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1. Evaluation of Crop Canopy Sensors as a Tool for Soybean Research and ProductionDetermining the variables that consistently increase yields in soybean  [Glycine max (L.) Merr.] continues to challenge researchers, agronomists and growers alike. Crop canopy sensors have emerged as a technology used in other cropping systems to monitor and manage agricultural inputs. The sensors measure reflectance in selected wavebands that are used to calculate vegetation indices that relate to unique leaf or canopy characteristics. The objectives of this study were to determine if a commercially... |
2. Effects of Nitrogen Managemetn on Maize Yield and Nitrate Leachingon Irrigated Sandy SoilsIrrigated sands are some of the most productive and environmentally sensitive areas in Minnesota. Reducing nitrate leaching is critical for corn (Zea mays L.) production as ground water is a major source of drinking water in these soils. The objective of this study was to evaluate agricultural technologies that may improve nitrogen (N) management for profitable corn production and mitigate negative effects in groundwater. A randomized complete block design with four replications was established... |
3. Quantifying the Effects of Nutrient Management and Cover Crops on Soil Microbial Communities and Soybean ProductionAgricultural productivity relies upon microbial communities to cycle nutrients from soil to plant yet little information is available concerning how nutrient management and cover cropping practices influence microbial activity and crop production. Lack of consistent soybean (Glycine max L.) yield response to applied fertilizer has resulted in a need to further investigate management practices focused upon enhancing soil biological activity which in turn may feed the crop. A field study was initiated... |
4. Effect of Ammonium to Nitrate Rations of Fertilizers Applied at Various Times Throughout the Growing Season on Yield and Nitrogen Concentrationof CornA number of recent investigations have produced evidenm that the ionic form of N taken up by roots affects the growth of plants. While soil- plants generally take up rest 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 prevent* the rapid miaxbial conversion of ammonium to nitrate in soil, this response has nat been well demnstrated in a field situation. The objective... |
5. 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.... |
6. Nitrogen Test Development Soil N Levels in 1989The developnent of a N test that can be used for fertilizer recamrendations of corn in the eastern areas of Minnesota is needed for environmental and econcmic reasons. A multi-site project was initiated in 1989 to extensively examine soil sampling time and depth as well as N forms in the soil. This will then enable statistical models to be develaped using one or mre of the variables. A subset of the entire project is reported--concentrating on the sites allowing the calibration of the soil N tests... |
7. Establishing (and Differentiating) On-farm Research and Demonstration TrialsAs the 1990s begin, funding agencies are looking beyond the traditional definition of who does "research." While university, USDA and private industry have traditionally conducted research in the past, grassroot organizations, local agency personnel and individual farmers are now proposing and implementing research of various types. An overall trend seems to be for research experiments to be evaluated on farmersf fields. Some of this movement may be a political statement against traditional methods... |
8. Assessing Crop Nitrogen Needs with Chlorophyll MetersTissue testing of corn leaves for nitrogen (N) concentration is not widely used because it is easier and perhaps more economical to apply sufficient fertilizer than to risk a yield reduction because of an N deficiency. Environmental concerns related to N fertilizer will require producers to improve N management practices to reduce the potential for nitrate leaching. Applying fertilizer N on an "As Needed" basis rather than using a "Lump Sum" approach has both environmental and economic implications.... |
9. Best Management Practices for Nitrogen in MinnesotaAtrention to nirrogen (N) nlanagemerzt and to rhe influence of N on ground- rvarer qzraliry was significanrly enhanced in Minnesota wirh the passage of the Conlprehensive Groundwater Protection Acr in 1989. That legislative act mandated the fonnarion of u Nirrogen Fertilizer Task Force whose duty was ro study the eflecrs and impacrs on water resources fro,n N fenilizer use so rhar besr management practice (BMPs), a fenilizer managenlenr plan, and N fem'l- izer use regulations could be developed.... |
