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1. 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 number... |
2. The Growth of MEY in Spring Wheat CountryAny ag orientated news source looked at in recent weeks in North Dakota or western Minnesota has had some kind of a MEY related story. The MEY usually has been identified as 19naximum economic yield," but recently some use of I1most efficient yield" has been seen. Yes, spring wheat country has a new buzz acronym - MEY. How did such a buzz term for tbis amount of press/news coverage develop in the spring wheat region? The kickoff for MEY club deve1-t ocaured on November 25, 1986. Before that was possible,... |
3. A Systems Approach to High Yields, Efficiency and Profits in Corn, Wheat and Doublecropped Soybean RotationUsing a systems approach friendly to the environment, a three-crop/two-year no-till system has shown significiant yield increases in a three-year research project conducted at the Poplar Hill Research and Education Facility in Quantico, Maryland. In each case, corn, wheat, and doublecropped soybean yields exceeded average yields produced on Maryland's Delmarva Peninsula. Instrumental in producing these superior yields were enhanced fertility, supplemental water, and appropriate variety selection.... |
4. Nitrogen Fertigation on SoybeansNutrient requirements for soybeans are greatest as seeds are developing during reproductive pod fill. This peak nutrient demand period physiologically coincides with decreased efficiencies in both symbiotic nitrogen (N) fixation and root efficiency (Brun, 1978). Large N applications during vegetative growth stages limit N fixation and fail to consistently increase grain yields (Fla~ery, 1986). However, smaller N applications during flowering and pod fill have been reported to augment plant N status... |
5. Identifying Critical Sources of Phosphorus Export from Agricultural WatershedsPhosphorus (P) is an essential element for plant and animal growth, and its input to agriculture is necessary to maintain profitable crop and animal production. Eutrophication, the natural aging of lakes or streams brought on by nutrient enrichment, can be accelerated by P inputs to fresh waters from human activities (Carpenter et al., 1998; Schindler. 1977). Eutrophication has been identified as the main problem in surface waters withimpaired water quality (USEPA. 1996). It restricts water use for... |
6. Challenges for making intensive soil sampling and VRT Pay. Ongoing Iowa Studies with PhosphorusSoil fertility evaluation and management can be greatly improved with the use of precision agriculture technologies. Differential global positioning systems @GPS), yield monitors, various forms of remote sensing, geographical information system (GIs) computer software, and variable rate technologies are available for use to producers. Intensive soil sampling, crop scouting, and other practices complete the new technological package. Soil testing is a diagnostic tool especially adapted for site-specific... |
7. Changes in Extractable P and Mineral N from Soil Recieving Fertilizer or Manure from Swine Fed Tradional or Highly Available Phosphorus Corn DietsWe compared extractable P and mineral N from soils receiving inorganic fertilizer or manure from swine fed either traditional (TC) or Highly Available Phosphorus (HAP) corn diets. The study was conducted at two sites, one with conventionally tilled irrigated corn and the other with no-tillage dryland sorghum. Manure application to a no-tillage site resulted in volatilization losses of N and greater variation in nutrient availability when cornpared to incorporated manure. When expressed as a percentage... |
8. Sulfur Influence on Corn and Soybean Yields in Eastern South DakotaClean air legislation, the increasing use of conservation tillage, and the manufacture of phosphorus fertilizers without sulfur have all contributed to lowering soil sulfur (S) availability to crops. Soil S availability has been affected to some extent by all three issues in eastern South Dakota. Hilltop erosion has exposed subsoil in which the pH is higher and organic matter content is lower than at lower landscape positions. In some eroded shoulder positions of the landscape in no-till fields.... |
