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1. 1989 Agronomic Implications of the 1988 DroughtHistorical Perspective Grain marketing analysts have a rule of thumb that says, "A short crop has a long tail". From the agronomist's point of view, a similar statement could be made for the agronomic implications of the 1988 drought. And coming on the heals of several years of depressed prices, there are some psychological effects that must be considered in working out management plans for farmers for the 1989 growing season. Since the 1988 season broke all previous records for extent and durat... |
2. An Evaluation of Nitrogen Application Methods for Ridge-Planted CornRidge planting is a conservation tillage method receiving some attention in the Midwest at the present time. In this system the crop is planted atop a ridge which was formed by cultivation of the previous year's crop. There is generally no tillage performed between ridge building and the next year's planting. The system is similar to no-till in that large quantities of residue are often present on the soil surface in the spring, most being concentrated in the ridge furrows. Research initiated in... |
3. Calcium Chloride Effects on Nitrogen Uptake by Small GrainsApplying calcium chloride (CaC12) with urea stimulated nitrogen uptake by small grains in six greenhouse studies. The effect was most dramatic for a sandy soil, moderate for a loam soil, and not observed for a clay soil. Allowing the urea to nitrify before plant uptake negated the CaC12 effect. In field studies, these effects were generally not observed, probably because the nitrification of the applied N was too rapid. However, this concept deserves further investigation, for example, when esta... |
4. Chemical and Biological Changes Resulting from Soil SubmergenceFlooding of a soil for rice production results in significant short and long term physical, chemical and biological changes in soil properties. These changes may have significant impact of the availability of nutrients for plant growth both for aquatic plants growing in the flooded soil and upland plants on the soil when not under flooded conditions. Chief among these nutritional effects are accelerated nitrogen (N) losses, conversion of phosphorus (P) to more available forms during flooding the... |
5. Credibility in Soil Testing- Analytical ResultsIn Illinois, soil testing to help farmers plan line and fertilizer programs are done by cumrnercial testing services. The Agronoiny Department, University of Illinois participates in the State Soil Testing Program in research and coordinating rules. Kecognizing that sources of error in the program may occur in FIELD SAMPLING, ANALYTICAL TESTING, INTERPRETATION OF TEST RESULTS, or FORUMLATION OF RECOMMENDATIONS this paper focuses on ANALYTICAL TESTING. Two quality assurarlce programs in ANALYTlC... |
6. Credibility of soil Testing- Results os the Iowa Task ForceSeveral factors led to the convening of the Iowa Soil Testing Task Force: (1) The Iowa legislature passed the 1987 Groundwater Protection Act; (2) The Big Spring study in northeast Iowa in a Karst topography region revealed presence of pesticides and nitrates in groundwater; (3) Public awareness of contaminants in public water supplies was enhanced by influential newspapers and other publications; (4) Influential publications did major stories on the results of soil test comparison studies of se... |
7. Cropping System Effects on Phosphorus Response of CornToday's corn producer performs less tillage than in the past and predictions indicate that even less will be done in the future. Changes in management practices involving different tillage and residue incorporation practices alter the dynamics of organic matter turnover in soil and may influence the supply of plant nutrients. To maximize efficiency, it is critical that information be available to guide fertilizer management adjustments for specific tillage and rotation systems. A tremendous amou... |
8. Effect of Application N timing and Plant Growth Regulator use in WheatWinter wheat is an important cash crop grown in the Midwestern states. However, progress in yield advancement has been slow compared to advances in other major wheat producing regions, notably Euro~e. This has lead to a competitive disadvantage of USA-produced wheat on the world market. In an effort to enhance wheat productivity and profitability a series of experiments were established in the fall of 1985 to assess the impact of more intensified management practices including the use of multipl... |
9. Effect of Chlorophyll Meter Readings on Improving Nitrogen use Efficiency in Corn ProductionChlorophyll meters have received widespread publicity as tools to measure nitrogen status of corn. Less information is available on whether the use of chlorophyll meters will decrease total nitrogen use or increased corn grain yield. One question that remains is, "How low chlorophyll readings need to go before additional nitrogen is needed?" To determine the impact of a 2 and 4% reduction in chlorophyll readings impact on yield (as measured by a SPAD 502 meter) zero, 50, 100, 150 and 200 lbs Nta... |
10. Effect of Climatic Variability on Grain YieldsThere are three cycles in climate and weather that affect the north central part of the United States. They are (1) a long term cycle of global temperature changes; (2) an 18.5 year wet and dry cycle; and (3) the El Ni�o cycle. ... |