10. A Nitrogen Soil Test for CornIn the past decade, many states have started including a soil test when making N recommendations. In order for a soil N test to be useful, it must provide information that is not known or incorporated when making N recommendations without a test. If a test does not provide explainable, qunlltifiable infarmation. the tcs: !cses its usefghess. In Minnesota, a falllspring preplant N test has been used in the western tier of counties, which have lower rainfall than the rest of the state, for many years.... |
11. Nitrogen and Water ManagementIt is difficult to separate N and water management when developing improved management systems for irrigated corn production. This is because adequate supplies of both N and water are critical for crop growth, but excesses of either or both can threaten ground water quality. Several N and water management systems were established at the Nebraska Management Systems Evaluation Area (MSEA) project to evaluate the impact of improved irrigation and N fertilizer management practices on production and/or... |
12. 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 aerial... |
13. Remote Sensing as a Tool for AgricultureThe tendency for nearlv everything in our society to be bigger, better, faster, easier, cheaper, and safer than in the past has resulted in many challenges. Agriculture is not immune from these trends, and in some cases agriculture even leads the way. Incorporation of remote sensing into site- specific management activities is one area where technologies are being merged to develop a new array of products that are intended to help producers and consultants make better and more timely management decisions.... |
14. Topsoil Thickness Influence on Phosphorus and Potassium Availability and Crop ResponseSoil testing to estimate nutrient availability and fertilizer needs is a widespread management practice for cropping systems in the United States. as well as in other countries. The purpose of soil testing is to simulate the ability of the plant roots lo uptake these various nutrients critical for normal growth. Crops generally uptake a s~nall amount of phosphorus (P) compared to potassium (K). The portion of soil P that is readily available for plant growth maybe limiting due to the small quantities... |
15. Remotely Sensed Crop Indices for Nitrogen StressCrop nitrogen (N) stress has a strong influence on plant vigor and growth. Under field conditions, crop N stress is frequently expressed through spatial variability in biomass production and grain yield. Remote sensing serves as a useful tool to monitor crop N status by characterizing canopy reflectance because certain wavebands (i-e., colors) are sensitive to chlorophyll and crop growth. Unfortunately, interpreting reflectance data in terms of crop stress is still an inexact science. Several indices... |
16. Early Season Stresses in CornSpatial variability in corn yield is frequently associated with lost yield potential caused by plant stresses. Early-season stresses are difficult to recognize because growing conditions (soil temperature and water status) are not ideal and seldom uniform throughout a field. The impact that climate has on plant growth is dificult to determine because it also affects nitrogen (N) availability. Nitrogen stress was imposed sequentially until the V8 growth stage and then all plots were sidedressed with... |
17. Vegetative Assessment of Phosphorus and Nitrogen Status in Maize Using Remote SensingAssess spatial variability of soil P and N is not only costly but also a time consuming processes. Remote sensing measurements of canopy spectral reflectance can provide a rapid and non- destructive method for assessing plant-canopy nutrient status. The main objective of this research was to detect P and N stress during the early corn growth by selecting specific wavelengths, or combinations of them, using narrow band field sensors. In 2001, two corn experiments were planted over an old manure experiment... |
18. 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... |
19. 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... |
20. 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... |
21. 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... |
22. 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... |
23. 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... |
24. 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... |
