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1. A Field Study of Soil Test Variability, Its Effects on Accuracy of Fertilizer Recommendations, and the Subsequent Effect of Variable Rate Fertilizer Application on Soil Test ValuesThree 2.5 acre blocks were selected for intensive soil sampling from within an approximate 90 acre field which had been partitioned into 35, 2.5 acre blocks by a farm supply dealer. The 2.5 acre blocks had previously been sampled on a central composite grid basis and a variable rate fertilizer spreader (VRS) programmed for fertilizing the field. Three other more intensive sampling techniques were used to sample the 3 blocks selected for more detailed studies. Results obtained showed that soil te... |
2. A Look at West, Texas(Blank Page for Notes) ... |
3. Adaptive Nitrogen Management(Blank Page for Notes) ... |
4. Agronomic and Environmental Assessment of Cover Crops in IllinoisCrop production systems have been changing for thousands of years and new ideas and practices are being implemented every day. In recent years, the practice of cover cropping systems has come into the spot light, and though research has been in effect, the practice has been slow to take root for producers in Illinois. Benefits of cover crops primarily center around increases in soil organic matter, which can lead to higher soil productivity, but the long-term agronomic, environmental, and econom... |
5. Alfalfa Response to K Rate, Source and Time of ApplicationThe potassium (K) requirement of alfalfa is greater than that for any other nutrient. Potassium influences several systems within-alfalfa plants, including enzyme activity, carbohydrate production and transport, stomata1 activity: photosynthesis through chlorophyll content and CO, exchange rate, and nitrogen fixation (Munson, 1985). Potassium also markedly influences alfalfa agronomically through yield increases and improvements in forage quality, disease resistance, and overwinter survival. A s... |
6. An Evaluation of Methods for Determining Site-Specific Management ZonesNumerous procedures have been examined for identifymg management areas within fields. Traditional soil surveys give a general understanding of the effects soil mapping units have on crop productivity. In the USA. county soil surveys report the average grain yield of major crops by soil series. Slope position and landform are topographic features thal also have been used to explain water and crop productivity relationships (Mulla et al., 1992; Sudduth et al., 1997). Generally, footslope positions... |
7. Comparison of the MRTN and Adapt-N Derived N Rates for CornNitrogen application to corn is a large determinant for high yield, and rate has important implications for economic profitability and off-field movement of nitrate-N. Nitrogen rate recommendation systems have varied over time. A popular system was yield-goal based, with grain yield multiplied by a per-bushel factor and then rate adjusted for previous crop and other N inputs. Modifications of this system are still used today in some states. Seasonal (site-year) variability in economic optimum N ... |
8. Considerations for Development of Optical Sensor Based Nitrogen Recommendation Algorithms for CornOptical sensor technology in Kansas has been used on winter wheat and grain sorghum with great success for predicting N fertilizer needs early in the growing season. However with both crops, there is a required minimum period of growth required before optical sensors can accurately detect N deficiencies. In both cases the target crop needs to have entered a period of vegetative growth where N uptake and utilization is increasing. In the case of wheat that generally corresponds to the Feekes 4 t... |
9. Corn and Soybean Response to Phosphorus Placement under Minimum Tillage SystemProducers often question the need for better fertilizer placement methods in reduced tillage systems. The objective of this study was to evaluate the effects of different placements and rates of phosphorus (P) fertilizer for corn (Zea mays) and soybean (Glycine max). The study was conducted at 3 locations from 2005 to 2012 (8 years). This paper presents results from one irrigated location. Tillage system was strip till before planting corn; and soybean was planted without previous tillage. Fert... |
10. Correlation and Calibration of the Mehlich 3 P Soil Test for Soybeans in KansasKansas currently uses the Mehlich 3 soil test for P, with a general P soil test (STP) critical level for all crops of 20 ppm (colorimetric). This critical level was established based on field research primarily with wheat in 2003. A review of the limited research data available from Kansas suggests that soybeans may not require as high a STP level as wheat for optimum yield. Therefore the objective of this study is to determine what the appropriate critical STP level is for optimum soybean prod... |
