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1. 4R Nutrient Stewardship: A Component Of Agricultural Non-Point Source PolicyA challenge of agriculture is to increase production and feed the world without adversely affecting the environment. Fortunately, there is an immediate connection between applying the 4Rs (the right fertilizer source at the right rate, the right time and in the right place) and their beneficial impacts on crop performance, soil health and decreased environmental pollution. While any approach to addressing non-point source nutrient losses from agriculture must involve fertilizer best management ... |
2. A Case for the use of Limestone in North DakotaFarmers in North Dakota have long believed that nearly all of the cultivated land in the state was alkaline in pH. A recent survey of the state revealed that between 27% and 50% of the fields tested below pH 7, depending on landscape position, with about 17% of the state with pH less than 6.5. In site-specific studies in fields with dominant pH above 7, nearly all fields contained at least one area with pH below 7. Herbicide carryover studies have shown that areas of even slightly acid pH can re... |
3. A Crop-Based Approach for In-Season N Management of CornOver-application of nitrogen (N) fertilizer on corn has resulted in elevated levels of N in ground and surface waters. A major factor contributing to decreased N use efficiency and environmental contamination for traditional corn N management schemes is routine pre-season application of large doses of N before the crop can effectively utilize this N. Our long-term research goal is to reduce these over-applications by using remote sensing to direct fertilizer only to areas needing N at times when... |
4. Assessing Nitrogen Use Efficiency Of Maize On Highly Productive Irrigated Sandy Soils As Affected By Three Nitrogen SourcesIrrigated soils in Minnesota account for only 500,000 acres, but these acres are some of the most productive and environmentally sensitive areas in the state. Ground water is the major source of drinking water in the sandy areas of Minnesota, so obtaining information on nitrogen use efficiency is critical for corn (Zea mays L.) grown on these soils. Slow release urea products have the potential to increase nitrogen (N) use efficiency by releasing N at a time when crop demands are highest. Two su... |
5. Assessment Of Enhanced Efficiency Urea Products On Maize In MissouriUrea is the most commonly used N fertilizer worldwide, but can be easily lost to the environment through ammonia volatilization. Enhanced efficiency fertilizers (EEF) have been developed to help prevent these losses. Field studies were conducted from 2009 to 2011 on a Mexico silt loam (fine, smectitic, mesic, Vertic Epiaqualf) to determine the efficacy of five EEF urea products compare to untreated urea when surface applied to no-till maize (Zea mays L.). Treatments included untreated urea, Agro... |
6. Changes in Crop Production Efficiency with High Yield ProductionIncreases in crop yields are due to changes in the genetic efficiency in the use of inputs. However, there are constraints on efficient use of resources, e-g., water, nitrogen, solar radiation, that limit consistent high yield response. The interactions of water, nitrogen, and light form a basis for understanding how crop production efficiency can be improved. Carbon dioxide is an input to crop production that has been overlooked and understanding this environmental component will help identify... |
7. Consequences Of Shallow NH3 Placement And Timing On N Use Efficiencies In Corn ProductionA field study in west-central Indiana was conducted to investigate the effects of shallow anhydrous ammonia (NH 3) placement and timing on N use efficiencies in a conventionally tilled corn production system following soybean crop. The spring NH 3 was applied either pre-plant (6- inches offset from future corn row) or side-dress (at mid-row position) at different rates (0, 80, 130 or 180 lbs N acre -1). Aboveground biomass harvest and combine harvested yield were used to determine N recovery, N ... |
8. Continuous Corn Production As Affected By Starter Fertilizers Containing Nitrogen, Phosphorus, and SulfurCrop rotations in the Midwest have changed from the traditional corn-soybean rotation to more corn-intensive rotations. Due to the expanding demand for corn to supply the ethanol industry and the increasing insect and disease challenges facing soybean producers, some farmers are switching to a corn-corn-soybean rotation or for some, continuous corn. These rotations produce large amounts of biomass (corn stover) that often remain on the soil surface with present day tillage systems. This is good... |
