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1. Aglime for Corn and Soybean ProductionLiming acid agricultural soils has been a long-time proven practice to maintain/improve crop yields, particularly forage legumes, and to favorably affect soil chemical, biological and physical properties. Summaries of soil test results from the Iowa State University Soil Testing Laboratory for the past 35 years have shown a consistent 2 to 3 percent of soil samples with a soil pH below 5.5 and 14 to 16 percent with soil pH between 5.6 and 6.0. There has been an increasing percentage (from 21 to ... |
2. Are We Getting Better at Supplying Corn with Nitrogen?While the MRTN approach to making N rate guidelines is an improvement over previous methods, there remains the question about whether or not the database is sufficiently large to support the results adequately. This question is brought into focus when N rates used according to the MRTN guidelines are seen (or at least perceived) as being be inadequate in a given field or area in a given year. Other entities now making N rate recommendations may also market against the MRTN approach by raising do... |
3. Assessing Crop Nitrogen Needs with Chlorophyll MetersTissue testing of corn leaves for nitrogen (N) concentration is not widely used because it is easier and perhaps more economical to apply sufficient fertilizer than to risk a yield reduction because of an N deficiency. Environmental concerns related to N fertilizer will require producers to improve N management practices to reduce the potential for nitrate leaching. Applying fertilizer N on an "As Needed" basis rather than using a "Lump Sum" approach has both environmental and economic implicati... |
4. Assessing the Status of Soil Phosphorus, Potassium and pH for Soybean Production in OhioSoybeans are one of the most valuable agronomic crops produced in Ohio, and in 2014, the value of Ohio⤙s soybean crop was $2.7 billion making soybean extremely important for agriculture and the economy. To achieve high soybean yields, it is essential to have the proper soil nutrient and pH levels; however, some nutrients can also have detrimental environmental effects. Phosphorus (P) can cause eutrophication of freshwater systems when high quantities enter waterways, furt... A. Brooker, L. Lindsey |
5. Assessing the Use of Enhanced Efficiency Fertilizers on Sugarbeet Yield and QualityA field study was initiated in Frankenmuth, MI to study the effects of enhanced efficiency fertilizers in comparison to standard nitrogen (N) programs on sugarbeet (Beta vulgaris L.) yield and quality. The study was arranged as an 8 treatment randomized complete block design with four replications. All treatments received 40 pounds N/A as 28% UAN applied as a 2x2 (in) at planting with total N applications at 160 pounds N/A. Treatments consisted of urea sidedressed with light cultivation, N appli... C. Bauer, K. Steinke |
6. Best Management Practices for Nitrogen in MinnesotaAtrention to nirrogen (N) nlanagemerzt and to rhe influence of N on ground- rvarer qzraliry was significanrly enhanced in Minnesota wirh the passage of the Conlprehensive Groundwater Protection Acr in 1989. That legislative act mandated the fonnarion of u Nirrogen Fertilizer Task Force whose duty was ro study the eflecrs and impacrs on water resources fro,n N fenilizer use so rhar besr management practice (BMPs), a fenilizer managenlenr plan, and N fem'l- izer use regulations could be developed... |
7. Better Maize Response to Optimal Fertilizer PlacementIncreasing trends in corn (Zea mays L.) yields require greater levels of applied nutrients per acre to maintain or increase yields; thus, we need to rethink how to best supply a crops⤙ required nutrients. One significant challenge associated with applying more fertilizer to support greater yields has been the negative environmental effects of increased levels of some nutrients, such as phosphorus. Fertilizer application technologies such as banding the fertilizer below the plant increases... |
8. Can Soil Information Better Inform Canopy Sensor Algorithms for Corn?Corn production is often limited by the loss of nitrogen (N) due to leaching, volatilization and denitrification. The use of canopy sensors for making in-season N fertilizer applications has been proven effective in matching plant N requirements with periods of rapid N uptake (V7-V11), reducing the amount of N lost to these processes. However, N recommendation algorithms used in conjunction with canopy sensor measurements have not proven accurate in many fields of the U.S. Cornbelt, resulting in... , N.R. Kitchen, J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, F.G. Fernandez, E.D. Nafziger, C.J. Ransom, , J. Shanahan, G.M. Bean |
