Proceedings
Authors
| Filter results24 paper(s) found. |
|---|
1. Residual Effects of P Fertiliration Lessons for the EightiesSeveral states in the North Central Region have established long-term phosphorus studies. These experiments were designed to evaluate the residual effects of P fertilizer and also generate P soil test calibration data in a situation where a range of soil test levels exist on one soil. These data are extremely useful for evaluating year-to-year fluctuations in crop response to soil test P and establishing response probabilities at a given soil test level. Valuable lessons can also be learned from... |
2. A Comparison of Point Injected and Knifed Phosphorus for Winter WheatThere are almost 2 million acres of winter wheat grown in South Dakota. Most is produced in the southwest part of the state on residual clay soils in a wheat fallow rotation with only limited, shallow sweep tillage. Very reduced tillage is necessary for wind and water erosion control, and water conservation on the long steep slopes. The continued use of shallow tillage on highly buffered, high pH soils has made broadcast phosphorus fertilizer inefficient in increasing wheat yields, even though phosphorus... |
3. The Soil Doctor- A Field TrialThe growing environmental concerns of the nation are causing some changes in production agriculture. One of the environmental areas receiving attention is NO,-N in the ground water. A number of universities and private companies have directed attention to this problem. The pre-sidedress nitrate test is the most common approach to reducing excess nitrogen application on corn in the humid eastern U.S. Several researchers have developed systems to use this test. Fields are sampled to a foot depth when... |
4. Role of Land Tenure-Other Factors in Soil P InterpretationsSoil test interpretation should recognize the residual value of applied PI the inherent limitations of soil P tests, and utilize an approach that can be easily personalized at the local level. These criteria were used to develop an interpretation approach utilizing a computer spreadsheet to estimate the optimum soil test level for an individual grower. The spreadsheet requires the following inputs: a calibration curve, acceptable marginal return, interest rate, land tenure, soil test buffer potential,... |
5. The State of the Art StartersInterest in reduced tillage has caused a resurgence in the use of starter fertilizer. Starter fertilizer research has been conducted on many crops across the country. The purpose of this paper is to highlight recent research on a variety of crops including corn. cotton, sorghum, soybean, canola, sugar beet, and potato. Increased yields from starter fertilizers are common in low P soils and several factors may lead to increased yields even when soil P and K levels are high. Geographic trends in yield... |
6. Corn Production as Affected by Daily Fertilization with Ammonium, Nitrate, and PhosphorusManipulation of N fertilization to control NH,+/NO,' ratios in the soil can affect corn (Zea mqs L.) growth and yield. Field study of these effects, however, has been difficult to conduct because nitrification of NH,+ andlor NO, leaching often occurs during the growing season. The objectives of this 4-year field experiment, were to investigate the effects of daily fertilization with various N sources and P on corn growth and yield. Pioneer 3343 was fertilized with solutions of urea (U), NH,CI, Ca(N03)2(CN),... |
7. Improving PSNT Based Sidedress N Recommendations for Corn with Site Specific FactorsThe pre-sidedress soil nitrate test (PSNT) has been found to be a valuable tool for improving nitrogen recommendations for corn grown in humid regions of the country. The PSNT has been especially useful for nunaging N on fmls where organic sources of N, like animal manures are important. This test was proposed by Magdoff et al. in 1984 and has been studied extensively since then (Magdoff et al., 1990; Roth et al., 1992; Fox et al., 1989; Blackmer et al., 1989; Klausner et a]., 1993, and Meisinger... |
8. Nutrient Management Following CRP- Concerns and On-Going ProjectsThe future of the Conservation Reserve Program (CRP) is uncertain as this paper is being prepared, however, most agree that at some point a significant acreage currently in CRP will be brought back into production. The peak of contract expirations for the 36 million acres of CRP will occur in the fall of 1996 with the first contracts originally due to expire in 1995 (Figure 1). Many of the Northcentral states have substantial CRP acreage's making post-CRP management an important topic for this region... |
9. Effect of N Fertilization on Accumulation and Release of Readily-Mineralized Organic NIncreased nitrogen (N) fertilizer use has generated concern about groundwater contamination by nitrate (NO,?. The objective of this work was to determine how previous N management and cropping system affect fertilizer N use efficiency. Research plots from a long-term N rate study on a silt loam soil were used to evaluate the impact of long term N rates on immobilization and mineralization of fertilizer N. Labeled '5~~,15~~, was applied at rates of 0, 60, 120, 180, and 240 lblacre to subplots of the... |
10. Predicting Plant Available Potassium using a Modified Sodium Tetraphenylboron MethodCurrent potassium (K) fertilizer. recommendations in the midwest are based primarily on the ammonium acetate exchangeable K (NH,OAc) soil test. In soils where nonexchangeable K comprises a major portion of plant available K, the ammonium acetate soil test is unreliable. Soil K extraction by sodium tetraphenylboron (Na-TPB) accesses both exchangeable and nonexchangeable K and mimics the action of K uptake by plant roots. A Na-TPB method utilizing a 5-minute extraction period is described, and the... |