11. Crop Yield Relationship to Remote Sensing Data Using Intensified Weighted Nonlinear Regression ModelsYield prediction is important for making in-season agronomic input decisions as well as for greater logistical decisions. In predicting the crop yield based on ground-based active optical sensing data, the ordinary statistical unweighted linear or nonlinear regression models are the most popular choices. However, these unweighted models may not be accurate enough for practical use because they are based on the assumption that each data point for regression is obtained with equal precision and t... |
12. Determining In-season Nitrogen Requirements for Maize Using Model and Sensor Based ApproachesThere is great value in determining the optimum quantity and timing of nitrogen (N) application to meet crop needs while minimizing losses. Applying a portion of the total N during the growing season allows for adjustments which can be responsive to actual field conditions which result in varying N needs. Two methods of determining in-season N needs were evaluated, a model-based approach and a crop canopy sensor approach. The Maize-N model was developed to estimate the economically optimum N fer... |
13. Dietary P Management to Reduce Soil P Loading from Pig ManureThe potential use of phosphorus (P) based land application limits for animal manure has increased the importance of optimizing animal feed P management. The specific objectives of this study were to determine the impacts of using high available P (HAP) corn and phytase on 1) P uptake and excretion by young pigs, and 2) total P, PA-P, and water-soluble P (WSP) levels in fiesh manure generated by these pigs during a seven day digestibility trial. Our results show that, compared to the control diet... |
14. Effect of Potassium Rates and Placement on Soil Test Variability Across Tillage SystemsExperiments were conducted from 1994 through 1996 at the Dixon Springs Agricultural Center and the Belleville Research Center to evaluate K rates (60, 120, and 180 Ib KzO per acre) and placement methods in a corn and soybean rotation using chisel tillage (CT) and no-till (NT) practices. Four placement methods were used: surface broadcast, dribble, 10-inch wide surface band over each row, and banding 30 Ibs K20 per acre 2 inches to the side and 2 inches below the planted seed (remainder of the K ... |
15. Effect of Tillage, Rotation, and Nitrogen Rate on Rainfed Corn Yield and Nitrogen UptakeDetermining the long term effect of tillage, rotation and nitrogen rate in typical cropping sequences is important in making sound agronomic decisions. In northeast Nebraska rainfall is the major deternlinant of yield. In 1956 a tillage study was initiated to determine the effect of tillage. rotation and nitrogen rate on corn and soybean yields. Spring plow. disk and no-till treatments were applied to continuous corn and co1-n follo\ving soybeans on a Kennebec silt loam. Five nitrogen rates (0. ... |
16. Effect of Time and Rate of N Application on N use Efficiency and Surface Water Contamination with NitratesNitrate levels in excess of the public health standard of 10 mg N/1 in public water supplies along - with concern about hypoxia in the Gulf of Mexico have drawn renewed interest to improving fertilizer N use efficiency. Prior research has indicated that some farmers may be unkaowingly contributing to these problems. The objectives of this research were to: determine the effect of rate and time of N application on nitrate-N concentrations in water from tile lines and to evaluate the effect of pre... |
17. Evaluation of Wavelength from Ground-Based Active Optical Sensors for Corn Yield Prediction in North DakotaGround-based active-optical (GBAO) crop sensors have been used successfully to predict crop yield when used during early growth stages. The objective of this study was to evaluate two GBAO sensors wavelengths regarding their usefulness under North Dakota corn (Zea mays, L.) growing conditions. Thirty experimental sites were used in North Dakota to conduct N rate trials on corn during 2011 and 2012. All sites were designed as randomized complete blocks with four replications and six nitrogen (N) ... |
18. Foliar Fertilization of SoybeansExtensive research addressed foliar fertilization of soybeans at reproductive stages during the 70s and 80s. The soybean plant has been characterized by markedly reduced root activity during late seed development and increased translocation of nutrients and metabolites fiom other tissue into the seed. This depletion of numents from leaves could result in decreased photosynthesis. leaf senescence. and lower grain yields. Researchers theorized that if nutrients were applied directly to the foliage... |