9. Comparison of Canopy Sensing Technologies for Corn Nitrogen Management in MinnesotaVarious crop canopy sensing tools are being used to manage nitrogen, but their utility to predict N needs in Minnesota remains unclear. The objectives of this study are to compare the effectiveness of different canopy sensing technologies at predicting corn (Zea mays L.) yield at different development stages, and compare their capability to determine in season N deficiency. Six to seven N rates at 35 to 45 kg N ha -1 increments were pre-plant applied in six fields throughout Minnesota and a rate... |
10. Comparison of Congranulated Fertilizer to Blends with S and Zn in Corn and SoybeansHigh yielding corn and soybean production systems in Missouri have renewed an interest in micronutrient management such as sulfur (S) which is essential for protein formation and zinc. (Zn) which is important for enzymes and metabolic reactions. Yield increases due to sulfur applications are more likely to occur during cool, wet springs when mineralization and crop growth are slow as a result of a decrease in atmospheric sulfur deposition. Soil tests in 2010 indicated that over 60% of the sam... M. Caldwell, K. Nelson, B. Burdick |
11. Corn Growth and Yield Responses to Pre-plant and In-season Nitrogen CombinationsIn-season N applications may help synchronize N availability with corn uptake but further investigation is needed to validate different combinations of pre-plant and in-season N strategies. Field experiments were initiated in 2014 to investigate corn response to N management programs involving multiple N-placements, timings, and sources applied at a single N rate at two Michigan locations. Nitrogen management programs were grouped into three strategies utilizing broadcast pre-plant incorporated ... |
12. Corn Nitrogen Evaluation in South DakotaCurrent Nitrogen (N) recommendations for corn in South Dakota use an N rate calculator approach (yield goal x 1.2 ⤓ soil test Nitrate-N (0-2 ft) ⤓ legume credits ⤓ other credits such as manure application or N in starter fertilizers + 30 lbs N/a for no-till). The N coefficient has been modified in the past from 1.45 in 1975, to 1.3 in 1982 and currently 1.2 determined 1991. The N coefficient is in dire need of re-evaluation becaus... A. Bly, S. Berg, P. Sexton, R. Gelderman |
13. Corn Response to Starter Phosphorus in Addition to Fertilizer Banded with Strip-tillageProducersoften question the need for starter fertilizer application in addition to deep band with strip-tillage. The objective of this study was to evaluate the effect of phosphorus (P) starter on corn (Zea mays) in addition to deep-banded application. A study was conducted at two locations, one under supplemental irrigation and one dry land, with a corn-soybean crop rotation established in the spring of 2006. Strip-tillage was completed before corn in the rotation and soybean was planted withou... |
14. Crop Responses to Starter Fertilizer... |
15. Crop Sensors as In-season Nitrogen Management Tool for Winter Wheat in WisconsinIn Wisconsin, current winter wheat (Triticum aestivum L.) nitrogen (N) rate guidelines are determined by soil type, previous crop, and pre-plant soil nitrate test (PPNT). Nitrogen management may be improved through site-specific assessments of N need in the spring, offering a more effective use of top-dressed N. The study objective was to determine if crop reflectance measurements could be used to determine optimal in-season N rates on silt loam soils in eastern Wisconsin. This study evaluated t... |
16. Determining Cropping System and Topsoil Depth Effects on Phosphorus and Potassium Nutrient DynamicsUnderstanding the effects of fertilizer addition and crop removal on long-term change in soil test phosphorus (STP) and soil test potassium (STK) is crucial for maximizing the use of grower inputs on claypan soils. Due to variable topsoil depth, nutrient supply from subsoils, and crop removal across fields, accurate P and K fertilizer management can be challenging. Current Missouri fertilizer recommendations rely on a single buffering capacity for all soils throughout the state for P, and are on... |
