Proceedings
Authors
| Filter results19 paper(s) found. |
|---|
1. Soybean Chlorosis Management ProgramChlorosis in soybeans is a problem wherever soybeans are grown on high pH soils. In Nebraska, most of the soybeans are grown in the southeastern half of the state. Here the upland soils are neutral to moderately acid; however, many of the river valley soils are alkaline. Thus, chlorosis is a problem in the Platte and Elkhorn River Valleys and to a lesser extent, in the Republican and Loup River Valleys. Not all soils in the river valleys are prone to chlorosis OF soybeans even though many are alkaline... |
2. An Overview of the Thompson/Baker Farming Systems StudyThere is a general lack of quantitative information, collected from field-scale studies, that can be used to assess long-term effects of alternative farming systems. The objective of an on-going study in central Iowa is to quantitatively evaluate several chemical, physical, biological, and economic parameters on the Richard Thompson (alternative) and Eugene Baker (conventional) farms. This project was initiated in 1989 on adjacent 32-ha tracts of land, that have Clarion loam, Nicollet loam, Canisteo... |
3. 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. ... |
4. 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 obtained... |
5. 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... |
6. Cover Crop Impacts on Corn and Soybean Nitrogen Accumulation and YieldThe need to retain soil N between economic crops has renewed interest in cover crops for the eastern cornbelt but their management remains a barrier to widespread adoption. We conducted a 3 site-yr study to determine effects of cover species (wheat or rye) and biomass management (burndown 40 d, 20 d, or 2 d preplant) on corn and soybean yields. Sites included a very poorly drained (wland wlo tile drainage) and a well drained silt loam. With adequate drainage, cover biomass 40 d preplant averaged... |
7. Nitrate Concentrations in Drainage Water from a Continuous Corn Production System- Impacts of Tile Spacing and Precipitation EventsCharacterization of agricultural drains as point sources for nitrates in surface waters has generated keen interest in regional grab-sample monitoring programs. Grab sample tile drain monitoring programs are being explored by numerous public and private organizations interested in encouraging BMPYs for nitrogen and/or implementation of TMDL policy. Our objective was to determine if nitrate concentrations in water collected from individual tile lines could be interpreted independent of information... |
8. How Does Your Garden Grow? Fertilizer- Friend or FoeGeo-spatial technologies are becoming common place in commercial agriculture and hands-on exercises using these concepts and technologies klfill many state K-12 education standards. The activity topics covered crop nutrients (nitrogen, phosphorus and potassium), global positioning systems (GPS), geographic information systems (GIs), types of agricultural field equipment, soil types and crop identification. Students developed and implemented plant growth experiments to test nutrient application hypotheses.... |
9. Nitrate Concentrations and Flux in Drainage Water- Impacts of Tile Spacing and Precipitation Events and Implications for TMDLSIn the humid region of the eastern cornbelt efforts to optimize productivity of poorly drained soils has led to increased spatial intensity of agricultural tile drains. This intensification in installation of drainage tile is often a primary management consideration when field cultivation is being minimized or eliminated entirely. The objective of this study was to quantify the effects of tile spacing on the concentration and flux of nitrate in tile effluent. Continuous corn was grown on a well-structured,... |
10. An Overview of On-Farm Nitrogen Rate ResearchBecause crop advisors, farmers, and some in the fertilizer industry questioned the University's N recommendations as being too low and raised concerns that the N calibration research had been done primarily in small plots on University Experiment Station land. numerous N calibration studies for corn after soybeans were conducted on farmers' fields in southern Minnesota and northeastern Iowa from 1989 through 2002 to validate present N recommendations. On-farm replicated trials were conducted by University... |
11. Site-Specific Nitrogen Management for Reducing Soil Residual NitrateSite-specific N management has potential for increasing the efficiency of N fertilizer use, and thereby reducing environmental impact. Field studies were conducted in 2000 and 2001 to evaluate the potential for site-specific N management to reduce residual soil nitrate in Missouri cornfields. Field-size side-by-side fertilizer N treatment strips were applied in cooperating farmers' fields. The site-specific crop N requirement (optimal N rate) was determined for sub- blocks that contained a full... |
12. Fertilizer Industry Update- Price, Availability, HistoryThis talk will review world and local factors that have been affecting fertilizer demand, pricing, and supply. The speaker will review fertilizer trends and usage in the world markets as well as discuss trends in the U.S. fertilizer industry. Due to the proprietary nature of most of the information, a paper is not included in the proceedings. Select slides may be available upon request. however. ... |
13. 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 geography.... |
14. iPhone Apps: Corn Nitrogen Fertilizer Rate Calculator and Nitrogen Fertilizer Price Comparison CalculatorAs communications technology advances, there is a need for Extension to deliver information and decision- making tools that leverage these new technologies to engage existing and new clientele groups in new wa ys. Smart technologies allow ac cess to pertinent information on-the- go and out in the field, right when it's needed. ... |
15. 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 inconvenient... |
16. What are the Benefits of Canopy Sensing for Variable-Rate Nitrogen Corn Fertilization?Canopy reflectance sensing for assessing crop N health has been proposed as a technology on which to base top-dress variable-rate N applicat ion. The objective of this research in Missouri was to evaluate the economic a nd environmental benefit of activ e-light crop-canopy reflectance sensors for corn N rate decisions. A total of 16 field-scale experiments were conducted over four seasons (2004-2007) in three major soil areas. Mu ltiple blocks of randomized N rate response plots traversed the length... |
17. Nitrogen Availability and Corn Production in Minnesota Following Cover CropsCover crops are often included in BMPs for reducing soil erosion, building soil organic matter, and reducing nitrate leaching. Because of additional management requirement and uncertainties about their impact on nitrogen availability and cash crop yields, cover crops have not been widely adopted in conventional fields. This study aims to reduce these uncertainties for corn growers in Minnesota by measuring the impact of select cover crops on corn yield, nitrogen demand,... S. Badger |
18. Exploring the Impact of Temporal Variability in Emergence on Corn Grain Yield and Development PatternsConcerns have raised among farmers in the Midwest regarding the impacts of uneven emergence of corn (Zea mays L.) seedlings. Research has showed that even a minor delay in emergence of a few hours could have a substantial influence on plant performance and ear weight; and one of the contributing factors to uneven seedling emergence in corn is the application of starter fertilizer. Placing fertilizers in the seed furrow increases the salt concentration surrounding the seed and as a result, delays... L. Dorissant, P. Kovács, J. Clark |
19. Nitrogen Fertilizer and Irrigation Effects on Soil and Plant Nitrogen DynamicsCropping systems can be exposed to different nitrogen (N) and water availabilities for a variety of reasons. Both N and water have been shown to have both positive and negative; direct and indirect effects on soil and plant N dynamics. Given that agronomic crops require large amounts of N to achieve high yields and often acquire a majority of their N from soil nitrogen mineralization (N min), it is important to understand how nitrogen and water interactions alter soil and plant N dynamics. Our... T. Donovan, J. Schneekloth, L. Comas, M. Schipanski |