19. Genotype Specific Management for Nitrogen Use Efficiency in Kentucky Soft Red Winter WheatThe complex interaction of genotype x environment x management (GxExM) that defines crop yield is often only explored with research on a single genotype or a select few genotypes. Improvements in crop management and understanding local adaptation to climate variability will require a broader understanding of specific genotype interactions with management systems across multiple environments. A multi-year study investigating the potential for variety specific management systems based on phenotypi... |
20. Geographic Trends in Alfalfa Stand Age and Crops that Follow AlfalfaTo gain perspective on alfalfa-annual crop rotations in the upper Midwest, USDA-National Agricultural Statistics Service cropland data layers and Soil Survey Geographic Database layers were combined for six states (North Dakota, South Dakota, Nebraska, Minnesota, Iowa, and Wisconsin) and seven years (2006-2012). Soil texture and geographic location both significantly affected the length of the alfalfa phase (stand age), and alfalfa stand age, soil texture, and year all significantly affected the... |
21. Hybrid, Plant Population, and Nitrogen Interactions in CornCharacterizing hybrids by their response to both plant population and N response will be needed to help make variable-rate population and N rate work. We planted four corn hybrids at three sites in Illinois over two years, using combinations of 18,000, 34,000, and 50,000 plants per acre 0, 80, 160, and 240 lb N/acre. Across three environments where shortage of water reduced yields, 50,000 plants/acre yielded less than the two lower populations, both of which yields about the same. There was lit... |
22. Identifying Critical Sources of Phosphorus Export from Agricultural WatershedsPhosphorus (P) is an essential element for plant and animal growth, and its input to agriculture is necessary to maintain profitable crop and animal production. Eutrophication, the natural aging of lakes or streams brought on by nutrient enrichment, can be accelerated by P inputs to fresh waters from human activities (Carpenter et al., 1998; Schindler. 1977). Eutrophication has been identified as the main problem in surface waters withimpaired water quality (USEPA. 1996). It restricts water use ... |
23. Influence of Sulfur Source on CornSulfur is an essential plant nutrient. Medium and fine texture high organic matter soils in South Dakota usually supply adequate levels of sulfur to plants. Very sandy soils are less capable of supplying sulfur to plants but even these soils usually provide adequate sulfur for plant needs. However, in recent years above average precipitation may have caused leaching of sulfur, possibly resulting in sulfur deficiencies. In addition, spring soil temperatures have stayed cool, likely slowing decay ... |
24. Low-Phytate Corn- A Genetic Approach to Manure-P ManagementManaging nitrogen (N) and phosphorus (P) contained in manure produced by monogastric animals (primarily poultry and swine) is complicated because the N:P in corn grain is 6: 1 but only 3: 1 or less, in the manure. The P content in manure fiom monogastric animals becomes elevated because corn grain and many other feed sources contain most of their P as phytic acid (phytate) which is unavailable to these species because they lack the intestinal enzyme, phytase, needed to metabolize phytic acid-P. ... |
25. Maximizing Yield, Income, and Water QualityTo improve farm profitability and minimize environmental impact of nitrogen (N) use by reducing N losses and increasing harvest yield. Nitrogen Management System: A planned approach to N use that achieves better plant utilization and higher harvest yield with less environmental loss. It promotes a multiple application approach to N Management. It reduces early N application rates while emphasizing post-emerge N nutrition. It is about making incremental N applications that will Minimize environm... |
26. Maximizing Yield, Income, and Water QualityN-WATCH is a management tool designed for N Management Systems to inventory, track, and verify plant-available N in the soil. N Management Systems hedge the risk of N loss by splitting up the N application following the 4Rs of Nutrient Management (Right source, Right rate, Right time, and Right place). It is all about Minimizing environmental impact by Optimizing harvest yield, and Maximizing nutrient utilization. It is all about focusing on M.O.M. Who is eligible: Ag Producers that are adoptin... |
