Proceedings
Conference
| Filter results39 paper(s) found. |
|---|
1. A Nitrogen Soil Test for CornIn the past decade, many states have started including a soil test when making N recommendations. In order for a soil N test to be useful, it must provide information that is not known or incorporated when making N recommendations without a test. If a test does not provide explainable, qunlltifiable infarmation. the tcs: !cses its usefghess. In Minnesota, a falllspring preplant N test has been used in the western tier of counties, which have lower rainfall than the rest of the state, for many ye... |
2. Agricultural Impact on Groundwater QurlityThere has been an increasing awareness within Iowa of the impact of agriculture on groundwater quality. The data of Iowa Geologic Survey scientists from studies in northeast Iowa have focused attention on the Big Spring Basin area. A project to intensively study groundwater in the Big Spring Basin is underway. The project includes the active cooperation and participation of the following agencies: ISU Agricultural Experiment Station, Clayton County Soil Conservancy District ISU Cooperative Exten... |
3. 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 agronomical... |
4. An Overview of the Thompson/Baker Farming Systems StudyThere is a general lack of quantitative information, collected from field-scale studies, that can be used to assess long-term effects of alternative farming systems. The objective of an on-going study in central Iowa is to quantitatively evaluate several chemical, physical, biological, and economic parameters on the Richard Thompson (alternative) and Eugene Baker (conventional) farms. This project was initiated in 1989 on adjacent 32-ha tracts of land, that have Clarion loam, Nicollet loam, Cani... |
5. Application of the Ceres-maize Model to Maximum Yield ResearchMaximum yields are obtained when as much assimilate as possible is partitioned into the grains of corn. The amount partitioned into the grains depends on several major factors. Grains per unit area is probably the most important of these factors. Other important considerations for grain filling in- clude the duration of the grain filling period, the amount that can be repartitioned from stem storage to the grains, the photo- synthesis rate, and the temperature. Several factors influence the numb... |
6. Assessing the Source of Groundwater Nitrates- And You Thought Good Wine Took TimeControversy continues with elevated groundwater nitrate concentrations being attributed to N fertilizer use. Current research defining best management practices in farming system K management seldom addresses the influence these practices have on groundwater. Why? The results of this Missouri research show that the influence of management on groundwater nitrates may last for decades. The study provides support for time requirements when assessing farming system impact on groundwater quality. ... |
7. 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... |
8. Certified Crop Adviser (CCA) ProgramThe Certified Crop Adviser (CCA) Program is being developed under the auspices of the American Society of Agronomy (ASA). The ad hoc steering committee is comprised of industry and university agronomists, state dealer associations, independent crop consultants, several organizations (including T.F.1, P.P.I., ARA, TVA) and ASA staff. This is a broad group representing wide geographic parts of the U.S., and has also included USDA officials, representing SCS and Extension. The purpose of the CCA pr... |
9. Economic Optimum Rates of N for Corn Production in IowaProper nitronen (N) fertilizer is essential if crop producers are to maximize profits and minimize environmental contamination. A study to determine 'economic optimum N fertilizer rates was conducted in Iowa from-1987 to 1991. The results show that Iowa crop producers over-applied N during those years primarily due to not considering residual N in the soil. This was especially true following the drought year of 1988.... |
10. Educational Applications of Digitized Soil SurveysThe North Dakota Agricultural Experiment Station Soil Survey of McHenry County Organized Irrigation Districts is approaching publication and represents a first for soil survey in North Dakota. The decision was made to digitize the soil maps to facilitate acreage tabulations and improve methods of generating soil interpretations. While the digitization procedure is costly in terms of start-up labor (programming) and data entry, the benefits allow more flexibility than conventional soil surveys. T... |
