged” to produce fruit and hence lint in this production system. Input management, including nitrogen fertilizers, are central to modern cotton production. Adequate nitrogen must be available to a cotton crop during the critical flowering period. In Missouri this is from mid-May to... D. Dunn |
28. Grid Sampling or Topography Sampling for Soil NutrientsSite-specific application of fertilizers uses field soil sampling for its information basis. Many fields are currently sampled using a grid approach. In North Dakota, examination of grid sampling showed nitrate-N to follow topographic patterns in a field, allowing the possibility of less intensive sampling for N. Reviewing previous grid sampling work in Illinois, some soil properties may be associated with landscape features, including nitrate-N in the surface 6 inches and soil pH. However, Ill... |
29. How Agronomic Management Affects Soil Nitrous Oxide EmissionsThe effects of crop and soil management practices on soil emissions of non-carbon dioxide (CO2) greenhouse gases (GHGs) such as nitrous oxide (N2O) are highly variable, and long-term field data are limited. Management strategies that impact nitrogen (N) mineralization are also likely to affect how N is lost to the atmosphere as N2O gas. This presentation covers the agroecosystem soil N cycling concepts leading to losses as N2O as well as... V.L. Jin, M.R. Schmer, B.J. Wienhold |
30. Impact of sulfur and its interaction with N rates on wheat and barley in North Dakota and Western MinnesotaEffects of S, N, and their interactions were assessed on grain yields and protein of spring wheat and barley, across eight site years in Western Minnesota (MN), and ten site years (hereafter, sites) in North Dakota (ND) from 2015 to 2019. The studies were to determine if S improves yields and protein in wheat, and if the effects were dependent on N rates. Treatments included all combinations of five N rates of N (0, 60, 120, 180, and 240 lbs/ac) and three rates of S (0, 10, 20 lbs/ac) in MN. ... J.M. Teboh, S. Yuja, B.G. Schatz, G. Pradhan |
31. Importance of Subsoil PotassiumRecent information has emphasized the importance of nutrient distribution by depth in soils. Information from across the Cotton Belt in the U.S. has demonstrated that cotton yields have been affected by accumulation of potassium (K) near the soil surface with subsequent depletion of subsoil K. This condition combined with changes in K demand by new, high-yielding cotton varieties has led to a change in cotton K deficiency symptoms and delayed diagnosis of the actual problem. Recent studies have ... |
32. In Search of EAN of Spring WheatMany spring wheat varieties respond reliably to enhanced ammoniunl nutrition (EAN) in the greenhouse. Three field studies were established in 1992 to determine if similar responses could be obtained in the field. Butte 86 spring wheat was fertilized (100 Ib N/A) with calcium nitrate, urea, urea + DCD, forestry-grade (0.1 g) urea pellets and forestry-grade urea pellets + DCD. The goal was to provide wheat with a large range of a1nmonium:nitrate ratios and to determine the effect 011 wheat develop... |
33. In-Field Determination of Anhydrous Ammonia Applicator Accuracy in NebraskaLiquid and dry fertilizer applicators have been studied for their application patterns and precision. However, anhydrous ammonia (AA) applicators are generally considered less accurate. Due to the difficulty of calibration, actual application errors have not been documented. In order determine if AA applicators were delivering the intended application rate, a standard AA nurse tank was fitted with load cells, temperature, pressure, travel speed and travel distance sensors. Initial data from 55 f... |
34. Influence of Elemental Sulfur on Soil pH and Soil Test LevelsSoil test summaries from South Dakota State University Soil Testing Lab show that 16 percent of South Dakota soils have a pH of 7.6 or higher. These high pH soils can reduce nutrient availability to plants. A major concern is for reduced phosphorus availability and fertilizer use efficiency. High pH soils also reduce the availability of micronutrients such as iron and zinc. Due to these issues, questions are often asked on how to reduce soil pH. A number of materials such as sulfuric acid, alumi... |
35. Influence of Phosphorus Soil Test Level on the Probabaility of Corn Yield ResponseData from a long term residual phosphorus study was analyzed to determine the probability of a corn yield response at low, medium, high and very high soil test levels. Analysis of 55 rate-site years showed a corn yield increase 59, 22, 43 and 17% of the time respectively for low, medium, high and very high soil test categories. The very high soil test category is defined as a Bray P soil test of greater than 20 ppm. The results suggest that the current South Dakota State University recommendatio... |