27. Maximizing Yield, Income, and Water QualityThose involved with Midwest production agriculture are aware that applications of nitrogen fertilizer can have unintended consequences upon water quality. It is our focus to minimize the potential of such environmental risks by working together to optimize harvest yields, and to maximize nitrogen utilization through the use of science-based initiatives, such as development of nitrogen management systems and N-WATCH. Sustainability of voluntary efforts to minimize the environmental impact of nitr... |
28. Maximizing Yield, Income, and Water QualityA program sponsored by the Illinois Council for Best Management Practices (CBMP) to provide local growers an estimate of the location, form, and concentration of plant- available N remaining in the soil. Plant-available N at a point in a field and a point in time can be estimated utilizing this technique and provide information that may help minimize environmental impact by improving harvest yield and maximizing nitrogen utilization. (This is not to be used as a stand-alone N recommendation syst... |
29. Maximizing Yield, Income, and Water QualityA program sponsored by the Illinois Council for Best Management Practices (CBMP) to provide local growers an estimate of the location, form, and concentration of plant-available N remaining in the soil. Plant-available N at a point in a field and a point in time can be estimated utilizing this technique and provide information that may help minimize environmental impact by improving harvest yield and maximizing nitrogen utilization. (This is not to be used as a stand-alone N recommendation syste... |
30. Minimizing Nitrate Loss from Manure-amended Wisconsin Sandy SoilsThe impact of dairy manure application on nitrate leaching was evaluated at two sites with no manure history. Manure treatment (separated-solid manure, separated-liquid manure, separated- liquid manure plus a nitrification inhibitor, and two treatments with no manure) was the main plot. Each manured plot was split into six subplots with three receiving a single sidedress fertilizer application of 0, 56, or 112 kg N ha -1 while the others had two sidedress applications totaling 112 kg N ha-1 with... |
31. Nebraska's Natural Resources Districts: Experiences in Managing Nitrate in Ground WaterNebraska's 23 Natural Resources Districts (NRDs or Districts) were formed in 1972, and are quasi-local entities which are charged with various responsibilities in managing the State's soil and water resources. The Districts are governed by locally-elected Boards of Directors, managed by professional staff, and have independent taxing authority. They have broad responsibilities in ground water quantity and quality management, and one of the major efforts NRDs have engaged in over the past several... |
32. Nitrogen Fertilization of SoybeanNitrogen (N) requirement of soybean is high because of the high protein seed produced. One bushel of soybean requires over 3.5 pounds of N in the grain alone. Symbiotic Nz fixation supplies N for soybean, but Harper (1 974) reported that only 25 to 60% of the N in a marure soybean piant comes from N fixation while the other 40 to 75% comes from the soil. However. application of N fertilizer to soybean remains a very controversial issue because of mixed results of previous research.... |
33. Nitrogen Loss from Sprinkler Applied Beef Feedlot EffluentLoss of nitrogen from sprinkler applied beef feedlot effluent can be costly for both the producer and the environment. Sprinkler application of effluent is common throughout the Great Plains, though little work has focused specifically on N losses from beef feedlot effluent. We quantified ammonia (NH 3) and nitrous oxide (N2O) losses from beef feedlot effluent applications under field conditions including variations in soil pH, soil water content, ammonium (NH 4+) concentration of the effluent, ... |
34. Nitrogen Management in Irrigated Corn Using Remotely-Sensed Imagery and Small-Plot ExperimentsNitrogen management for irrigated corn (Zea mays L.) grown along the Arkansas River Valley in Kansas is a concern due to the hig&ly leachable soils and high water tables (ranging fiom 10-50 A). Irrigated corn usually requires a high input of N fertilizer to achieve maximum yields, and most farmers in this area have been applying a uniform rate of nitrogen across their fields every growing season based on the following KSU N recommendation. N Rec = [YG * 1.35 lbs bu-'1 STA - PCA - PYM - PNST N Re... |
