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1. Water Quality Issues in NebraskaThe primary water quality issue in Nebraska at this the is related to groundwater as opposed to surface water. Groundwater provides irrigation for over 7 million acres of land in Nebraska and is the drinking water source for almost a1 1 of Nebraska's domestic and municipal water users. In rural areas groundwater provides about 85% of the drinking water (Cast, 1985). Numerous reports of groundwater contamination led to its emeqence as a major environmental issue for the 1980,s. Govenrment agencies... |
2. Improving Nitrogen Recommendations in NebraskaSoil nitrate tests offer a unique opportunity to fine tune our nitrogen management into the 90's. Nebraska has had a long history of research and extension programs using soil nitrate levels to modify fertilizer nitrogen recommendations. Because of our climatic regime nitrate tests work well across the whole state. We have a large data base on research plots that shows the tests are very effective. A large number of farmer demonstrations conducted over the last 10 years also show that the technology... |
3. Effects of Residue Management on Fertilizer use Efficiency on Corn in the Western Corn BeltInterest in residue management began in parts of the Great Plains following the "dirty thirties" when the government responded to wind and water erosion problems by creating the Soil Conservation Service. Stubble mulch in winter wheat production areas evolved into no-till as herbicides becan~e available. Interest in limited or no till systems in the Corn Belt began in the 1950's. Higher residue levels are required to reduce erosion while maintaining soil productivity but an additional reason is the... |
4. Assessing the Variability of Corn Response to NitrogenBecause results of experiments designed to test the response of corn to N rate tend to vary considerably with the environment. repetitions of such studies over time are essential. It is not clear, however, what number of repetitions are needed in order to deduce sound recommendations for application of N fertilizer to succeeding crops. We used the results from 16 years of a crop rotation x N rate study conducted at Monmouth, Illinois to assess the effect of duration of such an experiment on the stability... |
5. On-The-Go Sensors for variable rate Nutrient Management- Determining Soil K Status with a Flat-Surface Ion-Selective ElectrodeTraditional soil sampling approaches are frequently not sufficiently spatially dense to characterize within field variability in soil fertiiity. Recent technology advances have demonstrated the feasibility of using automated soil sampling systems and tractor mounted sensors to create nutrient availability maps from more continuous measurements. Our objective was to determine if a flat-surface ion selective K electrode could measure soil K status at field moisture content. Twenty-four agricultural... |
6. Field Estimate of Dairy Manure Nitrogen Availability to PotatoesWithin Wisconsin, there is a distinct movement toward dairy herd expansion and consolidation of small farms. With the increase in manure production, these large dairies are considering various land and manure management arrangements with non-livestock farmers, such as potato producers. The purpose of this study is to evaluate several potato production issues resulting from such partnerships including the availability of dairy manure nutrients to potatoes. Nitrogen and phosphorus availability were... |
7. 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 data... |
8. Providing Flexibility in P and K RecommendationsHistorically, land grant Universities have generally provided a single rate recommendation for nutrients such as phosphorus (P) and potassium (K). Depending on the particular University in question, these nutrient rate recommendations are generally based on two widely recognized approaches to managing soil and fertilizer P and K - the nutrient sufficiency approach and the build-maintenance approach. The goal of a nutrient sufficiency based soil fertility program is to apply just enough P andior K... |
9. 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... |
10. On-the-go Sensing Technology for Improved Crop Nutrient ManagementOne of the major objectives of precision agriculture technologies is the site-specific management of agricultural inputs to increase profitability of crop production, improve product quality, and protect the environment. Information about the variability of different soil attributes within a field is essential to the decision-making process. The inability to obtain soil characteristics rapidly and inexpensively remains one of the biggest limitations of precision agriculture. Numerous researchers... |