9. Corn and Soybean Response to Starters After Broadcast Fertilizer ApplicationCorn response to fertilization and placement methods has always been a subject of interest and extensive research; however studies on soybean response to placement have been limited in Kansas. The objective of this study was to evaluate the effect of starter and broadcast fertilizer application on corn and soybean in a typical corn-soybean rotation in Kansas. Grain and seed yield, early growth, nutrient concentration and uptake were evaluated over eight site-years trials in Kansas for both corn ... |
10. Corn and Soybean Response to Sulfur Applications on Iowa SoilsHistorically sulfur (S) application has not been recommended on Iowa soils for corn and soybean production. Prior research has not determined a consistent need for S fertilization in Iowa, with field research indicating no corn or soybean yield response to applied S at virtually every site studied (Thorup and Leitch, 1975; Webb, 1978; Alesii, 1982; Killom, 1984; Sexton et al., 1998; Mallarino et al., 2000). The soil supply, in combination with sources such as manure and atmospheric deposition ha... |
11. 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 ... |
12. Crop Sensor-Based N Rates Out-Performed Producer-Chosen N RatesOptimal N fertilizer rate for corn (Zea mays L.) and other crops can vary substantially within and among fields. Current N management practices do not address this variability. Crop reflectance sensors offer the potential to diagnose crop N need and control N application rates at a fine spatial scale. Our objective was to evaluate the performance of sensor-based variable-rate N applications to corn, relative to constant N rates chosen by the producer. Fifty-five replicated on- farm demonstratio... |
13. Delivering Continuing Education to Ag Professionals- The Crop Adviser InstituteContinuing education is essential for agricultural professionals, whether required by a certifjmg organization or completed voluntarily as a supplemental educational opportunity. Agricultural continuing education has traditionally been delivered on-site, but temporal, geographical, and other constraints often prevent individuals from attending these courses. The Crop Adviser Institute (CAI) has been established to provide an alternative method of delivering continuing education. Implementation o... |
14. Developing a Natural Resource Web Site as a Training Tool for Students and AgronomistsSouth Dakota State University. Brookings SD Introduction South Dakota agronomists, agricultural workers, and students often require visual aids to demonstrate a field procedure or understand the interaction among natural resources that contribute to agricultural production. Suitable commercial products are available to serve this purpose, but they may be neither readily accessible to the public, nor particular to the state. An Internet site accessible to the public is required to display aspects... |
15. Effect of Biosolids Application On Plant Available NutrientsBiosolids are a by-product of municipal wastewater treatment process which is extensively treated to meet all applicable federal and state regulations so that they can it can be safely applied to land. Approximately, 7.9 million dry metric tons of biosolids are produced annually in the United States (U.S.) and over 55% of this amount is beneficially utilized through land application (NEBRA, 2007). Farmland application of biosolids is considered to be one of the most economical and environmentall... |
16. Energy and Nutrient SuppliesA study by the Potash and Phosphate Institute on 2.5 million North American soil samples has determined that soil nutrients have been withdraw without adequate replacement for several years. Soil fertility levels have dropped below optimum. At the same time, energy prices have skyrocketed, increasing fertilizer production costs. The presentation explains natural gas supplyfdemand, and how it affects both the price for natural gas and the production costs for fertilizers. The impact of this price... |
17. Enhancing Alfalfa Production Through Improved Phosphorus and Potassium ManagementAddition of phosphorus (P) and potassium (K) fertilizer is vital to maintain alfalfa productivity. The objective of this study was to examine how P and K fertilizer application increases alfalfa yield. nutrient use, and plant persistence. Replicate plots of P (0, 50, 100, 150 1bs P205/acre) and K (0. 100, 200, 300, 400 Ibs K20/acre) treatments were arranged in a factorial design. Forage harvests occurred four times annually for 5 years and yield, mass per shoot, shoots per area, and herbage nut... |