9. Use of Fly Ash as as Alternative Liming Source for Irrigated Corn ProductionFly ash from the Gerald Gentleman Power Station in west central Nebraska can potentially serve as an alternative liming source without reducing corn grain yields. A study was conducted to assess the use of fly ash as an alternative liming source on three acid sandy soils of west central Nebraska where conventional limmg sources can be uneconomical due to transportation costs. Corn grain yield, and soil pH change over time were assessed. Lime sources failed to raise the soil pH in the upper 8 inches... |
10. Improving the Fermentation Characteristics of Corn Through Optimum Fertilization and Hybrid SelectionEthanol processors could increase production efficiency if they had access to corn grain better- suited for fermentation. The objective of this study was to determine the influence of hybrids and N fertility rates on fermentable starch content that will be used for dry-mill ethanol production. Six hybrids were grown under four N fertility levels at two locations in eastern SD. Ethanol yields increased as N fertility levels increased. Higher ethanol yields were achieved by hybrids that produced both... |
11. Corn Yield Response to Fall and Spring Applied Controlled- Release Urea vs. Spring Conventional UreaNitrogen (N) application to corn has been proven to increase yields, but concerns about nitrate-N in ground and surface water have led to investigation of controlled-release N fertilizer. The objective of these experiments is to compare corn grain response to controlled-release urea (ESN) and conventional urea. Two field studies are being conducted at two locations in Iowa and corn yield data will be reported from 2003-2005. All N treatments were hand broadcast in 30 lb N/a increments from 0 lbs.... |
12. Should We Abandon Soil Testing and Yield Goals in Estimating Nitrogen Rates for CornIf the prices of corn and fertilizer-N and the shape of the N response function relating crop yield to the amount of fertilizer used are known, calculating an economically optimal N rate (EONR) for maximizing the net return to applied N is straightforward: the EONR is the N rate at which no firher increase in net return occurs. In most cropping systems and under common price scenarios, crop yield at the EONR is within 95 to 99% of the maximum yield obtained for the specific management package. In... |
13. Utilizing Existing Sensor Technology to Develop a Late-Season Critical Value for Spring Wheat ProteinA premium is paid to producers for spring wheat with a protein content greater than or equal to 14%. Obtaining that protein content can be problematic without proper nitrogen (N) fertilizer management. Sensor-based technologies have been used for predicting yield. The question is whether ths technology can be used to determine the protein content in-season for spring wheat. Field studies were conducted in South Dakota in 2003 and 2005. Five N treatments (0, 34, 65, 102, 136 kg N ha-') were applied... |
14. Utilizing the Greenseeker to Evaluate Spring Wheat Growth and YieldThere is currently little information on the use of existing sensor-based technologies for in- season application of nitrogen (N) to spring wheat (Triticttm aestivztm L.) in the northern Great Plains. Over the past decade researchers in the southern Great Plains have developed the Greenseeker as a tool for on-the-go N application to winter wheat. Field experiments were established in Brookings and Gettysburg, SD to evaluate the Greenseeker Hand Held optical sensor (NTech Industries, Ukiah, CA) for... |
15. Evaluating the Removal of Corn Residue on Crop Production and Soil QualityRemoval for corn residue as a possible feedstock for the biofuels industry leaves many producers with a number of unanswered questions. These include what impact will this have on the following crop and also the impact on soil quality associated with this practice. A field study was established in 2000 to addr ess these and other questions. Experimental treatments include three corn residue removal levels (low, mid and high); corn harvested for grain and all residue remains on the soil surface,... |
16. Crop Yield Relationship to Remote Sensing Data Using Intensified Weighted Nonlinear Regression ModelsYield prediction is important for making in-season agronomic input decisions as well as for greater logistical decisions. In predicting the crop yield based on ground-based active optical sensing data, the ordinary statistical unweighted linear or nonlinear regression models are the most popular choices. However, these unweighted models may not be accurate enough for practical use because they are based on the assumption that each data point for regression is obtained with equal precision and that... |