11. Effect of Nitrogen Rate and time of Application on Mefluidide Treated Smooth BromeLivestock producers who graze beef cattle or dairy animals usually have an abundance of pasture during spring when cool-season grasses grow rapidly. As hot, summer weather arrives, cool-season grasses cease vegetative growth and produce seed. Forage quality decreases as the grasses become dormant. Without alternative pastures or forages, cool season pastures become over-grazed and cattle performance is reduced. Using pastures composed of warm-season grasses that produce maximum dry matter during... |
12. Effect of Time of N fertilizer Application on Corn Grain Yield in IowaThe current concern about the impact of nitrogen (N) fertilizer use on the environment has caused a shift in the thinking about N management. Crop producers are interested in techniques (application methods) that will maximize the amount of N fertilizer harvested in the crop, and conversely minimize the amount remaining in the soil after harvest. Split applications or sidedress applications are common approaches currently being studied as a way to increase the efficiency of N fertilizer manageme... |
13. Effects of Chloride Rates and Sources on Winter Wheat in KansasOn wheat, and some other cereal grains, chloride has been reported to have an effect on plant diseases, either suppressing the disease organism or causing the plant to be able to withstand infection. It is hypothesized that yield increases are due to these effects. Researchers from several states have been able to show yield increases from chloride containing fertilizers. The most common source is potassium chloride, KC1. In many cases, soil test potassium levels are high, and most soil test re... |
14. 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 cbvi... |
15. 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 diff... |
16. 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 id... |
17. Grid Sampling- The Worth of InformationSoil sample collection and chemical analysis is a time honored, scientific procedure for providing information used in determining limestone and nutrient needs in crop production fields. Ln fact, without that information one cannot make appropriate limestone and nutrient input decisions. At best they would be educated guesses. and most likely would be incorrect. Inherently then, in the soil testing process is a worth of the information derived. This worth is dependent upon the test results and t... |
18. 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 acc... |
19. High Yield Wheat Management StudiesInterest in high yield wheat management (i.e. intensive wheat management) has increased in Kentucky during the last few years. This interest has been created because of the improved yield potential of newer soft red winter wheat varieties, high yields obtained in inten- sive wheat management research in other states, and the high yields being obtained in Europe with their intensive management inputs. In several of the European countries, average winter wheat yields of 70 bu/acre or higher are co... |
20. 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-or... |
21. Influence of Seed Placed Fertilizer on Corn, Soybean and Sunflower EmergenceSix phosphorous fertilizer materials were placed with corn, soybean and sunflower seed to determine their influence on seed injury and emergence. Fertilizer rates used were 0, 12.5, 25, 50 and 100 Ib/A P,O, as dry TSP (0-46-O), MAP (1 1-55- 0), DAP (18-46-0) or liquid 10-34-0, 7-21-7 and 9-18-9. Seed emergence ranged from 0 to 100% depending on crop, fertilizer rate and materials used. Corn was most tolerant of fertilizer injury while soybean was extremely sensitive with stand reduction with eve... |
22. Influence of Tillage and Placement on the Location of Phosphorus in the Root ZoneIn recent years, the ridge-till planting operation and the use of the chisel plow have developed into the most widely accepted planting systems for conservation tillage in Minnesota. While there is opportunity to incorporate plant nutrients in the chisel plow system, previous studies have shown that this incorporation is shallow when compared to the moldboard plow system. The ridge-till system, on the other hand, offers only limited possibilities for fertilizer incorporation. Typical broadcast a... |
23. Intensive Wheat Managent in the Corn BeltIntensive wheat management (ICX) is based on European cropping systems including narrow row spacing, precise seeding rates, multiple nitrogen (N) fertilizer application, fungicide application for disease control, and plant growth regulator (PGR) application for lodging control. Components of this cropping system were compared to current recommended management (CRM) practices with 12 varieties during 1986-87. The purpose for the experiment was to determine the responsiveness of soft winter wheat ... |
24. N Loss Under Excessive Water ConditionsThe impact of excessive soil moisture on N availability was reasonably well understood at the end of the 19th century when Wiley (1896) commented " Even in the case of rainfall. which may carry the soluble plant food below the arable soil, there may not be any notable loss. especially if such a downpour be followed by dry weather. But in case of heavy rains, producing a thorough saturation and leaching of the soil. the losses in a field lying fallow during the summer will be very great and it is... |
25. Nitrogen Fertilizer Requirements for No-till cornConservation tillage is associated with higher surface crop residue levels, larger more stable soil aggregates, and generally higher surface soil water contents compared to conventional tillage. The changes in residue management and overall soil water regime under conservation tillage may result in different spatial distributions (laterally and with depth) of nutrients. In general, nitrogen fertilizer applied as broadcast urea is not recommended for no-till systems because of the possibility of ... |