25. A Smorgasbord of Preliminary Results from Field Trials in OntarioField scale trials may be established to support lo cal needs, but the results seldom reach a wider audience. This paper summarizes two recent fiel d studies by staff of the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) on fertilizer use in soybeans and corn. A study of starter fertilizer response in soybeans found that yield responses to fertilizer tended to be relatively small, and seldom large enough to cove r the cost of the added fertilizer. A second study of ammonia volatilization... |
26. Active-Crop Sensor Calibration Using the Virtual-Reference ConceptCalibration of laboratory and field instruments usually involves collecting data from some type of accepted standard materials or compounds. This approach works well for most physical and chemical measurements; however, such procedur es become problematic when dealing with biological systems like plants that go throug h a number of physiological states during the growing season. In addition, genetic composition differences between cultivars can affect the architecture of plant canopies a nd relative... |
27. 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 (Trifolium... S.J. Leuthold, M. Salmeron, O. Wendroth, E. Haramoto, H. Poffenbarger |
28. Active-Optical Reflectance Sensing Evaluated for Red and Red-Edge Waveband SensitivityUncertainty exists with corn (Zea mays L.) N management due to year-to-year variation in crop N need, soil N supply, and N loss from leaching, volatilization, and denitrification. Active-optical reflectance sensing (AORS) has proven effective in some fields for generating N fertilizer recommendations that improve N use efficiency. However, various sensors utilize different wavebands of light to calculate N fertilizer recommendations making it difficult to know which waveband is most sensitive... G. Bean, N. Kitchen, J. Camberato, R. Ferguson, F. Fernandez, D. Franzen, C. Laboski, E. Nafziger, J. Sawyer, P. Scharf, J. Schepers, J. Shanahan |
29. Side-dressing Nitrogen Influence on Nitrogen Release Dynamics of Early and Late-Terminated Cereal Cover CropTermination date and nitrogen application of corn (Zea mays L.) can influence the decomposition rate of cover crops in a corn cropping system. Our objective was to evaluate (i) the biomass accumulation and nutrient uptake of wheat (Triticum aestivum L.) fertilized with 34 kg N/ha and (ii) decomposition rate of wheat terminated early (4 weeks prior to planting) and late (at corn planting time) with and without side-dressing N at 168 kg N/ha. Our preliminary data... A. Sadeghpour, G. Singh, A. Weidhuner, R. Lange |
30. CORN YIELD AND NITROGEN USE EFFICIENCY RESPONSE TO WHEAT COVER CROP AND SPLIT NITROGEN APPLICATIONCorn (Zea mays L.) grain is a major commodity crop in Illinois and its production largely relies on timely application of nitrogen (N) fertilizers. Currently, growers in Illinois and other neighboring states in the U.S. Midwest use the maximum return to N (MRTN) decision support system to predict corn N requirements. However, the current tool does not factor in implications of integrating cover crops into the rotation, which has recently gained attention among growers due to several... R. Keshavarz-afshar, E. Jahanzad, M. Battaglia, Y. Luo, A. Sadeghpour, O. Adeyemi |
31. Precision planting impacts on winter cereal rye growth, nutrient uptake, spring soil temperature, and adoption costGrowing winter cereal rye (Secale cereale) (WCR) has been identified as an effective in-field practice to reduce nitrate-N and phosphorus (P) losses to Upper Mississippi River Basin (UMRB), USA. In the Midwestern USA, growers are reluctant to plant WCR especially prior to corn (Zea mays L.) due to N immobilization and establishment issues. Precision planting of WCR or “Skipping the corn row” (STCR) can minimize some issues associated with WCR ahead of corn while reducing... |
32. Carbon Credit and Sequestration in Agroecosystems; Lessons from Trials in Southern IllinoisA carbon (C) credit is the attribution of net CO2-C equivalent which can be used to decrease climate forcing through a given practice or farming system for a given unit time. Carbon credits allow industries to purchase C that is produced on a farm (i.e., offsets). Carbon can be captured in two ways; (i) by capturing and reducing greenhouse gasses (on a CO2-C equivalent basis), and/or (ii) by increasing soil organic C stocks. Therefore, to enable C credits in the agricultural... A. Sadeghpour, A.M. Weidhuner, G. Burkett, O. Zandvakili, O. Adeyemi, C. Kula, J. Berberich, J. Pike, A.J. Margenot |
