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1. 2009 - The Summer of Plant Analysis: What Did We Learn?There was a significant increase in the number of samples submitted for plant analysis to the UW Soil and Plant Analysis Laborat ory during the 2009 growing seas on. The objective of this study was to analyze the data from plant samples submitted to the UW Soil and Plant Analysis Laboratory over the past five years to determine if any relevant plant nutrition trends appear. ... |
2. 4R Nutrient Management for Corn Production on Upper Midwest SoilsCorn (Zea mays L.) demand for nitrogen (N) is often met using inorganic fertilizer on Upper Midwest soils. While applying the right rate of fertilizer N normally has the greatest impact on yield and N use efficiency (NUE), selection of the right fertilizer source, placement, and application timing can fine-tune rate recommendations, improve NUE by matching soil N availability to corn demand, and minimize loss to the environment. Given the diversity of corn production environments, th... J. Spackman, F. Fernandez, K. Fabrizzi |
3. A 2020 Vision on Nutrient Use DecisionsMany farmers this fall are facing significant financial stress due to several factors including low crop prices and weather-induced crop losses. Crop prices are currently much lower than they were in the first half of this decade but we have been here before … time tested principles continue to apply. Past studies of the characteristics of the most profitable farmers show that they tend to have higher yields, lower costs, and are more rapid adopters of technology than their less profit... P.E. Fixen |
4. A Nitrogen Rate of Return Calculator for Wheat, Barley, and Canola in ManitobaNitrogen (N) general guidelines in Manitoba ar e reviewed by a panel of government, industry and university experts on an annu al basis and revisions as well as additions and corrections are reflected in the Soil Fertility Guide that is published (as well as posted on the web-site) by Manitoba Agriculture, Food and Rural Initiatives. However, a comprehensive review of the N databases for barley, wheat and canola has not been undertaken since September 1990. Post 1988 database of experiments cond... |
5. Can nitrogen application rate and timing management contribute to yield benefit in dryland winter wheat?Nitrogen (N) is a key component that affects grain yield and protein content in wheat. Optimizing fertilizer N application rate and time may contribute to an increased yield along with an adequate protein level. To evaluate the effects of different rates and application timing of N on grain yield and quality, a field study was carried out at four different locations across Nebraska (Mead, Grant, Sidney, and Scottsbluff) in 2018/19. At all locations, the experimental layout was split-plot rand... D. Ghimire, B. Maharjan |
6. Corn Nitrogen Rate Response Trials in Northwest and Westcentral Minnesota, 2007=-2009With the growing number of corn producers and increased acres of corn in NW and WC Minnesota along with the revisions in the Univer sity of Minnesota Corn Nitrogen Guidelines (2006) many northern corn growers were asking a bout the validity of the new nitrogen guidelines for corn production in the region. Prior to 2007, University of Minnesota calibration and correlation data included in the new guidelines did not include any research sites north of Interstate 94. A request for funding from the ... |
7. Cover Crops Influence Soil Health and Nutrient Cycling in a Multi-Location Study in South DakotaSoil without living roots potentially loses mobile nutrients and retains excess water. Unprotected soil degradation and erosion enable the loss of carbon and nutrient rich top soil. Cover crops provide armor for the soil protecting from carbon and nutrient loss. Cover crop blends may influence soil health parameters and nutrient cycling. This multi-locational study depicts the influence of cover crop species blends with varying grass and broadleaf concentrations on established soil-health ind... D. Sanyal, J. Wolthuizen, D. Karki, J. Clark, A. Bly |
8. Current Perceptions on Soil Fertility Recommendations and Status of Soil Fertility in IllinoisWhile most soils in Illinois are generally recognized for their high productivity, regular application of phosphorus (P), pot assium (K), and limestone are necessary to maintain their productivity. Determination of soil P, K, and pH levels through soil analysis is necessary to guide application of these nutrients and limestone. Due to recent high fertilizer prices there has been interest from producers to temporarily reduce or eliminate P and K applications without reducing crop yield. In an ef... |