26. Nitrogen Management for No-Till Production SystemsNitrogen management practices including rates and sources were evaluated in high residue no-till production systems involving corn and grain sorghum. A urease inhibitor, N-(n-butyl) thiophosphoric triamide (NBPT) was evaluated. This research also assessed the impact of type of previous residue on performance of surface applied N. A chlorophyll meter was evaluated as an in-field N assessment tool. Results to date indicate that NBPT is effective in improving the performance of surface broadcast ur... |
27. Nitrogen Placement in No-till CornPlacement of nitrogen (N) fartilizers on no-till corn was evaluated in various single and multiple N rate experiments at the Belleville and Carbondale Research Centers of Southern Illinois University from 1983 to 1993. In 15 experiments in which granular urea placement was compared, ear leaf N and grain yield were essentially the same whether urea was broadcast or concentrated in surface bands near corn rows. Only a 2 bu/ac average yield advantage was observed for banding versus broadcasting ure... |
28. Nitrogen Recommendations for Wheat using the Chlorophyll MeterThe use of a hand held chlorophyll meter showed good promise in helping to make N recommendations for wheat on a field basis. Using 5 site-years on well drained soils over a 2- year period, a correlation index (R2) of 0.88 was found relating the March (Feekes 5) N needed for optimum yield with a differential chlorophyll reading. Research on this method will be continued and expanded to field trials. Soils in less than a well drained class may require a separate calibration or the method may not ... |
29. Perspective on Sustainable Agriculture- Sustaining Agribusiness in a Changing Rural EnvironmentAgriculture is an evolving industry -- it responds to market forces, tc improvements in technology, to government programs. LlJe also see changes as 3 result of new technologies, improved information about how to efficiently raise crops and livestock, and more integration with other sectors of society. In agriculture, as in arty business, to stand still is to fall behind the rest of the industry. !!le nnoed to be ready to adapt to change, to face ned rl-zli- ties, and even to initiate cnange in ... |
30. Probability of Success for Practices to Minimize Water Quality ProblemsI would like to spend my time this morning reviewing with you some of the practices and appraoches research has suggested as being useful in controlling quality of both surface water and groundwater. Given the limited time available, I will highlight only a few of the study findings, and confine my remarks primarily to the problems of nitrogen pollution of groundwater and phosphorus contamination of surface waters. This limited review is prompted more by what I perceive to be the major interests... |
31. Quantitative Risk AssessmentThank you for giving me the opportunity to speak to you today about carcinogens in drinking water and water quality standards. In the United States today, many if not most public water supplies contain chemicals that cause cancer in animals when, in laboratory tests, the animals are exposed to high levels of the chemical. Elost of these chemicals are man-made, but there are exceptions, such as the chlorinated methanes and, probably, related compounds. These chemicals are the byproducts of chlori... |
32. Remote Sensing Techniques to Identify N Deficiency in CornNitrogen management remains a primary concern for corn production. Environmental consciousness has increased the need for diagnostic techniques to identify N deficiencies to guide corrective measures or to provide feedback on management practices. This study was designed to evaluate several techniques that measure reflectance from corn plants to detect N stress. The experiment was located in Central Nebraska and involved four hybrids and five N rates. Leaf reflectance, canopy reflectance, and ae... |
33. Soil Carbon and Nitrogen Changes in a Long Term Cropping Systems StudyConserving soil C and N appears to a reasonable objective in the choice of a cropping system. Many long-term studies have been conducted where the effects of rotation or cropping system on soil C, N and other nutrients have been evaluated. A cropping systems study was initiated in 1972 on Michigan's lake bed area to 1) evaluate how often sugar beet and dry bean could be grown in a rotation and 2) determine how much crop residue needed to be returned to the soil to maintain productivity. Soil sam... |
34. Soil Fertility Research- MissouriRather than focus on one item for this years' report I thought an overview of some of the Missouri soil fertility work would be of interest. Our workgroup. though informal and scattered over campus. tries to meet weekly to provide some continuity. Much of the work is driven by grants with specific foci. For example. Newell Kitchen has reported to this group on MSEA a joint agency project to study pesticide and N movenlent into ground and surface water in a central Missouri watershed. ... |
35. Soil Fertility to Ameliorate Plant Stress from Root Feeding InsectsCorn rootworms (Diabrotica spp.) are the most serious insect pests of maize (Zea mays) in the United States. Larval stages ofthese insects feed upon maize root systems causing plant lodging and grain yield reductions. Newly developed area-wide corn rootworm adult suppression methods, which reduce pesticide rates used against this pest complex by greater than 90 percent, do not completely eliminate rootworm populations. If maize producers had the option of using crop production practices that imp... |
36. 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... |
