Plant Sciences Commons^™

Integration Of Cover Crops Into Midwest Corn-Soybean Cropping Systems And Potential For Weed Suppression, Joshua S. Wehrbein

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Cover crops have potential to provide benefits to agricultural systems, such as improved soil productivity, nutrient scavenging, weed suppression, and livestock forage. There are several challenges associated with cover crop integration into traditional Midwest corn-soybean cropping systems. One of these challenges is timely establishment in the fall, which is limited by the relatively late harvest of corn and soybean. Cover crop effectiveness is related to the amount of biomass produced, thus maximizing the growth period in the fall is desired. To address this challenge, we evaluated the potential to utilize early-season soybean maturity groups (MGs) to allow for earlier soybean …

Arkansas Corn And Grain Sorghum Performance Tests 2019, J. F. Carlin, R. D. Bond, J. A. Still

Arkansas Agricultural Experiment Station Research Series

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers. The 2019 corn performance tests contained 74 hybrids and were conducted at the Northeast Research and Extension Center (NEREC) at Keiser, the Lon Mann Cotton Research Station (LMCRS) near Marianna, the Bell Farming Company near Des Arc, the Rohwer Research Station (RRS) near Rohwer and the Rice Research and Extension Center (RREC) near Stuttgart. The 2019 …

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabián G. Fernández, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

John E. Sawyer

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and machine learning (ML) algorithms for utilizing soil and weather information for improving corn N recommendation tools. Eight algorithms [stepwise, ridge regression, least absolute shrinkage and selection operator (Lasso), elastic net regression, principal component regression (PCR), partial least squares regression (PLSR), decision tree, and random forest] were evaluated using a dataset …

Factors Influencing The Spatial Distribution Of Southern Rust In Corn, Justin Bailey

Graduate Theses and Dissertations

Southern rust caused by the fungus Puccinia polysora (Underwood) is the most economically important foliar disease in corn (Zea mays) (Linnaeus) (Cyperales: Poaceae)) for Arkansas. The objective of this work was to determine distribution of southern rust in corn and to determine factors that may control its distribution.

During the 2017 and 2018 season, seven corn fields in Arkansas were rated for southern rust. After disease confirmation, fields were marked with GPS sample point locations in a grid pattern across the entire field. Ratings for disease severity were taken below, at, and above the ear leaf at each point every …

Development Of A Nitrogen Recommendation Tool For Corn Considering Static And Dynamic Variables, Laila A. Puntel, Agustin Pagani, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Many soil and weather variables can affect the economical optimum nitrogen (N) rate (EONR) for maize. We classified 54 potential factors as dynamic (change rapidly over time, e.g. soil water) and static (change slowly over time, e.g. soil organic matter) and explored their relative importance on EONR and yield prediction by analyzing a dataset with 51 N trials from Central-West region of Argentina. Across trials, the average EONR was 113 ± 83 kg N ha⁻¹ and the average optimum yield was 12.3 ± 2.2 Mg ha⁻¹, which is roughly 50% higher than the current N rates used …

Evaluation Of Stabilized Fertilizer And Crop Canopy Sensors As Next-Generation Nitrogen Management Technologies In Irrigated Corn, Leonardo Mendes Bastos

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen (N) is often the most limiting nutrient to corn. Once applied to the field, N can be lost through different pathways, which contributes to low N use efficiency (NUE) by plants. Increases in NUE and decreases in N losses can be potentially achieved by using management options that allow a better synchrony between N supply and demand, such as stabilized fertilizers, and spatially-variable sensor-derived in-season N application. Three studies were conducted in order to assess the effects of different stabilized fertilizers and crop canopy sensors on irrigated corn yield. The first study evaluated the effect of urease inhibitor on …

Use Of Satellite Imagery To Predict Corn Phenology At A Regional Scale, L. Nieto, R. Schwalbert, I. A. Ciampitti

Kansas Agricultural Experiment Station Research Reports

Existing methods to report phenology are expensive, labor-intensive, time-consuming, and often not very accurate, especially at some specific crop growth stages. The objec­tive of this study was to develop large-scale phenology models via utilization of satellite imagery data and machine learning techniques for the southwest (SW) agricultural crop reporting district of Kansas. Different satellite images collected from Landsat were utilized as the main input to obtain different vegetation indices (normalized difference vegetation index, NDVI; enhanced vegetation index, EVI; green chlorophyll vegeta­tion index, GCVI; normalized difference water index, NDWI; and global vegetation moisture index, CVMI). Vapor Pressure Deficit (VPD), temperature, precipitation, …

Southeast Kansas Crop Production Summary – 2018, G. F. Sassenrath, L. Mengarelli, J. Lingenfelser, X. Lin

Kansas Agricultural Experiment Station Research Reports

This is a summary of the crop production conditions in southeast Kansas in 2018, and the results of the variety testing for corn, soybean, sorghum, sunflower, and wheat.