17. Nitrogen Rate Revisions for Corn in North DakotaNitrogen rates in North Dakota have been based on a yield-goal or yield-potential formula for over forty years. The currently published formula (Franzen, 2010) is: Recommended N rate = (Yield Potential, bushels per acre) X 1.2 less N credits from previous crops and soil test nitrate to 2 feet in depth. A yield-based strategy was practical when N costs were relatively low and yields in North Dakota were at most 100 bushels per acre. However, due to improved germplasm developed at North Dakota State... |
18. Nitrogen Loss from Sprinkler Applied Beef Feedlot EffluentLoss of nitrogen from sprinkler applied beef feedlot effluent can be costly for both the producer and the environment. Sprinkler application of effluent is common throughout the Great Plains, though little work has focused specifically on N losses from beef feedlot effluent. We quantified ammonia (NH 3) and nitrous oxide (N2O) losses from beef feedlot effluent applications under field conditions including variations in soil pH, soil water content, ammonium (NH 4+) concentration of the effluent, and... |
19. Determining In-season Nitrogen Requirements for Maize Using Model and Sensor Based ApproachesThere is great value in determining the optimum quantity and timing of nitrogen (N) application to meet crop needs while minimizing losses. Applying a portion of the total N during the growing season allows for adjustments which can be responsive to actual field conditions which result in varying N needs. Two methods of determining in-season N needs were evaluated, a model-based approach and a crop canopy sensor approach. The Maize-N model was developed to estimate the economically optimum N fertilizer... |
20. Phosphorus Loss with Runoff after Applying Fertilizer or Manure as Affected by the Timing of RainfallPublic concerns about agriculture impacts on water quality and the likelihood of further government regulation have been increasing. Phosphorus usually is the nutrient that limits and controls algae growth and eutrophication in freshwater bodies. The uninformed public and many in regulatory agencies see reducing fertilization rates as an effective way of reducing nutrient loss from fields and improving water quality, especially when animal manure is applied. Soil testing for P is a useful, although... |
21. Do Soil Nitrogen Tests Relate to Nitrogen Mineralization in First-year Corn Following Alfalfa?Corn (Zea mays L.) is the most frequent first-year crop grown following alfalfa (Medicago sativa L.) in the Upper Midwest. In the majority of cases, first-year corn does not respond to fertilizer N, but sometimes large amounts are needed to optimize yield. The pre-sidedress and Illinois soil N tests (PSNT and ISNT, respectively) are early-season tests used to predict corn yield response to fertilizer N. These tests measure specific fractions of soil N and define a critical concentration to separate... |
22. North Dakota Corn Recommendations for Preplant and Sensor Directed Sidedress NNitrogen rates for preplant N application in North Dakota have been drastically revised. The former yield-based strategy may have served when N costs were stable and relatively low and high yields in North Dakota were rarely higher than 100 bushels per acre. Due to improved germplasm developed at North Dakota State University and other northern Land-Grant Universities with favorable adaptation to North Dakota climate and soil conditions corn has become one of the most planted crops in the state.... |
23. 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 soil... |
24. 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, selenate... |
25. Precision Phosphorus Management for SoybeanSoybean responds to phosphorus fertilization in the Midwest. Most correlation and calibration data suggests that soybean is less responsive than corn. Because of this. normal management in the Upper Midwest is to fertilize before the corn crop in a corn-soybean rotation for both the corn crop and following soybean crops. This saves the cost of one application and the logistical problem of fertilization with P after a corn harvest. This management works well in soils tvith a pH less than 7.4 and... |
26. 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. In... J.M. Teboh, S. Yuja, B.G. Schatz, G. Pradhan |