37. Soil Nitrate Testing- A Guide for Adjusting Michigan Nitrogen Recommendations for CornPrevious attempts to use soil nitrate tests in Michigan for adjusting N fertilizer recommendations for corn have been less than satisfactory. Soil tests were typically performed on fall or spring samples taken weeks or months prior to planting. The use of residual nitrate to adjust N fertilizer recommendations in the semi humid regions of the U. S. has never been considered very re1 iable because of the large fluctuation in soil nitrate from the time of sampling to the time of maximum uptake. So... |
38. Soybean Response to Potassium Rates and PlacementSoils of northeast Missouri in heavy soybean producing counties have generally become depleted of available potassium. Reason for depletion can largely be pointed to soybean production and a general perception that soybeans do not respond to direct fertilizer application. With a significant portion of the soybean acres in east and northeast Missouri being tenant farmed, efficiency and utilization of direct fertilizer application by the current crop is even more important to the grower. Band appl... |
39. Spacial Variability of Soil Test Phosphorus in a Northern Corn Belt FieldFor some time, an increasing number of fertilizer dealers, crop consultants, and farmers have reported substantial year-to- year variability in soil test values for phosphorus (P) and potassium (K). Frequently, this variation could be explained by such factors as extremes in soil moisture content at the time of sample collection. In many situations, however, this variation was due to the fact that soil samples were not collected from the same location in the field in two consecutive years. The i... |
40. Starter Effects on Corn Grown on Previously Flooded SoilsThe devastating floods of 1993 prompted a great deal of concern about crop production in those areas the following year. These concerns were prompted both by scientific information (Fixen et al. 1984: Vivekanandan and Fixen, 1991) and by farmer observations from prior flood experience. In response to these concerns. projects, observations. and experiments were undertaken. These included collection of soil samples for chemical analysis in the fall of 1993, observations of corn grown in 1994 on fl... |
41. Survival of Plant Growth Enhancing Root Fungi, Vesicular-Arbuscular Mycorrhizae, After Flooding and Extended FallowIn 1993. large areas of the Midwest and Great Plains were inundated with water. Plant phosphorus (P) deficiency is often a problem after such an event. Soil and plant samples were collected from sites which had been flooded and fallowed in 1993 in Missouri and Iowa. Plants from soil which low levels of starter fertilizer applied were P deficient. The application of 80 Ib P /A as starter fertilizer produced plants which were not P deficient. The flood and fallow problem was associated with the lo... |
42. Sustainable Agriculture- A PerspectiveThere is little evidence tos uggest that agriculture as practices in a variety of ways is not sustainable. We think of sustainable agriculture as a management system that uses inputs ... both those available as natural resources on the farm and those purchases externally ... in the most eficient manner possible to obain productivity and profitabilty from a farming operations, while minizing advers effects on the environment. Several groups have published materials suggesting techniques that shou... |
43. The Components of Sustainable AgricultureSustainable agriculture has become a rallying phrase for many concerned about agricultural profitability and environmental quality in the rural sector. Advocates of sustainable agriculture seem to be convinced that the policies and structure of the agricultural industry are responsible for increasing environmental problems, low farm profitability, declining farm numbers, and reduced quality of life in rural America. The agricultural popular press has published numerous stories about those concer... |
44. The Role of Combine Yield Monitors in Nutrient ManagementA grain yield map is one of the key elements of site-specific crop management. Knowledge of spatial yield variations can serve three basic functions. First, a yield map can illuminate problems with drainage, fertility, diseases, or weed infestations that may have gone unnoticed by the producer. Secondly, a yield map is a feedback tool that will encourage a grain producer to compare different fertility treatments, planting rates, or other variations in cultural practices. Third, a yield map can d... |
45. Use of Near infrared-NIR- Reflecctance for Improving Nitrogen Management in Spring WheatAdvancements in agricultural technology are providing both producers and researchers with improved tools for farm management d ec is ion making . Reduced profit margins are requiring farm managers to use these advanced tools to optimize input management in order to improve prof it levels. Fertilizer nitrogen (N) is a major input foi spring wheat in the Great Plains. Each year, many farmers fertilize spring wheat with nitrogen to improve seedling vigor and plant developmenl. Nitrogen is a major n... |
46. Yield and N Concentraions of Corn with Different N Sources Applied at Different timesA number of recent investigations have produced evidence that the ionic form of N taken up by roots affects the growth of plants. While soil- grown plants generally take up most of their N as nitrate, there is evidence that increasing the relative proportion of ammonium in the culture (or soil) solution can enhance growth and yield. Owing to difficulties in preventing the rapid microbial conversion of ammonium to nitrate in soil, this response has not been well demonstrated in a field situation... |