Proceedings
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| Filter results14 paper(s) found. |
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1. Ammonia Band Spacing Effects on Ammonium Persistence in the BandResults from four field experiments (1991 and 1992) showed that anhydrous ammonia (AA) concentration in the band increased NH4-N persistence in the Hord and Sharpsburg soils in 1992, but not in the Cass and Zook soils in 1991. In 1992, average half-life across both soils was increased from 14 days when applied in a 38 cm spacing to 66 days when applied in a 152 cm spacing (every other row) at the high application rate (224 kg N ha-'). A half-life of 66 days indicates 25% of the applied AA would be... |
2. Comparing the Performance of Preplant and Presidedress Soil Nitrate Tests for the North-Central RegionSoil nitrate (NO3-N) testing is a recommended best management practice (BMP) for adjusting corn N fertilization rates across the North-Central region. Several approaches to soil NO3-N testing are used and vary in both recommended time and depth of sampling (Hergert, 1987). Nitrate is very mobile in soil and is subject to either loss from leaching and denitrification or gain from net mineralization of crop residue and manure. The processes that govem nitrate accumulation in soils are most active in... |
3. Effect of Tillage, Rotation, and Nitrogen Rate on Rainfed Corn Yield and Nitrogen UptakeDetermining the long term effect of tillage, rotation and nitrogen rate in typical cropping sequences is important in making sound agronomic decisions. In northeast Nebraska rainfall is the major deternlinant of yield. In 1956 a tillage study was initiated to determine the effect of tillage. rotation and nitrogen rate on corn and soybean yields. Spring plow. disk and no-till treatments were applied to continuous corn and co1-n follo\ving soybeans on a Kennebec silt loam. Five nitrogen rates (0. 36,... |
4. Identifying Critical Sources of Phosphorus Export from Agricultural WatershedsPhosphorus (P) is an essential element for plant and animal growth, and its input to agriculture is necessary to maintain profitable crop and animal production. Eutrophication, the natural aging of lakes or streams brought on by nutrient enrichment, can be accelerated by P inputs to fresh waters from human activities (Carpenter et al., 1998; Schindler. 1977). Eutrophication has been identified as the main problem in surface waters withimpaired water quality (USEPA. 1996). It restricts water use for... |
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. 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 greater... |
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. Evaluation of the Illinois Soil Nitrogen Test in the North Central RegionData from 96 locations across the North Central Region was complied to evaluate the usefulness of the Illinois soil nitrogen test (ISNT) in identifying fields where corn will not respond to additional N fertilizer and predicting the yield optimizing N rate (YONR) for each field. The ISNT could not accurately predict non-responsive sites, nor could it predict YONR. Sub-setting the data based on soil drainage class and previous crop did not improve the predictive capability of the ISNT. The ISNT was... |
9. Carbon Sequestration: The Lack of Initial Measurement Could Bias Interpretation of Management Effect on Soil CarbonMuch research has been done in the last decades to determine the effect of management practices on the rate of soil carbon (C) seque stration over time. Generally paired fields are sampled and soil organic carbon (SOC) content under each manage ment system is determined. Conclusions about the effectiveness of different management systems in sequestering soil C are established based on the SOC difference and le ngth of the experiment. However, properly archived historic samples are often unavailable.... |
10. Evaluating Relationships between Soil Respiration and Nitrogen Use Efficiency in CornAvailable nitrogen (N) often limits the agricultural production of corn (Zea mays) and the N fertilizer use efficiency is of primary concern for producers in Kansas and the Midwest. This study was carried out to understand the agronomic value of commercially available soil health tests (e.g. 24 hr CO2 burst) and their relationship to components of nitrogen use efficiency (NUE) in corn. Relationships between N response and soil CO2 evolution were investigated across multiple sites and management... D. Ruiz Diaz, B. Rutter |
11. Surface soil acidification and lime application in no-till systemsSurface soil acidification can develop after multiple years under no-tillage system, a primary effect of multiple years of broadcast fertilizer application and organic matter decomposition. The objective of this work was to evaluate the effects of surface lime application on crop yield response and changes in soil pH in the soil profile. Field experiments were established at two locations in Kansas and selected base on similarities in management history (approximately 30 years under no-till),... D. Ruiz Diaz, B. Rutter |
12. Comparison of Mehlich-3 and Haney H3A-4 Soil Tests in Kansas SoilsRecommended application rates of soil fertility amendments are often based on a soil test in agricultural production systems. Interpretation of these soil tests requires correlation and calibration to crop yield response, nutrient uptake, or existing soil tests. The Mehlich-3 soil test procedure is currently used to evaluate the plant availability of phosphorus (P) and potassium (K) in Kansas soils. However, the Haney soil test has gained attention in recentyear and has been used to adjust soil... B. Rutter, D. Ruiz Diaz |
13. Evaluation of Plant Tissue Analysis to Assess Phosphorus Nutritional Status in Corn and SoybeanPlant phosphorus (P) tissue analysis can be used to identify the nutritional status and potential response to P fertilization. This study aimed to determine critical P tissue concentration at different growing stages for corn and soybean. The experiment was conducted across multiple corn and soybean locations in Kansas. Tissue samples were collected as whole plant V6 stage and ear leaf R1 stage in corn, whole plant V4 stage, and trifoliate R3 for soybean. Plant tissue samples were dried, ground,... G. Roa, D. Ruiz Diaz, B. Rutter |
14. A Novel Calcimeter for Soil Carbonate Assessment with Implications for Accurate Soil Test MethodsCalcium carbonate equivalent content is an important soil characteristic, with rammifications for decisions made in agricultural production and soil testing labs alike. However, soil carbonate measurements are rarely included with soil fertility analyses in Kansas due to their tedius nature and the cost of analysis. The objectives of this study were to develop a reliable calcimeter using open-source electronics and readily available labware, and to evaluate it’s performance against procedures... B. Rutter, D. Ruiz Diaz |