27. 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, decreasing... C. Pfarr, M. Wilson |
28. Nitrogen Non-Cycling from Cover Crops Grown Before Corn and Spring Wheat-Unexpected Early Project ResultsNitrogen credits in North Dakota State University fertilization recommendations include those anticipated from the previous year annual legume crops (field pea, lentil, soybean, chickpea) and from terminated alfalfa. In addition, it was established in the region that sugarbeet tops returned to the soil may have an N credit potential of up to 80 pounds of N per acre (Crohain and Rixhon, 1967; Moraghan and Smith, 1994a; Moraghan and Smith, 1995a; Moraghan and Smith, 1995b; Franzen et al.,... D. Franzen, A. Wick, H. Bu, L. Ressler, J. Bell, M. Berti, C. Gasch |
29. Correlation of the Weak Organic Acids Test of a Soil Health Tool with Crop Yield Response to Phosphorus FertilizationThe field correlation of a soil P test with yield response to P fertilization is the foundation for sound soil-test interpretations and fertilizer recommendation guidelines. Weak organic acid extractants have been used to measure soil P for decades in some northeastern states of the US and other countries, but not in Iowa or the Midwest. A new test based on a mixture of malic, oxalic, and citric acids (H3A) was developed as a component of a Soil Health Tool to measure soil P and K. The H3A... A. Mallarino, J. Jones |
30. Effects of Sampling Time and Extraction Method on Soil-Test and Nonexchangeable Potassium in Iowa SoilsMore research is needed to better understand K cycling and high short-term temporal soil-test K (STK) variation. The objective of this research was to study soil-test K and nonexchangeable K pools across Iowa soils managed with corn-soybean rotations as affected by K application rates, soil properties, parent materials, and time of sampling. Three-year field trials that included a control and several broadcast K fertilizer rates were conducted at 35 Iowa sites. Soil samples (6-inch depth) were... R. Oltmans, A. Mallarino |
31. Nitrogen and Potassium Interactions in CornExtensive research in the North Central region has investigated separately nitrogen (N) and potassium (K) fertilizer management for corn. However, there is scarce information available about how N and K interactions affect corn grain yield and nutrient uptake. The objective of this study was to evaluate the effects of various combinations of N and K rates on corn yield, N and K tissue concentrations, and N and K removed with grain harvest. Two trials with continuous corn were conducted from 2013... J. Hirniak, A. Mallarino |
32. Evaluation of Agricultural Lime and Pelleted Lime to Increase Soil pH and Crop YieldAgricultural lime (aglime) is applied to increase pH of acidic soils to values optimum for crop production, and its effectiveness is affected mainly by it calcium carbonate (CaCO3) equivalent (CCE) and fineness. Availability and use of pelletized limestone has increased in recent years, but there is limited information about its effectiveness. Six field trials were established in 2014 at acidic Iowa soils (pH 4.9-6.1) with contrasting texture and organic matter. Treatments replicated three times... A. Mallarino, M. Haq |
33. N-Fertilizer Recovery Efficiency by Corn Using Controlled Release UreaLimited research has been conducted on the use of 15N-labeled controlled release urea fertilizers under field conditions for corn production. The objectives of this study were to: 1) evaluate the fate of N derived from a blend of two enhanced efficiency N fertilizers in corn plants throughout the growing season; and 2) to determine the N recovery efficiency of the two N sources from a blended application. A field study was conducted during the 2015-2016 growing season at Iracemápolis,... H. Gonzalez, D. Ruiz diaz, C. Filho, P. Trivelin |
34. Influence of Source and Particle Size on Agricultural Limestone Efficiency at Increasing Soil pHExcessive soil acidity is known to have potential negative impacts on crop production. The chemical and physical characteristics of a liming material determine its capacity to neutralize soil acidity. The calcium carbonate (CaCO3) equivalent (CCE) and estimates of particle size impact on the efficiency at increase soil pH are considered when assessing a material’s liming value. The reaction of limestone particles within the soil depends largely on the soil pH and the material surface area... J. Jones, A. Mallarino |
