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1. 4R Phosphorus Management for Soybeans in the Northern Frontier: Rate and Placement Effects on Plant Stand, Biomass and Seed YieldVery little research has been conducted to determine the best rate, source, placement, and timing of P fertilizer for modern soybean cultivars grown in the Canadian Prairies. Preliminary results of the two years of field studies at 10 locations in Manitoba showed that typical agronomic rates of seed row P did not decrease plant stand and seed yield at any sites; nor was seed yield increased at any site, even with Olsen P concentrations as low as 3 ppm.... |
2. A Comparison of Point Injected and Knifed Phosphorus for Winter WheatThere are almost 2 million acres of winter wheat grown in South Dakota. Most is produced in the southwest part of the state on residual clay soils in a wheat fallow rotation with only limited, shallow sweep tillage. Very reduced tillage is necessary for wind and water erosion control, and water conservation on the long steep slopes. The continued use of shallow tillage on highly buffered, high pH soils has made broadcast phosphorus fertilizer inefficient in increasing wheat yields, even though p... |
3. A Mechanistic Approach to Nitrogen Fertilizer RecommendationsIn efforts to improve Nitrogen (N) management, many new methodologies involving advanced technology such as optical sensors are being utilized. Although these new technologies have been proven to improve N management, their use in production agriculture is relatively low. The majority of farmers are still using mechanistic equations or simply pounds per bushel to determine their N rates due to low cost and ease of use. However, most of these N recommendation equations are becoming antiquated, an... |
4. 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... |
5. Accuracy of Credits and Soil Indicies for Predicting Nitrogen Response in Corn Following AlfalfaCorn is the most frequent first- and second-year crop following alfalfa in the upper midwestern United States. In the majority of reported cases, there is little need for additional fertilizer N to optimize yield of first-year corn following alfalfa. For second-year corn following alfalfa, fertilizer N is needed in about one-half of cases and the economically optimum N rate (EONR) has varied greatly in responsive fields. The objective of this research was to use literature data to evaluate the ... |
6. Ammonium Thiosulfate Effects on Corn ProductionAmmonium thiosulfate ((NH,),S,O,, ATS) and urea-ammonium nitrate solution (UAN) were applied in different combinations to corn grown in five site-year studies to assess any effects of ATS on corn performance. Ammonium sulfate ((NH4),S04, AS) was included in three of these comparisons as an alternate sulfur (S) treatment. Adding ATS to UAN increased corn yield in one comparison, decreased it in another and had no effect on yield in others. Adding AS had no effect on corn yield. Neither S material... |
7. 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 ... |
8. 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... |
9. Assessing the Benefits of Radish as a Cover CropOilseed radish (Raphanus sativus L) is a popular cover crop for no-till farmers in Wisconsin, especially among those that include winter wheat in rotation since radish can accumulate large amounts of nitrogen (N). However, previously presented research in Wisconsin has not shown a clear N credit for a subsequent corn crop. Additionally, there is a lack of information that quantifies other benefits of radish, including compaction reduction and nematode suppression. The objective of this project w... |
10. Banded Potassium for Ridge-till Planting SystemsThe ridge-till planting system is a proven tool for controlling soil erosion and providing maximum efficiency of water use by corn. The use of the ridge-till planting system in the northern Corn Belt has increased substantially in the past several years. Recently, however, potassium (K) deficiency symptoms have been reported in many fields. These observations have occurred even though soil test values for K have been in the high range. As the number of reports of K deficiencies increased, it was... |
11. Changes in Extractable P and Mineral N from Soil Recieving Fertilizer or Manure from Swine Fed Tradional or Highly Available Phosphorus Corn DietsWe compared extractable P and mineral N from soils receiving inorganic fertilizer or manure from swine fed either traditional (TC) or Highly Available Phosphorus (HAP) corn diets. The study was conducted at two sites, one with conventionally tilled irrigated corn and the other with no-tillage dryland sorghum. Manure application to a no-tillage site resulted in volatilization losses of N and greater variation in nutrient availability when cornpared to incorporated manure. When expressed as a per... |
12. Changes in P Uptake and Partitioning in Soybean Cultivars Released in the Last 90 YearsHistorical changes in nutrient uptake and partitioning of soybean [Glycine max (L.) Merr.] were not studied. Field studies were conducted in 2011 and 2012 to investigate phosphorus (P) uptake changes and partitioning through the growing season in 25 maturity group (MG) II, and 26 MG III cultivars. Plant samples were taken and partitioned at V4 (four trifoliates), R2 (full bloom), R4 (full pod), R6 (full seed), and R8 (physiological maturity) growth stages. In-season samples were partitioned into... |
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. Comparison of Soil Properties under Long-Term Crop Rotation and TillageShifts in cropping systems from long-term rotations including forages to mostly annual crops has intensified tillage, but has also led to the development of conservation tillage practices such as no-till. There is a shortage of information about the interactive, long-term effects of rotation and tillage on soil quality. The objective of this study was to assess soil chemical and physical properties after 15 years of crop rotation and tillage treatments. Continuous corn (Zea mays L.) (CCC), corn... |