18. Estimating Second- and Third Year Nitrogen Availability from Dairy manure: It is common practice to repeatedly apply dairy manure to the same fields. To accurately assess the total plant availability of rnanure nutrients, it is necessary to account for the nutrients remaining in soil fiom previous years applications. A corn (Zea mays) field experiment has continued since 1998 on a Plano silt loam. Residual manure N availability was estimated for two and three years after a single rnanure application fiom differences in whole-plant N uptake using 1) fertilizer N equiv... |
19. Evaluation Of Macro and Micronutrients For Double-Crop Soybean After WheatWith double crop soybean production, fertilizer is typically applied prior to planting wheat and intended for both crops; when wheat nutrient removal is higher than expected this may limit nutrient supply for the following soybean crop. The objective of this study was to evaluate the response of soybean grown after wheat to soil-applied and foliar fertilization, including changes in tissue nutrient concentration, and response in grain yield. Four sites were established in 2011 and 2012. All site... |
20. Fertilizer and Manure Management Comparisons for Corn-Soybean Rotataions in MinnesotaA study was designed to evaluate the impact of P sources (fertilizer and manure), nutrient application methods (broadcast and subsurface bands), P rates (crop removal and twice crop removal), and tillage systems (no-till and conventional) on corn-soybean response. Results to date show higher yields using manure as compared to fertilizer as the P source. This could be attributed to a higher rate of P being applied using the manure. No-till systems measured greater yields in 1999 and 2000, primari... |
21. Hybrid and Plant Density Effects on Nitrogen Response In CornThe development of corn hybrids that may be improved for nitrogen use efficiency along with the emphasis on higher plant density for maximum yields of modern hybrids have raised questions about interactions between N rate and plant density. We planted four hybrids (Pioneer 33D49, 33K44, 33W84, and 34F07) to represent a range of responses to N rate and plant density at four sites in Illinois at combinations of densities of 44,460, 83,980, and 123,500 plants ha -1 and N rates of 0, 90, 179, and 26... |
22. Iowa Soil-Test Field Calibration Research Update- Potassium and the Mehlich-3 ICP Phosphorus TestIowa soil-test interpretations and fertilizer recommendations for phosphorus (P) and potassium (K) were last updated in 1999. The only change from previous recommendations (Voss et al., 1996; Voss and Mallarino, 1996) was to add interpretations for the Mehlich-3 (M3) P and K tests to existing interpretations for the Bray-1 P, Olsen P, and ammonium-acetate K tests (Voss et al., 1999). The interpretations for the ammonium-acetate and M3 K tests are similar because comparisons of amounts of K extra... |
23. Nitrate Leaching Characteristics for Various Nitrogen Management Strategies on Irrigated CornEfficient use of nitrogen (N) fertilizer for corn production is important for maximizing economic return to the producer and minimizing NO3 leaching to groundwater. This is especially important on irrigated, sandy soils due to the high infiltration and saturated conductivity and potential risk to the local water supplies. This study is being conducted to quantifL the NO3 leaching potential in the irrigated sands along Kansas' waterways under current and alternative N and water management strateg... |
24. Nitrous Oxide Emissions From Nitrogen Fertilizers In IllinoisNitrous oxide (N 2O) has a large global warming potential (GWP). Agricultural applications of nitrogen (N) contribute to N 2O emissions but it might be possible to mitigate such emissions through different N sources. We investigated the potential for anhydrous ammonia (AA), urea, and polymer coated urea (ESN) to mitigate N 2O emissions while enhancing corn (Zea mays L.) production. This three-year study was conducted in Champaign County, Illinois on highly productive mollisols during 2009 to 201... |
25. Organic Nutrient And Weed Management With Sweet Corn On Sandy SoilThe Central Sands region of Wisconsin is host to commercial-scale vegetable production, requiring intense nitrogen (N) fertilization. The limited nutrient holding capacity and minimal organic matter content of sandy soils in the Central Sands contributes to water nitrate contamination. Organic management may help to alleviate problems associated with leaching by increasing organic matter and nutrient retention in this soil. For organic agriculture to be feasible in this region, organic N inputs... |