9. Dealing with Sulfur Deficincies in Crop Production: The Iowa ExperienceResearch conducted for more than forty years (pri or to approximately 2005) in Iowa rarely noted improved crop yield with sulfur (S) fertilization. Studies during that time period with corn and soybean found yield increase from S fertilizer application only three times out of approximately 200 trials. Research in the early 1980's had also documented sufficient plant available S in the soil profile for crop production on most Iowa soil associations. Results of recent studies (2000- 2005) in corn ... |
10. Do cover crops improve soil health and enhance nutrient availability to cash crops?Bare soils are prone to erosion and lose soluble nutrients. Cover crops provide protection to the soil against erosion and nutrient loss. We hypothesized that the cover crops should uptake available nutrients from the soils in the fall when there is no cash crop, assimilate the nutrients in their tissues, and in the following spring, should release the nutrients back to the soil during the next cash crop growing season. In our study, we are quantifying the nutrients taken up by the cover crop... D. Sanyal, A. Rahhal, H. Bielenberg, J. Wolthuizen, J. Clark, A. Bly |
11. Does cover crop composition improve soil health and enhance nutrient availability to cash crops?Crop and livestock producers in South Dakota are showing greater interest in cover crops for the multidimensional benefits it can provide towards enhanced nutrient availability to the cash crops and livestock nutrition. Growers use different blends of grasses and broad leaves, mostly legumes and brassicas, as cover crops. We hypothesized that carbon and nitrogen ratio and fiber composition in those cover crop residues regulate the nutrient release, thus influence the processes regarding nutri... D. Sanyal, A. Rahhal, H. Bielenberg, J. Clark, J. Wolthuizen, A. Bly |
12. Does Maize Need Pre-Plant N if Sub-Drip Fertigation Can be Used To Provide Season Long N?Multiple nitrogen (N) applications are becoming more common as a way to assure adequate N availability for optimum growth and yield of maize (Zea mays L.), while minimizing the potential for negative environmental consequences associated with N loss. Unclear, however, is how much N needs to be applied at planting in order to get the full value of in-season applications. Our objectives were to determine the amount of preplant N needed to maximize maize yield, when additional N is prov... B. Wiegmann, F. Below |
13. 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 U... E. Ritchey, H. York |
14. Early Season Nutrient Uptake from Combinations of N itrogen, Phosphorus, and Potassium Applies in Starter Fertilizer in Two Corn HybridsConventional small plot field trials were establ ished to study the effect nitrogen (N), phosphorus (P), and potassium (K) applied as starter ferti lizer on early season growth and nutrient uptake of two corn hybrids with a nd without the Bt-rootworm gene. Ei ght locations were studied over two years comparing a non-starter check, N only, K only, NP, NPK, and NK starter fertilizer combinations on early season growth and nutrient uptake. Sites tested High initially in both P and K. One or more st... |
15. Effect of Phosphate and Sulfate Application on Wheat (Triticum Aestivum) Grain Selenium Content and Yield ComponentsThe interest in Selenium (Se) has increased due to its potential anti-cancer attributes in human health. Wheat ( Triticum aestivum ) will assimilate Se according to soil availability. There is interest in developing a consiste nt grain supply of high Se wheat for markets in Europe and Asia since plant-available Se in soils of these continents are very low. Agricultural soils in some regions of central and western South Dakota ha ve high Se content. Yet the common plant available forms of Se, sel... |
16. Effects of Glyphosate Application and Manganese Fertiization on Leaf Manganese Concentration and Yield of Glyphosate-Resistant SoybeanGlyphosate-resistant (GR) soybean is widely accep ted in the United States. Recent research in Indiana and elsewhere has observe d that post-emergence foliar applications of glyphosate may cause or exacerbate manganese (Mn) deficiency and then limit yield of GR soybeans on low Mn availability soils. The objectives of this study were to 1) better understand how glyphosate application(s) might reduce the up take and translocation of Mn in GR soybean plants, and 2) determine the effectiveness of s... |