15. Corn and Soybean Yield Response to P and K at Different Landscape PositionsSoil sampling for fertilizer recommendations is most often from the surface 15 to 20 cm (6 to 8 inches). The nutrient pool available to crops however might be quite variable when considering the spatial variation in the sub-soil nutrient pool. The objective of this research was to assess the potential interaction between claypan soil topsoil thickness (i.e., depth to the claypan) and soil-test phosphorus (P) and potassium (K) on corn and soybean crop response. Plots were established in 1996 on a... |
16. Corn Nitrogen Rate Response and Crop Yield in a Rye Cover Crop SystemWater quality impairment related to N loss from crop production fields continues to be a concern in Iowa, including meeting the USEPA nitrate-N drinking water standard and reducing N export to the Gulf of Mexico. Therefore, in-field production practices would be helpful to aid in reduction of nitrate leaching and movement to water systems. One practice identified in the science assessment for the Iowa Nutrient Reduction Strategy is use of a winter cereal rye (Secale cereal L.) cover crop, where ... |
17. 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... |
18. Corn Yield Response to the Urease Inhibitor N-n-Butyl Thiophosphoric Triamide (NBPT) When Applied with UreaUrease inhibitors are applied to reduce ammonia volatilization and immobilization losses from surface-applied urea or urea-ammonium nitrate solutions (UAN). The urease inhibitor N-(n-buty1)thiophosphoric triamide (NBPT) was evaluated at rates of 0.25 to 1.0 % (w/w) in 78 U.S. trials conducted with corn (Zea mavs L.) during the period 1984 to 1989. When averaged over N rates for all locations and years, NBPT increased grain yields by 4.3 bu/acre when compared to similar rates of unamended urea. A... |
19. Cover Crops Effects on Nutrient Cycling and Fertilizer Recommendations... |
20. Cover Crops Following Corn Silage and Winter WheatCover crops are widely used in Wisconsin following corn silage or winter wheat harvest to control erosion, but effects on subsequent corn yields and their optimum N rates have not been documented. Two separate studies were conducted to: (1) determine the effect of rye as a cover or silage crop on corn yields at varying N rates and (2) determine the effect of radish on corn yields and optimum N rates. In two of three years, a reduction in corn silage yield was determined following rye silage comp... |
21. Crop Potassium Uptake and UtilizationCropping systems currently face dual challenges of maximizing yields in a sustainable approach. The importance of a balanced nutrition is critical for increasing crop production. In the past decades, comprehensive studies were performed for nitrogen (N) in corn and for phosphorus (P) in soybean. From a physiological standpoint, a synthesis-analysis on potassium (K) content, utilization, interaction with other nutrients and final impact on yield is relevant and needed for properly understanding s... |
22. 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 ... |
23. 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... |
24. Do We Really Need a Soil Test for SulfurThe importance of sulhr (S) in a fertilizer program for crop production has been recognized for over 50 years. The need for fertilizer S was not universal. Measured responses were limited to special or localized situations. Since S in a fertilizer program was not needed for all crops and all soils, it was only logical to attempt to develop a soil test that would accurately predict the need for the addition of this essential nutrient. Development of a soil test for S that would accurately predic... |
25. Effect of Alfalfa Stand Density or Cutting Management on Nitrogen Supplying CapacityEconomic, energy and environmental considerations are making the efficient use of nitrogen fertilizers increasingly important for Wisconsin crop producers. Excessive nitrogen applications cannot be tolerated environmentally due to the potential for N leaching to groundwater, or economically due to the relatively high cost of N fertilizers. The potential exists for many producers, farming in legume rotation, to unknowingly over-apply N by not fully applying credits for previously grown alfalfa. A... |
26. Effect of Alum Water Treatment Residuals on Soils with Very High Bray P1 Soil Test LevelsAs point discharges of phosphorus (P) and other pollutants to surface waters from industrial and municipal wastewater systems have been reduced, nonpoint sources of P are now contributing a greater portion of P inputs into freshwater resources. Agricultural runoff and/or erosion can be a main contributor to this nonpoint source pollution. Continued inputs of fertilizer and manure P in excess of crop requirements have led to a build-up of soil P levels which are of environmental, rather than agro... |
27. Effect of Irrigation and Nitrogen on Corn Yield and ProfitAn understanding of the interaction of various inputs on corn yield and profit is important in decision making for corn production. This study was conducted to evaluate 1) the effect of irrigation, hybrid, seeding rate and nitrogen rate on yield of corn and 2) the effect of these inputs on marginal return and cost per bushel for corn production. This study was conducted for three years at two 1 ocations on a Conover 1 oam and a Zi lwaukee clay soi 1 . The three years represented a normal rainfal... |
28. Effect of Starter Fertilizer and Plant Date on Soybean Growth, Nodulation, and YieldEnvironmental conditions at the time of planting are a crucial determinant to soybean (Glycine max) yield potential. In recent years, it has become common in Ohio to begin planting earlier in the growing season, as soon as mid- or late-April in some cases. However, soil conditions are typically cooler and wetter at this time as opposed to later planting dates, and nutrient availability may be limited. When planting soybeans into cool and wet soil, the application of a starter fertilizer may be b... |
29. Effect of Tillage on Legume N Credit to Winter WheatAlthough there has been a significant amount of work done on the availability of legume-nitrogen for corn following alfalfa, several questions have arisen as to the sufficiency and availability of the legume N when winter wheat is raised as a following crop. This is especially true if the wheat is planted soon after the alfalfa is killed. The synchrony of nitrogen released from legumes with crop demand for N has been a concern even with crops such as corn, where N uptake can occur through- out t... |
