Proceedings
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1. A Seed Company Perspective on Use of Crop Canopy Sensors for Making Corn Nitrogen Fertilizer RecommendationsCurrent nitrogen (N) management practices for corn production typically include significant quantities (e.g., 200 to 250 lbs/A) of pre-plant applied N at field-uniform rates. These conventional practices can sometim es result in sizeable N fertilizer losses, especially in extremely wet springs in the Corn Belt. The lo st N not only reduces grower profits through lost fertilizer and reduced yields in N deficien t areas, but can also lead to environmental contamination through nitrate leaching or... |
2. A Smorgasbord of Preliminary Results from Field Trials in OntarioField scale trials may be established to support lo cal needs, but the results seldom reach a wider audience. This paper summarizes two recent fiel d studies by staff of the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) on fertilizer use in soybeans and corn. A study of starter fertilizer response in soybeans found that yield responses to fertilizer tended to be relatively small, and seldom large enough to cove r the cost of the added fertilizer. A second study of ammonia vola... |
3. A Systems Approach to High Yields, Efficiency and Profits in Corn, Wheat and Doublecropped Soybean RotationUsing a systems approach friendly to the environment, a three-crop/two-year no-till system has shown significiant yield increases in a three-year research project conducted at the Poplar Hill Research and Education Facility in Quantico, Maryland. In each case, corn, wheat, and doublecropped soybean yields exceeded average yields produced on Maryland's Delmarva Peninsula. Instrumental in producing these superior yields were enhanced fertility, supplemental water, and appropriate variety selection... |
4. Active Crop Canopy SensorsActive crop sensor usage for managing crop nitrogen inputs has been an area of intense research over the last decade. The question on the minds of producers, consultants, and policymakers is how well does the technology functi on in the field? And is it robust enough for commercial usage? The goal of this proceedings article and subsequent presentation and panel discussion is to provide a little background on current approaches, research successes and failures, and commercial prospects and chal... |
5. Active-Crop Sensor Calibration Using the Virtual-Reference ConceptCalibration of laboratory and field instruments usually involves collecting data from some type of accepted standard materials or compounds. This approach works well for most physical and chemical measurements; however, such procedur es become problematic when dealing with biological systems like plants that go throug h a number of physiological states during the growing season. In addition, genetic composition differences between cultivars can affect the architecture of plant canopies a nd rela... |
6. Agronomic and Nutrient Cycling Responses in a Rotation StudyA twelve-year rotation study was established in the Divide soil near Brookings SD in 2000. Treatments of crop rotations (corn-soybean, s oybean-spring wheat, and corn-soybean-spring wheat), tillage (conservation till vs. no-till), and residue management (post-harvest residue removed vs. residue returned) were established. Grain yield, residue crop residue production, nutrient cycling, and carbon storage responses were documented. Mean grain yield for various crops was not significantly influenc... |
7. Biomas Removal: Effect on Soil Nutrients and ProductivityInterest in renewable alternatives to fossil energy has increased. There is also a growing awareness of the impact of greenhouse gas emission on global climate change. Crop biomass can be used to make liquid fuels like ethanol. These cellulosic materials are also potential feedstock for controlled combustion substituting fo r natural gas or coal. There are a wide range of potential feedstocks, trees, perennial grasse s and crop non-grain biomass (or residues.). Particularly in the Corn Belt, cor... |
8. Carbon Sequestration: The Lack of Initial Measurement Could Bias Interpretation of Management Effect on Soil CarbonMuch research has been done in the last decades to determine the effect of management practices on the rate of soil carbon (C) seque stration over time. Generally paired fields are sampled and soil organic carbon (SOC) content under each manage ment system is determined. Conclusions about the effectiveness of different management systems in sequestering soil C are established based on the SOC difference and le ngth of the experiment. However, properly archived historic samples are often unavail... |