17. 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 ... |
18. Efficacy of Variable-Rate Application Technology for Phosphorus, Potassium, and Lime ManagementVariable-rate (VR) application technology may improve P and K fertilizer and lime use efficiency, increase crop yield and the profitability of crop production, and reduce within-field soil-test variability. On-farm research assessed the potential of VR P or K fertilization and liming for corn and soybean in Iowa. Replicated strip-trials evaluated one to three cycles of the two-year rotation. Treatments for areas 10-30 acres in size were a non-fertilized or unlimed control, VR based on dense g... A.P. Mallarino |
19. Evaluating Relationships between Soil Respiration and Nitrogen Use Efficiency in CornAvailable nitrogen (N) often limits the agricultural production of corn (Zea mays) and the N fertilizer use efficiency is of primary concern for producers in Kansas and the Midwest. This study was carried out to understand the agronomic value of commercially available soil health tests (e.g. 24 hr CO2 burst) and their relationship to components of nitrogen use efficiency (NUE) in corn. Relationships between N response and soil CO2 evolution were investigated across multiple sites and manageme... D. Ruiz diaz, B. Rutter |
20. Evaluation of Nitrate Leaching Potential from Slow and Controlled Release Nitrogen Fertilizer Application to Irrigated CornThe use of slow and controlled release nitrogen (N) fertilizers as a practice to reduce nitrate leaching from irrigated corn was evaluated on coar se-textured soils in the Central Platte River Valley of Nebraska in 2007 & 2008. Slow-releas e methylene urea (MU) and polymer-coated urea (PCU) were compared to a standard fertil izer of urea ammonium nitrate (UAN) solution. Flooding in 2007 severely impacted the study site, and results are not reported here. Saturated soils were common at the site i... |
21. Evaluation of Soil Test Methods and Crop Response to Phosphorus Fertilization in KansasWheat (Triticum aestivum) is typically considered the most responsive crop to phosphorus (P) fertilization in Kansas. This study was conducted to evaluate wheat response to P fertilization using modern genotypes and soil test calibration/interpretation for Kansas soils. The study was conducted during the 2018-2019 growing season with eleven locations in Kansas. Randomized complete block design was used for four differe... C. Weber, D.A. Ruiz diaz |
22. Evaluation of Sulfur Fertilizers In Corn ProductionSulfur deficiencies and corn yield increases from S fertilization have been documented in Iowa since the mid-2000’s. Therefore, S fertilization management is an important component of high yield corn production. Many S fertilizers are available for use in correcting deficiencies. However, specific product evaluations have not been widely conducted in Iowa. In addition, a new S fertilizer has recently become available in the Midwest U.S., the mineral polyhalite. The research objectives w... J. Sawyer, M. Castellano, A. Sassman, J. Lundvall |
23. Fertilizer ManufacturingRock Phosphate + Sulfuric acidPhosphoric Acid + Gypsum Phosphoric Acid + Anhydrous Ammonia MAP or DAP (18-46-0) Phosphoric Acid + Rock Phosphate TSP (46-0-0) Concentrated Phosphoric Acid + Anhydrous Ammoni a APP (11-37-0) 1. Ore containing KCl and NaCl is mined, brought to the surface and ground up 2. Reagents added in a brine to remove clays 3. Reagents added to attach to KCl crystals 4. KCl crystals floated to the surface in flotation cells 5. NaCl separated to tailings pile or put back under... |
24. Foliar Fertilizer and Pyracolstrobin Fungicide Combinations for CornIncorporating a foliar applied fert ilizer with fungicide application could reduce application costs, improve disease suppression, increase nutrient re sponse, and enhance the management of crop response to environmental conditions within th e growing season. A two-year field trial was initiated in 2008 at three sites in northeast, southeast and northwest Mi ssouri. Treatments consisted of a factorial arrangement of 13 diffe rent commercially-available foliar fertilizers containing both macro- a... |
