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1. A Novel Use of Data Translation Allows 3D Prediction of Soil Fertility LandscapesSoil fertility managers need better estimates of the subsoil contribution to the nutrient pool. Thls need could be achieved through 3-D predictions of subsoil fertility using a novel method of soil- profile data translation in relation to a controlling genetic horizon. For this translation, the depth of a controlling pedogenic feature is used as the origin and the rest of the profile is linearly scaled to it. When applied to a group of soils, from across a local or regional landscape, with varyi... |
2. Aerial Photos Can Predict Corn Yield Loss Due to N DeficiencyFields that experience wet weather after N fertilizer is applied may lose N and consequently lose yield. Replacing N may be difficult or expensive after corn is too tall for tractor clearance. A tool to assess the degree of potential yield loss would help corn producers decide how much expense is justified in making late N applications. ... |
3. Agricultural Impact on Groundwater QurlityThere has been an increasing awareness within Iowa of the impact of agriculture on groundwater quality. The data of Iowa Geologic Survey scientists from studies in northeast Iowa have focused attention on the Big Spring Basin area. A project to intensively study groundwater in the Big Spring Basin is underway. The project includes the active cooperation and participation of the following agencies: ISU Agricultural Experiment Station, Clayton County Soil Conservancy District ISU Cooperative Exten... |
4. Alternative Approaches to Making Fertilizer RecommendationsThe objective of this research project was to evaluate, both agronomically and economically. some common altcrnative methods of making fertilizer recornmcndations for corn, soybeans, and soft-red winter wheat used in Indiana. Over a period of six years ( 1992- 1997) the effect of seven alternative fertilizer recommendation philosophies on soil test levels, crop yields, plant tissue analysis, and fertilizer additions were measured in an attempt to determine differences in performance between thes... |
5. Application of the Ceres-maize Model to Maximum Yield ResearchMaximum yields are obtained when as much assimilate as possible is partitioned into the grains of corn. The amount partitioned into the grains depends on several major factors. Grains per unit area is probably the most important of these factors. Other important considerations for grain filling in- clude the duration of the grain filling period, the amount that can be repartitioned from stem storage to the grains, the photo- synthesis rate, and the temperature. Several factors influence the numb... |
6. Arbuscular Mycorrhizal Dynamics Throughout Corn Growing SeasonPhosphorous is an essential plant nutrient and is the second most common fertilizer nutrient applied in crop production. The role of mycorrhizal fungi in phosphorous (P) nutrition of corn (Zea mays L.) in high fertility soils in unclear. A study was conducted to determine the effect of extractable P on myco~hizal biomass and to evaluate the temporal dynamics of mycorrhizal fungi during the growing season in two irrigated corn fields in Nebraska. The objectives were addressed by the installation ... |
7. Assessment of Nitrogen Supply From Poultry Manure Applied to CornThe production of poultry in the state of Iowa is one of the largest in the nation and growth has continued the past few years. Currently Iowa is the number one egg producing state in the USA (USDA, 2005). This increase in production also implies an increase in manure production from poultry sources. The common end use of manure is application for crop production. Concerns exist- regarding application at rates higher than needed for crop use, with potential for contamination of water bodies due... |
8. Balancing Agronomy and Environment: N Recommendations in Ontario for the 21st CenturyThe goal of a fertilizer program may be to maximize yields from each ficld, or to maximize profit, or to minimize environmental impact. Recent instances of groundwater contamination with nitrate have focused attention on the need for source water protection, and agriculture has been implicated as one of the sources of nitrate contamination. This has lead to concerns that environmental rules could reduce the profitability of crop production, by limiting fertilizer use and hence, crop yields. Addi... |
9. Bandded Phosphorus Applications to Winter Wheat - 1985-86While many producers recognize the importance of a sound P fertilization program for profitable wheat production? there are many potentially responsive wheat acres not receiving any fertilizer P - resulting in reduced grain yields and farmer profitability. over the years there have been many research studies conducted by land grant Universities throughout the Great Plains indicating the importance of fertilizer P applications for wheat production on low P testing soils. In the mid to late 1970's... |
10. Basic Concepts of Soil Acidity and LimingMost midwestern soils require periodic applications of aglitne or other liming materials for optimum crop production. Liming has several beneficial effects: I ) it reduces harmhl or potentially tosic conditions which can develop in acid soils; 2) it increases the availability of some of nutrients: 3) it replaces the supply of calcium and magnesium essential for plant growth which is depleted as soils become acid; 4) it ensures favorable conditions for the activity of certain herbicides; and 5) i... |
11. Changes in Iowa's Soil Test P and K Interpretations and RecommendationsResearch results from long-term and short-term experimentation in Iowa have been consistent in the response or lack of response of Iowa field crops to applications of fertilizer phosphorus (P) and potassium (K) at various soil test levels for P and K. Analyses of the research data have established critical soil test values for P and K and the most economic soil test range for P and K to maintain (Mallarino, Webb, and Blackmer, 1991a and 1991 b; Mallarino and Blackmer, 1992 and 1994; Webb, Mallar... |
12. Chloride Fertilization on Wheat, Corn, and Grain SorghumResearch in the Pacific Northwest and the Northern Great Plains has documented positive cereal grain responses to chloride (CI) fertilization. Field research was conducted in Kansas evaluating CI fertilization on winter wheat, corn, and grain sorghum. Chloride fertilization consistently and significantly increased plant CI concentrations in all crops. Chloride fertilization increased grain yields or one or more winter wheat cultivars at 3 of 4 sites. The most dramatic yield increases were at th... |