33. Cover Crop Species and Planting Methods Influence on Corn N Requirement in Southern IllinoisIt is well established that planting cover crops prior to corn (Zea mays L.) can influence soil temperature, moisture, and nitrogen (N) dynamics. These changes in soil along with the effects of cover crop on corn plant population can influence corn grain yield and N requirement. Two strategies to facilitate corn establishment and avoid N immobilization especially in winter cereal cover crops is by mixing cover crop species or skipping the corn row (precision planting). A randomized complete... A. Sadeghpour, C. Kula, G. Sener, C. Vick |
34. Impacts from Autumn Starter Fertilizer, Late-season Nitrogen, and Fungicide Timing on Winter Wheat Yield, Straw, and QualityIncreased demand for winter wheat (Triticum aestivum L.) and climate uncertainties have Michigan growers exploring intensive management strategies to improve both yield and profitability. Field studies investigated the influence of both early and late-season fertilizer applications with multiple fungicide timings on the yield and quality of winter wheat grain and straw. A full-factorial, randomized complete block design investigated two rates of autumn starter fertilizer (AS) (12-40-0-10-1,... K. Steinke, M.K. Suplito, M. Chilvers |
35. Corn Nitrogen Requirement in Winter Cereal Cover Crop Trials in Southern IllinoisWinter cereal cover crops, including wheat (Triticum aestivum L.) and winter rye (Secale cereale L.) are recommended as the best in-field management strategy by the Illinois Nutrient Loss Reduction Strategy (INLRS) to minimize nitrate-N leaching to the Mississippi River Basin and the Gulf of Mexico. We evaluated the effect of wheat and winter rye on corn grain yield, and nitrogen (N) requirement. Treatments were laid out in a randomized complete block design with four replicates... A. Sadeghpour, O. Adeyemi, O. Guzel, C. Kula, J. Mcgrath, G. Sener guzel |
36. 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 |
37. Does Nitrogen Management in Winter Wheat Affects Its Yield and Nitrate-N Leaching in a Wheat-Soybean Double Cropping System?Conventional corn (Zea mays L.)-soybean (Glycine max L.) rotation contributes to nitrate-N and phosphate leaching to waterbodies causing water quality concerns. Two strategies that could minimize N and P losses include (i) incorporating winter rye (Secale cereale L.) (WR) as a cover crop to capture residual nutrients or (ii) intensifying the corn-soybean rotation with winter wheat (WW) (Triticum aestivum L.) (Double cropping). Double cropping WW at a right N... A. Sadeghpour, O. Ola, O. Guzel, K.L. Gage, K. Williard, J. Schoonover, S. Mueller |
38. Does Nitrogen Fertilization with Manure Injection Versus Surface Application Influence Corn for Silage and Winter Rye Yield, Quality, Phosphorus Balance and Soil Test Phosphorus Over Three Years?Switching from nitrogen (N)-based to phosphorus (P)-based manure management has been shown to decrease P loss to the environment allowing for sustainable P management in dairy farms. At high P soils, dairy farmers often surface apply the liquid manure to corn (Zea mays L.) for silage at the P-based rates and supplement the limited N to corn with N fertilizers to ensure optimum crop production. With high fertilizer prices, one solution to reducing the N requirement of corn could be to... A. Sadeghpour, G. Burkett, S. Babaei, O. Adeyemi, K. Vaughn, C. Kula |
39. Response of Corn to Planting Methods of Cover Crop Species and Nitrogen Rate in Southern IllinoisIt is well established that planting cover crops prior to corn (Zea mays L.) can influence soil temperature, moisture, and nitrogen (N) dynamics. These changes in soil along with the effects of cover crop on corn plant population can influence corn grain yield and N requirement. Two strategies to facilitate corn establishment and avoid N immobilization especially in winter cereal cover crops is by mixing cover crop species or skipping the corn row (precision planting). A randomized complete... A. Sadeghpour, G. Sener guzel, C. Kula, C. Vick |
40. Cover Crop Species and Planting Methods Influence on Corn N Requirement in Southern IllinoisIt is well established that planting cover crops prior to corn (Zea mays L.) can influence soil temperature, moisture, and nitrogen (N) dynamics. These changes in soil along with the effects of cover crop on corn plant population can influence corn grain yield and N requirement. Two strategies to facilitate corn establishment and avoid N immobilization especially in winter cereal cover crops is by mixing cover crop species or skipping the corn row (precision planting). A randomized complete... A. Sadeghpour, C. Kula, G. Sener |
41. 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 |