9. Changes in Soil Test Phosphorus as a Function of Inorganic and Organic Phosphorus in Animal ManureUnderstanding how and why soil test phosphorus (P) levels increase with manure and fertilizer application is important to assist in improvi ng any nutrient management plan. An incubation study investigated the change in soil test P (STP) after 42 different animal manures (dairy, beef, swine, chicken, turkey, goat, sheep, and horse) or fer tilizer were applied at a rate of 40 mg total P kg -1 to 25 different agriculturally important soils of Wisconsin. Both liquid and solid dairy and swine manure... |
10. Comparing the Performance of Preplant and Presidedress Soil Nitrate Tests for the North-Central RegionSoil nitrate (NO3-N) testing is a recommended best management practice (BMP) for adjusting corn N fertilization rates across the North-Central region. Several approaches to soil NO3-N testing are used and vary in both recommended time and depth of sampling (Hergert, 1987). Nitrate is very mobile in soil and is subject to either loss from leaching and denitrification or gain from net mineralization of crop residue and manure. The processes that govem nitrate accumulation in soils are most active ... |
11. Comparison of Mehlich-3, Olsen, and Bray-P1 Procedures for Phosphorus in Calcareous SoilsFertilizer recommendations for P generally are based on soil testing. Although a variety of soil tests are reliable for evaluating plant available P of neutral or slightly acid soils. there is still uncertainty about appropriate soil tests and soil-test interpretations for calcareous soils. The Bray-P 1 and Olsen methods are the most widely used soil-test P methods in the North Central region. Extensive research has shown that the Bray-P1 test is reliable on neutral or acid soils but that it ten... |
12. Corn Production as Affected by Daily Fertilization with Ammonium, Nitrate, and PhosphorusManipulation of N fertilization to control NH,+/NO,' ratios in the soil can affect corn (Zea mqs L.) growth and yield. Field study of these effects, however, has been difficult to conduct because nitrification of NH,+ andlor NO, leaching often occurs during the growing season. The objectives of this 4-year field experiment, were to investigate the effects of daily fertilization with various N sources and P on corn growth and yield. Pioneer 3343 was fertilized with solutions of urea (U), NH,CI, C... |
13. Crop Residue Removal Effects on Soil PropertiesThree large challenges facing mankind are the n eed to feed a rapidly growing population, increasing concentration of greenhouse gases in the atmosphere, and reliance on fossil fuels. Expectations from agriculture include produ ction of food and fiber to meet demands, management of agricultural systems to sequester carbon and redu ce emission of other greenhouse gases, and provision of feedstock for a rapidly expanding biofuels industry. Some discussions involving use of crop residue for biofue... |
14. Delayed-Release Nitrogen Fertilizer Effects on In-Season Soil Nitrogen for Michigan Sugarbeet ProductionDelayed-release N fertilizers have received attention for Michigan sugarbeet production as producers seek to improve the timing of N ava ilability to better match plant demand and to maximize plant N use efficiency. The N release ch aracteristics of these products are particularly important in sugarbeet production, where excessive N availability late in the season can have adverse impacts on crop quality. The objective of this research was to evaluate delayed-release N fertilizer sources, alone... |
15. Drainage Management and Nitrogen LossNitrate-N loss through subsurface agricultural draina ge is of local and regional concern in the Midwest. Good drainage and nitrogen management practices have the potential to reduce nitrate- N concentrations and loss from subsurface drainage systems. The five year (2005-2009) nitrogen management study in Pocahontas County, IA suggests that while fall application of fertilizer may result in higher nitrate-N concentrations than spring application during certain period of the growing season; overa... |
16. Effect of Phosphorus and Potassium Fertilization on Corn Development and Root Distribution in Conservation TillageIn conservation tillage systems, like no-till (NT) and strip-till (ST), phosphorus (P) and potassium (K) typically become vertically and/or horizontally stratified in the soil. This stratification has the potential to make P a nd K less available and to limit corn yield. The objective of this study is to determine the infl uence of tillage and P and K placement and rate on soil P and K content, soil water status, root and shoot development, and grain yield of corn. The experiment was arranged i... |