36. Integrating Multiple-Input Management Systems to Improve Soft Red Winter Wheat Grain YieldContinued improvements in wheat (Triticum aestivum L.) grain yield have cast greater interest on utilizing multiple inputs within enhanced management systems. Less than recommended seeding rates of modern varieties may utilize inputs more efficiently when subjected to enhanced management. The objective of this study was to evaluate plant growth, grain yield, and expected economic profitability for multiple agronomic and nutrient inputs across different production intensity l... K. Steinke, S. Purucker |
37. Is There a Better Way to Fertilize Corn with Potassium?Potassium (K) is among the most abundantly needed plant nutrients. A 15.7 Mg ha-1 (250 bushel acre-1) corn (Zea mays L.) crop accumulates anywhere from 168-225 kg K2O ha-1 (150-200lbs K2O acre-1) over the course of a growing season, and according to the IPNI Soil Test Summary (2015), about 37% of Illinois’ soil tests are deemed as deficient for K. The objectives of this study were to investigate various methods o... S. Foxhoven, F. Below |
38. Long Term Phosphorus Research on Corn and Grain SorghumPhosphorus fertilizer is needed for optimum production and economic returns from irrigated corn and grain sorghuni in western Kansas. A long term study shows that the yield benefit from P increases over time from no yield difference initially to over 100 butacre higher corn yields after 30 years. Without fertilizer P, soil P levels declined from 17 pprn Bray- 1 P to less than 10 pprn within five years, where they stabilized for both corn and sorghurn. The addition of fertilizer P at 40 Ib P205la... |
39. Long-Term Alfalfa Study With K RatesA long-term potassium rate study was conducted on a Maury silt loam as part of the soil test calibration program to develop data for more soils in Kentucky. Beginning soil test K levels were established with initial applications of either 0, 150 or 300 lb of K20 per acre. Annual applications of 0, 120, 240 and 360 lb of K20 per acre were applied about 1 month before fall freezedown. Results indicated (1) there were significant yield responses to annual applications after the first year; (2) the ... |
40. Manure Management Policy IssuesTraditionally nutrient management has been concerned with optimizing the economic return from nutrients used to produce a crop. The main emphasis was on the expected crop response from adding nutrients. In practice however, manure is not always applied to optimize plant nutrient use. Historically, a common practice has been to apply commercial fertilizer without giving credit for nutrients already applied in manure. Applying manure in excess of plant needs, or at the wrong time, or handling it i... |
41. N x K Interactions- CornA study was conducted at OARDC-Western Branch near Springfield, OH for 4 years starting in 1992 to investigate the effects of N and K on corn production N uptake. The soil series was a Crosby Silt Loam with approximately 2.5% organic matter. All nutrients were in the above average levels on the soil test except for exchangeable K levels. See table 2 for soil test K levels. The corn hybrid Countryrnark 735 was seeded approximately the last week of April at 35,000 seeddacre. A split plot design w... |
42. Nitrogen and Sulfur Application Effects on Soybean Quality and YieldSulfur deficiency is only becoming more prevalent in the Midwest across soybean fields with higher yields resulting in lower quality seed. Sulfur is a key component of methionine and cysteine, which are important amino acids in the nutrition in foodstuffs. The objective in this study is to explore the impact of N:S applications at different growth stages and rates on the soybean yield and seed composition and quality. In 2018 the trial was performed both in West Lafayette and Wanatah Indiana.... D. Miller, S. Casteel |
43. Nitrogen Application, Biological N Fixation, and N UptakePrevious collaborative research in the Midwest has shown that there is likely little to no need of N for soybean, except under certain conditions (such as when low soil moisture limits N fixation, or when low initial soil nitrate-N limits overall N availability). However, none of the site-years used in this synthesis analysis were on sandy soils. Because sandy soils supply little nitrate-N, the potential impact of N on crop yield is greater in sandy environments than on silt loam soils. Howev... A.M. Walters, M.D. Ruark, J.M. Gaska, C. Zegler, S.P. Conley |