17. Do Soil Nitrogen Tests Relate to Nitrogen Mineralization in First-year Corn Following Alfalfa?Corn (Zea mays L.) is the most frequent first-year crop grown following alfalfa (Medicago sativa L.) in the Upper Midwest. In the majority of cases, first-year corn does not respond to fertilizer N, but sometimes large amounts are needed to optimize yield. The pre-sidedress and Illinois soil N tests (PSNT and ISNT, respectively) are early-season tests used to predict corn yield response to fertilizer N. These tests measure specific fractions of soil N and define a critical concentration to separ... |
18. Economic Perspective on Variable Rate FertilizationSoils form a continuum across every farmer's field, constantly changing in both physical and chemical characteristics. Sometimes these changes are visible; sometimes they are completely masked to the eye. Variables such as organic matter, water-holding capacity, pH, and soil nutrient levels differ, and combined, they affect crop yield goals. In either case, these differences should result in different management practices, including fertilizer applications, being recommended for different soils ... |
19. Evaluation of Crop Canopy Sensors as a Tool for Soybean Research and ProductionDetermining the variables that consistently increase yields in soybean  [Glycine max (L.) Merr.] continues to challenge researchers, agronomists and growers alike. Crop canopy sensors have emerged as a technology used in other cropping systems to monitor and manage agricultural inputs. The sensors measure reflectance in selected wavebands that are used to calculate vegetation indices that relate to unique leaf or canopy characteristics. The objectives of this study were to determine if a comme... |
20. Evaluation of Fertilizer Placement for Corn with Contrasting Rooting SystemCorn genetic improvements in recent year⤙s generated hybrids adapted for water limited conditions (drought tolerant-DT). Drought tolerant hybrids were developed with conventional breeding selection process, and therefore selected based on certain characteristics such as growth habits and root system. New transgenic DT corn hybrids are also becoming available to producers. A previous study demonstrated that corn response to starter fertilizer application can vary by hybrid (Gordon et al, 19... |
21. Evaluation of Macronutrient Uptake and Partitioning in Winter WheatA better understanding of nutrient uptake patterns during the growing season for winter wheat (Triticum aestivum) can help to improve nutrient management decisions at the farm level. The objective of this study was to evaluate the effect of macro and micronutrient fertilization on nutrient uptake and partitioning for a Kansas wheat variety. This study was conducted during the 2014-2015 growing season at the Manhattan North Farm research station, Kansas State University. The experimental design w... |
22. Evaluation of Phosphorus and Potassium Fertilization on Corn and Soybean Yields and Soil Test Levels in OhioThe most recent fertilizer phosphorus (P) and potassium (K) recommendations for corn and soybean grown in Ohio were established in the mid-90s and research is required to verify the appropriateness of these recommendations after 20 years. In this study, corn and soybean rotations were established and maintained at three sites from 2006 to 2014 and fertilizer P and K were applied at 1) zero rates, 2) estimated nutrient removal rates and 3) twice the estimated nutrient removal rates for each rotat... |
23. Evaluation of Soil Profile NO3-N for Prediction of N Fertilizer RequirementsCurrent N recommendation systems based on yield goal with adjustment for previous legume crop or manure applications have worked well in many situations. In the example given in Table 1, multiplying the 8 year average yield times 1.2 lb N/bushel would result in a recommendation within 20 Ibs N/acre of the optimum in 6 of the 8 years. As expected, this system resulted in significant over recommendation in the 1988 and 1989 drought years. While these results provide confidence that the system wor... |
24. Evaluation of Soybean Response to Micronutrients using Strip TrialsLimited studies are available on soybean response to micronutrients and particularly in field- scale strips. The objective of this study was to evaluate soybean tissue response to micronutrient fertilizers in fields with high soil variability. The experimental design consisted of two strips, an unfertilized and fertilized replicated three times. The treatments included an untreated control and a blend of Cu, Mn and Zn at a rate of 10 lb acre -1 and B at a rate of 2.5 lb acre-1. Soil samples were... |