17. Effects of Residue Density, Strip Tillage, and Starter K on No-till Corn Grown in Wheat StubbleField studies were conducted in 1992 to 1994 at 2 locations in southern Illinois to evaluate the influence of wheat straw residue density and stl-ip-tillage vs no-tillage on corn growth and yield. Corn growth and resultant yield is frequently reported by producers to Se depressed in the residues of a previous wheat crop. Allelopatliy is thought to be at least partially involved. The objective of the research was to evaluate straw level (removed, remain non-modif ied, and doubled), strip tillage,... |
18. Enhanced Efficiency Nitrogen Fertiizers Release in an Illinois SoilThe release rates of ammonium and nitrate from applications of enhanced efficiency nitrogen fertilizers to soil is not well understood. A better knowledge of th e soil processes involved with N release could allow for greater acceptance of these fertilizers. The objective of this study was to compare traditional quick release fertilizers w ith enhanced efficiency nitrogen fertilizers to examine their release rates. Th e fertilizers chosen were urea and a polymer-coated urea, which were applied t... |
19. Evaluation of Nutrisphere-N as aSoil Nitrification and Urease InhibitorNutrisphere-N is a fertilizer ad ditive, which is claimed to prev ent nitrogen loss from soil through the inhibition of urease and nitrif ication. The objective of this study was to evaluate the effects of Nutrisphere-N on urease, nitr ification, and ammonia volatiliza tion from soil under controlled condition. Nutrisphere-N was mixe d with urea solutions or impregnated on urea granules and before application to soil. In the three experiments conducted, adding Nutrisphere-N had little or no effe... |
20. Field Evaluations of Nitrogen Ramp Calibration Strips in ManitobaNitrogen Rate Calibration Strips (NRCS) were dem onstrated in some 30 farm fields of cereals, corn and canola. Mid-season assessments of crop yield sufficiency were useful in estimating the adequacy of nitrogen (N) supply. For cereals, rela tive plant height provided a simple and quick indicator of N sufficiency. This NRCS techniqu e has been used to demonstrate the provincial N rate calculator in extension and has been adapted for P de monstrations in alfalfa. ... |
21. Foliar Fertilization and Fungicide Application for SoybeanConcerns over fungal diseases in soybean have renewed interest in applying pesticides for disease control with the goal of increasing grain yi eld. Interest has especially been sparked by discussions of the possibility of Asian Soybean Rust (Phakopsora pachyrhizi) spreading north to the North Central region. Because of increasing prices of soybean grain and traditional fertilizers, many Midwest grower s are considering mixing fluid fertilizers and fungicides for foliar application to soybean. Ex... |
22. Foliar Manganese and Glyphosate Formulation Yield Effects on Glyphosate-Resistant Soybeans in OhioIn order to address the potential problems associated with glyphosate and manganese applications to glyphosa te-resistant soybeans (Glycine max [L.] Merr.), an experiment with varying glyphosate and manganese micronutrien t formulations and application timing was designed and carried out on two locations in Ohio to test effects on soybean yield. At the location in northwestern Ohio, th e yields for all of the manganese-treated plots were significantly higher ( P=0.1) than the untreated plots, re... |
23. Forage Quality Management- A Key to Successful Cattle Nutrition ProgramsIn 1992, the USDA reported 59.6 million acres were harvested for hay with an average yield per acre of 2.5 ton per acre. These values gave a projected total yield of 149.1 million tons of harvested hay. Using an average market price of $72.10 per ton, total value of hay produced exceeded 10.5 billion dollars. Also in 1992, alfalfa production represented over 50 percent of the forage harvested with 79.6 million tons produced. In addition to stored forage. pasture is also a significant source of f... |
24. Impact of Biofuel Crops on U.S. Agriculture: An OverviewBiofuel crops are having an impact on prices of commodities, land use, and environmental factors such as water quality, biod iversity, etc. There are critical linkages today that result in the phenomenon of oil and corn prices moving in lockstep. We also see that limited cropland leads to tradeoffs between different crops that aff ect not only food and feed production, current corn based biofuel production but also future cellulosic production. The current and potential impact of biofuels on the... |