13. Corn Nitrogen Tests in MissouriExperiments were carried out in farmer fields starting in 1995 with the objective of evaluating or developing field-specific tests to optimize N fertilizer rates for corn. Because some of the soil nitrate tests seem to work differently when manure or alfalfa is in the cropping system, most farms had pairs of experiments, one with an organic N source and the other with none. Descriptions of the experimental locations are given below. Location 1 2 Year 1995 1995 1995 1995 1995 PROCEDURES Countv Ca... |
14. Correlation and Calibratin of the SMP Lime Requirement Test with Direct Titration of Soil AcidityThe SMP Buffer method (Shoemaker, et al, 1961) of routinely determining lime requirement on soil samples has been used at the University of Kentucky Soil Testing Laboratory (UKSTL) since the mid-1960's. Initial correlation and calibration for Kentucky soils was a result of incubating several soil samples over a period of time after mixing different rates of lime with them (D.E. Peaslee, 1975, personal communication). During the ensuing years, county agricultural extension agents have raised many... |
15. Deep Banding Phosphorus and Potassium for No-till Corn and SoybeanThe information presented is part of ongoing research to identify effective fertilizer placement methods and diagnostic tools lor phosphorus (P) and potassium (K) in no-till corn and soybeans. There is uncertainty about soil test interpretations and cost-effective methods of fertilizer application for the no-till systcni. Moreover, producers are uncertain about the value of soil testing in conservation tillage because of large variability and lack of knowledge concerning techniques for collectio... |
16. Determining Economic Optimum Nitrogen Rates with the Illinois Soil Nitrogen Test and Soil Organic Nitrogen FractionsDevelopment of a diagnostic test to estimate soil N supplying capability is a continuing research need. The Illinois soil nitrogen test (ISNT) has been proposed as a method for adjusting corn (Zea Mays L.) N recommendations for to account for soil organic N contributions. We evaluated the ISNT as a tool for predicting corn N response in Wisconsin by comparing ISNT values and corn N response data from-81 experiments conducted between 1984 and 2004 with a range of crop rotations, management histo... |
17. Educational Applications of Digitized Soil SurveysThe North Dakota Agricultural Experiment Station Soil Survey of McHenry County Organized Irrigation Districts is approaching publication and represents a first for soil survey in North Dakota. The decision was made to digitize the soil maps to facilitate acreage tabulations and improve methods of generating soil interpretations. While the digitization procedure is costly in terms of start-up labor (programming) and data entry, the benefits allow more flexibility than conventional soil surveys. T... |
18. Effect of N Fertilization on Accumulation and Release of Readily-Mineralized Organic NIncreased nitrogen (N) fertilizer use has generated concern about groundwater contamination by nitrate (NO,?. The objective of this work was to determine how previous N management and cropping system affect fertilizer N use efficiency. Research plots from a long-term N rate study on a silt loam soil were used to evaluate the impact of long term N rates on immobilization and mineralization of fertilizer N. Labeled '5~~,15~~, was applied at rates of 0, 60, 120, 180, and 240 lblacre to subplots of ... |
19. Effect of Nutrient Combinations and Nitrapyrin in Starters on CornExperiments were conducted from 1994 to 1996 at the Belleville Research Center of Southern Illinois Univerity and the Dixon Springs Agricultural Center of the University of Illinois to evaluate the effect of starter fertilizers. nitrapyrin (N-Serve) amendment of the starters, and tillage on conn. The soil at the Belleville site was an Iva silt loam, a low organic matter soil with relatively high P and K soil test levels. At Dixon Springs a Bonnie silt loam (bottomland) soil was used and the soil... |
20. Effect of Rotation on Corn Yield and Economic Returns Under Composted Manure or Fertilizer ManagementThe benefits of growing corn in rotation with other crops as opposed to continuous corn have been mentioned in numerous research and technical publications. The benefits of adding to the crop mix include improved soil structure (Raimbault and Vyn, 1991) and soil nutrient availability (Copeland and Crookston, 1992). especially from rotations that include legumes such as soybeans or legume cover crops. Other benefits include better weed (Bhowmik and Dow, 1982). insect (Benson, 1985) and disease co... |
21. Effect of Subsoil Tillage on Crops Grown in No-Till and Reduced Till ManagementsThree different subsoil tillage experiments were conducted in southern Illinois on soils with root-limiting claypans that restrict crop growth. In the first experiment conducted at the SIU Belleville Research Center, subsoiling to 16 inches depth was compared to no subsoiling in a field that had been in long term, continuous no-till corn production. After 4 years of study, only small corn and soybean yield increases have observed with the tillage (2.0 bu/ac for corn and 1.0 bu/ac for soybeans) .... |
22. Effect of Timing of Broadcast Potassium (K) on Soybean Yield and Seed K ContentIn Indiana, the common practice is for K fertilizer to be applied in advance of the corn crop for both crops in the rotation, relegating soybean to feed on the application residual. Producers are concerned that current University guidelines and common practices for K management in corn- soybean rotations do not fully recognize the particular K needs of the soybean crop as differentiated from the corn crop. A four-location, six-year field study was conducted to investigate the effects of rate and... |
23. Evaluation of Slow Release Nitrogen Materials in Corn ProductionStudies were conducted over a two year period to evaluate two slow release urea nitrogen carriers with regular urea for the production of corn on iirigated Spinks loamy sand. Because nitrogen availability in the soil is quite transient fiom one season to the next, annual addition of nitrogen is important for maximu~n corn yields. Many corn producers prefer to apply most of the nitrogen prior to planting corn. Once incorporated into the soil, nitrogen containing materials, such as urea, are conve... |