11. Effects of Residue Density Levels on the Response of No-till Corn to N Fertilizers and InhibitorsExperiments were conducted from 1989-91 at tho southern Illinois locatio~ls (~elle\?ille and Car*bcrndale) to evaluate the effect of residue levels un the perfor-mance of N fertilizers, urease inhibitors, and placenient on the response of no-till conl. Levels of 0, 50, 100, and 200 percent of existing (pre-plant) amounts were established in the crop residues of previous corn. Kitrogen fertilizers were urea-ammonium nitrate (UAN) solution (dribble, injection. and split-applied) and urea (broadcas... |
12. Evaluation of Three N Recommendation Systems for Corn Yield and Residual Soil NitrateProper N application rates are required for continued economic and environmental viability of U.S. agriculture. Application at rates below that required for economic optimum will place U.S. farmers at a competitive disadvantage in the world market. On the other hand, excessive rates of N fertilizers may result in contamination of ground water. ... |
13. Fertilizer Use Vs. Crop ProfitsGrowing crops in farming is a complex that large investments in land and equipment, as well as considerable borrowing of money for capital. With these costs and low commodity most keenly of continuing difficulty in rnaintaining in operations. Usually farmers do not have much control over their fixed costs i n crop production. Variable costs. however-, can sometimes be adjusted. some of adjustments can reduce if the has not based his cost on wise judgement, backed with technical expertise. If one... |
14. Field Estimation of Ammonia Volatilization from Surface-applied UreaAccurate estimation of the potenial for NH3 volatilization from urea-based fertilizers is an important step in optimizing Nuse efficiency from these fertilizers. Published estimates of volatilization from surface-applied urea vary widely. Citations listing losses from 2% on up to 80% from various systems can be found. Consequently, many growers, to protect themselves, will apply urea at higher than recommended rates, assuming some arbitrary level of loss will occur. The objectives of the researc... |
15. How Fertilizer Dealers Use Research InformationThere i s not a great deal o f resource information t o draw from i n reference t o the t i t l e so most o f my comments are based on observations made and personal opinions formed during some 26 years of experience in the fertilizer industry, covering a majority of the principal agricultural states. Fertilizer dealers as a whole tend t o translate research information into dollars. They use it as a business tool. It provides support t o the sale of existing products and services and identifies... |
16. Importance of Subsoil PotassiumRecent information has emphasized the importance of nutrient distribution by depth in soils. Information from across the Cotton Belt in the U.S. has demonstrated that cotton yields have been affected by accumulation of potassium (K) near the soil surface with subsequent depletion of subsoil K. This condition combined with changes in K demand by new, high-yielding cotton varieties has led to a change in cotton K deficiency symptoms and delayed diagnosis of the actual problem. Recent studies have ... |
17. In Search of EAN of Spring WheatMany spring wheat varieties respond reliably to enhanced ammoniunl nutrition (EAN) in the greenhouse. Three field studies were established in 1992 to determine if similar responses could be obtained in the field. Butte 86 spring wheat was fertilized (100 Ib N/A) with calcium nitrate, urea, urea + DCD, forestry-grade (0.1 g) urea pellets and forestry-grade urea pellets + DCD. The goal was to provide wheat with a large range of a1nmonium:nitrate ratios and to determine the effect 011 wheat develop... |
18. In-Field Determination of Anhydrous Ammonia Applicator Accuracy in NebraskaLiquid and dry fertilizer applicators have been studied for their application patterns and precision. However, anhydrous ammonia (AA) applicators are generally considered less accurate. Due to the difficulty of calibration, actual application errors have not been documented. In order determine if AA applicators were delivering the intended application rate, a standard AA nurse tank was fitted with load cells, temperature, pressure, travel speed and travel distance sensors. Initial data from 55 f... |
19. Influence of Phosphorus Soil Test Level on the Probabaility of Corn Yield ResponseData from a long term residual phosphorus study was analyzed to determine the probability of a corn yield response at low, medium, high and very high soil test levels. Analysis of 55 rate-site years showed a corn yield increase 59, 22, 43 and 17% of the time respectively for low, medium, high and very high soil test categories. The very high soil test category is defined as a Bray P soil test of greater than 20 ppm. The results suggest that the current South Dakota State University recommendatio... |