25. Field to Market: The Alliance for Sustainable AgricultureField 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.... |
26. Foliar Fertilization of Soybeans in MissouriSoybeans may benefit from foliar fertilization during the reproductive phase of growth. Foliar fertilizers consisting of factorial combinations of boron, calcium, magnesium and phosphorus were applied to soybeans every other week for eight weeks beginning at flowering at three locations. The foliar fertilization treatment containing B+Mg (1.0 lb/acre B + 2.0 lb/acre Mg total) and split into four applications at Mt. Vernon and the Delta Center increased yields by 8 and 4 bulacre, respectively. Th... |
27. Ground Water Quality Research and Demonstration Projects in NebraskaTwo projects were initiated in Nebraska in 1990 to address concern with increasing levels of nitrate in ground water as part of USDA's Water Quality Initiative. The Nebraska Management Systems Evaluation Area (MSEA) Water Quality Project is a joint effort of USDA Agricultural Research Service (ARS) and University of Nebraska-Lincoln scientists. One phase of the project is investigating the direct impact of four management systems on ground water quality. Another phase of the project is evaluatin... |
28. Improved Nitrogen Management for the Food Industry Supply ChainA project is being led by the International Plant Nutrition Institute (IPNI) and The Fertilizer Institute (TFI), with cooperation by Fertilizers Canada (FC), to help strengthen the science underpinning the Field to Market Alliance for Sustainable Agriculture Fieldprint Calculator (FPC) and its field-scale greenhouse gas (GHG) emissions estimates. Cooperating Land Grant University nitrogen (N) management scientists and USDA NRCS and ARS nitrous oxide (N 2O) emission scientists were invited to wor... |
29. In-season N for Corn Reduced Nitrous Oxide Emissions and Drainage Water Nitrate ConcentrationFarmers want to get the N fertilizer they apply into their crop, not lose it to air and water. This can be difficult to accomplish during wet years when N loss processes are going strong. Applying N in-season can be difficult to accomplish during wet years, but reduces the odds that N will be lost before the crop has a chance to take it up. We compared 2 N management strategies (140 lb N/acre applied pre-plant and variable-rate N applied sidedress based on canopy sensor measurements) and 3 drain... |
30. Influence of Plant Growth Regulators and Nitrogen Rate on Soft Red Winter Wheat Growth and YieldExcessive spring nitrogen (N) applications on wheat (Triticum aestivum) can result in reduced stem rigidity leading to plant lodging prior to harvest. Lodged wheat may reduce grain quality due to inhibition of nutrient transport from roots to grain or decrease grain yield through the inability to thresh lodged plants. Palisade (trinexapac-ethyl [TE]) is a newly labeled plant growth regulator for wheat production in Michigan and was designed to decrease internode length and increase stem thicknes... |
31. Measuring Soil Quality Changes in Corn and Soybean RotationsSoil quality is described as the ability of the soil to sustain crop growth and development along with nutrient cycling and water infiltration and retention. One possible strategy to maintain or increase soil quality is crop rotation. Crop rotations have the potential to increase crop yields, disrupt diseaseand pest cycles, and when a legume is added to the rotation, reduce nitrogen fertilizer requirements. Although the long-term productivity and sustainability of agriculture are dependent on ma... M. Adams, G. Behke, E. Nafziger, M. Villamil |
32. Micronutrients Fertilization for Corn and Soybean: A Research UpdateEssential plant nutrients such as boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn), and others are absorbed by crops in very small amounts and are referred to as micronutrients. A deficiency can have a large impact on crop yield, however, because they perform important physiological functions. The soil parent material and soil formation processes over time along with effects of soil moisture, aeration, and temperature can significantly influence the amount of plant-a... |
33. Missouri Grid Soil Sampling ProjectA grid soil sampling project has been conducted over the past three years in S.E. htissouri for creating a database to provide for variable fertilizer application within fields. Results have shown widely varying soil test levels in excess of 100% variation for P and K. Gross returns to variable spreading of P and K are estimated using an expected soil test and nutrient response function. As may be anticipated, returns to variable fertilization application within a field are also highly variable... |