24. Fertilizer Nitrogen Source and Management Impacts on Greenhouse Gas EmissionsAgricultural soil management accounts for nearly 6.3% of all greenhouse gas emission in the U.S. Although fertilizer nitrogen is an essential coinponent of nearly all agricultural systems, the addition of reactive N to soils and the emission of nitrous oxide (N20) via soil microbiological processes (nitrification and denitrification) makes U.S. agriculture the largest source (62%) of total U.S. N20 emissions. Because N20 is a potent greenhouse gas with a forcing potential more than 300 times gre... |
25. Fertilizer Use Vs. Crop ProfitsGrowing crops in farming is a complex that large investments in land and equipment, as well as considerable borrowing of money for capital. With these costs and low commodity most keenly of continuing difficulty in rnaintaining in operations. Usually farmers do not have much control over their fixed costs i n crop production. Variable costs. however-, can sometimes be adjusted. some of adjustments can reduce if the has not based his cost on wise judgement, backed with technical expertise. If one... |
26. Field Estimation of Ammonia Volatilization from Surface-applied UreaAccurate estimation of the potenial for NH3 volatilization from urea-based fertilizers is an important step in optimizing Nuse efficiency from these fertilizers. Published estimates of volatilization from surface-applied urea vary widely. Citations listing losses from 2% on up to 80% from various systems can be found. Consequently, many growers, to protect themselves, will apply urea at higher than recommended rates, assuming some arbitrary level of loss will occur. The objectives of the researc... |
27. Grid Sampling or Topography Sampling for Soil NutrientsSite-specific application of fertilizers uses field soil sampling for its information basis. Many fields are currently sampled using a grid approach. In North Dakota, examination of grid sampling showed nitrate-N to follow topographic patterns in a field, allowing the possibility of less intensive sampling for N. Reviewing previous grid sampling work in Illinois, some soil properties may be associated with landscape features, including nitrate-N in the surface 6 inches and soil pH. However, Ill... |
28. How Fertilizer Dealers Use Research InformationThere i s not a great deal o f resource information t o draw from i n reference t o the t i t l e so most o f my comments are based on observations made and personal opinions formed during some 26 years of experience in the fertilizer industry, covering a majority of the principal agricultural states. Fertilizer dealers as a whole tend t o translate research information into dollars. They use it as a business tool. It provides support t o the sale of existing products and services and identifies... |
29. Hybrid Maize A Simulation Model for Improving Corn ManagementHybrid-Maize (www.hybridmaize.unl.edu) is a computer program that simulates the growth and yield of a corn crop under non-limiting or water-limited (rainfed or irrigated) conditions. The model can be used to (1) assess the overall site yield potential and its variability based on historical weather data, (2) evaluate changes in attainable yield using different combinations of planting date, hybrid maturity and plant density, (3) analyze yield in relation to silking and maturity in a specific yea... |
30. Hypoxia in the Northern Gulf of Mexico- Causes and ConsequencesSeasonally severe and persistent hypoxia, or low dissolved oxygen concentrations, occur on the inner to mid-Louisiana continental shelf to the west of the Mississippi River and Atchafalaya River deltas. The areal extent during mid-summer surveys of 1993- 1997 ranged from 15.800 to 18,200 km2. The shelfwide distribution in mid-summer for 1985 to 1992 averaged 8,000 to 9,000 km2. Hypoxia occurs below the pycnocline from as early as late February through early October, but is most widespread, persi... |
31. Impact of Nitrogen and Sulfur Fertilization on Wheat Yield and QualitySulfur (S) contributed by rainfall has decreased by 50% over the last twenty-seven years and may increase the need for S supplementation by fertilization. Nitrogen (N) application is typically split applied in Ohio with some applied in the fall and remainder applied in the spring near first green-up. The objective of this study was to compare N application source and timing with and without S fertilization. Two experimental locations were established in the fall of 2004. Urea and urea-ammonium n... |
32. Impact of Stratified Potassium and Water Content of No-Till Soils on Soybean Growth and YieldLow potassium (K) concentrations in subsurface soil and reduced water content in the K- enriched surface soil are thought to cause K-related yield reductions in rain-fed soybean (Glycine max L. Merr.). Our objectives were to examine root-to-shoot ratios through ontogeny and yield components in relation to stratified soil water and K. Soil and plant samples were collected at V6, R2, R4, and R6 from a 2-year field study. Additionally, a greenhouse split-root ot study in P a complete factorial des... |
33. Improving the Fermentation Characteristics of Corn Through Optimum Fertilization and Hybrid SelectionEthanol processors could increase production efficiency if they had access to corn grain better- suited for fermentation. The objective of this study was to determine the influence of hybrids and N fertility rates on fermentable starch content that will be used for dry-mill ethanol production. Six hybrids were grown under four N fertility levels at two locations in eastern SD. Ethanol yields increased as N fertility levels increased. Higher ethanol yields were achieved by hybrids that produced b... |
34. In Season RecommendationsWe are testing a prototype high-clearance tractor configured with active crop canopy sensors, drop nozzles with electronic valves, and a variable rate controller as means to deliver in-season variable rates of liquid N fertilizer based on crop needs as an alterative to preplant uniform applications of N. The active sensor we're evaluating is the model ACS-210 Crop Circle made by Holland Scientific. It generates it's own source of modulated light in the amber and near infrared (NIR) bands and the... |
35. Influence of Elemental Sulfur on Soil pH and Soil Test LevelsSoil test summaries from South Dakota State University Soil Testing Lab show that 16 percent of South Dakota soils have a pH of 7.6 or higher. These high pH soils can reduce nutrient availability to plants. A major concern is for reduced phosphorus availability and fertilizer use efficiency. High pH soils also reduce the availability of micronutrients such as iron and zinc. Due to these issues, questions are often asked on how to reduce soil pH. A number of materials such as sulfuric acid, alumi... |