30. Effect of Tillage, Rotation (Maize and Soybean), and Nitrogen Rate in a Long Term Study on Solvita, Water Extract, H3A Extract ValuesA long term rainfed tillage/rotation/N rate study was established in 1985 on a mostly Coleridge silty clay loam (fine-loamy, mixed, superactive, mesic Cumulic Haplustoll). The study is a factorial of plow, disk, and no-till under continuous corn (Zea mays) and corn following soybeans (Glycine Max) with five nitrogen rates (0, 40, 80, 120, 160 kg ha -1). Soil samples were taken from all rotation/tillage combinations and three N rates in the fall of 2013 to 0.20 m (8 in). They were analyzed using ... |
31. 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... |
32. Effects of Nitrogen Managemetn on Maize Yield and Nitrate Leachingon Irrigated Sandy SoilsIrrigated sands are some of the most productive and environmentally sensitive areas in Minnesota. Reducing nitrate leaching is critical for corn (Zea mays L.) production as ground water is a major source of drinking water in these soils. The objective of this study was to evaluate agricultural technologies that may improve nitrogen (N) management for profitable corn production and mitigate negative effects in groundwater. A randomized complete block design with four replications was established... |
33. Effects of Soil Test, Tillage, and Manure and Fertilizer Application Method on Phosphorus RunoffLoss of phosphorus from agricultural lands into surface waters is of growing environmental concein. Phosphorus transported by surface runoff often ends up in streams and lakes and accelerates eutrophication, which affects the ability to use the water for drinking, fishing. recreation. etc (Foy and Withers, 1995). The niajor mechanisms by which agriculture contributes phosphorus to surface water is through runoff and erosion (Sharpley et al., 1994). Controlling run~ff and erosion from agricultura... |
34. Establishing (and Differentiating) On-farm Research and Demonstration TrialsAs the 1990s begin, funding agencies are looking beyond the traditional definition of who does "research." While university, USDA and private industry have traditionally conducted research in the past, grassroot organizations, local agency personnel and individual farmers are now proposing and implementing research of various types. An overall trend seems to be for research experiments to be evaluated on farmersf fields. Some of this movement may be a political statement against traditional meth... |
35. Evaluating the Interaction between Chelated Fe Source and Placement on Phosphorus Availability in SoybeanIn agriculture, chelating agents are used to supplement micronutrients, such as iron (Fe). However, little research has been conducted on a field scale to evaluate chelating agent effects on phosphorus (P) uptake. The objectives of this study were to evaluate four commercially available chelated Fe sources on early soybean growth and nitrogen (N), P, and potassium (K) uptake. The study was conducted at two locations, and the experimental design was a randomized complete block with four replicati... |
36. Evaluation of Adapt-N in the Corn BeltNitrogen is the plant nutrient required in the largest quantity, the most likely to be deficient, and the most impactful on corn yield as well as grower profit. Providing N to a corn crop in the right amount while minimizing loss is difficult because of complex biological and chemical reactions that result in the loss of N from the crop root zone via deep percolation to ground water, lateral flow, runoff and erosion to surface waters, and volatile losses to the atmosphere as ammonia, nitrogen g... |
37. Evaluation of Secondary and Micronutrient for Soybean Production in KansasSecondary and micronutrients are being increasingly studied for their potential to contribute to yield increase. The objective of this study was to evaluate soybean response to secondary and micronutrient fertilizer application to maximize yields. A randomized complete block design was employed with four replications, at five locations during 2013 and five locations in 2014. Treatments consisted of micronutrient fertilizer as individual nutrient for B, Cu, Mn, S and Zn, in addition to a mix of t... |
38. 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... |
39. Evaluation of Weed Management Strategies on Grain Sorghum Nitrogen Status and Grain Yield Using Optical SensorsInformation on weed management options and relation to nutrient status is very limited for grain sorghum production. The objectives of this study were: (i) determine the effects of different weed management strategies on grain sorghum yield; and (ii) evaluate the impact on nitrogen (N) status and development of the crop. This study was established at two locations in 2014 (Smith and Reno Co in Kansas). The study used a randomized complete block design with 4 replications. Two main factors evalua... |
40. Fall Applied Controlled-Release Nitrogen as a Nitrogen Source for Soft Red Winter WheatSoil conditions are often not conducive for timely spring N applications on wheat. Fall applications may save labor and be more economical when blended with other nutrients such as phosphorus. However, many N sources may be susceptible to loss before uptake by the wheat plant. This study evaluated fall applied controlled-release N as a N source for wheat. ... |
41. 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 ... |
42. Fertilizer Placement and Tillage Interaction in Corn and Soybean ProductionDifferent tillage systems can affect the availability of phosphorus (P) in the soil. The objective of this study was to evaluate the effects and interaction of fertilizer placement, tillage, and varieties/hybrids for corn and soybean. The experiment was established at two locations in Kansas in 2014. The experimental design was a factorial in a randomized complete block with four replications. Three fertilizer treatments were combined with two tillage systems and two varieties/hybrids of soybean... |