25. Improving PSNT Based Sidedress N Recommendations for Corn with Site Specific FactorsThe pre-sidedress soil nitrate test (PSNT) has been found to be a valuable tool for improving nitrogen recommendations for corn grown in humid regions of the country. The PSNT has been especially useful for nunaging N on fmls where organic sources of N, like animal manures are important. This test was proposed by Magdoff et al. in 1984 and has been studied extensively since then (Magdoff et al., 1990; Roth et al., 1992; Fox et al., 1989; Blackmer et al., 1989; Klausner et a]., 1993, and Meisinge... |
26. Incorporating Cover Crops into No-till Production SystemsAlthough no-till soil management has many benef its, including protecting the soil from erosion, improving soil organic matter, and improving soil moisture storage, depending on environmental conditions there could be a number of potentia l problems. Implementation of no-till soil management in eastern South Da kota can lead to wet and cold soils at the time of planting. Cover crops have the potential to utilize exce ss soil moisture and improve soil conditions at planting. A field experiment wa... |
27. Influence of Potassium, Sulfur, and Zinc Fertilizer on Corn and Soybean Grown on High Tetsing SoilThe influence of potassium, sulfur and zinc fertilizer on corn and soybean yields grown on high testing soils was studied at two locations in Eastern South Dakota over a period of six years. Treatments were 50 Ibla K,O, 25 Ibla sulfur and 5 Ib/a zinc. The treatments were applied to the same plots at each location every year. Soil test levels were in the high range for all elements in question and additional nutrients would not have been recommended by the South Dakota State University Soil Testi... |
28. Management Zone Delineation Techniques to Aid In-Season Sensor Based Nitrogen ApplicationThe increased efficiency of nitr ogen fertilizer (N) use has been a long-term goal in reduction of nitrate contamination in the stat e of Nebraska. Preliminary rese arch has shown sensor based in- season application of nitrogen has the ability to be economic and environmentally viable. Although benefits have been published there is an opportunity for increased accuracy of N application through the integration of preprocesse d georeferenced management zones. In-season sensor based N application ... |
29. Manure Management Practices to Limit Nutrient Loss from Frozen Agricultural FieldsManure applied to crop areas can be an importa nt source of plant nutrients for crop production and may improve soil quality. Relatively small amounts of nutrients especially phosphorus (P) from manure reaching water bodies can signifi cantly increase eutrophication and impair water quality. Most recommendations indicate not to apply manure to fro zen soils because the risk of nutrient loss to surface water may be increased. Our research objective was to determine the influence of manure applica... |
30. Micronutrient Nutrition for Corn and Sobyean: Emerging Issues in KentuckyIn certain Kentucky regions, corn-Zn and soybean-Mn are well known crop-micronutrient problems. In response to grower observations/c oncerns in another region, soil and leaf tissue sampling indicated that pH P, K, B, Cu and Zn nutrition problems were co-mingled. A series of corn and soybean field studies were conduc ted between 2008 and 2010 to sort out/among possible problems/solutions, relati ve to similar soils in other areas of the state. The results indicate that when P and K nutrition are... |
31. Nitrogen Availability of Treated and Raw Dairy ManureThere is minimal information on the nitrogen (N) availability and composition of treated manures. Knowing how N availability differs w ith manure treatment will result in better N crediting guidelines. Raw dairy manure and anaer obically digested manure were incubated with five typical Wisconsin soils for 112 d. Net N mineralized from the different N sources were compared. Nitrogen mineralizatio n differed by manure type and also by soil. Overall, the digested slurry and the digested separated l... |
32. Nitrogen Fertilization Requirement and Corn-Soybean Productivity in a Rye Cover Cropping SystemNitrogen (N) fertilizer inputs for intensive corn-based cropping systems can increase nitrate (NO 3 -N) concentrations in groundwater. Nitrogen tr ansport in surface water to the Gulf of Mexico is also an on-going issu e for the upper Mississippi river ba sin, especially areas with large corn and soybean acreage. Education and policy efforts have focused on i\provement in N application rate, timing, management, and crop N us e efficiency. However, additional means to reduce N loss are needed. R... |
33. Nitrogen Management for Soft Red Winter WheatSoft red winter wheat was grown wi th various rates of four N materials, ammonium sulfate, urea, urea-ammonium nitrate and ESN, for harvest years 2004 through 2007. In all studies 21 lbs N/a was applied at planting. Over th ese four years top wheat yields were produced with 60 or 90 lbs topdress N/a depending on year. Av eraged over the four years 90 lbs N/a resulted in 1.6, 1.0 and 2.2 bu/a more yield than 60 lbs N/a for urea, UAN and ESN. This difference was neither significant nor economical.... |
