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1. Phosphorus and Potassium Response In No-Till Corn and Soybean ProductionCurrent UWEX fertilizer recommendations and plant analysis interpretation guidelines were developed prior to the release of GMO corn. There is some concern amongst University soil fertility specialists and industry agronomists that corn and soybean response to P and K fertilizer applications may be different with modern corn hybrids and soybean varieties. In addition, in the UW recommendation system, an estimate of the amount of nutrients removed in the harvested portion of the crop is used to... C. Laboski, T. Andraski |
2. Improving Alfalfa Production in Wisconsin with Sulfur and Potassium FertilizerThe longevity and quality of an alfalfa stand is an essential component for Wisconsin�s dairy rotations. A study was developed to determine the effects of sulfur and potassium applications on the growth and development of alfalfa stands. The objectives of this study were to determine the effect of i) S fertilizer rate, timing and form on alfalfa yield, ii) recommended or no K fertilizer application on alfalfa yield on soils testing optimum or low for K, and iii) S and K application on soil test... |
3. Environmental Sulfur Sources as Inputs for Predicting Sulfur NeedsCrop responses to sulfur fertilization have been damstrated in mt states in the midwest, but the frequency of these responses is relatively lm. Sulfur deficiencies are usually confined to areas where one or mre of the follcrwing conditions exist: (1) Sandy or shallow soils; (2) Low soil organic matter content; (3) No recent manure applications; (4) Low atmospheric sulfur deposition; (5) High crop sulfur requirement. Although diagnostic tests to predict crop response to applied sulfur are an cbvious... |
4. Soil Nitrate Test Performance on Medium and High-Yield Potential SoilsImproved N recommendation methods for corn (Zea mays L.) are essential for increased profitability and reduction of potential N losses to the environment. A 4-yr study (49 site-yr) was conducted to evaluate the performance of preplant (PPNT) and pre-sidedress soil nitrate tests (PSNT) for predicting optimum N rates for corn at sites with inorganic and organic N inputs. Soil samples were obtained before planting (PPNT) and when corn was 6 to 12 inches tall (PSNT). and analyzed for nitrate-N. Corn... |
5. Nitrogen Availability to Corn Following Small GrainsNitrogen rate recommendations for corn are generally reduced following legumes compared to following corn or small grains. A 4-yr field study was conducted on a Plano silt loam soil in southern Wisconsin to evaluate the capability of soil NO3 tests to predict N availability to corn follo~b-ing small grains. Previous crop small grains included \vinter wheat, winter qe. and oats harvested for grain and straw. Nitrogen fertilizer was applied to corn at rates of 0 to 180 Ib/a in 30 Ib increments. Grain... |
6. 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... |
7. Manure and Tillage Effects on Phosphorus in RunoffPhosphorus (P) loss in runoff from cropland is an environmental concern because this P often promotes weed and algae growth in lakes, rivers, and streams. Water bodies with a large supply of nutrients (well nourished) are termed eutrophic. Eutrophic conditions can result in excessive algae and plant growth and when these weeds and algae die and decompose, dissolved oxygen levels in the water is depleted resulting in odors, fish kills, and a general degradation of the aesthetic and recreational value... |
8. 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 (Correll,... |
9. Corn Nitrogen Response Across Environments and Crop RotationRecent research on corn has tended to show variability in N response. Brown et al. (1993) reported that economically optimal N rates among 77 sites in Illinois ranged from zero to more than 200 lb N per acre. Results from other studies show similar variability in time and space. Even with such variability, results over environments have been combined and used to develop an N fertilizer rate guideline in Illinois based on anticipated corn yield (Hoeft and Peck, 2002). This guideline suggests providing... |
10. Evaluation of the Amino Sugar-N Based Soil test in Iowa Corn ProductionAn important improvement in estimating economic N applications for corn production would be to predict the soil N supply capacity each year. The objective of this research is to evaluate the adaptability and potential calibration of the amino sugar-N based Illinois N Soil Test in corn production fields across diverse Iowa soils. Nitrogen rate trials were conducted at multiple sites over several years, many on producer fields. Soil samples were collected at 0-6 and 0-12 inch depths in the fall and... |
11. Managing Continuous Corn for High YieldsMany "contest-winning" corn yields have historically been produced in fields where corn is grown continuously, often with extensive tillage, hgh soil test values of P and K, high N rates, and high plant populations. We are conducting a series of research trials at four sites in Illinois, in whlch we are varying tillage, fertilizer rates, and plant population in a factorial experiment at several Illinois locations. Over ten site-years to date, tillage deeper than normal increased yield at two site-years.... |