43. Fertilizer Recommendations Based upon Nutrient Removal or Soil Testing- A Spatial AnalysisCosts for nutrient management are generally high in crop production systems. Those costs are associated with activities related to: a) gathering information regarding soil fertility and plant nutrition for a field, b) acquisition of the actual soil amendments intended to improve the field's fertility and future crop nutrition, and c) application of the purchased soil amendments at the right rate in the appropriate place within the field. Information gathering usually consists of plant tissue and... |
44. Fertilizer Recommendations in the Eastern Corn BeltThe purpose of this paper is to discuss fertilizer recommendations for corn and soybeans made by three universities and by three private institutions in the Eastern Corn Belt. For lack of a better term, the six sources of recommendations will be referred as "labs", a commonly-used abbreviation for soil testing laboratories. This term does not accurately describe Countrymark which uses the results from other labs on which to base its recommendations. ABSTRACT Nitrogen (N), phosphorus (P) and pota... |
45. Field Correlation of Tissue Testing for Phosphorus and Potassium in Corn and SoybeanInterest in tissue testing as a method of guiding fertilization and detecting nutrient deficiencies in corn and soybean in the upper Midwest is increasing. Tissue testing may be a helpful diagnostic tool for assessing in-season crop nutrients deficiencies. No current yield-response based interpretations for tissue test results are available in Iowa, although previous reports based on limited data collected during the 1990s and 2000s suggested that the value of tissue testing for phosphorus (P) a... |
46. Field Scale Evaluation of Innovative N Management Systems for CornPrevious research has shown that N fertilizer need for corn can vary widely, both between fields and within fields. Producers, however, almost always apply the same N fertilizer rate to whole fields, and vary N fertilizer rates minimally if at all over whole farms. Matching N fertilizer rates more closely to N needs could produce both economic and environmental benefits. Our objective is to test a range of innovative N management systems for their ability to match N rate recommendations to N nee... |
47. 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)... |
48. Greenhouse Gases and Carbon Sequestration Where They Fit With the Fertilizer IndustryFew things elicit more debate than the weather, and whether it is changing. Farmers in Nebraska are klly convinced that global warming is real. while farmers in Michigan arid Ontario aren't nearly as sure after this growing season. I am not going to debate whether climate change is real, or whether it is good or bad, but rather provide some background on the whole issue and how farmers and the fertilizer industry may be affected. Current scientific consensus is that greenhouse gas levels in the ... |
49. Groundwater Quality and Nitrogen Use Efficiency in Nebraska's Central Platte River ValleyIn response to increasing levels of nitrate-N in groundwater in the Central Platte River Valley of Nebraska, intensive education and then regulatory efforts were implemented starting in the 1980s, to encourage adoption of nitrogen fertilizer and irrigation management practices which can reduce nitrate leaching to groundwater. Since 1988, there have been steady declines in average NO 3-N concentrations in groundwater in the Central Platte River Valley, resulting from adoption of recommended pract... |
50. 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... |
51. 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... |
52. Improving Alfalfa Production in Wisconsin with Sulfur and Potassium FertilizerThe longevity and quality of an alfalfa stand is an essential component for Wisconsin�s dairy rotations. A study was developed to determine the effects of sulfur and potassium applications on the growth and development of alfalfa stands. The objectives of this study were to determine the effect of i) S fertilizer rate, timing and form on alfalfa yield, ii) recommended or no K fertilizer application on alfalfa yield on soils testing optimum or low for K, and iii) S and K application on soil tes... |
53. Improving Corn Yield Potential with Banded Phosphorus FertilizerHigh fertilizer costs and concerns about water quality issues have caused many Midwest corn producers to take a greater interest in improving the efficiency of phosphorus (P) fertilizer applications. The objective of this research was to determine the effects of P source, rate and placement on P use efficiency in high-yield corn production systems. The experiment was conducted in 2013 at two locations in Illinois. Two P fertilizer sources (mono-ammonium phosphate (MAP, 11-52-0) or an enhanced MA... |
54. Improving Nitrogen Recommendations in NebraskaSoil nitrate tests offer a unique opportunity to fine tune our nitrogen management into the 90's. Nebraska has had a long history of research and extension programs using soil nitrate levels to modify fertilizer nitrogen recommendations. Because of our climatic regime nitrate tests work well across the whole state. We have a large data base on research plots that shows the tests are very effective. A large number of farmer demonstrations conducted over the last 10 years also show that the techno... |
55. 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... |
56. Insuring Nitrogen Best Management PracticesWhether real or perceived, the risk of losing profit by implementing best management practices (BMPs) is a major barrier in a farmer's decision process to adopt these environmentally and economically positive practices. Farmers have come to rely on agri-chemicals and fertilizers to reduce risk. Even when scientific evidence proves they are unneeded, many are slow to reduce their reliance on these inputs. Farmers need assurance that the occasional failure of best management practices will not cau... |
57. Interpretation and Presentation of Research InformationCrop yields have increased over time as the knowledge base supporting crop production practices has increased. The educational process of transfer of information based on research bears a deep sense of responsibility. Selection of research results on which to base recommendations is a matter of judgement that can be enhanced by proper statistical analysis. Experimental objectives, experimental design, treatment selection, number and years of experiments, environments in which the experimentatio... |
