Proceedings
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| Filter results19 paper(s) found. |
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1. Can Soil Information Better Inform Canopy Sensor Algorithms for Corn?Corn production is often limited by the loss of nitrogen (N) due to leaching, volatilization and denitrification. The use of canopy sensors for making in-season N fertilizer applications has been proven effective in matching plant N requirements with periods of rapid N uptake (V7-V11), reducing the amount of N lost to these processes. However, N recommendation algorithms used in conjunction with canopy sensor measurements have not proven accurate in many fields of the U.S. Cornbelt, resulting in... , N.R. Kitchen, J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, F.G. Fernandez, E.D. Nafziger, C.J. Ransom, , J. Shanahan, G.M. Bean |
2. Influence of Tillage Systems on Corn Yields and Soil Test ValuesA long term tillage study was initiated at the Greenley Memorial Research Center (Novelty, MO) in 1976 to look at the effects of 4 tillage systemsoncornproduction. Thestudywasinitiatedandconductedby researchers in the Agricultural Engineering Department. Agronomy has become involved in the study beginning in 1985 to assess the effects of tillage systems on soil chemical and physical properties. The upland soils at this site are poorly drained and are generally refered to as "claypan" soils. The climate... |
3. Field Estimation of Ammonia Volatilization from Surface-applied UreaAccurate estimation of the potenial for NH3 volatilization from urea-based fertilizers is an important step in optimizing Nuse efficiency from these fertilizers. Published estimates of volatilization from surface-applied urea vary widely. Citations listing losses from 2% on up to 80% from various systems can be found. Consequently, many growers, to protect themselves, will apply urea at higher than recommended rates, assuming some arbitrary level of loss will occur. The objectives of the research... |
4. Site Specific Nitrogen and Irrigation Management Across Nebraska Agro-ecological ZonesNitrogen leaching below hrrow irrigated ground has caused nitrate contamination in Nebraska's groundwater. Alternate row irrigation and alternate row nitrogen fertilization is proposed as a method to decrease water use and decrease nitrogen leaching. Nitrogen was applied at a uniform and variable rates based on spring grid sampling for nitrate and soil organic matter. The experiment was conducted at three sites in Nebraska that represent a range of growing conditions. At these sites the average growing... |
5. Effects of Soil Test, Tillage, and Manure and Fertilizer Application Method on Phosphorus RunoffLoss of phosphorus from agricultural lands into surface waters is of growing environmental concein. Phosphorus transported by surface runoff often ends up in streams and lakes and accelerates eutrophication, which affects the ability to use the water for drinking, fishing. recreation. etc (Foy and Withers, 1995). The niajor mechanisms by which agriculture contributes phosphorus to surface water is through runoff and erosion (Sharpley et al., 1994). Controlling run~ff and erosion from agricultural... |
6. Site-Specific Nitrogen and Irrigation Management Across Nebraska Agro-Ecological ZonesNitrogen leaching below hrrow-irrigated ground has caused nitrate contamination in Nebraska's groundwater. Alternate row hrrow irrigation and alternate row nitrogen fertilization is proposed as a method to decrease water use and decrease nitrogen leaching. Nitrogen (N) was applied at a uniform and variable rate based on spring grid sampling for nitrate. The experiment was conducted at three sites in Nebraska that represent a range of growing conditions. At these sites, the average growing degree-days... |
7. Strategies for Establishing Management Zones for Site Specific Nutrient ManagementRecent precision agriculture research has focused on the use of management zones as a method to define areas for variable application of crop inputs. The goal of our work was to determine the relative importance of terrain information, aerial photographs, magnetic induction maps, and yield maps to define management zones. This work was conducted on a center-pivot irrigated field located near Gibbon. NE that has been planted to continuous corn for at least five years. Remotely sensed bare-soil images,... |
8. Use of Chlorophyll Flourescence Techniques to Detect Stresses in CornIncreased efficiencies in the use of water and fertilizer will require better methods of monitoring crop stress. This study was conducted to determine whether chlorophyll fluorescence was more sensitive to detecting water and nitrogen stress than chlorophyll meters in corn (Zea mays). The experiment was carried out near Shelton, NE in 2000, 200 1, and 2002. Treatments consisted of a factorial combination of 12 corn hybrids (1 1 Pioneer Hi-Bred internationali and B73 x M017), two water levels (deficit... |
9. Nutrient Management Implications of Relay Cropping on the EnvironmentResidual nitrogen (nitrate-N) remaining in the root zone after seed corn production is frequently greater than under commercial corn production. This nitrate is subject to leaching into the shallow ground water of the Platte River Valley in South-Central Nebraska. as noted by elevated nitrate-N concentrations under seed cornfields compared to other fields. Hard-red winter wheat was planted into seed corn residue in early October of 2001 as a cover crop to scavenge residual- N from the root zone and... |