12. Scale of Measurement Effects on Phosphorus Runoff Losses from CroplandAs phosphorus (P)-based nutrient management planning becomes necessary for some farms in Wisconsin, it will be critical to have reliable, research-based planning tools. The Wisconsin P- hdex provides one method for preparing P-based nutrient management plans. The P-Index was developed largely from small plot-scale data showing the relationships between various site and management variables and runoff P losses. Thls study was conducted to compare runoff composition measurements at the subwatershed... |
13. 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... |
14. Skip-Row Configuration and Plant Density Effects on Sorghum Grain Yield and Yield Component in Southern NebraskaEqual spacing of sorghum rows typically results in the highest grain yield when soil water is adequate throughout the season, but skip-row plan ting may be a means to reduce water deficits during reproductive growth stages. We evaluated the effect of skip-row planting configuration and plant population density on grain yield, yield components and water use efficiency at five locations in a transect across southern Nebras ka where annual mean precipitation ranges from 300 to 900 mm yr -1. Three row... |
15. Nitrogen Recalibration for Wheat in North DakotaThe general formula for determining N fertilizer ra te in North Dakota for about thirty-five years has been N-rate = (2.5 X Yield Potential (or Yield G oal) less credits from previous crops and soil test nitrate-N from a 2-foot soil core composite. Historically high fertilizer N costs and the ability to fertilize within fiel ds rather than whole field N management has resulted in a reexamination of N calibration data, and an effort to expand the modern N calibration database with new field experiments.... |
16. Nitrogen Recalibration for Wheat in North DakotaThe rise in grain prices and fertilizer costs, as well as the need for more soil-specific recommendations has spurred recent research into N response of wheat in North Dakota. Combining data from 1970 to 1990, together with recent studies has shown that new recommendations are in order. There is a rela tionship of wheat yield to available N. The relationship is better when residual soil nitrate is considered. Different areas of the state partition out with different response curves. Using the 'return... |
17. Weed Control Timing Effects on Corn Yield Response to NitrogenNitrogen (N) rate guidelines for corn are under c ontinued scrutiny to maximize N use efficiency in order to minimize potential N losses to th e environment while maximizing economic returns to growers, especially with significant N fertilizer price increases in recent years. In-season crop stress can potentially affect corn N needs for optimum production. Recently, postemergence weed control has become more common with th e availability of glyphosate resistant corn hybrids. Delaying weed control... |
18. Nitrogen Recalibration for Spring Wheat and Durum in North DakotaNorth Dakota will begin using new fertilizer r ecommendations beginning Dec. 1, 2009. Previous recommendations required a yield guess by growers with no rega rd to economics of nitrogen application. The new recommendations recogni ze different N response curves with yield and grain protein within three state agri-climatology zones. The reco mmendations use the "return to N" method, which vary the N recommendation based on crop price and N costs. The resulting rate is adjusted based on... D. Franzen, G. Endres, J. Lukach, R. Ashley, J. Staricka, K. Mckay |
19. Effects of Sampling Time, Soil Moisture Content, and Extractant on Soil Test Potassium LevelsAn accurate prediction of plant-available pota ssium (K) requires a thorough understanding of the mechanisms that might impact soil test K. A three year field study was developed to determine relationships between soil test potassium (STK) levels and time of soil sampling, soil moisture content, and extractant. Five field sites were established in 2006 throughout Wisconsin at Arlington, Hancock, Marshfield, and Lancaster Agricultural Resear ch Stations, and a private farm in Fond du Lac county each... |
20. 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... |
21. 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 considered... |
22. Soil pH and Crop Response to Lime Source and TillageAg lime recommendations are based on soil pH, buffer pH, and neutralizing index or effective calcium carbonate equivalent (ECCE) of the lime to be used (Laboski and Peters, 2012). Determination of neutralizing index may vary by state and is often codified in state regulations related to the sale of ag lime. In Wisconsin, the neutralizing index of a lime is a function of purity (calcium carbonate equivalent) and fineness (particle size) (Schulte et al., 2005). Pelletized lime is typically calcitic... |