58. 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... |
59. 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... |
60. Long Term Tillage and Fertility Effects in CornA long term study to evaluate tillage methods and fertilization practices on corn under monoculture was initiated in 1970. Effects on grain yields and soil property changes were evaluated over 20 growing seasons. Four tillages evaluated were continuous conventional, alter- nate till (2 years no-till: 1 year conventional till), continuous chisel till, and continuous no-till. The five fertilizer treatments evaluated were: control, 0-0-0; 175-0-0; 160-0-0 broadcast plus 15-80-120 row banded at plan... |
61. 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... |
62. 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... |
63. 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... |
64. Manure ManagementNutrient management should be looked at as an integrated, continuous process. It starts with an assessment of the overall nutrient balance on the farm If this simple assessment indicates a nutrient imbalance, a more detailed assessment will indicate specific field imbalances that need to be considered in the manure management process. Once an assessment has been accomplished, management options for dealing with the situation can be explored. If there is an overall nutrient imbalance on the farm,... |
65. Manure Treatment and Handling OptionsManure treatment and handling will need to be an integral part of the nutrient management systems on livestock farms. No one manure system will meet the varied needs of farms with their specific nutrient management situations. The method of manure handling that will best suit each farm will vary depending on labor, land and capital resources and the manure itself. Several criteria that each farm manager will need to evaluate the treatment system that will best meet their needs are presented. A v... |
66. Minnesota Long-Term Phosphorus Management Trials: Phase I, The Build PeriodPhosphorus (P) fertilizer recommendations are usually made using one of two philosophies, Build and Maintain or Sufficiency. In recent years, the Sufficiency approach has been questioned because of concerns of reducing soil test levels and yield sustainability and whether it has the same yield potential as the Build and Maintain approach. Trials were initiated in 2010 at six locations across Minnesota to develop various soil test P Interpretation Classes in replicated experiments. The initial ph... |
67. Nitrate Test Clinics in MichiganNitrate contamination of groundwater in Michigan is becoming an increasing public concern. Fertilizer N, animal manures and rural septic systems have been implicated as possible nonpoint sources of contamination. A state wide program of monitoring nitrate N in soil and well water was initiated. In the spring of 1989 and 1990, 74 nitrate testing clinics were conducted. Over 3,600 soil samples and 1,900 water samples were analyzed for nitrate N using the nitrate ion-specific electrode. More soil n... |
68. Nitrification of Banded Liquid FertilizersField studies were conducted in 1990 at three sites to compare the relative effectiveness of ammonium thiosulfate (ATS, 12-0-0- 26s) , dicyandiamide (DCD) , and nitrapyrin (NP, ' N-Serve 24E' ) as nitrification inhibitors in combination with banded urea-ammonium nitrate (UAN). Applications were banded prior to planting spring wheat, and soil samples taken 2, 4, and 8 weeks after application. ATS, DCD, and NP inhibited nitrification at all three sites. ATS inhibited nitrification at the 4 week sa... |
69. Nitrogen Availability, Time of Release and Movement in RotationsPrevious studies have found that N is released through the decomposition of sugarbeet tops (Moraghan and Smith, 1996: Reitmeier et a]., 1999). There is also evidence that N credits may be justified following other broadleaf crops, such as potato and sunflower. This evidence follows work by Vanotti and Bundy (1995) and Bundy et al. (1 993) suggesting that N credits from annual legumes are provided not by decomposition ofthe roots or release ofN directly into the soil from the roots as some might ... |
70. Nitrogen Management and its Influence on N Losses to Surface Water Through Subsurface Tile LinesSubsurface tile drainage from row-crop, agricultural production systems on high organic matter soils has been identified as a major source of nitrale entering surface waters in the Mississippi River Basin. Tile drainage studies have been conducted on three drainage research facilities at two locations in Minnesota since 1973. Nutrient and crop management systems including rate and time of N application. N sources (fertilizer, dairy manure and hog manure), nitrification inhibitors, cropping syste... |
71. Nitrogen Management of Bioenergy Miscanthus on Claypan Soil LandscapesBioenergy crop Miscanthus x giganteus has been well studied for its yield in Europe and certain parts of the US Midwest but little has been done to investigate Miscanthus production in settings economically marginal for grain production. This study was conducted to determine nitrogen (N) requirements and yield potentials of M. x giganteus in degraded claypan soils. The effects of N fertilizer rates were investigated at four different locations in central Missouri on a Mexico series soil (fine, s... |
72. Nitrogen Recommendations and Optimum Nitrogen Rates- How Do They CompareThe goals of University N recommendations for corn are to suggest adequate amounts of N to maximize economic return to the grower and simultaneously avoid excess N additions that can contribute to water quality problems. With increasing concerns about the contributions of aoricultural N to groundwater nitrate and to hypoxia in the Gulf of 3 Mexico. the appropnateness of N recomn~endations and their research basis are increasingly questioned. In addition, University N recommendations are often be... |
73. Nitrogen Timing, Loss, and Replacement... |