11. 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 this... |
12. Better Maize Response to Optimal Fertilizer PlacementIncreasing trends in corn (Zea mays L.) yields require greater levels of applied nutrients per acre to maintain or increase yields; thus, we need to rethink how to best supply a crops⤙ required nutrients. One significant challenge associated with applying more fertilizer to support greater yields has been the negative environmental effects of increased levels of some nutrients, such as phosphorus. Fertilizer application technologies such as banding the fertilizer below the plant increases... |
13. Corn Nitrogen Evaluation in South DakotaCurrent Nitrogen (N) recommendations for corn in South Dakota use an N rate calculator approach (yield goal x 1.2 ⤓ soil test Nitrate-N (0-2 ft) ⤓ legume credits ⤓ other credits such as manure application or N in starter fertilizers + 30 lbs N/a for no-till). The N coefficient has been modified in the past from 1.45 in 1975, to 1.3 in 1982 and currently 1.2 determined 1991. The N coefficient is in dire need of re-evaluation because... A. Bly, S. Berg, P. Sexton, R. Gelderman |
14. Evaluation of Phosphorus and Potassium Fertilization on Corn and Soybean Yields and Soil Test Levels in OhioThe most recent fertilizer phosphorus (P) and potassium (K) recommendations for corn and soybean grown in Ohio were established in the mid-90s and research is required to verify the appropriateness of these recommendations after 20 years. In this study, corn and soybean rotations were established and maintained at three sites from 2006 to 2014 and fertilizer P and K were applied at 1) zero rates, 2) estimated nutrient removal rates and 3) twice the estimated nutrient removal rates for each rotation.... |
15. Evaluation of Soybean Response to Micronutrients using Strip TrialsLimited studies are available on soybean response to micronutrients and particularly in field- scale strips. The objective of this study was to evaluate soybean tissue response to micronutrient fertilizers in fields with high soil variability. The experimental design consisted of two strips, an unfertilized and fertilized replicated three times. The treatments included an untreated control and a blend of Cu, Mn and Zn at a rate of 10 lb acre -1 and B at a rate of 2.5 lb acre-1. Soil samples were... |
16. Integration of Ultrasonic and Active Canopy Sensors to Estimate the In-Season Nitrogen Content for CornThe objectives of this research were to: (i ) determine the correlation between active canopy sensor (ACS) assessments of N status and ultr asonic sensor measurements of canopy height at several growth stages for corn receiving varying am ounts of N, (ii) test the ability of both sensors to distinguish N-mediated differences in canopy development and (iii) test the integrated use of both sensors. This experiment was conducted with varying N rates in an existing long-term study and farmer's fields... |
17. Alternative Approaches to Making Fertilizer RecommendationsThe objective of this research project was to evaluate, both agronomically and economically. some common altcrnative methods of making fertilizer recornmcndations for corn, soybeans, and soft-red winter wheat used in Indiana. Over a period of six years ( 1992- 1997) the effect of seven alternative fertilizer recommendation philosophies on soil test levels, crop yields, plant tissue analysis, and fertilizer additions were measured in an attempt to determine differences in performance between these... |
18. Basic Concepts of Soil Acidity and LimingMost midwestern soils require periodic applications of aglitne or other liming materials for optimum crop production. Liming has several beneficial effects: I ) it reduces harmhl or potentially tosic conditions which can develop in acid soils; 2) it increases the availability of some of nutrients: 3) it replaces the supply of calcium and magnesium essential for plant growth which is depleted as soils become acid; 4) it ensures favorable conditions for the activity of certain herbicides; and 5) it... |
19. Nitrogen Source and Timing Effects on CornThe 4R’s of nutrient management call for the right source, applied at right time, at the right rate at the right placement. Producers in South Dakota ask when the correct time to apply nitrogen fertilizers. Mean annual precipitation in the major South Dakota corn growing areas ranges from 16 to 26 inches. This is a relatively dry climate compared to other major corn growing regions and the effect of nitrogen timing might not be as important. Therefore, a research question that challenges... A. Bly, S. Berg, D. Karki |