35. Nitrogen Management of Temporary Waterlogged Soil to Improve Corn Production and Reduce Environmental N LossDuring the 2011 growing season excessive soil moisture in the Unites States accounted for at least 30% of the total crop loss to environmental stresses resulting in more than $3 billion dollars in insurance indemnities paid to farmers. The objectives of this study were to: (i) assess grain yield and N silage uptake for both rescue and non-rescue treatments of different enhanced efficiency products, (ii) determine soil N content among treatments throughout the growing season, and (iii) evaluate P... |
36. Nitrogen Rate Revisions for Corn in North DakotaNitrogen rates in North Dakota have been based on a yield-goal or yield-potential formula for over forty years. The currently published formula (Franzen, 2010) is: Recommended N rate = (Yield Potential, bushels per acre) X 1.2 less N credits from previous crops and soil test nitrate to 2 feet in depth. A yield-based strategy was practical when N costs were relatively low and yields in North Dakota were at most 100 bushels per acre. However, due to improved germplasm developed at North Dakota Sta... |
37. Nitrogen Timing and Nitrification Inhibitors for Corn in KansasAnhydrous ammonia is a common Nitrogen (N) source used for corn production in Kansas. Two common mechanisms of N loss in corn production in Kansas soils are denitrification and leaching. By minimizing these losses, producers can maximize yield with lower input use and have less impact on the environment. Time of application, particularly fall vs. spring application can have significant impact on N loss, particularly in some soils. The use of nitrification inhibitors (NI) with anhydrous ammonia ... |
38. On-Farm Assessment of Nitrogen Use and Management in Irrigated Corn Production in NebraskaHigh-yield irrigated crops have large nitrogen (N) requirements. For example, N uptake of a corn crop that yields 207 bu ac -1 (~13 t/ha) is about 180 lb N ac-1 (200 kg N ha-1). The amount of N that is not provided by indigenous sources (mineralization of previous crop residue and soil organic matter) needs to be supplied by crop producers through N fertilizer. High-yield irrigated corn accounts for 74% of total annual corn production of 1260 million bushels in Nebraska. With approximately 70,00... |
39. Optimizing Nitrogen Managament in Manure CornfieldsAnimal manure can provide N needed for production of corn. A major problem. however. is that manure is not perceived to be a reliable source of plant-available N. Much of the manure-N is known to be lost soon after application to soils, and much of the remaining N is known to persist as forms that are not readily available to the next crop. Recent studies involving 148 on- farm trials show that the late-spring test for soil nitrate has great potential for addressing this problem. The test involv... |
40. Overview of Manure Handling on Steroid Movement in Agricultural Fields from Beef Cattle SystemsManure generated from concentrated animal feeding operations may serve as a source of steroids in surface water and potentially in groundwater. The objectives of this research were to determine the amount of steroids and metabolites in runoff from beef cattle production pens, and from runoff and leaching from crop production fields. Cattle were fed a synthetic progestagen, MGA or melengestrol acetate and treated with zeranol, trenbolone acetate, and estradiol implants, while a second group was n... |
41. Quantifying Risk in Nitrogen Management through On-Farm EvaluationsThe process of nitrogen (N) management in corn (Zea mays L.) production is often reduced to finding ways to manage various risks. These risks include common difficulties of quantifying soil N availability, avoiding N fertilizer losses, and predicting the impact of weather before and after fertilizer applications. This poster provides a synopsis of several recent on-farm evaluation studies conducted across Iowa. These studies were designed and executed to identify management, soil, and weather f... |
42. Remotely Sensed Crop Indices for Nitrogen StressCrop nitrogen (N) stress has a strong influence on plant vigor and growth. Under field conditions, crop N stress is frequently expressed through spatial variability in biomass production and grain yield. Remote sensing serves as a useful tool to monitor crop N status by characterizing canopy reflectance because certain wavebands (i-e., colors) are sensitive to chlorophyll and crop growth. Unfortunately, interpreting reflectance data in terms of crop stress is still an inexact science. Several in... |
43. Searching for Inputs to Increase Soybean YieldCommodity prices and production costs are both at higher levels than in prior periods, encouraging growers to maximize returns by managing costs and raising yields. We conducted experiments at three Illinois sites in 2012 to evaluate foliar fertilizer, foliar insecticide, lactofen herbicide, seed treatment, foliar fungicide, foliar fungicide + foliar insecticide, cytokinin, , and fertilizer N, alone or in combinations of factors, including some deletion' treatments. Serious drought through the ... |