36. Influence of Nitrapyrin on Nitrate Concentrations in SoilsIn central Ohio most of the water used for d&g comes from the Scioto River Watershed. This water shed in primarily composed of farmland in which corn and soybeans are the dominant crops. Periodically the nitrogen in the Scioto River exceeds safe drinlung water standards of 10 ppm nitrate nitrogen. Several EPA studies have concluded the high nitrate nitrogen levels are the results of nitrate flushes through the underground tile in agricultural fields. These flushes of high nitrates usually from l... |
37. Influence of Tillage Systems on Corn Yields and Soil Test ValuesA long term tillage study was initiated at the Greenley Memorial Research Center (Novelty, MO) in 1976 to look at the effects of 4 tillage systemsoncornproduction. Thestudywasinitiatedandconductedby researchers in the Agricultural Engineering Department. Agronomy has become involved in the study beginning in 1985 to assess the effects of tillage systems on soil chemical and physical properties. The upland soils at this site are poorly drained and are generally refered to as "claypan" soils. The ... |
38. Intensive Nitrogen Management of Soft Red Winter WheatThe current system of making nitrogen recommendations for wheat in the Eastern cornbelt assumes that nitrogen fertilizer required is a simple function of yield potential. The higher the yield potential, the more N fertilizer needed. The problem with this assumption is that factors such as soil type and ability of a site to release N through mineralization, climate, variety. disease pressure and managetnent practices all affect nitrogen use efficiency, and are not considered in making nitrogen re... |
39. Interaction of Soil Applied Herbicides with Soil pHManagement of soil pH is important in enhancing the availability of certain plant nutrients and in minimizing toxic levels of other elements to crops. However, the reaction of herbicides with soils under varying soil pH levels can affect both crop growth and herbicide performance. Soil pH affects herbicide performance in several ways. When crops are under stress due to nutrient imbalance from unfavorable soil pH levels, application of certain herbicides may increase risk of crop injury. When soi... |
40. Introgressing Unique Sources of Germplasm to Improve N Use in Temperate MaizeThe vast majority of maize breeding efforts have been conducted under high N environments that primarily select for only one component of NUE, N uptake. Furthermore, these studies have employed US. and European genotypes, which have been selected for performance at high N. Historically, maize was grown in numerous low N tropical environments, suggesting that evaluation of adapted maize lines containing tropical germplasm may harbor useful genetic variation and novel alleles for improving NUE. Th... |
41. Limestone Sources and Factors Affecting Their QualityAddition of liming materials to correction soil acidity is an age old practice. According to Barber (1984). Cato and Varro used lime to correct soil acidity about 200 B.C. In America. benefits derived from liming acid soils were docuniei~ted in the early 1800's (Ruffin, 1821). In a sunfey conducted in 1980. all but two of the North Central States (North Dakota and South Dakota) reported that research had shown a need !'or limc (Whitney, 1980). The need has not changed over the last 17 years, i.e... |
42. Liming in No-till SystemsIn 1985 a study was initiated at Penn State to look at the effects of surface application of lime on a very acid, long-term no-till soil. Since 1977 this field had been in no-till corn production with no limestone applied. The initial pH of "plow layer" was 5.1 and the surface 2 inch pH was 4.5. The limestone recommendation, based on the SMP buffer pH and a target pH of 6.5, was 6000 Ib calcium carbonate equivalent (CCE) per acre. The study included four limestone rates (0. 3000, 6000.9000 Ib CC... |
43. Long Term Outlook On Nitrogen and Potassium SupplyThe North American fertilizer industry is operating in world market today. Worldwide fertilizer demand, competition for transportation, and natural gas prices are all putting pressure on North American fertilizer prices. The themc of this mornings' session is on strategies the supply industry and fanners may adopt to manage these pressures. This talk is about the near future outlook nitrogen and potassium fertilizer. Fertilizer sales figures indicate that nitrogen, phosphorus. and potassium fer... |
44. Making Urea Work in No TillNo-till and reduced tillage production systen~s are widely used today in the United States as well as around the world due to their capacity for reducing soil erosion and topsoil loss, reducing phosphorus movement to surface water, and reducing labor, fuel, and equipment requirements. In no-till systems, an average of 25% of the N applied as broadcast urea can be lost via ammonia volatilization. Therefore, N losses due to ammonia volatilization will decrease corn and wheat yields. independently ... |
45. Managing Continuous Corn for High YieldsMany "contest-winning" corn yields have historically been produced in fields where corn is grown continuously, often with extensive tillage, hgh soil test values of P and K, high N rates, and high plant populations. We are conducting a series of research trials at four sites in Illinois, in whlch we are varying tillage, fertilizer rates, and plant population in a factorial experiment at several Illinois locations. Over ten site-years to date, tillage deeper than normal increased yield at two sit... |
46. Manure Management Policy IssuesTraditionally nutrient management has been concerned with optimizing the economic return from nutrients used to produce a crop. The main emphasis was on the expected crop response from adding nutrients. In practice however, manure is not always applied to optimize plant nutrient use. Historically, a common practice has been to apply commercial fertilizer without giving credit for nutrients already applied in manure. Applying manure in excess of plant needs, or at the wrong time, or handling it i... |
