Proceedings
Authors
| Filter results24 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. Tolerance to Low pH- Soluable Aluminum by Winter Wheat Grown in KansasThe majority of Kansas soils are relatively young ic terms of geologic development. Low pHs and the need for liming are not common in other than the eastern third of Kansas. In South Central Kansas, isolated very low pK's have been reported in fields predo~inantly cropped to continuous wheat since the late 1970s. However, in the past three to four years, an increasing number of low pH soils have been reported. A summary of the soil test results from the KSU Soil Testing Lab by year shows a dramatic... |
3. Bandded Phosphorus Applications to Winter Wheat - 1985-86While many producers recognize the importance of a sound P fertilization program for profitable wheat production? there are many potentially responsive wheat acres not receiving any fertilizer P - resulting in reduced grain yields and farmer profitability. over the years there have been many research studies conducted by land grant Universities throughout the Great Plains indicating the importance of fertilizer P applications for wheat production on low P testing soils. In the mid to late 1970's... |
4. Compaction - K Fertility Interactions in Corn ProductionSoil compaction is recognized as a significant factor affecting yield in crop production today. The pressure to produce crops profitably has often led gruwers to farm greater acreages, with larger equipment under soil conditions which favor compaction. Effects of compaction are not limited to the surface lay- of a soil but often may be apparent cut much of the root zone. With the interest in soil compaction and its effects on crop growth, a research project was initiated to accomplish the fol lowing... |
5. Phosphorous Management for Wheat ProductionProfitable wheat production depends on many factors, including a sound phosphorus (P) management program. Except for sunlight and water, soil fertility generally represents the most limiting factor in crop yields. Even with perfect weather and climatic conditions, a farmer that does everything right except to meet the nutrient needs of the crop will never reach optimum yield potential. Water, N, and P are generally the dominant yield limiting factors for wheat in the United States. Potassium, S,... |
6. Alfalfa Responses to PotassiumThe potassium requirement of alfalfa is greater than that for any other nutrient. Potassium influences several systems within alfalfa plants including enzyme activity, carbohydrate production and transport, stornatal activity, photosynthesis through chlorophyll content and C02 exchange rate, and nitrogen fixation. Excellent reviews on the role of K in physiological processes are provided in the most recent potassium monograph (Munson, 1985). Potassium also markedly influences alfalfa agronomically... |
7. Phosphorus Management on Extremely Acid Soils in South Central KansasResearch was conducted to evaluate the effectiveness of phosphate fertilizer in reducing the toxicity of soluble aluminum (Al) on very acidic soil for production of winter wheat. Banded P fertilizer increased wheat grain yields significantly with the response being greater on unlimed compared to lime conditions. Based on the findings of this research coupled with Oklahoma State University research, banded P is an alternative to liming for wheat production on extremely acidic soils with considerable... |
8. Crop Residue and Fertilizer Management Effects on Soybean, Wheat, and Grain Sorghum in Eastern KansasRemoval of crop residue is being considered for many non- agricultural uses. The agronomic consequences of these practices are not fully known, especially for different levels of fertilizer management. An experiment was begun in eastern Kansas in 1980 to determine the effects of returning different levels of crop residue on soil properties and crop yields in a soybean-wheat-grain sorghum rotation, fertilized with different amounts of N-P-K fertilizer. Crop residue treatments included residue removed,... |
9. Fertilizer Recommendations- Fact or FictionFertilizers are all important and expensive part of the crop production systenl in Indiana. Indiana farmers spend nearly a half billion dollars each year on fertilizer and lime. The question is. is this expense really nccessary? Farmers obtain fertilizer reconlmendations from a number of sources. Soil testing labs. fertilizer dealers. crop consultants and extension all make fertilizer reconunendations. In many cases the reconlmendations are quite different. Is there a valid reason for these differences... |
10. Flooded Soil Syndrom and P Deficiencies on Four Iowa SoilsSeveral million acres of Midwest cropland were inundated during the floods of 1993. The length of inundation was from a few days to several months. In some areas growing crops were drowned out and other fields could never be planted. As the water receded and acres of barren ground were exposed, the reality of the disaster gave way to concerns for the 1994 crop and the development of Flooded Soil Syndrome. Flooded Soil Syndrome produces' symptoms similar to Fallow Syndrome which was originally identified... |
11. Grid Soil Sampling for Precision and ProfitSite specific management of plant nutrients for crop production begins with an inventory of soil test levels in a field. Fertilizer recommendations are based on the expected response to addition of fertilizers as a function of soil test levels. Therefore, the accuracy of site specific fertilizer applications depends on the precision of the soil test map from which the fertilizer recommendations are based. Precision usually increases as fields are divided and sampled as smaller areas. Mapping accuracy... |
12. Horse Manure ManagementIt is common in the United States to find large concentrations of horses being stabled in suburban counties, immediately adjacent to large cities. Wood sawdust is one of the most common bedding materials used for horses. The high CIN ratio present in horse manure and hardwood sawdust mixtures makes this material problematic for use in agronomic or horticultural production. The high CIN ratio can induce a nitrogen deficiency in growing crops, due to the inmobilization of soil nitrogen by micro-organisms... |
