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1. Changes in P Uptake and Partitioning in Soybean Cultivars Released in the Last 90 YearsHistorical changes in nutrient uptake and partitioning of soybean [Glycine max (L.) Merr.] were not studied. Field studies were conducted in 2011 and 2012 to investigate phosphorus (P) uptake changes and partitioning through the growing season in 25 maturity group (MG) II, and 26 MG III cultivars. Plant samples were taken and partitioned at V4 (four trifoliates), R2 (full bloom), R4 (full pod), R6 (full seed), and R8 (physiological maturity) growth stages. In-season samples were partitioned into... |
2. Soybean Chlorosis Management ProgramChlorosis in soybeans is a problem wherever soybeans are grown on high pH soils. In Nebraska, most of the soybeans are grown in the southeastern half of the state. Here the upland soils are neutral to moderately acid; however, many of the river valley soils are alkaline. Thus, chlorosis is a problem in the Platte and Elkhorn River Valleys and to a lesser extent, in the Republican and Loup River Valleys. Not all soils in the river valleys are prone to chlorosis OF soybeans even though many are alkaline... |
3. Residual Soil NO3 N Variability Sampling Interpretation and Effect on Corn YieldResidual nitrate-N (NO3-N) in the soil profile (crop root zone) is seldom uniformly distributed. There is lateral as well as vertical variability. Numerous factors influence variability. Some of them are: 1) any factor that influences water movement through the soil such as - soil texture, compacted zone, topography and water distribution under irrigation - 2) previous crop, 3) fertilizer history (organic and inorganic sources) and 4) sampling time - caused primarily by factors influencing mineralization... |
4. Nitrogen Fertilizer Equivalency of Anaerobically Digested Municipal SludgeCrop yield response to municipal sludge is largely affected by the amount of nitrogen (N) made available during the growing season. The effect of sludge rate and N fertilizer rate on either grain sorghum [Sorghum bicolor (L.)] or corn [Zea mays (L.)] yield response was studied on three fms in Lancaster county, Nebraska. A combination of five rates of dewatered (80% H20) anaerobically digested sludge and five rates of N fertilizer (NH&03) were applied before planting and incorporated by discing within... |
5. Estimating Second- and Third Year Nitrogen Availability from Dairy manure: It is common practice to repeatedly apply dairy manure to the same fields. To accurately assess the total plant availability of rnanure nutrients, it is necessary to account for the nutrients remaining in soil fiom previous years applications. A corn (Zea mays) field experiment has continued since 1998 on a Plano silt loam. Residual manure N availability was estimated for two and three years after a single rnanure application fiom differences in whole-plant N uptake using 1) fertilizer N equivalence... |
6. Do Different Corn Hybrids Have Different N NeedsThere continue to be claims that N management can be tailored to better fit specific hybrids. but there has been no recent confirmation that hybrids differ consistently in their N response. We tested the response of ten hybrids to N rates over two years (2003 and 2004) in a productive. silt loam soil near Urbana, Illinois. The previous crop was corn. Main plots consisted of five N rates (0, 60. 120, 180, and 240 Ib Nlacre), and ten Burrus corn hybrids (438Bt, 330, 442, 576, 583Bt, 625. 645, 727,... |
7. Plant Density Consequences on Nitrogen Uptake Dynamics of Maize Plants from Vegetative to Reproductive StagesThere are few studies to date that have inte nsively examined the simultaneous effects of differences in plant crowding and fertilizer N availability for different hybrids and locations on N uptake and maize (Zea mays L.) grain yield. The main research objective was to utilize a quantitative framework to bett er understand the physiological mechanisms that govern N dynamics in maize plants at varying plant densi ties and N rates. Two field experiments involving paired near-isogenic hybrids (i.e.... |
8. Validating Potassium Fertilizer Guidelines in Alfalfa-corn RotationsIn 2008 to 2010, on-farm research was conducted on 10 fields with medium soil test K (STK) to validate Minnesota K fertilizer guidelines by determining the effect of K fertilizer applications on alfalfa yield and quality in its last production year, and estimating the carryover of excess fertilizer K to first-year corn. We were surprised to find that no K fertilizer was needed to maximize alfalfa yield or overall forage feed value and quality. Luxury consumption of K occurred because as K application... |