74. No-till Nitrogen Management Research in MissouriNo-till nitrogen management research on corn in Missouri has focused on the field response of N sources and placement. Results suggest consistent significant response to the use of a non-volatile N source when broadcast on the soil surface compared to N sources that contain urea and potentially can lose ammonia through volatilization. Knifed application of N in no-till has . consistently provided higher yields and N uptake compared to either surface band or broadcast application of potentially v... |
75. North Dakota Corn Recommendations for Preplant and Sensor Directed Sidedress NNitrogen rates for preplant N application in North Dakota have been drastically revised. The former yield-based strategy may have served when N costs were stable and relatively low and high yields in North Dakota were rarely higher than 100 bushels per acre. Due to improved germplasm developed at North Dakota State University and other northern Land-Grant Universities with favorable adaptation to North Dakota climate and soil conditions corn has become one of the most planted crops in the state.... |
76. 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 ... |
77. On-The-Go Sensors for variable rate Nutrient Management- Determining Soil K Status with a Flat-Surface Ion-Selective ElectrodeTraditional soil sampling approaches are frequently not sufficiently spatially dense to characterize within field variability in soil fertiiity. Recent technology advances have demonstrated the feasibility of using automated soil sampling systems and tractor mounted sensors to create nutrient availability maps from more continuous measurements. Our objective was to determine if a flat-surface ion selective K electrode could measure soil K status at field moisture content. Twenty-four agricultura... |
78. Phosphorus and Potassium Effects on Yield Components, Nutrient Accumulation and Persistence of Alfalfa (Medicago Sativa L.)Our objective was to determine why phosphorus (P) and potassiun~ (K) are essential for high yield by analyzing alfalfa yield components. Plots of P treatments (0, 25. 50, and 75 kg/ha) and K treatnients (0. 100, 200, 300, and 400 kgha) arranged in a factorial design were replicated four times. Forage was harvested four times per growi~lg season (1998-2000), and yield. mass per shoot, shoots per area. and herbage nutrient concentrations determined. In May and December, plants were dug to determin... |
79. Phosphorus and Water Quality Issues in Lake ErieWhat are harmful algae blooms? Harmful algal blooms (HABs) are so named because they can produce toxins (or poisons) that can cause illness or irritation sometimes even death in pets, livestock, and humans. The term algae is somewhat misleading since HABs are actually cyanobacteria, which are commonly referred to as blue-green algae, and are not true algae. These organisms act like many other plant and use photosynthesis to capture sunlight but unlike most plants and algae some can fix their own... |
80. Phosphorus Dynamics of Land-Applied Compost Bedded Pack Dairy Barn Product in Low and High Soil Test Phosphorus EnvironmentsCharacterizing and understanding the nutrient dynamics of land applied compost bedded pack dairy barn (CBP) products is necessary because this waste management system and its fertility use are increasingly common. An aerobic mineralization study was conducted to observe the phosphorus (P) dynamics of land-applied CBP product in low and high soil test P (STP) environments. An innovative phosphorus fractionation strategy employing UV-assisted organic P decomposition helped quantify fractions corre... |
81. Phosphorus Sorption Behavior of Kentucky Soils with Varying Indigenous Phosphorus ContentThe risk of phosphorus (P) losses from agricultural lands through surface transport to waterways increases with increasing levels of soil P. Agricultural soils in the Inner and Outer Bluegrass of Kentucky have high indigenous P content. This study investistigates the phsophorus sorption characteristics that influence the soils potential for P loss to water bodies. Four soils from the Inner Bluegrass and four soils from the Outer Bluegrass were identified as eing agriculturally significant soils ... |
82. Planting Date, Nitrogen Rate, and Nitrogen Timing Interactions to Optimize Winter Wheat ProductionWinter wheat (Triticum aestivum L.) planting date is a large contributing factor for high yield production systems located within the central Great Lakes Basin, and nitrogen (N) rate and timing strategies offer the opportunity to improve both the production and efficiency of winter wheat when considered in combination with planting date. A field study was initiated in East Lansing, MI to determine the effects of planting date, N application timing, and total N application rate on winter wheat y... |
83. Potassium Deficiency in South DakotaSouth Dakota soils are typically very high in plant available potassium (K). However in the last several years there have been increasing reports of K deficiency on corn. A number of observations have been made concerning where K deficiency occurs and what factors are involved. A few research studies have been initiated to answer frequently asked questions by producers on K management for corn and soybean rotations in the state. Preliminary results indicate differential corn variety response to... |
84. Potassium Management, Soil Testing and Crop ResponseNew field research is conducted in Iowa as issues or questions arise to assure that nutrient management guidelines are up to date and to address new issues. This article briefly summarizes two major projects with potassium (K) whose results are useful to improve the efficacy of nutrient management and crop production. One project focused on correlating soil-test K methods with response of corn and soybean to fertilization and on obtaining better estimates of the concentration of K in corn and so... |
85. Profile Distribution of Available Potassium in Des Moines Lobe SoilsPlant potassium (K) concentrations and soil fertility evaluations to predict available K have received renewed attention during the past few years due to increasing interest in harvesting crop residues as feedstock for production of bioenergy and other bio-products [e.g., button mushroom (Agaricus Bisiporus) compost]. Interest in K crop nutrition has also increased as more producers adopt reduced or no-tillage production practices. This latter situation is not new, because the potential for K de... |