20. Influence of Tillage Systems on Corn Yields and Soil Test ValuesA long term tillage study was initiated at the Greenley Memorial Research Center (Novelty, MO) in 1976 to look at the effects of 4 tillage systemsoncornproduction. Thestudywasinitiatedandconductedby researchers in the Agricultural Engineering Department. Agronomy has become involved in the study beginning in 1985 to assess the effects of tillage systems on soil chemical and physical properties. The upland soils at this site are poorly drained and are generally refered to as "claypan" soils. The ... |
21. Long Term Phosphorus Research on Corn and Grain SorghumPhosphorus fertilizer is needed for optimum production and economic returns from irrigated corn and grain sorghuni in western Kansas. A long term study shows that the yield benefit from P increases over time from no yield difference initially to over 100 butacre higher corn yields after 30 years. Without fertilizer P, soil P levels declined from 17 pprn Bray- 1 P to less than 10 pprn within five years, where they stabilized for both corn and sorghurn. The addition of fertilizer P at 40 Ib P205la... |
22. Long-Term Alfalfa Study With K RatesA long-term potassium rate study was conducted on a Maury silt loam as part of the soil test calibration program to develop data for more soils in Kentucky. Beginning soil test K levels were established with initial applications of either 0, 150 or 300 lb of K20 per acre. Annual applications of 0, 120, 240 and 360 lb of K20 per acre were applied about 1 month before fall freezedown. Results indicated (1) there were significant yield responses to annual applications after the first year; (2) the ... |
23. New Techniques and Methods of Disseminating Information in View of Budgetary Constraints by the University of IllinoisThe Cooperative Extension Service a t the University faces increased demands for educational services. This increaase is in an environment marked by increasing costs, and stable to decreased financial support--especially from the Federal partner. The situation we face in Illinois is similar to that faced by many other State Cooperative Extension Services. We are better o f f than some states--worse o f f than others. What of the future? Will we be able to deliver viable programs to farmers and a... |
24. Nitrogen Management Systems for Ridge-tilled Corn ProductionThe use of conservation tillage methods, including ridge- tillage, increases crop residue cover which can lead to loss of urea-based fertilizers applied broadcast. ~ield tests were conducted during 1987-1991 at the ~rrigation ~xperiment Field, located near Scandia, Kansas, on a Crete silt loam soil (fine, montmorillionitic, mesic, Panchic, Arguistoll). Treatments included anhydrous ammonia (AA) applied preplant knife-injected; 28% urea-ammonium nitrate solution (UAN) applied preplant knife- inje... |
25. 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 consider... |
26. Potassium RecommendationsMost soils have relatively large contents of total K but relatively small amounts of plant- available K+. Potassium is found as a component of several minerals that release it to soluble and exchangeable forms by weathering at greatly differing rates. These forms are shown in the adjacent figure. Some of these minerals also have the capacity to reabsorb (fix) added K+ back into their structures in nonexchangeable form. Even the exchangeable K+ is bonded with different strengths depending on the ... |
27. Potassuim Chloride Fertilization and Common Root Rot of BarleyCommon root rot (CRR, incited by Cochliobulus sativus) is one of the most widespread diseases of wheat and barley in the Great Plains and Prairie Provinces. Average yield losses, based on extensive surveys in the Prairie Provinces, average around 5% for wheat and 10% for barley, althoughinindividualfieldslossescanbemuchhigher. Potassium chloride fertilization has been effective in reducing CRR of barley in North Dakota, and I believe we are close to understanding why CRR is reduced by KC1 fertil... |
28. Preplant Soil Nitrogen Test for CornSoil ammonium N and nitrate N were measured at the pre-plant and sidedress stages on 59 Michigan fields in 1992. Total inorganic soil N (ammonium N plus nitrate N) at pre-plant stage averaged to 12.6 ppm, about 50% of which was present in the nitrate form and 50% in the ammonium form. Total inorganic N at sidedress stage was 18.9 ppm, of which the nitrate N component was 12.2 ppm. The NH JNO, ratio decreased from 1.06 at prep1 ant stage to 0.54 at sidedress stage. Multiple correlation analysis ... |
29. Presenting Key Issues in a Rational Manner to the Non-Ag CommunityA quick scan of the program for your workshop might lead one to believe my subject is out of place here. In terms of agricultural credentials, I could certainly be consideredoutofplace: Iconsidermyselfajournalist gone straight; I was educated as a journalist and was a reporter for The Kansas City Star before entering public relations work and then joining Monsanto nearly 20 years ago. But I don't believe either the subject or the speaker is out of place for this gathering. And I think perhaps mo... |