25. Four R Nitrogen management for cotton. MU-FDRC research update.Cotton is a much different crop than corn. In addition to the dicot vs. monocot difference, cotton is a perennial plant cultivated as an annual crop. A cotton crop must be “encouraged” to produce fruit and hence lint in this production system. Input management, including nitrogen fertilizers, are central to modern cotton production. Adequate nitrogen must be available to a cotton crop during the critical flowering period. In Missouri this is from mid-May to... D. Dunn |
26. How Agronomic Management Affects Soil Nitrous Oxide EmissionsThe effects of crop and soil management practices on soil emissions of non-carbon dioxide (CO2) greenhouse gases (GHGs) such as nitrous oxide (N2O) are highly variable, and long-term field data are limited. Management strategies that impact nitrogen (N) mineralization are also likely to affect how N is lost to the atmosphere as N2O gas. This presentation covers the agroecosystem soil N cycling concepts leading to losses as N2O as well as... V.L. Jin, M.R. Schmer, B.J. Wienhold |
27. Impact of Phosphorus and Potassium Fertilization on Corn and Soybean Productivity and Soil Nutrient LevelsA common production practice in the Eastern Corn Belt is to supply enough phosphorus (P) and potassium (K) in the fall prior to corn planting to satisfy the nutrient needs of both corn and soybeans in a rotation. This practice is most likely a viavle option for fields with more than adequate soil nutrient levels, but on marginal fields this practice may be limiting production (specifically with regard to K). Two field experiements were estabished to evauate the impact of P and K fertilization... K.A. Dietrick, R.W. Mullen, C.E. Dygert |
28. Impact of sulfur and its interaction with N rates on wheat and barley in North Dakota and Western MinnesotaEffects of S, N, and their interactions were assessed on grain yields and protein of spring wheat and barley, across eight site years in Western Minnesota (MN), and ten site years (hereafter, sites) in North Dakota (ND) from 2015 to 2019. The studies were to determine if S improves yields and protein in wheat, and if the effects were dependent on N rates. Treatments included all combinations of five N rates of N (0, 60, 120, 180, and 240 lbs/ac) and three rates of S (0, 10, 20 lbs/ac) in MN. ... J.M. Teboh, S. Yuja, B.G. Schatz, G. Pradhan |
29. Integrating Multiple-Input Management Systems to Improve Soft Red Winter Wheat Grain YieldContinued improvements in wheat (Triticum aestivum L.) grain yield have cast greater interest on utilizing multiple inputs within enhanced management systems. Less than recommended seeding rates of modern varieties may utilize inputs more efficiently when subjected to enhanced management. The objective of this study was to evaluate plant growth, grain yield, and expected economic profitability for multiple agronomic and nutrient inputs across different production intensity l... K. Steinke, S. Purucker |
30. 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 field... |
31. Is There a Better Way to Fertilize Corn with Potassium?Potassium (K) is among the most abundantly needed plant nutrients. A 15.7 Mg ha-1 (250 bushel acre-1) corn (Zea mays L.) crop accumulates anywhere from 168-225 kg K2O ha-1 (150-200lbs K2O acre-1) over the course of a growing season, and according to the IPNI Soil Test Summary (2015), about 37% of Illinois’ soil tests are deemed as deficient for K. The objectives of this study were to investigate various methods o... S. Foxhoven, F. Below |
32. Long Term Phosphorus Studies and How they Effect RecommendationPhiosophiesProfitable crop production requires adequate levels of phosphorus (P) and other nutrients. Careful planning is required because of volatile grain and fertilizer prices and increasing public concerns about water quality impa irment due to excess nutrient loss from fields. Higher fertilizer prices may not be a major issue as long as the hist orical ratio between crop and fertilizer prices is approximately maintained, becomes more favora ble, or increases can be predicted. Largely unpredictable pri... |
33. Micronutrients in Northern ClimatesEarly work on micronutrients in northern US dates back to the late thirties and early forties and dealt primarily with boron (B) (Cook 1939; Cook a nd Millar 1940; Pierre and Allaway 1941). In Manitoba, it was initiated in the sixties and id entified zinc (Zn), copper (Cu) and manganese (Mn) as potential problem micronutrients. Early work also id entified organic (peat) soils as a primary target for micronutrient deficiencies. Work on mineral soils would produce significant yield responses in th... |