44. Nitrogen Availability from Composted ManureComposting of manure has been proposed to play a role in manure management programs designed to protect water quality. It is known that the biological activity involved in composting changes the nutrient availability of the material and in some cases will reduce the nutrient content. The major role of composting in alleviating some of the on-farm manure nutrient excess problems is by facilitating manure movement from a farm with an excess to a farm with a deficit of nutrients. There are several ... |
45. Nitrogen benefits when interseeding red clover into continuous cornInformation pertaining to the benefits of intereseeding cover crops is lacking. Red clover is a leguminous cover crop that can grow in low radiation environments, is winter hardy for much of the northern USA, and is a low cost weed suppressant that has been shown to provide a nitrogen credit and improve corn yield. While it is clear that red clover is a cover crop that can provide immediate economic benefits in grain-based cropping systems, the potential N credit and the effect of interseedin... H. Francis, M. Ruark, C. Zegler, D. Smith, J. West |
46. NITROGEN CREDIT FOR LONG-TERM NO-TILL CROP PRODUCTION IN NORTH DAKOTAFeedback from farmers who had been in no-till crop production for over twenty years indicated that crop production could be maintained at high levels with a reduction in N rate from the universally recommended rates. Nitrogen rate studies in spring wheat/durum, corn and sunflower have confirmed that N rates can be reduced when a farm is under continuous long-term no-till production. A portion of the N credit may be uptake of N by microorganisms, thereby reducing the amount of N exposed to lea... D. Franzen |
47. Nitrogen Fertigation on SoybeansNutrient requirements for soybeans are greatest as seeds are developing during reproductive pod fill. This peak nutrient demand period physiologically coincides with decreased efficiencies in both symbiotic nitrogen (N) fixation and root efficiency (Brun, 1978). Large N applications during vegetative growth stages limit N fixation and fail to consistently increase grain yields (Fla~ery, 1986). However, smaller N applications during flowering and pod fill have been reported to augment plant N sta... |
48. Nitrogen Fertilizer Equivalency of Anaerobically Digested Municipal SludgeCrop yield response to municipal sludge is largely affected by the amount of nitrogen (N) made available during the growing season. The effect of sludge rate and N fertilizer rate on either grain sorghum [Sorghum bicolor (L.)] or corn [Zea mays (L.)] yield response was studied on three fms in Lancaster county, Nebraska. A combination of five rates of dewatered (80% H20) anaerobically digested sludge and five rates of N fertilizer (NH&03) were applied before planting and incorporated by discing ... |
49. Nitrogen Management Systems for Ridge-tilled Corn ProductionThe use of conservation tillage methods, including ridge- tillage, increases crop residue cover which can lead to loss of urea-based fertilizers applied broadcast. ~ield tests were conducted during 1987-1991 at the ~rrigation ~xperiment Field, located near Scandia, Kansas, on a Crete silt loam soil (fine, montmorillionitic, mesic, Panchic, Arguistoll). Treatments included anhydrous ammonia (AA) applied preplant knife-injected; 28% urea-ammonium nitrate solution (UAN) applied preplant knife- inje... |
50. Nitrogen Source and Application Timing to Improve Corn Yield and Reduce Nitrate in Tile-Drain WaterNitrogen (N) fertilizer is among the most important inputs for corn because of this crop’s large N requirements. When N fertilizer applications exceed crop needs, that N can be lost to the environment or be incorporated into the soil organic matter Many farmers in the US Midwest install subsurface drainage to remove excess water from the soil. The drained water leached from the farms contains nitrate-N (NO3), which poses risks to surface waters. Midwest agriculture ... S. Menegaz, F. Fernandez |
51. No-till and Cover Crops Influence Soil Health and Nitrogen Rate and Timing Recommendations: Early ResultsThe idea of improving soil health has become increasingly more talked about by researchers, agronomists, and farmers in the past five years. Management practices such as no- or reduced-tillage and planting cover crops are recommended to improve soil health because of their potential to improve organic matter and soil structure leading to a greater capacity to hold water and nutrients needed for plant growth. Research in South Dakota has been occurring these past two years to determine the inf... J.D. Clark, A. Bly, D. Karki, D. Sanyal, J. Wolthuizen, P. Kovacs |
