Proceedings
Authors
| Filter results16 paper(s) found. |
|---|
1. Respiration as a Measure of Soil Health: Challenges and OpportunitiesIn recent years, respiration has become a commonly-used soil health metric. It has been used as a standalone predictor of soil N supplying capacity and in conjunction with other metrics to assess overall soil health. However, the sources of variation underlying respiration itself have not been thoroughly assessed. We show that across growing regions in California, respiration was unable to accurately predict soil N supply. The R2 values were much higher in fields that had received a recently-incorporated... J. Wade, S. Culman, T. Hurriso, W. Horwath, R. Miller |
2. Assessing Spatial and Temporal Nutrient Dynamics with a Proposed Nutrient Buffering IndexContinued adoption of precision agriculture will lead to the accumulation of spatially and temporally dense soil fertility and yield data. Current soil fertility recommendation strategies use regional estimates of soil buffering properties to adjust application rates. A site specific nutrient buffering index (BI) is presented that uses accumulated yield maps and soil test data to locally estimate soil buffering properties relative to fertilizer additions and crop removal. BI is a quantity-intensity... |
3. In-Furrow Starter and Broadcast Phosphorus and Potassium Fertilization for CornIncreasing awareness of potential impacts of farming on the environment has renewed interest in further study of fertilizer management strategies that reduce nutrient inputs. Fertilizer recommendations for phosphorus (P) and potassium (K) usually are based on soil-test values and nutrient removal with crop harvest. Many Midwest fmers follow these recommendations. but many others apply removal-based P and K fertilizer rates even in high-testing soils. The typical farmer applies P and K fertilizer... |
4. Manganese Fertilizer Antagonism of Glyphosphate EfficacyMichigan soybean producers have observed antagonism of glyphosate efficacy in tank mixtures with foliar manganese (Mn) fertilizers. The objectives of this study were to (1) evaluate four Mn fertilizer formulations for their effect on glyphosate activity. (2) evaluate the effect of Mn fertilizer application timing on glyphosate activity, (3) evaluate the efficacy of three adjuvants in overcoming the Mn fertilizer antagonism of glyphosate. (4) determine the spray solution ratio of h4n2' and glyphosate... |
5. Relationship Between Response Indices Measured In-Season and at Harvest in Winter WheatCurrent methods for making nitrogen recommendations in winter wheat (Triticum aestivurn L.) do not adjust for in-season temporal variability of plant available non-fertilizer nitrogen (N) sources. The purpose of this study was to compare the use of different nitrogen response indices determined in-season @INDVI and RIPLANTHEIGkm) to the nitrogen response index measured at harvest (RIHARvEST). In addition, this study evaluated the use of the in-season response indices for determining topdress nitrogen... |
6. Starter Fertilizer for Row Crop Production Under No-till Conditions in Eastern NebraskaStarter fertilizer application often results in increased corn and sorghum yield under no-till conditions, probably due to lower soil temperatures as compared to tilled soil. Five dryland and 5 irrigated corn trials. and 12 dryland grain sorghum trials were established after soybean in 2002 and 2003 on rolling land in eastern Nebraska with different soil types and topographic positions. Three placement positions were compared: in the seed furrow. over the row. and 2" to the side and 2" deep (2x2).... |
7. 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... |
8. Starter Potassium for Corn: Why and WhenStarter fertilizer application can complement broa dcast P and K fertilization for corn and other crops. Questions about its use relate mainly to the conditions in which it is most effective (such as soil-test level, tillage syst em, and broadcast fertilization rates among others), application methods and rates that do not damage seedlings, and nutrient ratios. Many studies in Iowa and the Midwest have shown that starter mixtures (usu ally N-P or N-P-K) often increase early corn growth. Corn yield... |
9. Enhanced Efficiency Nitrogen Fertiizers Release in an Illinois SoilThe release rates of ammonium and nitrate from applications of enhanced efficiency nitrogen fertilizers to soil is not well understood. A better knowledge of th e soil processes involved with N release could allow for greater acceptance of these fertilizers. The objective of this study was to compare traditional quick release fertilizers w ith enhanced efficiency nitrogen fertilizers to examine their release rates. Th e fertilizers chosen were urea and a polymer-coated urea, which were applied to... |
10. Recent Perspectives for Starter Fertilizer Use on Corn in MinnesotaApplication of fertilizer with the seed at planning has been a popular choice for Minnesota corn farmers to get their crop off to a fast start. Traditionally the salt index of a fertilizer has been important in farmers' management decisions. A research study was conducted at six locations on fine and coar se textured soils around Minnesota. Three fertilizer grades, 4-10-10, 10-34-0, and 3-18-18 were compared at two rates and in three placements relative to the seed. Nitrogen (N) and phosphorus (P)... |
11. Foliar Fertilization and Fungicide Application for SoybeanConcerns over fungal diseases in soybean have renewed interest in applying pesticides for disease control with the goal of increasing grain yi eld. Interest has especially been sparked by discussions of the possibility of Asian Soybean Rust (Phakopsora pachyrhizi) spreading north to the North Central region. Because of increasing prices of soybean grain and traditional fertilizers, many Midwest grower s are considering mixing fluid fertilizers and fungicides for foliar application to soybean. Extensive... |
12. Nitrogen Management for Soft Red Winter WheatSoft red winter wheat was grown wi th various rates of four N materials, ammonium sulfate, urea, urea-ammonium nitrate and ESN, for harvest years 2004 through 2007. In all studies 21 lbs N/a was applied at planting. Over th ese four years top wheat yields were produced with 60 or 90 lbs topdress N/a depending on year. Av eraged over the four years 90 lbs N/a resulted in 1.6, 1.0 and 2.2 bu/a more yield than 60 lbs N/a for urea, UAN and ESN. This difference was neither significant nor economical.... |
13. Early Season Nutrient Uptake from Combinations of N itrogen, Phosphorus, and Potassium Applies in Starter Fertilizer in Two Corn HybridsConventional small plot field trials were establ ished to study the effect nitrogen (N), phosphorus (P), and potassium (K) applied as starter ferti lizer on early season growth and nutrient uptake of two corn hybrids with a nd without the Bt-rootworm gene. Ei ght locations were studied over two years comparing a non-starter check, N only, K only, NP, NPK, and NK starter fertilizer combinations on early season growth and nutrient uptake. Sites tested High initially in both P and K. One or more starter... |
14. 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... |
15. Response to Starter Applied Sulfur in Combination with Nitrogen and Phosphorus Across a LandscapeCorn ( Zea Mays L.) response to starter fe rtilizer combinations containing sulfur were studied using a replicated strip trial methodology. Combinations of ni trogen (20 lbs N), phosphorus (20 lbs P 2O5), and sulfur (25 lbs S) were applied two inches beside and below the seed with the planter and compared with a no-starter control a nd 25 lbs broadcast sulfur. Early plant growth was consistently increased by starter P and so metimes by starter N, while sulfur uptake was increased by S and P application.... |
16. Sulfur Cycling from Corn in Corn-Corn and Corn-Soybean RotationsSulfur fertilizer requirements for corn grown on medium and fine textured soils have increased over the past ten years. The effect of sulfur rate and timing on the potential for sulfur cycling and carryover within a two year crop rotation, corn-corn and corn-soybean, were studied. Sulfur was applied as ammonium sulfate on the soil surface at planting and the V3-V5 growth stages at rates of 0, 10, 20, 30, and 40 lbs of S per acre during the first cropping year. Each plot was divided in two prior to... |