34. Nitrogen and Sulfur Application Effects on Soybean Quality and YieldSulfur deficiency is only becoming more prevalent in the Midwest across soybean fields with higher yields resulting in lower quality seed. Sulfur is a key component of methionine and cysteine, which are important amino acids in the nutrition in foodstuffs. The objective in this study is to explore the impact of N:S applications at different growth stages and rates on the soybean yield and seed composition and quality. In 2018 the trial was performed both in West Lafayette and Wanatah Indiana.... D. Miller, S. Casteel |
35. Nitrogen Application, Biological N Fixation, and N UptakePrevious collaborative research in the Midwest has shown that there is likely little to no need of N for soybean, except under certain conditions (such as when low soil moisture limits N fixation, or when low initial soil nitrate-N limits overall N availability). However, none of the site-years used in this synthesis analysis were on sandy soils. Because sandy soils supply little nitrate-N, the potential impact of N on crop yield is greater in sandy environments than on silt loam soils. Howev... A.M. Walters, M.D. Ruark, J.M. Gaska, C. Zegler, S.P. Conley |
36. Nitrogen benefits when interseeding red clover into continuous cornInformation pertaining to the benefits of intereseeding cover crops is lacking. Red clover is a leguminous cover crop that can grow in low radiation environments, is winter hardy for much of the northern USA, and is a low cost weed suppressant that has been shown to provide a nitrogen credit and improve corn yield. While it is clear that red clover is a cover crop that can provide immediate economic benefits in grain-based cropping systems, the potential N credit and the effect of interseedin... H. Francis, M. Ruark, C. Zegler, D. Smith, J. West |
37. NITROGEN CREDIT FOR LONG-TERM NO-TILL CROP PRODUCTION IN NORTH DAKOTAFeedback from farmers who had been in no-till crop production for over twenty years indicated that crop production could be maintained at high levels with a reduction in N rate from the universally recommended rates. Nitrogen rate studies in spring wheat/durum, corn and sunflower have confirmed that N rates can be reduced when a farm is under continuous long-term no-till production. A portion of the N credit may be uptake of N by microorganisms, thereby reducing the amount of N exposed to lea... D. Franzen |
38. 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 ... D. Franzen, G. Endres, J. Lukach, R. Ashley, J. Staricka, K. Mckay |
39. Nitrogen Source and Application Timing to Improve Corn Yield and Reduce Nitrate in Tile-Drain WaterNitrogen (N) fertilizer is among the most important inputs for corn because of this crop’s large N requirements. When N fertilizer applications exceed crop needs, that N can be lost to the environment or be incorporated into the soil organic matter Many farmers in the US Midwest install subsurface drainage to remove excess water from the soil. The drained water leached from the farms contains nitrate-N (NO3), which poses risks to surface waters. Midwest agriculture ... S. Menegaz, F. Fernandez |
40. No-till and Cover Crops Influence Soil Health and Nitrogen Rate and Timing Recommendations: Early ResultsThe idea of improving soil health has become increasingly more talked about by researchers, agronomists, and farmers in the past five years. Management practices such as no- or reduced-tillage and planting cover crops are recommended to improve soil health because of their potential to improve organic matter and soil structure leading to a greater capacity to hold water and nutrients needed for plant growth. Research in South Dakota has been occurring these past two years to determine the inf... J.D. Clark, A. Bly, D. Karki, D. Sanyal, J. Wolthuizen, P. Kovacs |
41. Optimizing Nitrogen Rate to Maximize Winter Malting Barley Grain Yield While Meeting ProteinWinter malting barley (Hordeum vulgare) acreage is increasing across Ohio due to demand from the local craft brewing industry; however, grain used for this market must pass specific quality requirements. The objective of this study was to identify optimum spring nitrogen rates for winter malting barley that maximize yield while meeting protein requirements. Small plot trials were conducted at three locations in Ohio: Northwest Agriculture Research Station (NWARS) in Custar, Western A... G. Mcglinch, L. Lindsey, R. Shrestha, M. Hankinson |