52. Nutrient Credits for Manure--Differences Between Theory and RealityIt has been a mainstay recommendation for many years--take credit for the nutrients in the manure you spread on your fields. While it may seem that everyone is referring to an identical procedure, there are numerous strategies to crediting nutrients contained in manure. Although it appears to be simple, the complexities involved in crediting have resulted in few livestock and crop producers properly crediting nutrients from manure. Research and educational efforts have sharply increased in the p... |
53. Optimizing Nitrogen Rate to Maximize Winter Malting Barley Grain Yield While Meeting ProteinWinter malting barley (Hordeum vulgare) acreage is increasing across Ohio due to demand from the local craft brewing industry; however, grain used for this market must pass specific quality requirements. The objective of this study was to identify optimum spring nitrogen rates for winter malting barley that maximize yield while meeting protein requirements. Small plot trials were conducted at three locations in Ohio: Northwest Agriculture Research Station (NWARS) in Custar, Western A... G. Mcglinch, L. Lindsey, R. Shrestha, M. Hankinson |
54. Phosphorus Losses in Runoff Water as Affected by Tillage and Phosphorus FertilizationPhosphorus (P) in runoff from cropland can contribute to nutrient enrichment and eutrophication of surface water bodies. Research was continued during 1996 to determine which tillage systems and which methods of applying P fertilizer will result in the least P losses in runoff water for grain sorghum production under somewhat poorly drained soil conditions in east-central Kansas. The tillage systems evaluated were a chisel-disk-field cultivate system, a ridge-till system, and a no-till system. F... |
55. Phosphorus Management on Extremely Acid Soils in South Central KansasResearch was conducted to evaluate the effectiveness of phosphate fertilizer in reducing the toxicity of soluble aluminum (Al) on very acidic soil for production of winter wheat. Banded P fertilizer increased wheat grain yields significantly with the response being greater on unlimed compared to lime conditions. Based on the findings of this research coupled with Oklahoma State University research, banded P is an alternative to liming for wheat production on extremely acidic soils with consider... |
56. Potassium RecommendationsMost soils have relatively large contents of total K but relatively small amounts of plant- available K+. Potassium is found as a component of several minerals that release it to soluble and exchangeable forms by weathering at greatly differing rates. These forms are shown in the adjacent figure. Some of these minerals also have the capacity to reabsorb (fix) added K+ back into their structures in nonexchangeable form. Even the exchangeable K+ is bonded with different strengths depending on the ... |
57. Predicting Plant Available Potassium using a Modified Sodium Tetraphenylboron MethodCurrent potassium (K) fertilizer. recommendations in the midwest are based primarily on the ammonium acetate exchangeable K (NH,OAc) soil test. In soils where nonexchangeable K comprises a major portion of plant available K, the ammonium acetate soil test is unreliable. Soil K extraction by sodium tetraphenylboron (Na-TPB) accesses both exchangeable and nonexchangeable K and mimics the action of K uptake by plant roots. A Na-TPB method utilizing a 5-minute extraction period is described, and the... |
58. Preplant Soil Nitrogen Test for CornSoil ammonium N and nitrate N were measured at the pre-plant and sidedress stages on 59 Michigan fields in 1992. Total inorganic soil N (ammonium N plus nitrate N) at pre-plant stage averaged to 12.6 ppm, about 50% of which was present in the nitrate form and 50% in the ammonium form. Total inorganic N at sidedress stage was 18.9 ppm, of which the nitrate N component was 12.2 ppm. The NH JNO, ratio decreased from 1.06 at prep1 ant stage to 0.54 at sidedress stage. Multiple correlation analysis ... |
59. Re-Evaluating Rate, Time, and Placement of Urea and Other Nitrogen Sources in MinnesotaUrea is increasingly an important nitrogen (N) source in Minnesota. Approximately 43% of our farmers use urea as their major N source. In the southwestern, south-central and west-central areas approximately 45% of the N is applied in the fall, 50% is applied in the spring, and 5% is applied at sidedress. While most of those that use urea as the major N source apply it in the spring, approximately 4% do the major application with urea in the fall and there are others that apply some of their N... F. Fernandez, K. Fabrizzi, J. Vetsch, D. Kaiser |
60. Response of Ridge-till Corn to Potash FertilizationIn recent years there has been an increased interest in growing corn with either ridge-till or no-till planting systens. This interest has been stimulated by concern for conservation compliance, farm profitability and the environment. Many problems have surfaced as these tillage systems are adopted by more and more farmers. The appearance of potassiu,~ deficiency symptoms has been a major concern for those who grow corn and soybeans with these tillage systems for the past four or five years. For... |