9. Predicting Fertilizer Nitrogen Response In Corn Following AlfalfaCorrect prediction and application of alfalfa N credits to first-year corn can reduce fertilizer N costs for growers, reduce over-application of N, and reduce the potential for water contamination. For decades, researchers have found that first-year corn following alfalfa often requires no fertilizer N to maximize grain yield. However, a review and analysis of nearly all the research on this topic in North America and Spain (442 site-years of research) indicates that corn following alfalfa can respond... |
10. Geographic Trends in Alfalfa Stand Age and Crops that Follow AlfalfaTo gain perspective on alfalfa-annual crop rotations in the upper Midwest, USDA-National Agricultural Statistics Service cropland data layers and Soil Survey Geographic Database layers were combined for six states (North Dakota, South Dakota, Nebraska, Minnesota, Iowa, and Wisconsin) and seven years (2006-2012). Soil texture and geographic location both significantly affected the length of the alfalfa phase (stand age), and alfalfa stand age, soil texture, and year all significantly affected the... |
11. 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 |
12. Iowa Soybean Nitrogen Fixation Consider in Nitrogen BudgetsSoybean (Glycine max) is one of the most important agricultural commodities grown in Midwestern states of the US and some other parts of the world. Like many other legumes, soybean can associate symbiotically with nitrogen (N) fixing bacteria, which can transform the N2 from the atmosphere into NH3 a more available N form, through a process known as biological N fixation (BNF). However, BNF is an energy expensive process for soybean that requires carbohydrates from... S. Cordova, R. Dietzel, M. Licht, S. Archontoulis, M. Castellano |
13. Oh, K? When is Too Much K Too Much?Potassium is required in large amounts by crop plants and is a staple fertilizer, mainly as KCl. Recent data across three midwestern states suggests that sometimes, especially at high rates and shortly before planting, KCl may have negative impacts on corn and/or soybean yields. Three researchers will briefly describe their research in this area and then field questions from the audience. - Kaiser Twenty-nine potassium (K) fertilizer trials were conducted in eastern... D. Kaiser, S. Casteel, D. Franzen |
14. Can ProveN Reduce Corn Nitrogen Requirement in Minnesota?ProveN is a microbial product applied in-furrow with the goal of reducing the total amount of nitrogen fertilizer needed for corn (Zea mays L.). Six field trials were established over three growing seasons in Minnesota to evaluate corn response to nitrogen with and without ProveN applied at planting on the seed. Nitrogen was applied as urea prior to planting at five locations and split applied with 1/3 of the total rates of nitrogen applied at -planting, at V4, and V8 growth stages. ProveN... D. Kaiser, J. Vetsch, M. Currie |
15. Examination of Topography and Soil Health Properties and Their Relationship to Corn Yield Stability in Central Iowa Agricultural FieldsCroplands in the North Central region are managed for high crop yields that are stable across years and fields. Nevertheless, yields fluctuate from year to year. Moreover, the magnitude of these fluctuations can vary across the field such that yield in some portions of the field is relatively stable and relatively variable in other portions of the field. Previous research has found that yield stability can be partially explained by topographic variables, but potential relationships between yield... L. Makens, M. Castellano |
16. A Direct Approach to Measure Cover Crop Nitrogen Uptake from Dairy Manure Via 15N EnrichmentFall manure applications are a standard practice across Wisconsin, primarily due to manure storage constraints and unpredictable spring field conditions. Unfortunately, manure derived nitrogen (N) is at risk for runoff and leaching into groundwater without an appropriate mechanism for N retention. Fall-planted grass cover crops can serve as N scavengers, reducing losses of manure N to the environment, especially post-silage harvest, however potential tradeoffs between sufficient N uptake and spring... T. Judd, M. Ruark, Z. Freedman |