47. Methods and Limitations of Zone Sampling Using Topography as a Logical BasisTwo forty-acre fields in North Dakota were sampled in a 110 foot grid. Each field was measured for elevation in the same 110 foot grid. Topographic sampling zones were identified in each field and a correlation of the sampling based on these zones was compared to the correlation values from a 220 foot grid. Nitrate-N and the 220 foot grid were both correlated to the 110 foot sampling values for nitrate-N and P. A map of field nitrate-N levels from topography sampling compared to the 220 foot gr... |
48. N x K Interactions- CornA study was conducted at OARDC-Western Branch near Springfield, OH for 4 years starting in 1992 to investigate the effects of N and K on corn production N uptake. The soil series was a Crosby Silt Loam with approximately 2.5% organic matter. All nutrients were in the above average levels on the soil test except for exchangeable K levels. See table 2 for soil test K levels. The corn hybrid Countryrnark 735 was seeded approximately the last week of April at 35,000 seeddacre. A split plot design w... |
49. Near Seed Application of Fluid Fertilizer for Corn Soybean and Sugarbeet ProductionIn recent years, crop producers in Minnesota have shown increased interest in placing fertilizer near the seed at planting. The more traditional 2x2 "starter" band was not an option. Guidelines were needed for banded placement of fertilizer near the seed at the time of planting. This study was conducted in 2004 and 2005 in fields of cooperating crop producers. Three fluid . materials (10-34-0, 4-10-10, 3-18-18) were applied at two rates for corn, soybeans and sugarbeets. In 2004, the materials w... |
50. New Techniques and Methods of Disseminating Information in View of Budgetary Constraints by the University of IllinoisThe Cooperative Extension Service a t the University faces increased demands for educational services. This increaase is in an environment marked by increasing costs, and stable to decreased financial support--especially from the Federal partner. The situation we face in Illinois is similar to that faced by many other State Cooperative Extension Services. We are better o f f than some states--worse o f f than others. What of the future? Will we be able to deliver viable programs to farmers and a... |
51. Nitrogen Availability from Composted ManureComposting of manure has been proposed to play a role in manure management programs designed to protect water quality. It is known that the biological activity involved in composting changes the nutrient availability of the material and in some cases will reduce the nutrient content. The major role of composting in alleviating some of the on-farm manure nutrient excess problems is by facilitating manure movement from a farm with an excess to a farm with a deficit of nutrients. There are several ... |
52. Nitrogen Availability to Corn Following Small GrainsNitrogen rate recommendations for corn are generally reduced following legumes compared to following corn or small grains. A 4-yr field study was conducted on a Plano silt loam soil in southern Wisconsin to evaluate the capability of soil NO3 tests to predict N availability to corn follo~b-ing small grains. Previous crop small grains included \vinter wheat, winter qe. and oats harvested for grain and straw. Nitrogen fertilizer was applied to corn at rates of 0 to 180 Ib/a in 30 Ib increments. Gr... |
53. Nitrogen Fertigation on SoybeansNutrient requirements for soybeans are greatest as seeds are developing during reproductive pod fill. This peak nutrient demand period physiologically coincides with decreased efficiencies in both symbiotic nitrogen (N) fixation and root efficiency (Brun, 1978). Large N applications during vegetative growth stages limit N fixation and fail to consistently increase grain yields (Fla~ery, 1986). However, smaller N applications during flowering and pod fill have been reported to augment plant N sta... |
54. Nitrogen Fertilizer Equivalency of Anaerobically Digested Municipal SludgeCrop yield response to municipal sludge is largely affected by the amount of nitrogen (N) made available during the growing season. The effect of sludge rate and N fertilizer rate on either grain sorghum [Sorghum bicolor (L.)] or corn [Zea mays (L.)] yield response was studied on three fms in Lancaster county, Nebraska. A combination of five rates of dewatered (80% H20) anaerobically digested sludge and five rates of N fertilizer (NH&03) were applied before planting and incorporated by discing ... |
55. Nitrogen in the Mississippi River Basin- Sources and Factors Affecting Loss of Nitrate to the RiverNitrogen (N) is a naturally occurring element that is essential to plant growth and crop production. In a soil system, nitrate-N is continually supplied through mineralization of soil organic matter. Other sources of N include fertilizers, animal manures, municipal sewage wastes, agricultural and industrial wastes, atmospheric deposition. and dinitrogen fixation, all of which either occur as nitrate-N or can be converted to nitrate-N through mineralization and nitrification. ... |
56. Nutrient Credits for Manure--Differences Between Theory and RealityIt has been a mainstay recommendation for many years--take credit for the nutrients in the manure you spread on your fields. While it may seem that everyone is referring to an identical procedure, there are numerous strategies to crediting nutrients contained in manure. Although it appears to be simple, the complexities involved in crediting have resulted in few livestock and crop producers properly crediting nutrients from manure. Research and educational efforts have sharply increased in the p... |
57. Opportunities and Limitations of Automatic Steering TechnologiesIn the short span of 10 years we have gone from using the Global Positioning System (GPS) to locate ourselves in a farm field, to automatically steering a machine working in the field. This application requires about 15 conlponents with each component evolving at a rapid pace. A number of conlpanies have formed to provide automatic steering packages as aftermarket retrofits. At a slightly slower pace, the main equipment manufactures are engineering machines that will be factor ready or factory e... |
58. Performance of Early vs. Late Maturing Corn Hybrids in MichiganThe planting of fill-season, or late maturing hybrids in Michigan is encouraged by their tendency to produce higher yields. Full-season hybrids can take advantage of the entire growing season available at a particular location. Shorter season hybrids reach physiological maturity sooner and generally yield less. Recent experience with cool, wet springs resulting in delayed planting, and growing seasons that provided less growing degree days (GDD) than normal has caused corn producers to question ... |