20. Estimation of Nitrogen Losses from Char Amended Fertilized Soils: a Laboratory StudyMore than 50% of nitrogen (N) fertilizer added to agricultural soil is lost to the environment through volatilization, denitrification, and leaching. Proper management of soil carbon (C) may reduce N losses since soil C affects soil properties and N cycling. There are a wide range of soil C management practices, including direct addition of high C content materials to the soil. A 30-day laboratory study was conducted to evaluate effects of char on N losses from fertilized loam and sandy loam soils.... D. Panday, B. Maharjan |
21. Identifying Which Management Factors Have the Greatest Impact on Soybean YieldsSoybean [Glycine max (L.) Merr.] grain yields are the final products of numerous factors that affect crop growth and development during the growing season; therefore, it is critical to understand the interactions of these factors evaluated as a whole in order to efficiently maximize yield and exploit the yield potential of modern soybean varieties grown under increased levels of management. The objective of this experiment is to evaluate the synergies between several management... T. Beyrer, F. Below |
22. Arbuscular Mycorrhizal Fungi and Their Role in Modern AgricultureArbuscular mycorrhizal (AM) fungi are obligate symbionts of over 90% of land plants, including most of the worlds economically important food crops. This symbiosis is believed to have evolved some 400 million years ago concurrentwith land plant flora to assist in phosphate uptake, an ion of poor mobility in soil. A key feature of the symbiosis is the ‘arbuscule’, a fungal organ that penetrates root cortical cells and forms a convoluted peri-arbuscular membrane of large surface... R. Drijber |
23. Effect Of High Carbon Char in Conjunction with Composted Manure and Urea on Corn YieldAn integrated approach to optimize fertilizer input through use of high carbon char (also called cinder), a by-product from a local industry in Western Nebraska, was set up for determination of optimal rate of char along with a given nitrogen (N) fertilizer or composted manure on corn (Zea mays L.) yield. Char is a potential soil amendment, since it contains around 30% total carbon (C) in addition to many essential plant nutrients. The experiment was started in 2016 in sandy loam... D. Panday, B. Maharjan |
24. Tillage, Crop Rotation, and Cover Crop Impact on Corn Nitrogen Requirements in Southeastern South DakotaNitrogen is the lifeline of corn production. There is uncertainty whether nitrogen (N) requirements are the same for corn raised under long term no-till versus conventional till production systems. The objective of this study was to evaluate N fertilizer requirements for long term no-till soils in southeastern South Dakota, while considering effects from cover crops and crop rotation. This was a two year study at the SDSU Southeast Research Farm near Beresford, SD on long term no-till plots established... S. Berg, P. Sexton, R. Gelderman, A. Bly, C. Derdall |
25. Do Soil Tests Predict Yield Response to Phosphorus in Modern Corn and Soybean Production?Modern corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] production systems produce higher yields, and consequently, may remove more nutrients than fertilizer rates based upon existing soil test recommendations for these yields. With greater emphasis on soil test levels for nutrient stewardship strategies, soil tests need to also predict critical levels in which fertilized nutrient responses are likely. Current soil test recommendations for Illinois have negligibly... T. Beyrer, F. Below |
26. Corn Nitrogen Calibration in South DakotaSouth Dakota (SD) corn nitrogen (N) rate recommendations were last established in 1991 and based on the coefficient of 1.2 lbs N/bu of the yield goal. The South Dakota corn N rate calculator subtracts the pre-plant soil test NO3-N (0-2ft) and legume credits and adds 30 lbs N/a for recently established no-till. Much improved corn genetics, shifting farming practices, and climate changes warrant re-calibration of corn N rate recommendations. During 2013-2105, N rate studies were conducted at 20... A. Bly, S. Berg |
27. Effects of Applied Soil Micronutrients on Corn and Soybean Yields in Eastern South Dakota EnvironmentsMicronutrients although taken up by plants in small quantities, their deficiencies can have significant detrimental effects on grain yield. As growers aim for maximum corn and soybean yields, availability of micronutrients in agricultural market both as individual source or combined with other secondary nutrients have also increased. However, effects of micronutrients on corn and soybean grain yields are not well documented for South Dakota (SD) soils, and growers seem to be concerned if application... D. Karki, A. Bly, S. Berg |