34. Nitrogen Recalibration for Wheat in North DakotaThe rise in grain prices and fertilizer costs, as well as the need for more soil-specific recommendations has spurred recent research into N response of wheat in North Dakota. Combining data from 1970 to 1990, together with recent studies has shown that new recommendations are in order. There is a rela tionship of wheat yield to available N. The relationship is better when residual soil nitrate is considered. Different areas of the state partition out with different response curves. Using the '... |
35. Nitrous Oxide Emissions in Claypan Soils Due to Fertilizer Source and Tillage/Fertilizer PlacementNitrogen fertilization for agricu ltural production is a major contri butor to increased soil nitrous oxide emissions. These emissi ons may contribute to global warming and ozone depletion. Nitrogen fertilizer source and placeme nt can influence soil nitrous oxide (N 2O) emissions by affecting the concentration of ammonium and nitrat e available for nitrification and denitrification throughout the growing season. The objectives of this research were to quantify the effect of tillage / fertilize... |
36. Nutrient Management and Starter Fertilizer for No-till CornNo-till corn acreage has steadily increased in Illinois. No-till presents unique problems of nutrient stratification, increased surface residue, and cool, wet soils which may influence nutrient availability. Two experiments were initiated in 1993 at 4 locations to evaluate the response of no-till corn to: 1) primary N applications of anhydrous ammonia preplant, UAN broadcast preplant, and ammonia sidedressed at V6; 2) starter fertilizers with factorial combinations of N, P, and K banded 2 inches... |
37. Nutrient Management Following CRP- Concerns and On-Going ProjectsThe future of the Conservation Reserve Program (CRP) is uncertain as this paper is being prepared, however, most agree that at some point a significant acreage currently in CRP will be brought back into production. The peak of contract expirations for the 36 million acres of CRP will occur in the fall of 1996 with the first contracts originally due to expire in 1995 (Figure 1). Many of the Northcentral states have substantial CRP acreage's making post-CRP management an important topic for this r... |
38. One-Time Tillage of No-Till Crop Land: Five Years Post-TillageField research was conducted at two eastern Nebr aska locations to test the hypotheses that one- time tillage of no till (NT) land results in increased grain yield, reduced stratification of available soil phosphorus but reduced wet aggregate stabili ty, and increased soil organic carbon (SOC), without a long term effect on the soil microbial community. Research was conducted in long- term NT fields under rainfed corn [ Zea mays (L.)] or sorghum [Sorghum bicolor (L.) Moench.] rotated with soybea... |
39. Organic Farming in Nebraska: Establishing Organic Research for the Organic Farming CommunityFour sites in Nebraska were developed to have land available to conduct research on certified organic land. All sites will be certified organic by the end of 2008. The goal of the project is to conduct research relevant to the organic farmi ng community and not to compare organic systems with conventional systems. Resear ch is being conducted on the use of flaming to control weeds, winter wheat variety development and selection for the organic market, variety testing of organic winter wheat, pro... |
40. Plant Density Consequences on Nitrogen Uptake Dynamics of Maize Plants from Vegetative to Reproductive StagesThere are few studies to date that have inte nsively examined the simultaneous effects of differences in plant crowding and fertilizer N availability for different hybrids and locations on N uptake and maize (Zea mays L.) grain yield. The main research objective was to utilize a quantitative framework to bett er understand the physiological mechanisms that govern N dynamics in maize plants at varying plant densi ties and N rates. Two field experiments involving paired near-isogenic hybrids (i.e... |
41. Planting Equipment for No-tillPlanters or drills have to cut and handle the residue, penetrate the soil to desired seeding depth, and establish proper seed-to-soil contact. Keeping these three items in mind, a producer can evaluate the strengths or weaknesses of any piece of planting equipment and make any adjustments or changes necessary to make no-till planting successful. Fortunately. most currently available planters and drills can be used for no-till with few, if any, modifications. In the early days of no-till, produce... |