59. Phosphorus and Potassium Place in Corn-Soybean Systems in the Midwest: Possibilities with Automatic Guidance TechnologyGlobal positioning system teclmology available to the public has become more accurate in recent years. Current Real Time Kinematic (RTK) techniques allow relative positions of equipment to be recorded with 3/8 - 2 in. precision (Dana, 1991). Being able to return to the same location in the field year after year with high precision may have implications for corn-soybean systems where banded applications of phosphorus (P) and/or potassium (K) are made at a time other than at planting. The importan... |
60. Phosphorus Losses in Runoff Water as Affected by Tillage and Phosphorus FertilizationPhosphorus (P) in runoff from cropland can contribute to nutrient enrichment and eutrophication of surface water bodies. Research was continued during 1996 to determine which tillage systems and which methods of applying P fertilizer will result in the least P losses in runoff water for grain sorghum production under somewhat poorly drained soil conditions in east-central Kansas. The tillage systems evaluated were a chisel-disk-field cultivate system, a ridge-till system, and a no-till system. F... |
61. Potassuim Chloride Fertilization and Common Root Rot of BarleyCommon root rot (CRR, incited by Cochliobulus sativus) is one of the most widespread diseases of wheat and barley in the Great Plains and Prairie Provinces. Average yield losses, based on extensive surveys in the Prairie Provinces, average around 5% for wheat and 10% for barley, althoughinindividualfieldslossescanbemuchhigher. Potassium chloride fertilization has been effective in reducing CRR of barley in North Dakota, and I believe we are close to understanding why CRR is reduced by KC1 fertil... |
62. Precision Phosphorus Management for SoybeanSoybean responds to phosphorus fertilization in the Midwest. Most correlation and calibration data suggests that soybean is less responsive than corn. Because of this. normal management in the Upper Midwest is to fertilize before the corn crop in a corn-soybean rotation for both the corn crop and following soybean crops. This saves the cost of one application and the logistical problem of fertilization with P after a corn harvest. This management works well in soils tvith a pH less than 7.4 and... |
63. Predicting N Fertilizer Rates for CornSixteen N rate experiments were carried out in farmer fields in 1995 and 1996. The objective was to measure optimum N fertilizer rates and see whether they could be reliably predicted ahead of time. Yield response to N was measured in each experiment along with soil N measurements (planting and sidedress), and tissue N and chlorophyll meter reading at sidedress time. A very wide range of economically optimum N fertilizer rates was found, fairly evenly spread from 0 to 200 Ib N/acre, with an aver... |
64. Predicting Plant Available Potassium using a Modified Sodium Tetraphenylboron MethodCurrent potassium (K) fertilizer. recommendations in the midwest are based primarily on the ammonium acetate exchangeable K (NH,OAc) soil test. In soils where nonexchangeable K comprises a major portion of plant available K, the ammonium acetate soil test is unreliable. Soil K extraction by sodium tetraphenylboron (Na-TPB) accesses both exchangeable and nonexchangeable K and mimics the action of K uptake by plant roots. A Na-TPB method utilizing a 5-minute extraction period is described, and the... |
65. Presenting Key Issues in a Rational Manner to the Non-Ag CommunityA quick scan of the program for your workshop might lead one to believe my subject is out of place here. In terms of agricultural credentials, I could certainly be consideredoutofplace: Iconsidermyselfajournalist gone straight; I was educated as a journalist and was a reporter for The Kansas City Star before entering public relations work and then joining Monsanto nearly 20 years ago. But I don't believe either the subject or the speaker is out of place for this gathering. And I think perhaps mo... |
66. Regional Approach to Making Nitrogen Fertilizer Rate Decisions for CornNitrogen fertilizer is one of the largest input costs for growing corn. Across the Corn Belt, N is typically the most yield-limiting nutrient. Facing record high N fertilizer prices and potential supply problems, producers are concellled about N fertilization rates. Soil fertility researchers and extension specialists froin seven states across the Corn Belt (see list in acknowledgements section) have been discussing corn N fertilization needs and evaluating N rate recommendation systems for appr... |
67. Remote Sensing as a Tool for AgricultureThe tendency for nearlv everything in our society to be bigger, better, faster, easier, cheaper, and safer than in the past has resulted in many challenges. Agriculture is not immune from these trends, and in some cases agriculture even leads the way. Incorporation of remote sensing into site- specific management activities is one area where technologies are being merged to develop a new array of products that are intended to help producers and consultants make better and more timely management ... |
68. Residual Effects of P Fertiliration Lessons for the EightiesSeveral states in the North Central Region have established long-term phosphorus studies. These experiments were designed to evaluate the residual effects of P fertilizer and also generate P soil test calibration data in a situation where a range of soil test levels exist on one soil. These data are extremely useful for evaluating year-to-year fluctuations in crop response to soil test P and establishing response probabilities at a given soil test level. Valuable lessons can also be learned from... |
69. Response of Minimum-till Corn to Starter Fertilizer and ACAStarter fertilizer containing N and P often increases grain yield under no-till management. but yield responses to starter have riot been consistently observed under conventional tillage. Experiments were established in 1996 and 1997 at six sites varying in latitude, soil type. fertility, and crop rotation to evaluate the effect of starter fertilizers on corn grown under high-residue minimum-till systems. In one experiment, a factorial combination of 3 N. 2 P, and 2 K rates placed in a 2x2 band ... |