23. CORN YIELD AND NITROGEN USE EFFICIENCY RESPONSE TO WHEAT COVER CROP AND SPLIT NITROGEN APPLICATIONCorn (Zea mays L.) grain is a major commodity crop in Illinois and its production largely relies on timely application of nitrogen (N) fertilizers. Currently, growers in Illinois and other neighboring states in the U.S. Midwest use the maximum return to N (MRTN) decision support system to predict corn N requirements. However, the current tool does not factor in implications of integrating cover crops into the rotation, which has recently gained attention among growers due to several... R. Keshavarz-afshar, E. Jahanzad, M. Battaglia, Y. Luo, A. Sadeghpour, O. Adeyemi |
24. Precision planting impacts on winter cereal rye growth, nutrient uptake, spring soil temperature, and adoption costGrowing winter cereal rye (Secale cereale) (WCR) has been identified as an effective in-field practice to reduce nitrate-N and phosphorus (P) losses to Upper Mississippi River Basin (UMRB), USA. In the Midwestern USA, growers are reluctant to plant WCR especially prior to corn (Zea mays L.) due to N immobilization and establishment issues. Precision planting of WCR or “Skipping the corn row” (STCR) can minimize some issues associated with WCR ahead of corn while reducing... |
25. Carbon Credit and Sequestration in Agroecosystems; Lessons from Trials in Southern IllinoisA carbon (C) credit is the attribution of net CO2-C equivalent which can be used to decrease climate forcing through a given practice or farming system for a given unit time. Carbon credits allow industries to purchase C that is produced on a farm (i.e., offsets). Carbon can be captured in two ways; (i) by capturing and reducing greenhouse gasses (on a CO2-C equivalent basis), and/or (ii) by increasing soil organic C stocks. Therefore, to enable C credits in the agricultural... A. Sadeghpour, A.M. Weidhuner, G. Burkett, O. Zandvakili, O. Adeyemi, C. Kula, J. Berberich, J. Pike, A.J. Margenot |
26. Effects of Variable Nitrogen Fertilizer Rates on Corn Grain Yield, Profitability, and Nitrogen Losses in Southwestern MinnesotaGlobal crop production heavily relies on the application of nitrogen (N) fertilizers, which unfortunately comes with environmental concerns. The primary pathways N is lost to the environment is through nitrate leaching into groundwater, ammonia volatilization, and nitrous oxide emissions to the atmosphere. This ongoing study started in 2021 at the University of Minnesota Southwest Research and Outreach Center in Lamberton, MN, to comprehensively assess the effects of varying N fertilizer rates... Z.J. Aanerud, F.G. Fernández, R.T. Venterea, P.H. Pagliari, A.M. Cates, J.L. Nieber |
27. Corn Nitrogen Requirement in Winter Cereal Cover Crop Trials in Southern IllinoisWinter cereal cover crops, including wheat (Triticum aestivum L.) and winter rye (Secale cereale L.) are recommended as the best in-field management strategy by the Illinois Nutrient Loss Reduction Strategy (INLRS) to minimize nitrate-N leaching to the Mississippi River Basin and the Gulf of Mexico. We evaluated the effect of wheat and winter rye on corn grain yield, and nitrogen (N) requirement. Treatments were laid out in a randomized complete block design with four replicates... A. Sadeghpour, O. Adeyemi, O. Guzel, C. Kula, J. Mcgrath, G. Sener guzel |
28. Does Sensor-based Nitrogen Management Maintain Crop Production and Decrease Nitrate-N Leaching?To improve water quality, nitrogen (N) management in corn production systems should shift from current N decision support system [maximum return to N (MRTN)] which suggests a single rate N addition to sensor-based (GreenSeeker) active N management (variable N rate approach). Single rate N recommendations often result in under- and over-N addition and either increase environmental N losses or cause corn yield penalty. Our objectives were to evaluate corn optimum nitrogen N requirement (EORN) in... A. Sadeghpour, M. Guzel, J. Mcgrath, O. Adeyemi, B. Arnall, O. Guzel |
29. Does Nitrogen Fertilization with Manure Injection Versus Surface Application Influence Corn for Silage and Winter Rye Yield, Quality, Phosphorus Balance and Soil Test Phosphorus Over Three Years?Switching from nitrogen (N)-based to phosphorus (P)-based manure management has been shown to decrease P loss to the environment allowing for sustainable P management in dairy farms. At high P soils, dairy farmers often surface apply the liquid manure to corn (Zea mays L.) for silage at the P-based rates and supplement the limited N to corn with N fertilizers to ensure optimum crop production. With high fertilizer prices, one solution to reducing the N requirement of corn could be to... A. Sadeghpour, G. Burkett, S. Babaei, O. Adeyemi, K. Vaughn, C. Kula |
30. Nitrogen Rate and Harvesting Time Based on Growing Degree Days Influenced Winter Cereal Rye Morphological Traits, Forage Yield, Quality, and Farm Profit in Poorly Drained AlfisolsWinter cereal rye (Secale cereale L.) (WCR) is often double cropped with maize for silage (Zea mays L.) to increase farm forage supply and profit. Spring nitrogen (N) fertilization to WCR could influence its production and quality at different harvesting times. Therefore, two on-farm trials were conducted in the 2019-2020 and 2020-2021 growing seasons to evaluate the effect of harvesting time (late-March to end-of-April considering the growth stage) and spring N fertilization... G. Burkett, K. Vaughn, O. Adeyemi, O. Zandvakili, M. Battaglia, S. Babaei, J. Nair, S. Still, A. Sadeghpour |