42. Preparing for No-till Planting into CRP LandAs CRP contracts expire, many producers are considering bringing the land back into crop production. In order to conserve soil and water, and to keep the soil building benefits of idling the land for ten years, no-till is the best production system to use. Tillage will destroy the soil structure that has built up from the freeze-thaw and wetting-drying cycles. In addition, it will plant surface weed seeds and stimulate seeds which have been buried for the last ten years. Tillage will also fluff ... |
43. Quantifying Corn Nitrogen Deficiency and Application Rate with Active Canopy SensorsPrecision agriculture technologies are an integral part of many crop production operations. However, implementation for N application has lagged, primarily due to lack of a viable system for variable N rate decisions. Ac tive canopy sensors have been developed as a tool to determine plant N stress deficiency and provide an on-the- go decision for implementing variable rate. Two general approaches could be implemented. On e is to plan on conducting canopy sensing each year, with a reduced N rate ... |
44. Real-Time Soil Nitrate SensingIon-selective field effect transistors (ISFETs) have inherent features such as small dimensions. low output impedance. high signal-to-noise ratio, low sample volumes and the potential for mass production, which are required for a real time soil sensor. However, ISFETs have the disadvantage of long-term drift, which is diminished by the use of a Flow Injection Analysis (FIA) system. In fact, FIA and ISFETs are complementary since the small sample volumes and rapid response of ISFETs allow the mi... |
45. Recent Perspectives for Starter Fertilizer Use on Corn in MinnesotaApplication of fertilizer with the seed at planning has been a popular choice for Minnesota corn farmers to get their crop off to a fast start. Traditionally the salt index of a fertilizer has been important in farmers' management decisions. A research study was conducted at six locations on fine and coar se textured soils around Minnesota. Three fertilizer grades, 4-10-10, 10-34-0, and 3-18-18 were compared at two rates and in three placements relative to the seed. Nitrogen (N) and phosphorus (... |
46. Response of Corn to Residue Management and Nitrogen FertilizationInterest in the production of cellulosic fuel production for bioenergy has identified corn (Zea mays L.) as a suitable option. However, residue removal can affect the growth and yield of a following corn crop and its response to N fertilizer. Residue removal may also influence the optimal tillage system with regard to yield and N-use efficiency. In southern Minnesota, concern about yield reductions due to cool, wet soil conditions, partially attributed to high amounts of crop residue, have limit... |
47. Response to Starter Applied Sulfur in Combination with Nitrogen and Phosphorus Across a LandscapeCorn ( Zea Mays L.) response to starter fe rtilizer combinations containing sulfur were studied using a replicated strip trial methodology. Combinations of ni trogen (20 lbs N), phosphorus (20 lbs P 2O5), and sulfur (25 lbs S) were applied two inches beside and below the seed with the planter and compared with a no-starter control a nd 25 lbs broadcast sulfur. Early plant growth was consistently increased by starter P and so metimes by starter N, while sulfur uptake was increased by S and P app... |
48. Returning Conservation Reserve Program Land to Crop Production: Weed Management ConsiderationsThe conservation reserve program (CRP) was formulated in the 1985 Food Security Act and established to help prevent soil erosion on more than one third of the crop acres in the United States (USDA, 1986). Soil erosion represents the greatest threat in agriculture to the environment. Nationally, an estimated 750,000,000 tons of soil have been conserved as a result of CRP representing an estimated annual savings of $2 billion in off-farm clearing of eroded soil. Other benefits of CRP wildlife enha... |
49. Seed Inoculations and Nitrogen Fertilizer Trials with SoybeansCurrently there is a lot of interest in soybean seed inoculation. There are some new products on the market that are creating renewed interest in seed inoculation even on fields that have a history of soybean production. Some of the new inoculants have claims for higher potency, new and better strains of Rhizobium. higher numbers of Rlzizobiurn per gram of material, sterilized peat media, seed sticker additions and etc. Many companies are beginning to pay more attention to storage and handling o... |