70. Rye Cover Crops in No-till Corn ProductionField studies have been conducted for several years in Ohio to determine the effects of including a ry.e cover crop in no-till production situations. These studies were conducted at two locations, on a moderately well drained Canfield silt loam at Wooster, and a very poorly drained, but tiled, Hoytville silty clay at Hoytville. At Wooster, no-till corn was planted into corn or soybean residue, with or without a fall-seeded rye cover crop (2 bu/A seeding rate). Individual plots received 200 lb N/... |
71. Scale of Measurement Effects on Phosphorus Runoff Losses from CroplandAs phosphorus (P)-based nutrient management planning becomes necessary for some farms in Wisconsin, it will be critical to have reliable, research-based planning tools. The Wisconsin P- hdex provides one method for preparing P-based nutrient management plans. The P-Index was developed largely from small plot-scale data showing the relationships between various site and management variables and runoff P losses. Thls study was conducted to compare runoff composition measurements at the subwatershe... |
72. Should P and K Fertilization be Matched to Plant Populations for CornFertilization practices and plant populations are major factors involved with corn production. Several researchers have investigated the effects of various fertilizer management practices. Likewise, the impact of plant population on corn production has been evaluated in a variety of production environments. The combined effects of plant popillation and fertilization. however, have not been thoroughly evaluated. Specifically. there has bcen very little study of the influence of plant populations ... |
73. Site-Specific Nitrogen ManagementApplying only the amount of nitrogen fertilizer needed for a crop at a particular point in the field makes intuitive sense - and is hard to argue against conceptually. However, in practice site-specific nitrogen (N) management is quite challenging. That is to be expected, since routine. uniform N management is often more challenging than is management of other nutrients. Because of nitrogen's mobility in soil. the fact that it is subject to a wide range of transformations and loss processes, and... |
74. Site-Specific Prediction of Soybean Nitrogen ContributionsSoybean has long been recognized for its nitrogen (N) contributions and yield enhancing effects in crop sequences. Soybean N credits in the Midwest range fiom 20 to 40 Ib of Nlacre (Kurtz et al., 1984). Several Midwestern states recommend a legume credit of 40 Ib of Nlacre following an average crop of soybean. Current Wisconsin recommendations suggest a reduction in nitrogen fertilizer rates for corn following soybean of 1 Ib N hushel of soybean yield up to a maximum credit of 40 Ib Nacre (Kelli... |
75. Slow Release Nitrogen Fertilizer and Dynamics in Soil Systems Part I Incubation StudyA lab study was conducted at Southern Illinois University soil fertility research facility to investigate the effects of soil type on the nitrogen (N) release dynamics. The objective of this study was to identify the effect of soil type on the release rate of N from slow release nitrogen (SRN) fertilizers under controlled conditions (moisture and temperature). Two contrasting soils from Iowa and Georgia (pH and mineralogy) were combined with 500 mg kg-, of SRN or urea and kept for 90 days under ... |
76. Spatial Analysis of Yield-Limiting FactorsThe spatial relationship between crop yields and soil and site parameters was modeled using several methods. Yield maps estimated by projection pursuit regression and neural network analysis agreed well with measured yields. These methods also allowed generation of response curves for estimated yield as a function of each of the input parameters. These response curves were useful for investigating the relationship between yields and individual soil and site parameters. ... |
77. Spatial Prediction of Crop Productivity Using Electromagnetic InductionAn inexpensive and accurate method for measuring water-related, within-field soil productivity variation would greatly enhance site-specific crop management strategies. This paper reports on investigations to use an electromagnetic induction (EM) sensor to map claypan (Udollic Ochraqualfs) and alluvial (Typic and Aquic Udipsarnnlents, and Aeric Fluvaquents) soil conductivity variations and to evaluate the relationship of EM measurements to grain crop production. Grain yield measurement was obtai... |
78. Spoke Injection of Fertilizer Phosphorus for GrassesFertilization of forge grasses with phosphorus has shown limited forage increases in South Dakota, even with low soil tests. Lack of response to added phosphorus may partially be due to fertilizer placement on established grass stands. Traditionally broadcasting fertilizer has been the only placement method available. Since P moves very iiiile in the soil, root feeding from tne added P must occur very ciose to the soil surface. A dry soil surface could limit P uptake by grasses, limiting any yie... |
79. Strip Tillage and No Tillage Fertilization Systems Evaluated for Eastern Kansas Rain Fed CornRow-crop agriculture in East-Central and Southeast Kansas is facing increasing pressure to reduce sediment and nutrient losses via runoff. Edge-of-field measurements show that no-tillage with fertilizers placed below the surface of the soil has significantly less sediment and total P losses in runoff compared to conventional tillage (Janssen et al., 2000). However, for rain-fed corn, no-tillage in these regions can provide serious challenges some years because of frequent spring rains and an abu... |
80. Study on Phosphorus and Nitrogen Concentration of Corn Adapted in South DakotaThough nitrogen (N) and phosphorus (P) are vital in several physiological and developmental processes in plants and animals, they pose several environmental, nutritional and health problems, if present in excess amounts. Reduction in the excess input of these nutrients into the soil, thereby reducing environmental problem and consequently nutritional and health problem, can be achieved by balancing their concentration in animal feed. Therefore, this research aims to quantify the nitrogen and pho... |
81. Summary of How Fertilizer Dealers Integrated Manure into Their Nutrient Management ProgramsTwo fertilizer dealers established manure brokerages in Ohio in the spring of 1992. One was in Holrnes County in Northeast Ohio with Progressive Crop Service, an independent fertilker dealer. This county is in an area which has a high concentration of poultry located in the eastern part of the county. Most of the row crop agriculture is in the western side of the county. The terrain is rolling and this is an Amish community which tends to have small fkms. The second site is in Darke County in we... |