34. Nitrogen and Harvest Impact on Biomass Yield of Perennial Warm-season GrassesUncertainties of the supply of fossil fuels from finite resources and the negative environmental impacts of their use are the two major driving forces for the search of alternative burning fuels. Perennial warm-season grasses have drawn interest as bioenergy feedstocks due to the high yielding capacity with minimal amounts of inputs under a wide range of geography, and the capability to produce multiple environmental benefits. Nitrogen (N) fertility and harvest management are considered as crit... |
35. Nitrogen and Phosphorus Fertilization of Cool Season GrassStudies were initiated at two locations on cool season grass in central South Dakota to evaluate the effects of nitrogen and phosphorus on forage and seed yields. Nitrogen rates (0,30,60,90,120,1501b Nacre) and phosphorus rates (0,30,60,90,180 Ib P,Odacre) were applied to established crested or intermediate wheatgrass once and harvested for either two or three years depending on location. Nitrogen increased dry matter yield by 48 and 62% at the two locations and seed yield by 166 percent. Phosph... |
36. Nitrogen and Phosphorus Recalibration for Sunflower in the Northern Great PlainsSunflower producers in the northern Great Plains states of North Dakota, South Dakota, and Minnesota are presently directed to N and P recommendations that originate from research performed in the late 1960s and early 1970s. These three states alone produce more than 80% of the sunflowers in the United States on a yearly basis (USDA-NASS, 2015). The current general formulas determining N and P fertilizer rate in these top-producing states are equivalent. The N recommendation is represented here ... |
37. Nitrogen Contribution from Different Manure SourcesNitrogen fertilizer equivalencies (NFE) from manure are influenced by manure type, application method, crop selection, and environmental conditions. Much of the research to determine NFE of manure was conducted in tilled systems but many producers use no-tillage (NT) to reduce soil erosion and labor requirements. The objective of this study was to determine NFE for different manure types used in corn (Zea mays L.) cropping systems. Manures consisted of composted swine manure (CSM), poultry litte... |
38. North Central Regional Nitrate Soil Testing ProjectAlthough preplant soil nitrate (NO -N) tests have a long history of 3 successful use in semi-arid regions of the Western and Great Plains region of the United States (Hergert, 1987), soil NO -N testing in humid 3 regions is currently receiving substantial research attention. One of the most promising approaches to KO testing in the higher rainfall areas 3 of the Midwest and Eastern states is use of the pre-sidedress soil NO test (PSNT) (Magdoff et al., 1984). Research conducted in the humid 3 re... |
39. Nutrient Reduction StrategiesThe Hypoxia Task Force (HTF) 2008 Action Plan set a goal or reducing the nitrogen and phosphorus load reaching the Gulf by 45% in order to reduce the size of the hypoxic zone to 5,000 km 2. Each of the 12 states along the main stem of the Mississippi and Ohio rivers were to develop a state specific strategy by 2013 to achieve the goal by 2015. These plans have been developed and work is underway to implement the strategies, but the time line was not realistic. In February 2015, the HTF announced... |
40. On-Farm Nitrogen Fertilizer DemonstrationsThe Magdoff Pre-Sidedress Nitrate Test (PSNT) has been successful 1y used in the Northeast and humid parts of Midwest to improve N fertilizer recommendations. A modified version of the Magdoff PSNT was evaluated in 1989 and 1990 in Michigan. Fifty-three large scale on-farm corn N demonstrations were carried out. Two rates of N (a reduced rate and a high rate) were rep1 icated 3 to 6 times in each field. Forty-six sites showed no significant (p=.05) yield reduction due to the reduce N rate. Forty... |
41. Optimizing P Based In-Furrow Starter Fertilizer in Fields with Variable Soil Test P LevelsSoils in Minnesota are highly variable in chemical properties, particularly pH which can range from acidic to basic within a single field. In-furrow starter fertilizer is popular if fields with variable- and high (>7.5) pH fields to enhance early plant growth. The purpose of this study was to determine if in-furrow starter fertilizer rate should be varied in fields with varying pH and if starter fertilizer can increase yield in the presence of broadcast P applied at a non- limiting rate. Eight f... |