50. Sensing Soybean Canopy Development Responses to and K Nutritional StressNormalized difference vegetative index (NDVI) has been correlated with physiological plant parameters and used to evaluate plant growt h. Recently, active canopy reflectance sensors have been used to determine N nutrition al needs of corn, wheat and forage grasses. There is little information about the use of this technique to detect soybean nutrient deficiencies. The objective of this work was to determine th e ability of the NDVI sensor to detect P and K deficiencies, and grain yield reductio... |
51. Site-Specific Management of N Fertilization in OntarioSignificant within field variability of soil properties, such as soil fertility, and plant growth have been well docome~ited. Standard soil testing practices and fertilizer recommendations which enco~npass an average soil test value for a field and a constant rate of fertilization will obviously result in certain areas of a field being either over or under fertilized. As indicated by Kachanoski and Fairchild (1995), for a single (constant) rate of fertilizer application, reconimendations based o... |
52. Site-Specific Management Research in MIssouri- Swamped in Spatial DataWith a maturing GPS technology, we have over the past couple of years become very enamored with producing maps on crop production fields. It wasn't long ago that the only map available was the soil map from county soil surveys. Continued sensor development and aerial photography and sensing, along with decreasing costs to store and manipulate spatial data, will mean that in the future measuring and mapping data will be the rule. There have been a lot questions raised regarding the minimum amount... |
53. Site-Specific Research in North DakotaSite specific fertilizer application is currently being practiced in the Red River Valley of North Dakota/Minnesota A study has been initiated to determine sampling practices suitable for North Dakota producers using sitespecific farming both within and west of the valley. Two forty acre fields were sampled in 1994 in a 110 ft. grid, separating each sample into 0-6" and 6-24" subsamples. Smaller grid sizes were also obtained at 10 and 2 ft. grid distances in selected areas of each field. Nitrate... |
54. Slow-Release Nitrogen Fertilizers and Nitrogen Additives for Field CropsNitrogen management continues to be difficult due to transformations of nitrogen fertilizers that are possible when applied to soil and the uncertainties of weather (Cabrera et al., 2008). Nitrogen fertilizer in the form of urea is subject to ammonia volatilization through the activity of the urease enzyme found ubiquitously in soil (Kissel et al., 2008). Nitrate fertilizer is subject to leaching (Randall et al., 2008) or denitrification (Coyne, 2008) depending on the water content of the soil ... |
55. Soil Test Phosphorus Trends in OhioAgriculture is often sited as th e primary factor for high P loads polluting Lake Erie and Ohio's watersheds, but its exact contribu tion is actually unknown. This proj ect evaluated historical soil phosphorus (P) trends in the state of Ohio by collecting historical soil data from the three largest commercial laboratories servicing Ohio to dete rmine if P levels at a county resolution are changing over time. This helps address to what extent widespread over-applications of P (either commercial ... |
56. Starter Fertilizer Interactions with Corn HybridsThe objective of this study was to evaluate the response of corn hybrids grown in a dryland, no-tillage production system on a soil high in available phosphorus to starter fertilizer. Treatments were corn hybrids (5 in 1993 and 6 in 1994) grown with or without starter fertilizer. Starter fertilizer (30 Ib N and 30 Ib P,O,) was applied 2 inches to the side and 2 inches below the seed at planting. Nitrogen was balanced on all plots to give a total of 180 IbIA. Bray-I P level in the experimental ar... |
57. Starter Potassium for Corn: Why and WhenStarter fertilizer application can complement broa dcast P and K fertilization for corn and other crops. Questions about its use relate mainly to the conditions in which it is most effective (such as soil-test level, tillage syst em, and broadcast fertilization rates among others), application methods and rates that do not damage seedlings, and nutrient ratios. Many studies in Iowa and the Midwest have shown that starter mixtures (usu ally N-P or N-P-K) often increase early corn growth. Corn yie... |
58. The Conservation Reserve Program- Changes on the HorizonTen years ago, Congress passed the foundation of current conservation programs--the Food Security Act of 1985. Today, one program in particular, has exceeded many peoples' expectations. The Conservation Reserve Program (CRP) yas designed to take 40 - 45 million acres of highly erodible cropland out of production for a 10 - 15 year period. As the first CRP contracts begin to expire, Congress and the Administration are grappling with the program's future in the context of the 1995 farm bill. Will ... |