13. Soil pH and Corn-Soybean Rotation Yield Responses to Limestone Applications and TillageFarmers growing corn and soybean in northwest Iowa must carefully consider liming needs and economics. This is because of high liniestone material cost and the fact that soils in northwest Iowa have high pH subsoil, which can moderate negative effects of acid surface soils. Another factor that must be considered is the variable effect from limestone mixing depth associated with different tillage systems. An experiment designed to evaluate six rates of aglime (0 to 6,000 Iblacre of effective calcium... |
14. Adjusting N Recommendations Based on a Previously Grown CropNitrogen recommendations in North Dakota are based on a yield goal multiplied from some empirically derived factor in a linear formula. There are a three adjustments to the N recommendations that result form these formulas (Franzen and Cihacek, 1996). They are the soil test nitrate-N to some depth, a sampling date adjustment ifthe sampling was conducted in the fall prior to September 15, and a previous crop credit. Two of these three adjustments are based on some knowledge regarding mineralization... |
15. 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... |
16. Cropping Systems Management Effects on Soil N Mineralization DynamicsChanges in soil organic matter (SOM) content due to cultivation also impacts the amount of indigenous soil nitrogen (IN) supply. Crop management practices designed to achieve high yields also result in high residue inputs, which can contribute to SOM build up and enhanced indigenous N supply. The objective of this study was to evaluate the long term effect of crop rotation and nutrient management in conventional and intensive maize based systems on the change in soil N supply. Soil samples fiotn... |
17. Silage Specific Corn Hybrids for Silage Production in KentuckyFour corn hybrid types at three plant densities and two nitrogen rates were evaluated for forage yield, forage quality and ensiled quality. The four hybrid types included nutri-dense (ND), waxy (WX), leafy (LF), and dual-purpose (DP); while the three target plant densities were 54 000, 68 000, and 81 000 plants ha; and the nitrogen rates were 134 and 224 kg ha". WX consistently had low forage and grain yields compared with the otl~er types. When averaged over nitrogen rate and hybrid: plant density... |
18. Time of Harvest Alters Nutrient Management of SwitchgrassSwitchgrass is one of many cellulosic crops bei ng considered as a biomass feedstock for the production of bioenergy, including ethanol. It is being promoted as a crop that can grow well on marginal lands with low nutrient inputs as well as on more fertile soils. Nutrient removal is important for long-term perennial crop production. A study, establishe d to evaluate the effects of nitrogen rate and harvest management system, was used to evaluate the nutrient removal in switchgrass harvested at different... |
19. Nitrogen Management of Temporary Waterlogged Soil to Improve Corn Production and Reduce Environmental N LossDuring the 2011 growing season excessive soil moisture in the Unites States accounted for at least 30% of the total crop loss to environmental stresses resulting in more than $3 billion dollars in insurance indemnities paid to farmers. The objectives of this study were to: (i) assess grain yield and N silage uptake for both rescue and non-rescue treatments of different enhanced efficiency products, (ii) determine soil N content among treatments throughout the growing season, and (iii) evaluate PCU... |
20. Does Starter Fertilizer Benefit Late Planted Corn?Starter fertilizers are used by producers to help overcome wet and cool soils often encountered with early planted corn. Early planted corn in no-tilled fields and limited drainage typically have the greatest chance of response from starter fertilizers. Starter fertilizers can range from a mixture of UAN, ammonium polyphosphate (APP), and other fertilizers to low salt (LS) formulations containing N, P, K and various micronutrients. Some that promote LS starter fertilizer products claim that UAN... E. Ritchey, H. York |
21. Evaluation of Plant-Available Phosphorus of Dried Residuals from Wastewater Processed for Phosphorus Reduction with Aluminum or IronABSTRACT Wastewater effluent from industrial and municipal water treatment plants requires phosphorus (P) removal before being discharged to surface waters. The resulting residual materials, with elevated P concentration, are usually land applied. Basing P application rates on the nutrient value for crops is the most rational way to utilize this P resource because it would improve farmers economic return while... |
22. 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 |
23. High Gypsum Application Rates Impacts on Iowa Soil Properties, Dissolved Phosphorus Loss, and Crop YieldGypsum (calcium sulfate) is a common sulfur (S) source for crops and rates in the northcentral region seldom are > 250 lb/acre. It is known that even higher gypsum rates do not raise soil pH. Research in eastern or southeast states showed that in some conditions high gypsum rates can improve other chemical or physical properties and can reduce dissolved phosphorus (P) loss from fields. However, little research has evaluated potential benefits in prairie-developed soils of Iowa and the region.... A.P. Mallarino, M.U. Haq |
24. Pelleted Lime Application Strategies for Iowa Corn and Soybean ProductionResearch has shown inconsistent results about the efficiency of pelleted lime at increasing soil pH or crop yield compared with aglime. Our previous Iowa research (2015-2016) showed that pelleted lime manufactured with limestone from northern Iowa quarries attained maximum soil pH with the same rate and at the same time than finely ground calcium carbonate, but more time was needed for aglime. However, there were no yield differences between the sources for corn-soybean rotations when one-time... A.P. Mallarino, M.U. Haq |