Proceedings
Authors
| Filter results26 paper(s) found. |
|---|
1. Impact of Nitrogen Application Timing on Corn ProductionWater quality issues have renewed interest in timing of nitrogen (N) application as a means to improve use efficiency in corn and reduce losses. Improved economic return is also desired as N fertilization is one of the most costly inputs to corn production. Time of fertilizer application is a component of the site-specific 4R nutrient management stewardship programs. In Iowa, the Nutrient Reduction Strategy has a 7% (37% std. dev.) nitrate-N reduction with a 0% (3% std. dev.) corn yield change... J. Sawyer, D. Barker, J. Lundvall |
2. Roto and Shoot Biomass and Nutrient Composition in a Winter Rye Cover CropNitrogen loss from applied fertilizer can be a significant environmental quality issue if NO 3 moves to surface or ground water. The Iowa nutrient reduction strategy science assessment identified winter cereal rye (Secale cereal L.) cover crop as a practice that can significantly reduce N and P loss (41% NO 3-N and 21% P reduction) from corn (Zea mays L.) and soybean [Glycine max. (L.) Merr.] fields. Cereal rye, when used as a cover crop, through its fibrous root system is able to explore the soil... |
3. Effect of Application N timing and Plant Growth Regulator use in WheatWinter wheat is an important cash crop grown in the Midwestern states. However, progress in yield advancement has been slow compared to advances in other major wheat producing regions, notably Euro~e. This has lead to a competitive disadvantage of USA-produced wheat on the world market. In an effort to enhance wheat productivity and profitability a series of experiments were established in the fall of 1985 to assess the impact of more intensified management practices including the use of multiple... |
4. Relationship Between Soil P and P in Surface Runoff and Subsurface Drainage- An Overview of Ongoing ResearchNonpoint source pollution fiom agricultural fields has the potential to accelerate eutrophication of fieshwater ecosystems. In a report of water quality in the United States, the Environmental Protection Agency sited agriculture as the primary source of pollution in 60% of impaired river miles, 30% of the impaired lake acres and 15% of estuarine square miles @PA, 1998). Phosphorus, in particular, has received much attention due to its role as limiting nutrient in many fieshwater ecosystems (Correll,... |
5. Soil Phosphorus Spatial Distribution in Pastures Receiving Poultry Litter ApplicationsEnvironmentally-based P management strategies could be improved by debeating management zones incorporating the effects of landscape position on soil morphology, hydrology, and soil P distribution. Three farm pasture sites in SW Missouri receiving long-term poultry litter applications were sampled by landscape position (summit, shoulder, upper backslope. middle backslope, lower backslope, footslope, drain) for soil P (Bray 1 P, CaCl2 P, total P) at two depths (0-5 cm, 5- 15 cm). Low landscape positions... |
6. Fertilizer Placement in Fall Strip TillageFall strip-tillage potentially provides an opportunity to increase conservation-till corn yields while sirnplifylng corn planters by minimizing the need for multiple coulters and application of relatively high rates of starter-band fertilizer associated with no-till. However. little is known about the relative efficiency of P and K application using fall strip-till systems co~npared to when starter-band applied in no-till systems. The objectives of the research reported in this study were to evaluate... |
7. 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 varying... |
8. 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), undesirable... |
9. Should We Abandon Soil Testing and Yield Goals in Estimating Nitrogen Rates for CornIf the prices of corn and fertilizer-N and the shape of the N response function relating crop yield to the amount of fertilizer used are known, calculating an economically optimal N rate (EONR) for maximizing the net return to applied N is straightforward: the EONR is the N rate at which no firher increase in net return occurs. In most cropping systems and under common price scenarios, crop yield at the EONR is within 95 to 99% of the maximum yield obtained for the specific management package. In... |
10. 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... |
11. 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 relies... |
12. Slow-Release Fertilizer Effect on Groundwater Nitrogen Concentration in Sandy Soils under Potato ProductionCurrent nitrogen (N) fertilizer management practices for potato farming have led to elevated levels of N in the local groundwater. Slow-release fertilizer, specifically Environmentally Smart Nitrogen® (ESN®) polymer coated urea (PCU ) may reduce the amount of N leaching to groundwater; however no field scale studies have been performed in Wisconsin to validate these assertions. Field experiments were conducted at the Hancock Agricultural Research Station using Russet Burbank potato, planted in... |
13. Managing Riparian Buffers to Improve Soil Structural PropertiesFifty-five percent of Kentucky's stream impairments have been attributed to agriculture. Riparian buffer management may improve buffer effectiveness and reduce agricultural contaminants impairing water quality. Three mowing regimes and one native grass establishment regime were imposed in the riparian buffer zone surrounding a tributary of Cane Run Creek in Fayette County KY. Treatment plots measured 10m x 15m, with 10 replications of each treatment. One year after treatment, root biomass, soil aggregate... |
14. A Look at West, Texas(Blank Page for Notes) ... |
15. Nitrogen Loss from Sprinkler Applied Beef Feedlot EffluentLoss of nitrogen from sprinkler applied beef feedlot effluent can be costly for both the producer and the environment. Sprinkler application of effluent is common throughout the Great Plains, though little work has focused specifically on N losses from beef feedlot effluent. We quantified ammonia (NH 3) and nitrous oxide (N2O) losses from beef feedlot effluent applications under field conditions including variations in soil pH, soil water content, ammonium (NH 4+) concentration of the effluent, and... |
