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1. 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... |
2. Phosphorus Stratification- is it Relevent to P uptake by SoybeanStratification of nutrients, observed in soils under continuous no-till management, remains an issue. Two experiments were conducted during 2001 and 2002 to evaluate the effect of stratification on P nutrition of soybean (Glycine nzax (L.) Merr.). At the fist site there were five blocks with stratified and unstratified main plots and five levels of soil test P as subplots. In the second trial there were four blocks with two stratification treatments as main plots, the absence and presence of in-row... |
3. Use of Fly Ash as as Alternative Liming Source for Irrigated Corn ProductionFly ash from the Gerald Gentleman Power Station in west central Nebraska can potentially serve as an alternative liming source without reducing corn grain yields. A study was conducted to assess the use of fly ash as an alternative liming source on three acid sandy soils of west central Nebraska where conventional limmg sources can be uneconomical due to transportation costs. Corn grain yield, and soil pH change over time were assessed. Lime sources failed to raise the soil pH in the upper 8 inches... |
4. The Analysis of Nitrogen and Plant Population InteractionsNitrogen and plant population are significant factors for corn production. Accurate nitrogen fertilizer and seeding rate recommendations are essential for optimizing profitability for the fmer and minimizing nitrogen losses. Research and development of yield response curves provide important information that can be used to understand the relationships between these inputs (nitrogen fertilizer and corn seeds) and output (grain yield). Over the varying levels of inputs. yield response functions can... |
5. Changes in Nitrogen use Efficiency and Soil Quality After Five Years of Managing for High Yield Corn and SoybeanAverage corn gain yields in the USA have increased linearly at a rate of 1.7 bulacre over the past 35 years with a national yield average of 130 bdacre. Corn yield contest winners and simulation models, ho ~ever, indicate there is -100 bda in exploitable corn yield gap. Six years (1999-2004) of plant development, grain yield and nutrient uptake \yere compared in intensive irrigated maize systems representing (a) recommended best management practices for a yield goal of 200 bdacre (Ml) and (b) intensive... |
6. Relationship of Mehlich-3 ICP and Mehlich-3 Colorimetric Phosphorus Determinations with the Bray-P1 ExtractantThe Bray P1 extractant has traditionally been the common extractant used for soil testing in the Midwest and Great Plains. while the Olsen P tests has been the dominant phosphorus (P) extractant used in many westem states. The use of the Meldich-3 extractant for determining soil test P in private and state operated soil test laborato~ies becotne more commonplace in recent years. The ability to extract multiple elements is a 11lajor advantage of the Mehlich-3 test. While the Mehlich-3 test is often... |
7. 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 year,... |
8. 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. The... |
9. Tillage and Nitrogen Application Methodology Affects Corn Grain YieldMore efficient use of fertilizer nitrogen (N) is essential for improved yields and environmental stewardship. While university N recommendations for corn are based on observations typically made in conventional tillage systems, few universities have established research to evaluate if N recommendations should be different for alternative tillage systems. Generally spealung, no-till or minimum tillage systems have been identified as needing additional N to compensate for microbial immobilization of... |
10. Corn and Soybean Grain Yield and Concentration of Potassium in Plant Tissues and Soil as Affected by Potassium FertilizationResearch in the Midwest has shown that K fer tilization tends to increase plant K uptake by corn and soybean and the K concentration of vegeta tive tissues. Several studies found that K fertilization usually increases the K concentrati on of vegetative plant parts, often regardless of the soil-test K (STK) level a nd grain yield response (Malla rino et al., 1999; Borges and Mallarino, 2000; Yin and Vyn, 2002a, 2002b; Borg es and Mallarino, 2003; Yin and Vyn, 2003). It is well known that the K concentration... |
11. Swine Manure Applications for Soybean Production - Environnmental and Pathological ImplicationsSoybeans are leguminous plant sp ecies capable of fixing nitrogen (N) from the atmosphere to support their growth and development. Despite th e fact that soybeans can fix their own N, in a soil environment rich in inorgani c N they will scavenge for available N decreasing the level of root nodulation (Schmidt et al., 2000; Hester man and Isleib, 1991). Studies conducted to measure the impact of N fertilization of soybean s reveals that crop response to commercial N fertilizer does not result in increased... |
12. Triple-Stacks, Genetics, and Biotechnology in Improving Nitrogen Use of CornGenetic improvement in N use efficiency (NUE) is a clear strategy fo r enhancing yield and fertilizer N management of corn ( Zea mays L.), and has been the subj ect of our ongoing research. Calculation of the N requirement (N fertilizer usage/grain yield) based on statewide average grain yields and fertilizer sales shows a stead y decrease since the mid 1980's, suggestive of a genetic improvement in N use. Direct comparis on of the response to N for a 1980�۪s hybrid with its modern counterpart... |