86. 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 ... |
87. Quantifying the Effects of Nutrient Management and Cover Crops on Soil Microbial Communities and Soybean ProductionAgricultural productivity relies upon microbial communities to cycle nutrients from soil to plant yet little information is available concerning how nutrient management and cover cropping practices influence microbial activity and crop production. Lack of consistent soybean (Glycine max L.) yield response to applied fertilizer has resulted in a need to further investigate management practices focused upon enhancing soil biological activity which in turn may feed the crop. A field study was init... |
88. 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... |
89. Response of Corn to N Fertilization in Fall, Spring, and (or) SummerPrecision farming technologies (remote sensing of canopy reflectance and yield monitoring) were used to study the response of corn after soybean to fertilizer N applied at different times in three field-scale trials in central Iowa in 1999. Weather conditions were unusually favorable for losses of fall-applied N and crop responses to N indicated that substantial losses occurred. Yields of corn could be maintained by adding a nitrification inhibitor or additional N, but the greatest profit was at... |
90. 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 ... |
91. Site-Specific Nitrogen and Irrigation Management Across Nebraska Agro-Ecological ZonesNitrogen leaching below hrrow-irrigated ground has caused nitrate contamination in Nebraska's groundwater. Alternate row hrrow irrigation and alternate row nitrogen fertilization is proposed as a method to decrease water use and decrease nitrogen leaching. Nitrogen (N) was applied at a uniform and variable rate based on spring grid sampling for nitrate. The experiment was conducted at three sites in Nebraska that represent a range of growing conditions. At these sites, the average growing degree... |
92. 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... |
93. Soil and Site Factors Responsible for Yield Variations in Two Southern Illinois Farm FieldsYield variability within a field is largely influenced by the soil physical. chemical. and topographic features of that field. On-farm field research studies were conducted from 1997 through 1999 on two southern Illinois farm fields (one in Jefferson County and the other in Pope County) with varying soil physical, chemical, and topographic features to determine which factors most influenced crop yield variability. Each location was GPS-gridded utilizing a grid cell size of 0.45 acres. Detailed ... |
94. 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... |
95. Soil Mineralogy and Potassium AvailabilityIn this talk, I will try to answer four questions. The outline below gives the overall framework for the presentation. 1. What are the mineral sources of potassium? Primary minerals crystallize from the magma. Those that contain K are: Feldspars (microcline and orthoclase) Micas (biotite and muscovite) Primary minerals weather decompose by several mechanisms. Chemical bonds are destabilized by acid attack. Al ions are complexed by orga... M.L. Thompson |
96. Soil pH and Corn-Soybean Rotation Yield Responses to Limestone Applications and TillageFarmers growing corn and soybean in northwest Iowa must carefully consider liming needs and economics. This is because of high liniestone material cost and the fact that soils in northwest Iowa have high pH subsoil, which can moderate negative effects of acid surface soils. Another factor that must be considered is the variable effect from limestone mixing depth associated with different tillage systems. An experiment designed to evaluate six rates of aglime (0 to 6,000 Iblacre of effective calc... |
97. Soybean Whole Plant, and Trifoliate Phosphorus Concentration Relationships to Yield and Phosphorus Removal RatesPlant tissue analysis is becoming a more popular tool to diagnosis nutrient deficiencies. Whole plant samples may be taken early ( corrections. Leaf samples taken just before grain fill may be used to diagnose problem spots in a field. Benton Jones Jr. et al. (1991) reports that the phosphorus (P) sufficiency range for upper most developed trifoliates is between 0.26 and 0.50 percent P. There is no published data on whole plant P sufficiency ranges from V4 to V6. Nutrient grain analysis is valua... |
98. Spatial Variability of Soil Test Phosphorus, Potassium, pH and Organic Matter ContentAs part of a larger study investigating the potential for variable fertilizer N application in corn production, 18 field sites were established on farms across Ontario intensively sampled in the 1995 and 1996 field seasons to assess the spatial variability of soil test P, K, pH and organic matter content. Soil parameters typically display a log-normal distribution (positive skew) which would generally result in the under-fertilization of a greater area of a field if the rate of fertilization wa... |
99. Stand Age Affects Fertilizer Nitrogen Response in First-Year Corn Following AlfalfaThrough a symbiotic relationship with soil bacteria, alfalfa can acquire nitrogen (N) from the atmosphere, use the N for its own growth, and contribute large amounts of N to subsequent crops. To estimate this N contribution, most land-grant universities use book-value N credits based on alfalfa stand density at termination. However, a recent literature analysis indicated that alfalfa stand density is not a reliable predictor of grain yield response to fertilizer N in first-year corn. That analys... |
100. 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... |
101. Strategies for Establishing Management Zones for Site Specific Nutrient ManagementRecent precision agriculture research has focused on the use of management zones as a method to define areas for variable application of crop inputs. The goal of our work was to determine the relative importance of terrain information, aerial photographs, magnetic induction maps, and yield maps to define management zones. This work was conducted on a center-pivot irrigated field located near Gibbon. NE that has been planted to continuous corn for at least five years. Remotely sensed bare-soil i... |