26. Phosphorus Placement For Corn, Soybeans, and WheatRoot-Soil Interface Transport Pathways Three mechanisms are commonly cited for how nutrients reach plant roots: 1) root interception, 2) mass flow, and 3) diffusion. Root interception occurs when a plant root, as it grows, comes into direct contact with a nutrient. Quantities of nutrients reaching plant roots in this manner are estimated to be proportional to the volume of soil occupied by roots (Barber et al., 1963). For instance, if roots occupy one percent of the soil volume, then the quantit... |
27. Phosphorus Runoff From Incorporated and Surface-Applied Fertilizer and ManureContinued inputs of fertiher and manure in excess of crop requirements have led to a build-up of soil phosphorus (I?) levels, creating an environmental rather than agronomic concern (Sharpley et al., 1994). The objective of this study was to evaluate the effects of soil test P level, source of P amendments, tillage, and manure application method on P runoff from agricultural soils. The treatments consisted of swine manure surface applied and injected at rates of 29 and 59 Ib acre-' of P, and tri... |
28. 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... |
29. Plant Availability of Phosphorus From Struvite Produced During Corn Bioenergy ProcessingThere is strong interest on recovering nutrients from the waste stream of industrial processing of crop biomass for bioenergy so they can be efficiently utilized as fertilizer materials. Phosphorus (P) can recovered as struvite [NH 4Mg(PO4).6H2O] from the aqueous stream. A low P water- solubility in struvite and previous research with the pure mineral or struvite precipitated from liquid animal manure suggest a slow-release of P from struvite. However, a recent short-term greenhouse study in Iow... |
30. Poly-Coated Urea Responses For Winter Wheat In The Northern PlainsManaging nitrogen applications for winter wheat production and quality includes limiting N volatilization with surface urea applications in the northern Great Plains. Two winter wheat sites located in central and western (W) South Dakota were established in the fall of 2011. Treatments were broadcast poly-coated urea (ESN) and urea at different blend proportions applied at rates of 0, 40, 60, 80, and 100 lb N/a and two timings (fall and spring). An additional winter wheat site was established in... |
31. Predicting Fertilizer Nitrogen Response In Corn Following AlfalfaCorrect prediction and application of alfalfa N credits to first-year corn can reduce fertilizer N costs for growers, reduce over-application of N, and reduce the potential for water contamination. For decades, researchers have found that first-year corn following alfalfa often requires no fertilizer N to maximize grain yield. However, a review and analysis of nearly all the research on this topic in North America and Spain (442 site-years of research) indicates that corn following alfalfa can r... |
32. Recoverable Yield: A New Component for Improving Algorithms Used For Sensor Based Nitrogen Management In WheatIncreased interest in N management over the past decade has stimulated interest in using optical sensors to predict N needs in a number of crops. Many universities have created N recommendation algorithms for winter wheat, with slightly differing approaches. While many university algorithms operate under the assumption that 100% of the yield potential difference between the N rich strip and the farmer practice can be recovered, we believe that this will not always be possible. The objective of ... |
33. 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 (Cor... |
34. Remote Sensing of Corn Canopy Dynamics and Biophysical Variables Estimation in MichiganThis study was initiated to evaluate sensor-based nitrogen and water application for corn (Zea mays L.) in Michigan. The specific objectives of this study were: 1) to identi@ wavelengths that are more sensitive to N deficiency in corn, 2) to determine when to predict corn grain yield fiom spectral remote sensing data, and 3) to estimate biophysical variables ofcorn such as leafareaindex (LAI) and fractional cover (Fc) fiom spectral vegetation indices (SVI) obtained fiom radiometric measurements ... |
35. Response Surface Models Of Subsoil K Concentration For Loess Over Till Soils In MissouriCrop uptake of potassium (K) has demonstrated sensitivity to subsoil variation in K content. This fact has not been sufficiently considered in K management strategies in part due to logistical difficulties in sampling spatially variable subsoil K. We propose a simplified soil factorial model, a response surface, to enable site-specific accounting of whole root zone K supply for loess over till soils. We compared the performance of two peak functions and a non-parametric local regression procedu... |