44. Soil pH and Crop Response to Lime Source and TillageAg lime recommendations are based on soil pH, buffer pH, and neutralizing index or effective calcium carbonate equivalent (ECCE) of the lime to be used (Laboski and Peters, 2012). Determination of neutralizing index may vary by state and is often codified in state regulations related to the sale of ag lime. In Wisconsin, the neutralizing index of a lime is a function of purity (calcium carbonate equivalent) and fineness (particle size) (Schulte et al., 2005). Pelletized lime is typically calciti... |
45. Soybean Nitrogen Aquisition and UtilizationBecause of its high seed protein concentration soybean has a huge nitrogen demand, about 350 IbdA for a 65-bu/A crop. The nitrogen is supplied by two acquisition systems that operate in tandem. In early season the plant uses soil nitrate; later its nitrogen is acquired largely through Nz fixation. On highly fertile, Midwestern soils nitrate utilization peaks at about R3 and then declines sharply. With heavy nitrogen fertilization peak nitrate utilization can be extended through R5, but ordinaril... |
46. Soybean Nitrogen Contributions and Rotation EffectsCorn-soybean rotations are widely used in Midwestern grain production. These rotations usually produce higher corn yields and require less supplemental nitrogen (N) than corn grown following corn. The yield benefits are usually attributed to rotation effects, although the precise mechanisms responsible for the yield enhancement are often not well defined. Nitrogen contributions from soybean in rotations are also not well understood because nitrogen budgets for soybean show that soybean harvested... |
47. Soybean Production Research: A National ApproachU.S. soybean growers are looking for alternative methods to increase soybean yields and recent increases in commodity prices have given producers more freedom to invest in additional crop inputs or products. Unfortunately, quality data from studies addressing multiple contemporary inputs is scarce. The objective of this work was to evaluate the effectiveness of combined soybean inputs on seed yield. These high input systems were tested in six states to evaluate their value across a broad geograp... |
48. Soybean Response to Sulfur Placement and Starter Fertilizer ApplicationReduced rates of early season nutrient mineralization from earlier planting dates, increased nutrient removal from greater yields, and reductions in atmospheric sulfur (S) deposition have increased concern regarding S availability for optimal soybean (Glycine max L.) growth. A field study was established to determine the effects of 25 lbs. S per acre with or without starter fertilizer consisting of 20 lbs. nitrogen (N) per acre and 50 lbs. P2O5 per acre on soybean grain yield and quality. Main p... |
49. Spring Wheat Response to Copper Fertilization in North DakotaTraditionally, copper responses have been tllought to be associated with organic soils. However, recent Canadian research has found that copper responses by wheat are possible on low organic matter, coarse textured soils. A yield response to copper in spring wheat was found in North Dakota on a coarse textured, low organic matter soil. Yield responses were not found in similar copper soil test levels of higher organic matter, heavier textured soils. A two-tiered recommendation strategy is sugges... |
50. Sulfur and Micronutrient Fertilization for Wheat Production in KansasGenetic advances in wheat (Triticum aestivum) and increased yield potential may require changes in fertilization programs including the addition of secondary and micronutrients. The objective of this study was to evaluate wheat response to sulfur and micronutrient fertilization and evaluate soil testing and tissue analysis as a diagnostic tool. Seven locations were established in 2012 and 201, all locations were established in under dryland conditions (four locations presented in this paper). Fe... |
51. Sulfur Cycling from Corn in Corn-Corn and Corn-Soybean RotationsSulfur fertilizer requirements for corn grown on medium and fine textured soils have increased over the past ten years. The effect of sulfur rate and timing on the potential for sulfur cycling and carryover within a two year crop rotation, corn-corn and corn-soybean, were studied. Sulfur was applied as ammonium sulfate on the soil surface at planting and the V3-V5 growth stages at rates of 0, 10, 20, 30, and 40 lbs of S per acre during the first cropping year. Each plot was divided in two prior ... |