102. Sulfur Fertility for Kentucky AgricultureSulfur (S) fertility concerns are becoming more common in Kentucky due to the reduction in atmospheric deposition resulting from more stringent air quality concerns. The most likely crops where S deficiency would first occur are winter wheat and alfalfa, due to mineralization rates or high removal rates. Currently few, if any, fields in Kentucky show consistent S deficiency problems. Tissue surveys were conducted in alfalfa fields during 2013 and 2014 to assess S status in alfalfa. Twenty-one pe... |
103. Sulfur Fertilization of Smooth BromegrassStudies were initiated in 1987-88 on established smooth bromegrass at two sites in eastern Kansas to evaluate the effects of sulfur fertilization on bromegrass forage production and quality. Sulfur rates (0, 15, 30 lb S/ac) and sources (ammonium sulfate and ammonium thiosulfate) were evaluated. The addition of sulfur consistently and, in most cases, significantly increased bromegrass forage yields and forage S concentrations. Sulfur had little effect on forage protein levels. Ammonium thiosulfa... |
104. Supplemental N on Soybeans After FloweringThis one year study evaluated the yield response of soybeans to three urea-N sources applied at R3 (early pod), R5 (early bean fill), and R6 (late bean fill) growth stages. Nitrogen sources were urea, urea plus a urease inhibitor (~grotain~) and a controlled-release N (POLYON AG@ polymer-coated urea). Seventy-five Ib per acre of actual N was applied by hand to 10 x 40 foot plots. Experimental design was a completely randonlized block with four replications. Analysis was a 3 x 3 factorial and a z... |
105. Switchgrass Rhizobacterial Community Structure as a Function of Cultivar and Nitrogen Fertility at Two Sites in MinnesotaBiofuel production using native perennial grasses such as switchgrass (Panicum virgatum) has potential to reduce U.S. dependence on foreign oil and curtail greenhouse gas emissions. Switchgrass can also provide significant ecosystem services, such as nutrient loss reduction and carbon sequestration. Best management practices (BMPs) for switchgrass fertility are being established on a regional basis, yet little work has been done to examine the intersection of soil fertility with soil biology in ... |
106. 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... |
107. 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... |
108. 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... |
109. The Influence of Variably Applied Potassium Fertilizer on Yield Variations in Two Southern Illinois Farm FieldsThe basis of Variable Rate Technology (VRT) is to apply nutrients where they are needed and to reduce the application of nutrients where they are not needed. However, there is considerable uncertainty as to whether the variable application of nutrients to farmers fields should be on the basis of soil test levels or yield potentials. A field study was conducted at two locations in southern Illinois from 1997 to 1999 to evaluate VRT as a management tool for corn and soybean production on fields w... |
110. The New Wisconsin Soil Test Recommendation ProgramThe modern Wisconsin soil testing program was originally developed in the early 1960's. It was revised rather thoroughly in 1970 and again in 1981. New research advances, additional correla- tion and calibration data, changes in user needs, and shifts in philosophical viewpoint make it necessary to periodically review the soil testing program and the recommendations that emanate from that program. The current revision is an attempt to incorporate additional research, eliminate certain inconsiste... |
111. The Total Maximum Daily Loads Process in KansasThe Clean Water Act of 1972 required states to establish Total Maximum Daily Loads (TMDLs) for surface water bodies that contain one or more pollutants that exceed water quality standards. A TMDL is a written, measurable assessment of a specific stream segment and its water quality problems and contributing pollutants. This assessment outlines the amount of a pollutant that needs to be reduced to meet water quality standards. allocates control responsibilities among pollution sources in a waters... |
112. 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... |
113. Trends in Soil Test P and K in IowaThe Iowa State University Soil Testing Laboratory has provided soil test information to Iowa farmers since 1931 when Professor Firkins began the service for no charge. The predecessor of today's lab was initiated in February, 1946 (~ik~) . The lab's records provide us with valuable information on the trends in the plant nutrient status of Iowa's soils (Figure 1). During the period from 1960 to 1981, the consumption of nitrogen (N), phosphate (P), and potash (K) fertilizer materials rose from 7.5... |
114. 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... |
115. Use of Nitrogen Fertilizer Sources to Enhance Tolerance and Recovery of New Corn Hybrids from Early Season Soil WaterloggingCorn (Zea mays L.) production losses due to temporarily flooded or saturated soils resulting from excessive precipitation are a persistent problem in Missouri and the Midwest Region of the United States. In 2011 alone, monetary losses for corn and soybean (Glycine max) production due to excessive flooding in the Midwest were calculated to be more than $1.6 billion. Application of different sources of nitrogen (N) fertilizer may promote increased flood tolerance and recovery in interaction with d... |
116. 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... |
117. 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... |
118. Winter Annual Legume Cover Crops in a Wheat Grain Sorghum Rotation in South Central KansasWinter annual legumes in humid regions ofthe country can have a positive effect on subsequent corn (Zea mays) and grain sorghum (Sorghum bicolor) crops, mainly through N contribution of the legume and. in some cases, soil improvement. However, water use by the cover crop in drier regions has the potential to reduce yields in subsequent crops. This study was initiated in south-central Kansas to look at the agronomic implications of adding a winter annual legume cover crop to a winter wheat (Triti... |