42. Overview of Soil Fertility Research in Ontario, 1991The major areas of focus in soil fertility research at the Department of Land Resource Science, University of Guelph over the past year have concerned increased nuhent use efficiency and environmental impact. These studies have examined the development of nitrogen soil test for corn, nitrate movement to groundwater, the fate of manure N, the placement of phosphorus fertilizer and the role of VA mycorrhizae in plant phosphorus numtion. The following is a summary of the projects being conducted in... |
43. Phosphorus Loss with Runoff after Applying Fertilizer or Manure as Affected by the Timing of RainfallPublic concerns about agriculture impacts on water quality and the likelihood of further government regulation have been increasing. Phosphorus usually is the nutrient that limits and controls algae growth and eutrophication in freshwater bodies. The uninformed public and many in regulatory agencies see reducing fertilization rates as an effective way of reducing nutrient loss from fields and improving water quality, especially when animal manure is applied. Soil testing for P is a useful, altho... |
44. Phosphorus Placement and Tillage Effects on Corn and Soil P LevelsIncreasing crop production costs have producers scrambling to gain the greatest efficiency possible from added fertilizers. A field study was conducted at two locations in southern Illinois is assess the effect of phosphorus (P) rates and placement methods on yield and P uptake by corn under no-till (NT) and conventional (chisel and disk) tillage (CT) systems. Phosphorus rates consisted of 0, 20, and 40 pounds P205/Ac with placement methods of surface broadcast, dribble and 2x2 at planting. Afte... |
45. Predicting Subsoil Nitrate Content from Surface MeasurementsPreplant soil profile nitrate (NO,-N) tests are effective for I predicting corn (Zea mays L.) responsk to applied N. The difficulty of obtaining profile soil samples is one of the main obstacles to more extensive use of preplant tests. One approach to overcoming this barrier is to develop and use models to predict subsoil NO -N contents 3 from surface soil NO -N measurements. Data from 2295 routlne field 3 samples submitted to the University of Wisconsin Soil and Plant Analysis Laboratory from 1... |
46. Reducing the Severity of Phyophthora Root Rot Damage in Soybeans with Selected Management OptionsPhytophthora root rot of soybeans (PRR) is a major concern for soybean growers in south-central and southeastern Minnesota, where it can be responsible for major yield reductions. In these regions, PRR is generally a serious problem when soybeans are grown on poorly drained soils and/or there is a moderate amount of rainfall within 2 to 3 days of planting. Previous research has shown that PRR causes a reduction in the number of harvestable plants per acre and this is the major contributing facto... |
47. Residue Harvest Effect on Irrigated, No-till Corn Yield and Nitrogen ResponseImmobilization of applied N is expected when much high C:N crop residue remains in the field as is typical following corn grain harvest. Immobilization of N is expected to be less if crop residue is less. The effect of reduced immobilization on N availability may more than compensate for N removed in residue harvest. Therefore, applied N requirement for a following corn crop may be less if crop residue is reduced through harvest. Residue removal decreased the economically optimal N rate (EONR) ... |
48. Roto and Shoot Biomass and Nutrient Composition in a Winter Rye Cover CropNitrogen loss from applied fertilizer can be a significant environmental quality issue if NO 3 moves to surface or ground water. The Iowa nutrient reduction strategy science assessment identified winter cereal rye (Secale cereal L.) cover crop as a practice that can significantly reduce N and P loss (41% NO 3-N and 21% P reduction) from corn (Zea mays L.) and soybean [Glycine max. (L.) Merr.] fields. Cereal rye, when used as a cover crop, through its fibrous root system is able to explore the so... |