36. Responses To K Fertilizer On High Testing SoilsSoil testing is the foundation for nutrient management decisions, and is based test method research and calibration models in the Midwest has been generated in the public sector by Land Grant Universities (LGU) over the last 75 years. The successes of soil testing over the past three decades has been in large part been due to the inherent value of the testing method, monitoring over time, and adoption of precision Ag technology. Soil testing for potassium (STK) in the Midwest, is based on the co... |
37. Soil Nitrogen Mineralization In Different Tobacco Tillage-Rotation SystemsSoil nitrogen mineralization, the microbial and biochemical transformation of organic N (e.g. proteins) into inorganic N compounds (e.g. NH 4+, NO3-), is of central importance to the nitrogen management and productivity of agricultural soil. Effects of different burley tobacco tillage and crop rotation systems on net soil N mineralization were studied, their correlation with soil organic matter, and the vertical distribution of mineralized N. Net soil N mineralization was measured by long-term ... |
38. 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 po... |
39. Soybean Response to Nitrogen ApplicationsSoybean yield increases due to N fertilizer have been reported recently, particularly for N applications during the reproductive stages. It is also known that nitrate inhibits nodulat ion and nodule activity and could potentially reduce yield. Our objective was to evaluate the effect of N fertilizer on soybean yield. Forty-six experiments were conducted with N fertilizer applied at times ranging fiom planting to late reproductive stages. Some experiments had significant positive or negative resp... |
40. Starter Fertilizer Application Effect on Reduced and No-tillage Grain Sorghum ProductionThis experiment was conducted at the North Central Kansas Experiment Field, located near Belleville, on a Crete silt loam soil. Soil test P was in the high@ range. Treatments consisted oftillage systems and starter fertilizer placement and composition. Tillage systems were no-tillage and minimum tillage (spring disc and harrow treatment). Methods of starter fertilizer application included placement 2 inches to the side and 2 inches below the seed at planting (2x2) and dribbled in a band on the s... |
41. Starter, Nitrogen Management and Nitrogen Calibration- Localizing Management PracticesWhen I first started consulting with some of the fertilizer dealerships in my area, they hired me to make them different from the dealership down the road. The best way to do this was to become a local expert on scientifically-based best management practices for growing corn and soybeans in my territory. This included knowing how best to manage nutrients to grow productive and profitable crops. University and soil test laboratory recommendations provided a good starting point. However, these dat... |
42. Strip till Nitrogen Placement, and Starter Fertilizer Effects on Corn Growth and YieldStrip tillage, a system where residue is removed and small ridges are formed in the fall in the position of next year's rows, has become an increasingly popular alternative to 0-till for corn in Illinois. Over three years and eight environments in Central and Northern Illinois, tillage had no effect on grain yield: conventional tillage, strip tillage, and 0-till produced 1 1.67, 11.67, 1 1.57 Mg/ha, respectively. There were also no differences in yield due to N timing, N placement, or starter fe... |
43. Sulfur Influence on Corn and Soybean Yields in Eastern South DakotaClean air legislation, the increasing use of conservation tillage, and the manufacture of phosphorus fertilizers without sulfur have all contributed to lowering soil sulfur (S) availability to crops. Soil S availability has been affected to some extent by all three issues in eastern South Dakota. Hilltop erosion has exposed subsoil in which the pH is higher and organic matter content is lower than at lower landscape positions. In some eroded shoulder positions of the landscape in no-till fields.... |
44. Sulfur Responses and the Wisoconsin Alfalfa Sulfur SurveyFor more than 30 years, agronomists, soil scientists, consultants and farmers have recognized the potential for significant responses to applied sulfur fertilizer in northern and western Wisconsin on lighter textured, low organic matter soils that had not recently received manure (Rand et al., 1969; Hoefi and Walsh, 1975; Schulte, 1976; Peters and Kelling, 1987). More recently, crop consultants and others have reported seeing sulhr responses on soils or in locations where they typically were no... |