59. Time of Harvest Alters Nutrient Management of SwitchgrassSwitchgrass is one of many cellulosic crops bei ng considered as a biomass feedstock for the production of bioenergy, including ethanol. It is being promoted as a crop that can grow well on marginal lands with low nutrient inputs as well as on more fertile soils. Nutrient removal is important for long-term perennial crop production. A study, establishe d to evaluate the effects of nitrogen rate and harvest management system, was used to evaluate the nutrient removal in switchgrass harvested at ... |
60. Trapping Function of Grassed FiltersThe potential to contaminate rivers, streams, and other natural water bodies with sediment, nutrients, pesticides and bacteria in runoff from agricultural land is a very important water quality issue. Conservation tillage has proven to be effective in decreasing soil exposure to rainfall, thus decreasing water runoff and erosion potential. Vegetative filters slow down runoff that allows sediment, nutrients, pesticides and bacteria to be deposited. Combining conservation tillage with vegetative f... |
61. Using High-Tech Media Tools to Transfer the Principals of System Research to FarmersBeginning in 1981, research and extension personnel at Virginia Tech and the University of Maryland formed Intensive Wheat Management Teams. Over the next six years these Teams developed a higher yielding, more profitable and environmentally superior soft red winter wheat production system. Yields greater than 100 bu/a were achieved every year. This was at a time when average wheat yields were in the 40 bu/a range (Table 1). Intensive wheat research continues today to refine and update the syste... |
62. Utilizing Fertilizer Technologies to Reduce Nitrate Leaching in the Central Sands Region of WisconsinLeaching of nitrate into the groundwater has been a continuing and extensively researched problem in the sandy soils of Wisconsin. However, no proven solution to this problem has been identified as yet. Research results from our studies in 2009 showed that several products had potential in reducing nitrate-nitrogen (NO 3-N) leaching. Although not always statistically significant, one slow-release fertilizer, Environmentally Smart Nitrogen (ESN), produced greater yields than conventional fertiliz... |
63. Weed Control Timing Effects on Corn Yield Response to NitrogenNitrogen (N) rate guidelines for corn are under c ontinued scrutiny to maximize N use efficiency in order to minimize potential N losses to th e environment while maximizing economic returns to growers, especially with significant N fertilizer price increases in recent years. In-season crop stress can potentially affect corn N needs for optimum production. Recently, postemergence weed control has become more common with th e availability of glyphosate resistant corn hybrids. Delaying weed contro... |
64. What Do You Do When Your N-Rich Reference Fails?In recent years, canopy reflectance sensing has b een investigated for in-season assessment of crop N health and fertilization. Typically, the procedure followed co mpares the crop in an area known to be non-limiting in N (the N-rich area) to the crop in a target area, which may be inadequately fertilized. Measurements from the two areas are used to calculate a relative reflectance to represent the potential need for add itional N fertilizer. Establishing N rich areas or strips is often inconve... |
65. What Grid Cell Size is Best for P and K Soil Testing in MinnesotaA study to evaluate the best grid cell size and best soil san~ple system for immobile nutrients was conducted in South-Central Minnesota from 1993 to 1995. A corn/soybean cropping system was used. The soils at the research sites were formed in glacial till. Three grid cell sizes, 60 x 60 ft., 180 x 180 ft., and 300 x 300 ft. were evaluated. The sampling patterns included a mid-plot sample, a 60 x 60 ft. grid all-point pattern. and five to nine sample pattern. The smaller the grid cell the better... |
66. Winter Annual Weeds Effect on Corn Response to NitrogenThe timing to control winter annua l weeds is a management concern for producers. In regards to corn response to nitrogen, the objective was to determine how important the timing of winter annual weed control is for no-till, rainfed co rn production following soybeans by assessing: soil water and nitrate; early growth and nitrogen uptake of corn; nitr ogen status of corn at silking- blister; and grain yield. Field research was conduc ted in 2010 at seven locations in Kansas. There were four diff... |