61. Role of Land Tenure-Other Factors in Soil P InterpretationsSoil test interpretation should recognize the residual value of applied PI the inherent limitations of soil P tests, and utilize an approach that can be easily personalized at the local level. These criteria were used to develop an interpretation approach utilizing a computer spreadsheet to estimate the optimum soil test level for an individual grower. The spreadsheet requires the following inputs: a calibration curve, acceptable marginal return, interest rate, land tenure, soil test buffer pote... |
62. Should P and K Fertilization be Matched to Plant Populations for CornFertilization practices and plant populations are major factors involved with corn production. Several researchers have investigated the effects of various fertilizer management practices. Likewise, the impact of plant population on corn production has been evaluated in a variety of production environments. The combined effects of plant popillation and fertilization. however, have not been thoroughly evaluated. Specifically. there has bcen very little study of the influence of plant populations ... |
63. Sidedressed swine manure slurry via dragline hose produces comparable corn grain yields as commercial fertilizersSpring in the upper Midwest can be short and often wet, providing challenges for producers to apply manure and plant crops in a timely manner to maximize yield. As a result, producers apply a significant amount of their manure in the fall after the crop is harvested. Fall applied manure has adequate time to mineralize and leave the root zone before next season’s crop can utilize the nutrients the following summer. These nutrients can end up in rivers and other freshwater bodies, decreas... C. Pfarr, M. Wilson |
64. Site-Specific Nitrogen ManagementApplying only the amount of nitrogen fertilizer needed for a crop at a particular point in the field makes intuitive sense - and is hard to argue against conceptually. However, in practice site-specific nitrogen (N) management is quite challenging. That is to be expected, since routine. uniform N management is often more challenging than is management of other nutrients. Because of nitrogen's mobility in soil. the fact that it is subject to a wide range of transformations and loss processes, and... |
65. Site-Specific Prediction of Soybean Nitrogen ContributionsSoybean has long been recognized for its nitrogen (N) contributions and yield enhancing effects in crop sequences. Soybean N credits in the Midwest range fiom 20 to 40 Ib of Nlacre (Kurtz et al., 1984). Several Midwestern states recommend a legume credit of 40 Ib of Nlacre following an average crop of soybean. Current Wisconsin recommendations suggest a reduction in nitrogen fertilizer rates for corn following soybean of 1 Ib N hushel of soybean yield up to a maximum credit of 40 Ib Nacre (Kelli... |
66. Soil N2O emissions in continuous corn as affected by 4R and cover cropsCover crops and 4R nitrogen (N) management are promoted as key practices for reducing nitrate leaching losses, but their impacts on nitrous oxide (N2O) emissions remain less certain. This study evaluated soil N2O emissions and grain yield under different timing of N application and cover crops for two years in a tile-drained continuous corn system. Treatments were 224 kg N ha-1 split-applied in fall + pre-plant (Conventional), pre-plant + side-dress (4R), 4R +... G. Preza fontes, L.E. Christianson, C.M. Pittelkow |
67. Spatial Analysis of Yield-Limiting FactorsThe spatial relationship between crop yields and soil and site parameters was modeled using several methods. Yield maps estimated by projection pursuit regression and neural network analysis agreed well with measured yields. These methods also allowed generation of response curves for estimated yield as a function of each of the input parameters. These response curves were useful for investigating the relationship between yields and individual soil and site parameters. ... |
68. Spatial Prediction of Crop Productivity Using Electromagnetic InductionAn inexpensive and accurate method for measuring water-related, within-field soil productivity variation would greatly enhance site-specific crop management strategies. This paper reports on investigations to use an electromagnetic induction (EM) sensor to map claypan (Udollic Ochraqualfs) and alluvial (Typic and Aquic Udipsarnnlents, and Aeric Fluvaquents) soil conductivity variations and to evaluate the relationship of EM measurements to grain crop production. Grain yield measurement was obtai... |