10. Relationship Between Response Indices Measured In-Season and at Harvest in Winter WheatCurrent methods for making nitrogen recommendations in winter wheat (Triticum aestivurn L.) do not adjust for in-season temporal variability of plant available non-fertilizer nitrogen (N) sources. The purpose of this study was to compare the use of different nitrogen response indices determined in-season @INDVI and RIPLANTHEIGkm) to the nitrogen response index measured at harvest (RIHARvEST). In addition, this study evaluated the use of the in-season response indices for determining topdress nitrogen... |
11. Active Sensor Orientation Over Corn Rows and Effect on Assessment of BiomassOur long-tern mresearch goal is to develop practical N application systems that use on-the-go remote sensing as a nleans to assess crop N status and only apply N where needed at times when the crop can most efficiently utilize N. Our preliminaty testing of two active sensor systems has shoxl-11 considerable promise for rapid and accurate assessment of canopy N status and crop biomass. In this work, the effect of sensor positioning and orientation over the canopy and their effects on assessment of... |
12. An Update on Crop Canopy Sensors for In-Season N ManagementRemote sensing in agriculture has focused 011 the spectral and spatial properties of plants. Remote sensing provides the capability for rapid collection of vast quantities of spatial data that can be analyzed quickly for use in detel-mining a course of action. This creates the potential for using remote sensing to assess and manage in-season production practices. Past research has shown that a change in canopy rel-lectance inay not be unique for a given stress. Also, other agents may have effects... |
13. In Season RecommendationsWe are testing a prototype high-clearance tractor configured with active crop canopy sensors, drop nozzles with electronic valves, and a variable rate controller as means to deliver in-season variable rates of liquid N fertilizer based on crop needs as an alterative to preplant uniform applications of N. The active sensor we're evaluating is the model ACS-210 Crop Circle made by Holland Scientific. It generates it's own source of modulated light in the amber and near infrared (NIR) bands and then... |
14. In-Season Nitrogen Recommendations for CornMaking fertilizer N recommendations involves a great deal of guess work and uncertainty because much, essentially all, of the fertilizer N is applied before the crop is planted and the amount is based on estimated crop use from historical data. In addition, producers, consultants, and fertilizer dealers try to anticipate how much N might be lost because of untimely or excess precipitation or how much additional N might be required if the weather conditions are favorable. Sidedress and in-season... |
15. Crop Residue Removal Effects on Soil PropertiesThree large challenges facing mankind are the n eed to feed a rapidly growing population, increasing concentration of greenhouse gases in the atmosphere, and reliance on fossil fuels. Expectations from agriculture include produ ction of food and fiber to meet demands, management of agricultural systems to sequester carbon and redu ce emission of other greenhouse gases, and provision of feedstock for a rapidly expanding biofuels industry. Some discussions involving use of crop residue for biofuel... |
16. 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 fields... |
17. Management Zone Delineation Techniques to Aid In-Season Sensor Based Nitrogen ApplicationThe increased efficiency of nitr ogen fertilizer (N) use has been a long-term goal in reduction of nitrate contamination in the stat e of Nebraska. Preliminary rese arch has shown sensor based in- season application of nitrogen has the ability to be economic and environmentally viable. Although benefits have been published there is an opportunity for increased accuracy of N application through the integration of preprocesse d georeferenced management zones. In-season sensor based N application relies... |
18. Fertilizer management and cover crop effects on phosphorus use efficiency, environmental efficiency and crop yieldPhosphorus loss from agricultural production is a significant contributor to the degradation and contamination of surface and ground waters. To help protect these waters, it is vital to maximize agronomic and environmental efficiency of phosphorus in the cropping system. The objective of this study was to quantify the effects of cover crops and different phosphorus fertilizer management practices on nutrient use efficiency, environmental efficiency and yield in a no-tillage corn-soybean rotation.... R. Carver, N. Nelson, G. Kluitenberg, K. Roozeboom, P. Tomlinson |
19. Nitrogen Rate and Harvesting Time Based on Growing Degree Days Influenced Winter Cereal Rye Morphological Traits, Forage Yield, Quality, and Farm Profit in Poorly Drained AlfisolsWinter cereal rye (Secale cereale L.) (WCR) is often double cropped with maize for silage (Zea mays L.) to increase farm forage supply and profit. Spring nitrogen (N) fertilization to WCR could influence its production and quality at different harvesting times. Therefore, two on-farm trials were conducted in the 2019-2020 and 2020-2021 growing seasons to evaluate the effect of harvesting time (late-March to end-of-April considering the growth stage) and spring N fertilization... G. Burkett, K. Vaughn, O. Adeyemi, O. Zandvakili, M. Battaglia, S. Babaei, J. Nair, S. Still, A. Sadeghpour |