82. Swine Manure Phosphorus Use for Crop Production in IowaImproving manure phosphorus (P) management guidelines should result in a more efficient use of thls resource for crop production and in lower risk of P loss to surface water resources. Phosphorus fertilizers are widely used in crop production, there is a great deal of information about their use, and farmers have little doubt about their value to improve crop yield in low- testing soils. However, there is a great deal of uncertainty concerning the value of manure nutrients for crops and about co... |
83. The Effect of Sulfur Fertilization of Yield and Quality of Corn and AlfalfaThe importance of sulfur (S) fertilizers for crop production in Minnesota has been recognized for several years. Inpast research, the use of S had increased crop production only on the sandy soils. Since the soil organic matter is a major reservoir of S for plant use, there is always some question about the need for S in a fertilizer program where soils are not sandy but, yet, have a low organic matter content. It is well known that S is an important component of some amino acids in wlants and t... |
84. The Effects of Rate and Timing of Nitrogen Applications on the Yield and Nitrogen Recovery of Irrigated CornHigh crop yields require that adequate amounts o f N be present and available to the root at the times it i s needed to support growth. However, for a production system to be efficient in the use of the nitrogen and to minimize any potential adverse environmental effects, care must be used to minimize loss during the growing season and minimize amounts of residual N remaining in the soil at the end of the cropping season. This requires that proper N rates be applied and that the N be applied in ... |
85. The Influence of Nitrogen Rate and Foliar Fetilization on Yield and Nitrosamine Levels in Burley TobaccoMany burley tobacco (Nicotiana tabactm~ L.) producers believe that additions of nitrogen (N) rates greater than those recommended by university extension senices will result in increased yield and income. In addition to high rates of N, many producers feel that additional foliar fertilizer will further increase yield and quality of burley tobacco and result in greater revenue. Concerns with excessive N additions include improper curing, elevated levels of tobacco specific nitrosamines (TSNA's), ... |
86. Topsoil Thickness Influence on Phosphorus and Potassium Availability and Crop ResponseSoil testing to estimate nutrient availability and fertilizer needs is a widespread management practice for cropping systems in the United States. as well as in other countries. The purpose of soil testing is to simulate the ability of the plant roots lo uptake these various nutrients critical for normal growth. Crops generally uptake a s~nall amount of phosphorus (P) compared to potassium (K). The portion of soil P that is readily available for plant growth maybe limiting due to the small quant... |
87. Using Soil Properties to Predict Soluable Phosphorus Losses from Indiana SoilsEscessive phosphorus (P) levels in surface water can degrade water quality by causing algal blooms and accelerating the eutrophication process. Agriculture has bceri implicated as a major nonpoint source of P, so many states have considered restricting P applications from inorganic fertilizers, manures, and other Pcontaining materials once soil test P levels esceed "threshold values". Relationships between soil properties and soluble P loss potential have not been welldocumcnted. This laboratory... |
88. Using Sufficiency and Recommendation Information to Calculate Fertilizer Response Curve and Profitability Estimates.The importance of sound fertility programs in efficient, profitable farming operations is well known - especially in times of low crop prices. Likewise, the importance of a sound soil testing program - and recommendation guidelines that relate these soil test values to credible, long-term research results - is recognized as the best way of obtaining maximum economic returns from fertilizer dollars. Unfortunatly, there are few tools available for evaluating the profitabi1it.y of a specific fertil... |
89. Validating the Wisconsin P Index with Measured Runoff P Losses From Agricultural FieldsPhosphorus (P) indices have been developed by most states in the USA for use as planning tools to assess the risk of P loss and identify appropriate management alternatives to control these losses where needed. Little information is available on the relationshp between P index values and actual P runoff losses in the field. We compared annual P losses in runoff measured at 2 1 field or sub-watershed locations with Wisconsin P index values calculated for the same areas. The research sites include... |
90. Variable Fertilizer Nitrogen Application Based on the Delta Yield Index- A Field StudyA quick review of the both the scientific and popular literature indicates that many different approaches have been suggested for the prediction of variable fertilizer N applications in the field. In previous meetings of this conference we have presented the general outline and approach taken for our site-specific crop management project in Ontario. Briefly, historical data sets of grain corn response trials to fertilizer N (encompassing some 300 site-years worth of data) indicated that most yi... |
91. Yield Monitoring- The Beginning or the EndAs site specific management or precision farming gains acceptance with the agricultural producer, the question remains: '.Where do I begin?". As technology creates and makes available new machines for the site specific environment: ''How do they fit into the picture?". As the yield monitor has become the most popular and accepted of these technological innovations for the agricultural producer, what role does it play in the sitc specific management concept? What is site specific management and w... |
92. Zone Delineation for Nitrogen ManagementManaging nitrogen through zone soil sampling has been shown effective in revealing residual soil nitrate patterns in North Dakota. Zone delineation has been constructed using several types of data, including yield maps, remote imagery, topography and soil EC sensor data. A study was conducted in North Dakota, Montana and Minnesota to evaluate zone delineation methods. Across the region, yield frequency maps, topography, remote inlagery and soil EC data were effective in helping to construct zon... |