42. Potassium in Corn Starter Fertilizers RevisitedDespite the importance of potassium in crop nutriti on, there has been relatively little assessment of potassium in starter fertilizer s, and particularly where sufficie nt preplant broadcast K has been applied to meet the needs of the crop. Initial re sults from the first year of a multi-year study in Southern Ontario showed that corn yields were increased by about 0.4 t ha -1 by the inclusion of potassium in a starter fertilizer on low P and K testing soils, above the response to added P. Fur... |
43. Re-Evaluating Rate, Time, and Placement of Urea and Other Nitrogen Sources in MinnesotaUrea is increasingly an important nitrogen (N) source in Minnesota. Approximately 43% of our farmers use urea as their major N source. In the southwestern, south-central and west-central areas approximately 45% of the N is applied in the fall, 50% is applied in the spring, and 5% is applied at sidedress. While most of those that use urea as the major N source apply it in the spring, approximately 4% do the major application with urea in the fall and there are others that apply some of their N... F. Fernandez, K. Fabrizzi, J. Vetsch, D. Kaiser |
44. Recommendation Development Under 4R Nutrient StewardshipThe 4R Nutrient Stewardship concept defines the right source, rate, timing and placement of plant nutrients as those leadi ng to the economic, social and e nvironmental benefits desired by stakeholders. This implies roles for both science and stakeholder engagement . Scientific data on the linkages to outcomes needs to be communicat ed to stakeholders to ensure their valid participation and to build public confidence. Th e 4R Nutrient Stewardship concept helps to link science to practice and co... |
45. Sidedressed swine manure slurry via dragline hose produces comparable corn grain yields as commercial fertilizersSpring in the upper Midwest can be short and often wet, providing challenges for producers to apply manure and plant crops in a timely manner to maximize yield. As a result, producers apply a significant amount of their manure in the fall after the crop is harvested. Fall applied manure has adequate time to mineralize and leave the root zone before next season’s crop can utilize the nutrients the following summer. These nutrients can end up in rivers and other freshwater bodies, decreas... C. Pfarr, M. Wilson |
46. Soil N2O emissions in continuous corn as affected by 4R and cover cropsCover crops and 4R nitrogen (N) management are promoted as key practices for reducing nitrate leaching losses, but their impacts on nitrous oxide (N2O) emissions remain less certain. This study evaluated soil N2O emissions and grain yield under different timing of N application and cover crops for two years in a tile-drained continuous corn system. Treatments were 224 kg N ha-1 split-applied in fall + pre-plant (Conventional), pre-plant + side-dress (4R), 4R +... G. Preza fontes, L.E. Christianson, C.M. Pittelkow |
47. Soil pH and Lime Management for Corn and Soybean: An Ongoing On-farm ProjectSoil acidity can affect plant growth directly and indirectly by affecting the plant-availability of nutrients, levels of phytotoxic el ements, microbial activity, and ot her soil properties. Soils may become acidic in the long term as a result of several natural processes. In the short term, however, soil acidity develops mainly due to application of N fertilizers or manure, primarily those having high concentrations of ammonium or urea because nitrification releases hydrogen (H) ions. Soil pH ... |
48. Soybean foliar manganese recommendations on chronically Mn deficient soils.Soil Mn availability decreases with increasing pH and organic matter concentrations, leading to seasonal Mn deficiency symptoms in soybeans pr oduced on these soils. In Michigan, high pH conditions are often found in alluvial calcareous lakebed soils where conditions lead to low Mn solubility. High organic matter co ncentrations in organic soils reduce Mn availability due to formation of unavailable chelated Mn 2+ compounds and organic complexes in the soil. While Mn deficiencies on lakebed soil... |
49. Soybean Growth Components as Influenced by No-till and Strip-till Systems and Different P and K Rates and PlacementsReduced tillage and broadcast phosphorus (P) a nd potassium (K) applications can lead to accumulation of these nutrients in the soil surfa ce. The objective of this study was to determine the impact of conservation tillage (no-till and strip-till) and rate/placement of P and K on soybean production. The experiment was arranged in a split-split-block design with three replications with tillage/placem ent no-till broadcast (NTBC), no-till deep placement at 15 cm (NTDP), and strip-till deep placeme... |
