Proceedings
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| Filter results13 paper(s) found. |
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1. Effect of Ammonia Knife Spacing on Corn YieldExperiments were conducted at DeKalb on a Drummer sicl, Dixon Springs on a Alford silt loam and Elwood on a Blaunt sicl to evaluate the effect of ammonia knife spacing at varying N rates and on different tillage systems on the yield of corn Nitrogen was awlied at 180 1bs N/acre at bath DeKalb and El& and at 210 lbs N/acre at Dixon Springs in the knife spacing by tillage study. In the rate by knife spacing by time of application study at DeKalb, the preplant nitrogen was placed under where the rows... |
2. Soil Fertility Research- MissouriRather than focus on one item for this years' report I thought an overview of some of the Missouri soil fertility work would be of interest. Our workgroup. though informal and scattered over campus. tries to meet weekly to provide some continuity. Much of the work is driven by grants with specific foci. For example. Newell Kitchen has reported to this group on MSEA a joint agency project to study pesticide and N movenlent into ground and surface water in a central Missouri watershed. ... |
3. Nitrogen Availability, Time of Release and Movement in RotationsPrevious studies have found that N is released through the decomposition of sugarbeet tops (Moraghan and Smith, 1996: Reitmeier et a]., 1999). There is also evidence that N credits may be justified following other broadleaf crops, such as potato and sunflower. This evidence follows work by Vanotti and Bundy (1995) and Bundy et al. (1 993) suggesting that N credits from annual legumes are provided not by decomposition ofthe roots or release ofN directly into the soil from the roots as some might assume,... |
4. Adjusting N Recommendations Based on a Previously Grown CropNitrogen recommendations in North Dakota are based on a yield goal multiplied from some empirically derived factor in a linear formula. There are a three adjustments to the N recommendations that result form these formulas (Franzen and Cihacek, 1996). They are the soil test nitrate-N to some depth, a sampling date adjustment ifthe sampling was conducted in the fall prior to September 15, and a previous crop credit. Two of these three adjustments are based on some knowledge regarding mineralization... |
5. Corn Hybrids With Contrasting Root Systems: Response To Soil And Fertilizer PhosphorusWith current corn genetic improvements for water-limited scenarios, root system architecture and growth are being considered which may affect overall nutrient uptake particularly for immobile nutrients. The objective of this study was to evaluate plant response and phosphorus uptake with contrasting, generally shallow and generally deep rooted corn hybrids. Over the two years there were a total of seven sites, two sites in 2011 and five sites in 2012. The sites are all rain fed except for three sites... |
6. Determining In-season Nitrogen Requirements for Maize Using Model and Sensor Based ApproachesThere is great value in determining the optimum quantity and timing of nitrogen (N) application to meet crop needs while minimizing losses. Applying a portion of the total N during the growing season allows for adjustments which can be responsive to actual field conditions which result in varying N needs. Two methods of determining in-season N needs were evaluated, a model-based approach and a crop canopy sensor approach. The Maize-N model was developed to estimate the economically optimum N fertilizer... |
7. 4R Phosphorus Management for Soybeans in the Northern Frontier: Rate and Placement Effects on Plant Stand, Biomass and Seed YieldVery little research has been conducted to determine the best rate, source, placement, and timing of P fertilizer for modern soybean cultivars grown in the Canadian Prairies. Preliminary results of the two years of field studies at 10 locations in Manitoba showed that typical agronomic rates of seed row P did not decrease plant stand and seed yield at any sites; nor was seed yield increased at any site, even with Olsen P concentrations as low as 3 ppm.... |
8. Effect of Starter Fertilizer and Plant Date on Soybean Growth, Nodulation, and YieldEnvironmental conditions at the time of planting are a crucial determinant to soybean (Glycine max) yield potential. In recent years, it has become common in Ohio to begin planting earlier in the growing season, as soon as mid- or late-April in some cases. However, soil conditions are typically cooler and wetter at this time as opposed to later planting dates, and nutrient availability may be limited. When planting soybeans into cool and wet soil, the application of a starter fertilizer may be beneficial... |
9. Nitrogen Management of Bioenergy Miscanthus on Claypan Soil LandscapesBioenergy crop Miscanthus x giganteus has been well studied for its yield in Europe and certain parts of the US Midwest but little has been done to investigate Miscanthus production in settings economically marginal for grain production. This study was conducted to determine nitrogen (N) requirements and yield potentials of M. x giganteus in degraded claypan soils. The effects of N fertilizer rates were investigated at four different locations in central Missouri on a Mexico series soil (fine, smectitic,... |
10. 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 the... |
11. Can Co-additives Alter the Phosphorus Fertilizer Reaction Pathways in P-Fixing Soils?In many calcareous and strongly weathered acid soils, only a small proportion of applied fertilizer P is available for plants in the year of application due to rapid transformation of applied P to insoluble forms (“fixed” P) with limited plantavailability. The residual effectiveness of applied P fertilizer decline over time due to further transformation of applied P to more insoluble forms. High nutrient loading intended to overcome P availability limitations in high P-fixing... G. Hettiarachchi |
12. Independence of Crop Yield and Nitrogen Rate Across SitesHistorically soil fertility specialists in the North Central States of the USA have constructed nitrogen (N) rate recommendations based on ‘yield goals’ or ‘expected yield’. Within the past ten years, there has been a general realization by soil fertility researchers that within a site or field there is a relationship between N rate and yield; however, because of soil and weather differences between sites there is no relationship in N rate studies with a large number of... D. Franzen, L. Sharma, H. Bu, E. Schultz, J. Breker, A. Denton |
13. Improving Nitrogen Management in Dryland Winter Wheat Production in NebraskaWheat producers in Nebraska endured a significant loss in profit due to reduced grain protein in years that had wet springs such as in 2016 and 2017. Among many potential factors, soil nitrogen (N) is the most central factor that affects protein levels in wheat. To investigate the effect of N on wheat grain yield and protein content, field trials across the State were initiated in 2018. The specific objectives of the field study were to evaluate the effects of different N rates and application... |