35. What Can Long Term Experiments Provide for Improving Phosphorus and Potassium Management?Agricultural research utilizes both short-term and long-term experiments. Short-term experiments provide useful information on how a system is affected at the time of management changes, and evaluate short-term responses by the soil or crop. Agricultural systems are complex systems with multiple components that operate on different time scales of response, however. Therefore, the initial response of either the whole system or individual components may not necessarily indicate the direction or... A. Mallarino |
36. Corn uptake of soil- and fertilizer-derived nitrogen in response to rate and timing of fertilizer application.While nitrogen (N) fertilizer is essential for high-yielding corn (Zea mays L.) production, over-application or application of fertilizer N before rapid corn N uptake may result in N loss that negatively impacts the environment and reduces fertilizer use efficiency. To better understand how fertilizer rate and application timing impact corn grain yield and fertilizer recovery in the soil-corn system, six two-year field studies were conducted at Minnesota field sites of contrasting soil... |
37. Can Kura Clover and Winter Rye Covers Mitigate Nitrate Leaching In Irrigated Sands?Cover crops are gaining more popularity as a mitigation tool to prevent nitrate (NO3--N) leaching from the corn (Zea mays L.) and soybean [Glycine max (L.) merr.] fields of Minnesota. Leaching of NO3--N is not only a monetary loss for growers, but also results in groundwater contamination. Winter rye (Secale cereale), a commonly grown cover crop in Minnesota and kura clover (Trifolium ambiguum), a less... |
38. Benchmarking Nitrogen Recommendation Tools for Nebraska Winter WheatAttaining high yield and high nitrogen (N) use efficiency (NUE) remains a current research challenge in crop production. Digital ag technologies for site-specific N management have been demonstrated to improve NUE. This is due to the ability of digital technologies to account for the spatial and temporal distribution of crop N demand and available soil N in the field, which varies greatly according to soil properties, climate, and management. In addition, winter wheat protein content is highly... J. Cesario pinto, L. Thompson, N. Mueller, T. Mieno, L. Puntel, G. Balboa |
39. A Minnesota-Wide Assessment of Critical Pre-Plant and in-Season Soil Nitrate for Adjusting Nitrogen Rate GuidelinesThe pre-plant (PPNT) and pre-sidedress (PSNT) soil nitrate tests are often used as indicators of soil nitrogen (N) availability in Minnesota. The assessment of available soil nitrogen (N) provides corn (Zea mays L.) growers with key information on N credits to adjust their N fertilizer rates. However, current N management recommendations in Minnesota were based on research conducted 40-yr ago and did not specify differences between environments and management. Through a comprehensive... E. Souza, F.G. Fernandez, J. Coulter, M. Wilson, J.A. Vetsch, P.H. Pagliari, R.T. Venterea, D.E. Kaiser, K.P. Fabrizzi, D. Bernau, C.J. Rosen, K. Mizuta, Y. Miao, V. Sharma |
40. Does Sensor-based Nitrogen Management Maintain Crop Production and Decrease Nitrate-N Leaching?To improve water quality, nitrogen (N) management in corn production systems should shift from current N decision support system [maximum return to N (MRTN)] which suggests a single rate N addition to sensor-based (GreenSeeker) active N management (variable N rate approach). Single rate N recommendations often result in under- and over-N addition and either increase environmental N losses or cause corn yield penalty. Our objectives were to evaluate corn optimum nitrogen N requirement (EORN) in... A. Sadeghpour, M. Guzel, J. Mcgrath, O. Adeyemi, B. Arnall, O. Guzel |
41. County-Level Phosphorus Balances for 2017 in IllinoisCropland phosphorus (P) balances (manure and fertilizer P minus crop P removal) are great sustainability tools to assess long-term managements at farm, county, and state levels. Our objectives were to estimate county, regional, and state-level cropland P balances for Illinois in 2017. Based on the census data in 2017, Illinois county P balance ranged from -14.38 to 36 lb/acre/yr. Overall, Illinois had a negative P balance at about -3 lb/acre/yr. About 71% of counties, had a negative P balance,... X. Liu, S. Xu, A. Margenot, A. Sadeghpour, O. Zandvakili, M. Guzel |