69. Summary of How Fertilizer Dealers Integrated Manure into Their Nutrient Management ProgramsTwo fertilizer dealers established manure brokerages in Ohio in the spring of 1992. One was in Holrnes County in Northeast Ohio with Progressive Crop Service, an independent fertilker dealer. This county is in an area which has a high concentration of poultry located in the eastern part of the county. Most of the row crop agriculture is in the western side of the county. The terrain is rolling and this is an Amish community which tends to have small fkms. The second site is in Darke County in we... |
70. Summary of P Fertilizer use Effects on Soil Test PhosphorusOver the years, much research has centered on the use of various soil P extractants for developing soil fertility programs. While P soil test values are most reliable for estimating the historical probability of obtaining a crop response from fertilizer P application and tracking the effects of past P fertility programs - P soil tests are more commonly used as to estimate future fertilizer P rate requirements. Depending on the objectives of a grower, P soil testing is used to predict future P ra... |
71. Tillage, Fertilizer Placement Equipment and Residue Compliance- Is There a ConflictConservation compliance is no longer a nightmare for crop producers farming highly erodible land. Instead, it is rapidly becoming reality if those crop producers plan to participate in USDA agricultural assistance programs. In Missouri, farmers are adopting conservation and no-till cropping practices at a very rapid rate. Though not verified, it appears that no-till acres in many north Missouri counties more than doubled from 1991 to 1992. The most cost effective means of reducing soil erosion r... |
72. Understanding Spatial Variability in Cover Crop Growth and DecompositionIn many agricultural landscapes, topographic variability leads to downslope movement of soil, water, and nutrients, causing heterogeneity in both crop yield and soil fertility throughout production fields. Cover crops can slow these processes, but the impact of topography on cover crop growth and residue persistence is uncertain. We measured the growth, mixture biomass composition, and decomposition of a cereal rye (Secale cereale L.) cover crop, and cereal rye /crimson clover (T... S.J. Leuthold, M. Salmeron, O. Wendroth, E. Haramoto, H. Poffenbarger |
73. Variation Among Commercial Corn Hybrids in Response to Agronomic ManagementStrategic selection and utilization of corn (Zea mays L.) hybrids for a given yield environment and agronomic management system will require better understanding and documentation of the interactions between current commercial hybrids and agronomic factors that have sizeable impacts on yield. Therefore, this study evaluated the effects of N fertility, plant population, and row spacing on grain yield of corn and assessed the range in yield responses among commercial hybrids to these a... E.T. Winans, F.E. Below |
74. What's Ahead- Soil Conservation Service Nutrient Management PlansFarmers have been going through a major change in their relationship with Government during the past ten years. Many in the agricultural community are anticipating possibly more changes in the future from such Legislation as the Clean Water Act and the Endangered Species Act. Each act has potential of having even more impact on the agricultural community. Immediately following those two acts will be the 1995 Farm Bill. The last two Farm bills have been slanted more to environmental concerns than... |
75. Winter Cereal Rye Nitrogen Response and Fertilization RequirementWinter cereal rye (Secale cereale L.) has been a common cover crop choice due to seed cost, winter hardiness, and rapid spring growth. It could also be an alternative grain crop to include in a corn-soybean rotation. Also, a rye crop would provide soil coverage during the springtime when corn and soybean do not. No known research has investigated the N fertilization requirement for winter cereal rye seed production in Iowa. The objectives of this study were to evaluate N response in ... C. Martins, J. Sawyer, J. Lundvall |
76. Yield Monitoring- The Beginning or the EndAs site specific management or precision farming gains acceptance with the agricultural producer, the question remains: '.Where do I begin?". As technology creates and makes available new machines for the site specific environment: ''How do they fit into the picture?". As the yield monitor has become the most popular and accepted of these technological innovations for the agricultural producer, what role does it play in the sitc specific management concept? What is site specific management and w... |