45. Testing Field-Moist Soil For Potassium And Other Nutrients - What's It All About?Potassium (K) is present in the soil in water-soluble, exchangeable (both readily available for crops), non-exchangeable or fixed (may become available over time), and mineral (unavailable) forms. Estimates of soil exchangeable K with the ammonium-acetate and Mehlich-3 extractants from air-dried or oven-dried soil samples are the most widely used soil-test methods for K. These methods provide comparable K test results, and are suggested for the north-central region by the North-Central Regional ... |
46. The Effect of Tillage and P Fertilizer Placement on P Runoff from Sugar Beet Production SystemsThe objective of this study was to determine the differences in the amount of phosphorus (P) in runoff fiom land under sugar beet production caused by different management practices and phosphorus fertilizer placement. The study was set up as a split plot experimental design, replicated three times. The whole plot treatments were: 1 ) codsoybean rotation, with moldboard plow as primary tillage before soybean; 2) corntsoybean rotation, with chisel plow as primary tillage before corn; 3) sugar bee... |
47. Understanding Components To High Yielding Soybean Production SystemsThe increasing amount of products and techniques available to producers, coupled with increasing input costs, lends greater importance to the evaluation of management options for optimization of yield and economic return. This study was conducted to determine: 1) soybean yield potential when five additional inputs are combined in a high-intensity production system; 2) soybean yield impact of each additional input when removed from the high-intensity system; 3) soybean yield potential of each add... |
48. Update on the Illinois N TestEstimation of plant-available N is complicated enormously by the dynamic nature of soil N, owing largely to the effects of temperature and moisture supply on N-cycle processes. Numerous biological and chemical methods have been proposed as an index of soil N availability (Brernner, 1965; Keeney, 1982; Stanford, 1982; Bundy and Meisinger, 1994), but none has been adopted widely for soil testing. Biological methods are necessarily time-consuming because of the need for incubation, and the results ... |
49. Uptake and Leaching Potential Of Potassium And Sulfur When Split Applied For Corn on Irrigated SoilCoarse textured soils used in irrigated agriculture often face nutrient losses through the soil profile due to low cation exchange capacity (CEC). Split fertilizer application on sandy soils has been recommended for the corn crops in MN to avoid the leaching of fertilizers nutrients. Our study aimed to look at the potential for potassium and sulfur to be taken up or leached out in corn production. Two K and two S fertilizers studies were set up in Minnesota on coarse irrigated soils. Each site h... |
50. Use of Chlorophyll Flourescence Techniques to Detect Stresses in CornIncreased efficiencies in the use of water and fertilizer will require better methods of monitoring crop stress. This study was conducted to determine whether chlorophyll fluorescence was more sensitive to detecting water and nitrogen stress than chlorophyll meters in corn (Zea mays). The experiment was carried out near Shelton, NE in 2000, 200 1, and 2002. Treatments consisted of a factorial combination of 12 corn hybrids (1 1 Pioneer Hi-Bred internationali and B73 x M017), two water levels (de... |
51. Use Of Corn Height To Improve The Relationship Between Active Optical Sensor Readings And Yield EstimatesPre-season and early in-season loss of N continues to be a problem in corn (Zea mays, L.). One method to improve nitrogen use efficiency is to fertilize based on in-season crop foliage sensors. The objective of this study was to evaluate two different ground-based, active-optical sensors and explore the use of corn height with sensor readings for improved relationship with corn yield. Two different ground-based active-optical sensors (Greenseeker�, Trimble, Sunnydale, CA; and Holland Crop Cir... |
52. Use of Enhanced Efficiency Nitrogen Fertilizers To Reduce Leaching And Volatilization LossA laboratory study was conducted to explore interactions of N source and treatment with precipitation events on a coarse-textured soil. Nitrogen sources included urea-ammonium nitrate solution (UAN), UAN with additives of either nitrapyrin (Instinct �) or a carboxylated polymer (Nutrisphere-N�), or a polymer-coated dry urea (PCU) (ESN�). These products were applied to soil chambers which allowed measurement of ammonia (NH 3-N) volatilization or nitrate leaching over 31 days. Precipitation ... |