13. Nitrogen Recalibration for Wheat in North DakotaThe general formula for determining N fertilizer ra te in North Dakota for about thirty-five years has been N-rate = (2.5 X Yield Potential (or Yield G oal) less credits from previous crops and soil test nitrate-N from a 2-foot soil core composite. Historically high fertilizer N costs and the ability to fertilize within fiel ds rather than whole field N management has resulted in a reexamination of N calibration data, and an effort to expand the modern N calibration database with new field experiments.... |
14. 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, regardless... |
15. 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 'return... |
16. 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.... |
17. Mitigating Phosphorus Movement from Agricultural FieldsAgriculture is often cited as the primary factor for the high P loads polluting Lake Erie and Ohio�۪s watersheds, but the contributions of agriculture as a system, a combination of tillage, best management practice (BMP) and fertilizer source rather than an industry is unknown. This study supplied either commercial fertilizer or poultry litter to tilled or no-till production systems with their corresponding BMPs of incorporation and cover crops, respectively, to determine the P lost via surface... |
18. Identification of Reasons for High Temporal Soil-Test Potassium VariationExtensive research has focused on potassium (K) fertlization and soil K testing during several decades in the Corn Belt. IN Iowa, more t han 200 conventional or on-farm strip trials were conducted since the iddle 1990s until the early 2000s. Results of this research were used to update Iowa State University (ISU) K recommendations in 1999 and in 2002. In spite of increasd knowledge about soil-test K calibration, K fertilizer placement meethods, and needed K fertilizer rates, this research demonstrated... |
19. 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.... |
20. 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 or... |
21. 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 challenge... |
22. Nitrogen Recalibration for Spring Wheat and Durum in North DakotaNorth Dakota will begin using new fertilizer r ecommendations beginning Dec. 1, 2009. Previous recommendations required a yield guess by growers with no rega rd to economics of nitrogen application. The new recommendations recogni ze different N response curves with yield and grain protein within three state agri-climatology zones. The reco mmendations use the "return to N" method, which vary the N recommendation based on crop price and N costs. The resulting rate is adjusted based on... D. Franzen, G. Endres, J. Lukach, R. Ashley, J. Staricka, K. Mckay |
23. Impact of Phosphorus and Potassium Fertilization on Corn and Soybean Productivity and Soil Nutrient LevelsA common production practice in the Eastern Corn Belt is to supply enough phosphorus (P) and potassium (K) in the fall prior to corn planting to satisfy the nutrient needs of both corn and soybeans in a rotation. This practice is most likely a viavle option for fields with more than adequate soil nutrient levels, but on marginal fields this practice may be limiting production (specifically with regard to K). Two field experiements were estabished to evauate the impact of P and K fertilization... K.A. Dietrick, R.W. Mullen, C.E. Dygert |
24. Biological N Fixation on Soybeans: N Nutrition and Incidence on N BalanceSoybean [Glycine max (L.) Merr.] nitrogen (N) demand is partially met (50-60%) by the biological N fixation (BNF) process. Study of the “N-gap” (plant N demand minus N-BNF) and the partial N balance (fixed N in aboveground biomass minus N removed by seeds) are still unanswered scientific knowledge gaps. Focusing on these two components a review of 60 studies reporting on BNF was conducted in order to study the limits to which BNF can satisfy plant N demand. This... I. Ciampitti |
25. Active and Passive Spectral Sensing for Predicting the Optimum Nitrogen Rate and Timing in CornThere are many in-season plant diagnostic tools available for predicting the rate and timing of in-season nitrogen fertilizer in corn (Zea mays L.). However, soils in Southern Minnesota are generally high in organic matter and can carry over nitrate- nitrogen from one season to the next. Subsequently, there is oftentimes sufficient soil nitrogen early in the growing season to supply much of the crop requirement, limiting the use of sensor-based N management tools. Past work... T. Nigon, D. Kaiser, C. Yang, D. Mulla |
26. Promoting Adoption of Precision Nitrogen Management Technologies Through On-farm ResearchThe Nebraska On-Farm Research Network helps farmers evaluate products and practices that impact the productivity, profitability, and sustainability of their operations. There are many technologies that have potential to increase nitrogen use efficiency (NUE) on corn and winter wheat but typically these technologies have low adoption. At the same time, farmers have technologies such as GPS, yield monitors, and variable-rate application equipment on their farmers that enables them to easily conduct... L. Thompson, L. Puntel, T. Mieno, J. Iqbal, B. Maharjan, J. Luck, S. Norquest, J. Guilherme cesario pereira pinto, C. Uwineza |