52. The Effects of 40 Years of Tillage and Fertility Practices on Soil Organic Carbon and Fungal PopulationsSoil organic carbon plays an integral role in long-term soil productivity. In cultivated systems, potential productivity is directly related to soil carbon concentrations, highlighting the need to protect current organic matter levels and develop management practices that will enhance soils with declining soil carbon contents. There have been variable responses in soil carbon levels to both tillage and fertility treatments. Tillage alters the physical and chemical properties of the soil environm... |
53. The Impacts and Magnitude of N Loss from Midwest Cropping Systems: What can we do about it?(Blank Page for Notes) ... |
54. The Nitrogen Index as a Tool to Reduce Nitrogen Loss to the EnvironmentContinued population growth creates a need for increased productivity of agricultural systems around the world. Increased agricultural productivity will be needed to support a population that is anticipated to have an additional 2.5 billion people by the year 2050. Nitrogen was part of the 20th century�۪s green revolution. Nitrogen continues to be essential for the viability and sustainability of agricultural systems that are important for feeding the growing global population. It is well kno... |
55. The Potential use of Polymer-Coated Urea as a Spring Nitrogen Source for WheatMost of the soils in Northwest Ohio are medium to fine texture with poor internal drainage. Tile drainage has improved these fields, but nitrogen loss still often occurs from denitrification, especially during cold and wet springs. Growers compensate for this potential loss by applying more N at green-up or split spring applications. both of which add costs. -4 slow release N fertilizer may reduce the need for more N or split applications. One of the new time release N products is polymer-coated... |
56. The Potential use of Polymer-coated Urea as an In-Furrow Fertilizer for CornMost of the soils in Northwest Ohio are medium to fine texture with poor internal drainage. Tile drainage has improved these fields, but nitrogen loss still often occurs from denitrification, especially during cold and wet springs. The use of no-till practices has accentuated the problem. Starter fertilizers at planting have often improved the early growth of corn under these cold and wet conditions. IIowever, weather conditions may prevent timely sidedressing after planting, and cause N deficie... |
57. The Use of Organic Soil Amendments for Winter Wheat Production in KentuckyMost animal manures are land-applied in the fall and spring after crops have been harvested or prior to planting. Surface application of manures in the fall have more potential for nitrogen (N) loss when applied to fallow land compared to land cropped to winter wheat. This study was conducted to determine the N availability of fall applied organic fertilizers and resulting wheat grain yields compared to urea-N fertilizer. The effects of three organic fertilizer sources and rate on wheat yield an... |
58. Tillage and Potassium Effects on Potassium use Efficiency in a Corn-Soybean RotationA field study was conducted from 1994 through 1996 at the Dixon Springs Agricultural Center @SAC) on a Bonnie sil soil and at the SlU Belleville Research Center (BRC) on a Herrick sil soil. No-till (NT) and spring chisel tillage (CT) systems were compared in a corn-soybean rotation. Within each tillage system, potassium (K) rates of 60, 120 and 180 Ib K20 per acre were combined with four placement methods that included surface broadcast, 10-inch surface band over the intended row, surface dribbl... |
59. Using Soil and Tissue Testing to Predict Soybean Yield Response to Foliar Applied Micronutrients in IowaPrior research with foliar application of micronutrients for soybean has shown inconsistent yield responses in Iowa and the western Corn Belt. Iowa has no interpretations for soil or tissue tests for micronutrients in soybean. This study's objectives were to evaluate soybean plant-tissue and grain yield responses to foliar application of boron (B), copper (Cu), manganese (Mn), and zinc (Zn) in Iowa. There were 22 field trials in 2012 and 21 in 2013, which were established in 20 counties and incl... |
60. Variability of Soil Test Phophorus and Management of Phosphorus FertilizerSoil avdable phosphorus (P) can have appreciable spatial variation wluch could result in inefficient ferthzer use. The hlgh cost of mapping ttus variab&ty may make sit2 spedc management of P uneconomic. Seed-placing a small amount of P fertrli2er has been shown to increase gain yield of corn. Therefore. it may have potential for improving P use efficiency. Ah txperiment was conducted to evaluate the spatial pattern of soil test P and the spatial response of applied P fertilizer. The scale of P v... |