49. Soybean and Corn Yield Response to Fertilizar Placement and Tillage SystemNutrient availability and, consequently, yields can be strongly influenced by tillage system and fertilizer placement. Also, different genotypes and rooting systems can affect nutrient uptake and plant growth. The objective of this study was to evaluate fertilizer placement and tillage system effects on yields in soybean and corn with different varieties/hybrids. The experiment was established in two locations in Kansas and the experimental design was a randomized complete block with a split-plo... |
50. Soybean Response to Broadcast Application of Boron, Chloride, Manganese, and ZincMicronutrients are essential for plant growth but in low concentration. There has been increased pressure for farmers to apply micronutrients to soybean [Glycine max (Merr.) L.] due to a perception that deficiencies have increased. The objective of this study was to evaluate soybean yield and quality response to broadcast micronutrients. A study was conducted in Minnesota from 2013 to 2014. Treatments consisted of B (0 or 2 lb ac ï¤_1), Cl (0 or 20 lb acï¤_1), Mn (0 or 10 lb acï¤_1), and Z... |
51. Starter Fertilizer and High Yield Management Impacts on Corn Production... |
52. Starter N and P Effects on Early Maturing Corn Planted EarlyShort-season corn planted early is a water-use management option being investigated in the central plains states. This study was conducted in an attempt to determine optimum starter N and P fertilizer rates and to compare subsurface banded versus surface applications of P for short-season corn planted early. Each location had a 3x3 factorial arrangement of N and P (0, 20 and 40 lbs N or P205/acre) placed 2 inches below and beside the seed as well as one or both application methods of surface bro... |
53. Studies of Agricultural Effects on Groundwater Quality in KentuckySeveral small watersheds and tiled fields have been selected in Kentucky to assess the influence of agricultural practices on groundwater quality. Sites were selected to represent the dominant agricultural systems used in the most agriculturally important areas of the state. Within each study site, water samples from springs, wells, streams, or tile lines are being sampled monthly to monitor content of N03-N, atrazine. alachlor, and fecal bacteria. Although sampling will continue for at least an... |
54. Sulfur Sources, Chemistry, Extent of Deficiencies, and Application Considerations in the North Central Region of the USASulfur (S) has not been considered in the North Central USA region as more than a special-case fertilizer until recently. Originally recommended for canola in the northern plains of North America and throughout the region in sandy, eroded soils, then commonly required in many soils in the western-most states in the region. Reasons for a more widespread need include depleted atmospheric sources, use of low S fertilizers, higher crop yields, and greater annual rainfall in some years. The S soil te... |
55. The Soil Doctor- A Field TrialThe growing environmental concerns of the nation are causing some changes in production agriculture. One of the environmental areas receiving attention is NO,-N in the ground water. A number of universities and private companies have directed attention to this problem. The pre-sidedress nitrate test is the most common approach to reducing excess nitrogen application on corn in the humid eastern U.S. Several researchers have developed systems to use this test. Fields are sampled to a foot depth w... |
56. Topsoil Depth Influences Switchgrass Nitrogen Managment on Claypan SoilsSwitchgrass (Panicum virgatum L.) is an attractive forage or bioenergy crop option for eroded portions of claypan landscapes where grain crop production is marginally profitable. Topsoil depth to the claypan can vary widely within fields and little information exists on the impacts of the topsoil depth on nitrogen (N) management of switchgrass. Therefore, a study was initiated in 2009 at University of Missouri South Farm located near Columbia, MO on a site known as Soil Productivity Assessment f... |
57. Which Corn Nitrogen Fertilization Rate Tools Preforms the Best in the Midwest?Publicly-available nitrogen (N) rate recommendation tools are utilized to help maximize yield in corn production. These tools often fail when N is over-applied and results in excess N being lost to the environment, or when N is under-applied and results in decreased yield and economic returns. Performance of a tool is often based on the specific soil and weather conditions of a growing season. Research is needed to determine which tools are the most effective at recommending economical optimal N... |