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. Overview of Manure Handling on Steroid Movement in Agricultural Fields from Beef Cattle SystemsManure generated from concentrated animal feeding operations may serve as a source of steroids in surface water and potentially in groundwater. The objectives of this research were to determine the amount of steroids and metabolites in runoff from beef cattle production pens, and from runoff and leaching from crop production fields. Cattle were fed a synthetic progestagen, MGA or melengestrol acetate and treated with zeranol, trenbolone acetate, and estradiol implants, while a second group was not... |
18. Evaluation of Sulfur Fertilizers In Corn ProductionSulfur deficiencies and corn yield increases from S fertilization have been documented in Iowa since the mid-2000’s. Therefore, S fertilization management is an important component of high yield corn production. Many S fertilizers are available for use in correcting deficiencies. However, specific product evaluations have not been widely conducted in Iowa. In addition, a new S fertilizer has recently become available in the Midwest U.S., the mineral polyhalite. The research objectives were... J. Sawyer, M. Castellano, A. Sassman, J. Lundvall |
19. Winter Cereal Rye Nitrogen Response and Fertilization RequirementWinter cereal rye (Secale cereale L.) has been a common cover crop choice due to seed cost, winter hardiness, and rapid spring growth. It could also be an alternative grain crop to include in a corn-soybean rotation. Also, a rye crop would provide soil coverage during the springtime when corn and soybean do not. No known research has investigated the N fertilization requirement for winter cereal rye seed production in Iowa. The objectives of this study were to evaluate N response in cereal... C. Martins, J. Sawyer, J. Lundvall |
20. Does cover crop composition improve soil health and enhance nutrient availability to cash crops?Crop and livestock producers in South Dakota are showing greater interest in cover crops for the multidimensional benefits it can provide towards enhanced nutrient availability to the cash crops and livestock nutrition. Growers use different blends of grasses and broad leaves, mostly legumes and brassicas, as cover crops. We hypothesized that carbon and nitrogen ratio and fiber composition in those cover crop residues regulate the nutrient release, thus influence the processes regarding nutrient... D. Sanyal, A. Rahhal, H. Bielenberg, J. Clark, J. Wolthuizen, A. Bly |
21. Do cover crops improve soil health and enhance nutrient availability to cash crops?Bare soils are prone to erosion and lose soluble nutrients. Cover crops provide protection to the soil against erosion and nutrient loss. We hypothesized that the cover crops should uptake available nutrients from the soils in the fall when there is no cash crop, assimilate the nutrients in their tissues, and in the following spring, should release the nutrients back to the soil during the next cash crop growing season. In our study, we are quantifying the nutrients taken up by the cover crops... D. Sanyal, A. Rahhal, H. Bielenberg, J. Wolthuizen, J. Clark, A. Bly |
22. Fertilizer management and cover crop effects on phosphorus use efficiency, environmental efficiency and crop yieldPhosphorus loss from agricultural production is a significant contributor to the degradation and contamination of surface and ground waters. To help protect these waters, it is vital to maximize agronomic and environmental efficiency of phosphorus in the cropping system. The objective of this study was to quantify the effects of cover crops and different phosphorus fertilizer management practices on nutrient use efficiency, environmental efficiency and yield in a no-tillage corn-soybean rotation.... R. Carver, N. Nelson, G. Kluitenberg, K. Roozeboom, P. Tomlinson |
23. Cover crops nutrients uptake did not cause yield loss in cornBare soils are susceptible to erosion and nutrient loss. Cover crops and residues provide physical protection against erosion and nutrient loss, and improve nutrient cycling as well as biodiversity. We hypothesized that cover crops store available nutrients from the soil in the fall and release them the next spring for the next cash crop, minimizing potential nutrients loss with no adverse effect on cash crop yield. A four site-year study throughout South Dakota was conducted to compare... |
24. Can Cover Crops Help to Improve Soil Health While Having a Positive Effect on Corn Grain Yield?Cover crops have recently gained attention in the U.S. Mid-west because of their potential to increase soil organic matter and improve overall soil health. There is some concern however, that cover crops may negatively impact corn grain yield. This study was conducted to determine the effects that different cover crop mixtures have on soil health measurements and corn grain yield at increasing nitrogen rates. Cover crops were planted in the fall as a dominantly grass mixture, dominantly... |
25. Manure Total Nitrogen Variability Due to Analytical Method and Total Solids ContentKnowing the nutrient analysis of a fertilizer source is essential to ensure adequate nutrients for crop growth, while not causing potential environmental impacts by overapplying nutrients. Using manure as a nutrient source can complicate matters as the nutrient content can be variable and the manure can come in a range of liquid to solid consistencies. There are multiple laboratory methods to determine different nutrient parameters and for manure total nitrogen levels the most common methods... N.L. Bohl Bormann, M.L. Wilson, E.L. Cortus, J. Floren, R.O. Miller, L. Gunderson |
26. US Midwest Dairy Manure Nutrient Observations 2012-2022Dairy manure is a source of organic nutrients with variable manure characteristics. This analysis drew 2012-2022 data from ManureDB, the manure and organic amendment database developed by the University of Minnesota. Thousands of solid dairy and liquid dairy manure samples across 2012-2022 were evaluated for book value comparisons, temporal trends, and regional differences for total N, NH4-N, P2O5, and K2O analytes. The only significant trend detected... N. Bohl Bormann, M. Wilson, E.L. Cortus, K.A. Silverstein, K.A. Janni, L. Gunderson |