30. 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... |
31. Response of Ridge-till Corn to Potash FertilizationIn recent years there has been an increased interest in growing corn with either ridge-till or no-till planting systens. This interest has been stimulated by concern for conservation compliance, farm profitability and the environment. Many problems have surfaced as these tillage systems are adopted by more and more farmers. The appearance of potassiu,~ deficiency symptoms has been a major concern for those who grow corn and soybeans with these tillage systems for the past four or five years. For... |
32. 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 pote... |
33. Rye Cover Crops in No-till Corn ProductionField studies have been conducted for several years in Ohio to determine the effects of including a ry.e cover crop in no-till production situations. These studies were conducted at two locations, on a moderately well drained Canfield silt loam at Wooster, and a very poorly drained, but tiled, Hoytville silty clay at Hoytville. At Wooster, no-till corn was planted into corn or soybean residue, with or without a fall-seeded rye cover crop (2 bu/A seeding rate). Individual plots received 200 lb N/... |
34. Summary of P Fertilizer use Effects on Soil Test PhosphorusOver the years, much research has centered on the use of various soil P extractants for developing soil fertility programs. While P soil test values are most reliable for estimating the historical probability of obtaining a crop response from fertilizer P application and tracking the effects of past P fertility programs - P soil tests are more commonly used as to estimate future fertilizer P rate requirements. Depending on the objectives of a grower, P soil testing is used to predict future P ra... |
35. The Effect of Sulfur Fertilization of Yield and Quality of Corn and AlfalfaThe importance of sulfur (S) fertilizers for crop production in Minnesota has been recognized for several years. Inpast research, the use of S had increased crop production only on the sandy soils. Since the soil organic matter is a major reservoir of S for plant use, there is always some question about the need for S in a fertilizer program where soils are not sandy but, yet, have a low organic matter content. It is well known that S is an important component of some amino acids in wlants and t... |
36. The Effects of Rate and Timing of Nitrogen Applications on the Yield and Nitrogen Recovery of Irrigated CornHigh crop yields require that adequate amounts o f N be present and available to the root at the times it i s needed to support growth. However, for a production system to be efficient in the use of the nitrogen and to minimize any potential adverse environmental effects, care must be used to minimize loss during the growing season and minimize amounts of residual N remaining in the soil at the end of the cropping season. This requires that proper N rates be applied and that the N be applied in ... |
37. Tillage, Fertilizer Placement Equipment and Residue Compliance- Is There a ConflictConservation compliance is no longer a nightmare for crop producers farming highly erodible land. Instead, it is rapidly becoming reality if those crop producers plan to participate in USDA agricultural assistance programs. In Missouri, farmers are adopting conservation and no-till cropping practices at a very rapid rate. Though not verified, it appears that no-till acres in many north Missouri counties more than doubled from 1991 to 1992. The most cost effective means of reducing soil erosion r... |
38. Using Sufficiency and Recommendation Information to Calculate Fertilizer Response Curve and Profitability Estimates.The importance of sound fertility programs in efficient, profitable farming operations is well known - especially in times of low crop prices. Likewise, the importance of a sound soil testing program - and recommendation guidelines that relate these soil test values to credible, long-term research results - is recognized as the best way of obtaining maximum economic returns from fertilizer dollars. Unfortunatly, there are few tools available for evaluating the profitabi1it.y of a specific fertil... |
39. What's Ahead- Soil Conservation Service Nutrient Management PlansFarmers have been going through a major change in their relationship with Government during the past ten years. Many in the agricultural community are anticipating possibly more changes in the future from such Legislation as the Clean Water Act and the Endangered Species Act. Each act has potential of having even more impact on the agricultural community. Immediately following those two acts will be the 1995 Farm Bill. The last two Farm bills have been slanted more to environmental concerns than... |