50. The Changes in Soil Test Potassium in Kentucky Soils Following Incubation and the Addition of Potassium FertilizerSoil test potassium levels across the state of Kentucky have been declini ng for the past several years. The high price of potash fertilizer has definitely played a role in this decrease, but crop removal rates have also been increasing. This re search is being conducted to improve fertilizer recommendations, to help producers raise or ma intain K soil test level, and to obtain an optimum, profitable yield. Curr ently, University of Kentucky has a single set of K recommendations regardless of so... |
51. Understanding Spatial Variability in Cover Crop Growth and DecompositionIn many agricultural landscapes, topographic variability leads to downslope movement of soil, water, and nutrients, causing heterogeneity in both crop yield and soil fertility throughout production fields. Cover crops can slow these processes, but the impact of topography on cover crop growth and residue persistence is uncertain. We measured the growth, mixture biomass composition, and decomposition of a cereal rye (Secale cereale L.) cover crop, and cereal rye /crimson clover (T... S.J. Leuthold, M. Salmeron, O. Wendroth, E. Haramoto, H. Poffenbarger |
52. Use of Nitrogen Mangaement Products and Practices to Enhance Yield and Nitrogen Use Efficiency in No-till CornLong- term research has shown that nitrogen (N) fertilizer is usually needed to optimize corn production in Kansas. Research has also shown differences in the response to various N fertilizers, products, and practices , particularly in the eastern portion of the state, where soil and climatic conditions regularly can lead to N loss. A project was initiated in 2008 and continued in 2009 to quantify how a number of currently marketed products and commonly utilized management practices performed at... |
53. Using Optical Sensors to Make N Recommendations for Sorghum, Wheat and Corn in KansasEfforts were begun in 2005 focused on developi ng sensor based N recommendations for grain sorghum ( Sorghum bicolor L. Moench), winter wheat ( Triticum aestivum L) and corn (Zea mays L.). The objective of these studies was to develop sensor based mid-season N recommendations using active crop sensors currently available on the commercial market. Sensors used to date include the GreenSeeker and CropCircle. Our appr oach used has been to establish multiple in- field well fertilized reference str... |
54. Variation Among Commercial Corn Hybrids in Response to Agronomic ManagementStrategic selection and utilization of corn (Zea mays L.) hybrids for a given yield environment and agronomic management system will require better understanding and documentation of the interactions between current commercial hybrids and agronomic factors that have sizeable impacts on yield. Therefore, this study evaluated the effects of N fertility, plant population, and row spacing on grain yield of corn and assessed the range in yield responses among commercial hybrids to these a... E.T. Winans, F.E. Below |
55. What are the Benefits of Canopy Sensing for Variable-Rate Nitrogen Corn Fertilization?Canopy reflectance sensing for assessing crop N health has been proposed as a technology on which to base top-dress variable-rate N applicat ion. The objective of this research in Missouri was to evaluate the economic a nd environmental benefit of activ e-light crop-canopy reflectance sensors for corn N rate decisions. A total of 16 field-scale experiments were conducted over four seasons (2004-2007) in three major soil areas. Mu ltiple blocks of randomized N rate response plots traversed the le... |
56. Winter Cereal Rye Nitrogen Response and Fertilization RequirementWinter cereal rye (Secale cereale L.) has been a common cover crop choice due to seed cost, winter hardiness, and rapid spring growth. It could also be an alternative grain crop to include in a corn-soybean rotation. Also, a rye crop would provide soil coverage during the springtime when corn and soybean do not. No known research has investigated the N fertilization requirement for winter cereal rye seed production in Iowa. The objectives of this study were to evaluate N response in ... C. Martins, J. Sawyer, J. Lundvall |