11. Effect of Time and Rate of N Application on N use Efficiency and Surface Water Contamination with NitratesNitrate levels in excess of the public health standard of 10 mg N/1 in public water supplies along - with concern about hypoxia in the Gulf of Mexico have drawn renewed interest to improving fertilizer N use efficiency. Prior research has indicated that some farmers may be unkaowingly contributing to these problems. The objectives of this research were to: determine the effect of rate and time of N application on nitrate-N concentrations in water from tile lines and to evaluate the effect of previous... |
12. Phosphorus and Potassium Effects on Yield Components, Nutrient Accumulation and Persistence of Alfalfa (Medicago Sativa L.)Our objective was to determine why phosphorus (P) and potassiun~ (K) are essential for high yield by analyzing alfalfa yield components. Plots of P treatments (0, 25. 50, and 75 kg/ha) and K treatnients (0. 100, 200, 300, and 400 kgha) arranged in a factorial design were replicated four times. Forage was harvested four times per growi~lg season (1998-2000), and yield. mass per shoot, shoots per area. and herbage nutrient concentrations determined. In May and December, plants were dug to determine... |
13. The Illinois Nitrogen Soil TestNitrogen fertilizer recommendations for corn production are often estimated on the basis of a realistic yield goal, with adjustments to allow for N credits fiom other sources, such as legumes or manure. A yield-based recommendation may have merit on a long-term basis. but under- or over- fertilization is apt to occur in any given growing season since soil N availability is not taken into account. Insufficient application of N can have serious economic consequences for the farmer, whereas excessive... |
14. 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 represent... |
15. Impacts of Management, Moisture, and Phosphorus Form on Phosphorus Loss PotentialPhosphorus (P) is considered one of the major nutrients contributing to degradation of water quality in the United States. Our objectives were to examine P loss potential associated with: 1) high moisture conditions. 2) application (surface and incorporated) of manure from animals fed different diets and 3) sorption dynamics of inorganic and organic P compounds. The study of high moisture conditions evaluated the effects of near surface moisture conditions (wet and saturated), time (up to 28 days... |
16. 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... |
17. Use of Yield Goals for Providing N Rate Suggestions- General ConceptsRecent studies in the North Central region have shown a poor relationshp between optimum yield of individual sites and optimum fertilizer N rate (Sawyer et al., 2006). The outcome has been the development of fertilizer recommendation approaches that do not consider site yield goal (Vanotti and Bundy, 1994a; Sawyer and Nafiiger, 2005). This causes one to ponder how so many recommendation programs utilizing yield goal were developed in the fist place and have continued in use for more than 40 years.... |
18. 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, Agrotain,... |
19. 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... |
20. 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... |
21. Changes in Soil Test Phosphorus as a Function of Inorganic and Organic Phosphorus in Animal ManureUnderstanding how and why soil test phosphorus (P) levels increase with manure and fertilizer application is important to assist in improvi ng any nutrient management plan. An incubation study investigated the change in soil test P (STP) after 42 different animal manures (dairy, beef, swine, chicken, turkey, goat, sheep, and horse) or fer tilizer were applied at a rate of 40 mg total P kg -1 to 25 different agriculturally important soils of Wisconsin. Both liquid and solid dairy and swine manure... |
22. Using Soil Properties to Predict Soluable Phosphorus Losses from Indiana SoilsEscessive phosphorus (P) levels in surface water can degrade water quality by causing algal blooms and accelerating the eutrophication process. Agriculture has bceri implicated as a major nonpoint source of P, so many states have considered restricting P applications from inorganic fertilizers, manures, and other Pcontaining materials once soil test P levels esceed "threshold values". Relationships between soil properties and soluble P loss potential have not been welldocumcnted. This laboratory... |
23. Evaluation of Soil Test Methods and Crop Response to Phosphorus Fertilization in KansasWheat (Triticum aestivum) is typically considered the most responsive crop to phosphorus (P) fertilization in Kansas. This study was conducted to evaluate wheat response to P fertilization using modern genotypes and soil test calibration/interpretation for Kansas soils. The study was conducted during the 2018-2019 growing season with eleven locations in Kansas. Randomized complete block design was used for four different... C. Weber, D.A. Ruiz diaz |
24. The Alfalfa Yield Plateau: is Soil Fertility the Cause?Alfalfa is a perennial forage legume known for its ability to produce high quality hay, earning it the title the “Queen of Forages.” It is produced across the United States as feed for the beef, dairy, and equine industries. During the 1950s, alfalfa yields rose exponentially due to advances in technologies such as improved varieties, synthetic fertilizers, and pesticides. However, yields plateaued at approximately 3.3 tons per acre in the 1980s for reasons not fully understood and... W. Fleming, E. Ritchey, C. Teutsch, J. Grove |