53. 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 in... |
54. Variable Nitrogen Rate ManagementIt is now more or less acknowledged that lime and N are potentially more profitable than P and K variable rate management. There is a lot of variability in optimal N rates within fields so that there is a need for variable N management. The benefits related to variable N management are generally ranked as: o Less N fertilizer used per unit yield. Savings of 15 USDIac on average for small grains. up to 41 USDIac. o Greater uniformity in crop stand, yield, grain humidity, specific weight and prot... |
55. Variable Rate Nitrogen Fertilizer for Corn Grown in KentuckyIn Kentucky, nitrogen recommendations for corn have historically been based on soil type. soil drainage class, and previous crop rather than on an anticipated yield or yield potential. Because of the growing popularity of yield monitors and GPS technology, corn producers are now accurately mapping yield variations within fields. A three year study was conducted in the karst region of western Kentucky to determine if past yield history (collected with a yield monitor using GPS) could be used as a... |
56. Variable Seeding Rates in Twin Row Planting and Micro Management of NutrientsA large scale study to determine if twin row planting, utilizing particular fertility concepts and conservational practices, out produces conventional methods of planting and fertilizing. The primary goal of the study was to increase fmer profitability and promote methods of conservational tillage. ... |
57. Varying Nitrogen and Seeding Rates of Corn Across Productivity Regions in FieldsA field study was conducted fiom 1999 to 2001 to determine the effects of variable seeding rates and variable nitrogen rates on corn (Zeu muys L.) in southern Ihois. In whole field experiments, variable seeding rates ranging fiom 18,000 to 38,000 seeds ac-' in 4.000 seed increments were planted in randomized strips (in a randomized complete block design) across the field that had soils with varying productivity based upon historical yield maps. From the yield data it was determined that the opti... |
58. Visual Correlation of Aerial Imagery with Topography and Crop YieldA study is currently being conducted on several farms to evaluate the usefulness of aerial imagery of soil and of a growing crop to delineate within-field management zones for the purposes of site-specific management. Presented is information for one site in Kent county Ontario for which correlations between aerial images taken of the soil and of the growing crop with the spatial patterns of measured topography, soil texture, and corn yield were examined. Visual interpretation indicated a very g... |
59. What Do Recent Plant Tissue Analysis Surveys In Soybean And Alfalfa Tell Us?Plant tissue analysis surveys were conducted for soybean in 2011 and 2012 and alfalfa in 2010 and 2011. Seventy-three random alfalfa fields throughout Wisconsin were sampled at bud to first flower prior to first or second cutting. For alfalfa, 49% of samples were low in potassium (K) based on sufficiency levels, and results were related to soil test K level and amount of K applied. Sulfur (S) was low in 62% of all alfalfa samples. This result was surprising, as only 18% of the fields were consid... |
60. Winter Rye Cover Crop Biomass Production, Degradation, And N RecyclingWinter rye (Secale cereale L.) as a cover crop can take up residual inorganic N between annual row crops and therefore be used to help reduce NO 3--N loss from fields and movement to water systems. However, does the rye N uptake affect N recycling to soil and add to plant available N? The rye carbon:nitrogen (C:N) ratio could also influence N recycling. The objectives of this study were to evaluate rye biomass degradation and N recycling after spring rye termination in a no-till corn (Zea mays L... |
61. Zinc Deficiency Response of Sorghum, Wheat, and CornZinc (Zn) deficiency in corn (Zea mays L.) is more common than in sorghum (Sorghum bicolor (L.) Moench) or wheat (Triticum sp.). The ability of wheat to withstand low soil Zn conditions is related to increased release of phytosiderophore, a natural chelate, fiom its roots. The reasons for sorghum's ability to utilize low levels of soil Zn have not been adequately explored. The objective of this research was to: 1) ascertain if Zn deficiency can be induced with sorghum, wheat, and corn grown in a... |