Pre-Plant Nitrogen Rate And Application Method And Side-Dress Nitrogen Rate Effects On Corn Grown No-Till On A Claypan Soil, D. W. Sweeney, D. Ruiz-Diaz

Kansas Agricultural Experiment Station Research Reports

Corn yield in 2018 was increased by about 5 bu/a with knife application of pre-plant nitrogen (N) fertilizer compared with broadcast application. Fertilizing with increasing rates of N applied pre-plant, at side-dress, or both had little effect on yield or yield components of corn in 2018.

Large-Scale Dryland Cropping Systems, A. Schlegel, L. Haag, A. Burnett

Kansas Agricultural Experiment Station Research Reports

This study was conducted from 2008–2018 at the Kansas State University Southwest Research-Extension Center near Tribune, KS. The purpose of the study was to identify whether more intensive cropping systems can enhance and stabilize production in rainfed cropping systems to optimize economic crop production, more efficiently capture and utilize scarce precipitation, and maintain or enhance soil resources and environmental quality. The crop rotations evaluated were continuous grain sorghum (SS), wheat-fallow (WF), wheat-corn-fallow (WCF), wheat-sorghum-fallow (WSF), wheat-corn-sorghum-fallow (WCSF), and wheat-sorghum-corn-fallow (WSCF). All rotations were grown using no-tillage practices except for WF, which was grown using reduced-tillage. The efficiency of precipitation capture …

Effects Of Supplementation With Corn Or Dried Distillers Grains On Gains Of Heifer Calves Grazing Smooth Bromegrass Pastures, L. W. Lomas, J. L. Moyer

Kansas Agricultural Experiment Station Research Reports

A total of 150 heifer calves grazing smooth bromegrass pastures were used to compare supplementation with 0.5% of body weight per head daily of corn or dried distillers grains (DDG) in 2014, 2015, 2016, 2017, and 2018. Daily gains of heifers supplement­ed with corn or DDG were similar (P>0.05) in all years except 2018, when heifers supplemented with DDG had greater (P<0.05) gains than those supplemented with corn.

Alternative Cropping Systems With Limited Irrigation, A. Schlegel, D. Bond

Kansas Agricultural Experiment Station Research Reports

A limited irrigation study involving four cropping systems and evaluating four crop rotations was initiated at the Southwest Research-Extension Center near Tribune, KS, in 2012. The cropping systems were two annual systems (continuous corn [C-C] and continuous grain sorghum [GS-GS]) and two 2-year systems (corn- grain sorghum [C-GS] and corn-winter wheat [C-W]). In 2018, corn yields were similar for all rotations, although averaged across the past 6 years, corn yields were greater following wheat than following corn. There were no significant differences in grain sorghum yields in 2018, which was similar to the multi-year average. Wheat yields were near the …

Tillage And Nitrogen Placement Effects On Yields In A Short-Season Corn/Wheat/Double-Crop Soybean Rotation, D. W. Sweeney, D. Ruiz-Diaz

Kansas Agricultural Experiment Station Research Reports

In 2018, adding nitrogen (N) greatly improved average wheat yields with about a 10% increase with knife compared to broadcast application methods. Even though tillage did not affect wheat yields, soybean yield was about 10% greater with no-till.

Kansas Field Research 2019

Kansas Agricultural Experiment Station Research Reports

Research from Kansas State University experiment fields on crop varieties, tillage, irrigation, weed management, and fertilizers.

Changes In Soil Nitrate And Ammonium During The Corn Growing Season As Affected By Nitrification Inhibitors, F. D. Hansel, D. A. Ruiz Diaz

Kansas Agricultural Experiment Station Research Reports

Nitrification inhibitors (NI) are used to delay the nitrification process, increasing nitrogen fertilization efficiency. The objective of this study was to evaluate the effect of NI on soil nitrate (NO₃-N) and ammonium (NH₄-N) content throughout the growing season for corn. The study was conducted at four locations (Manhattan, Scandia, Rossville, and Ashland, KS) during the 2017 and 2018 crop seasons. Most of the NI effects on soil NH₄-N and NO₃-N were observed early in the season and when the higher nitrogen (N) fertilizer rate was used. An increase in NO₃-N …

Tillage Study For Corn And Soybeans: Comparing Vertical, Deep, And No-Tillage, E. A. Adee

Kansas Agricultural Experiment Station Research Reports

Trends from a tillage study conducted since 2011 have shown no clear differences between tillage systems for either corn or soybeans in lighter soils under irrigation. One out of seven years has shown a yield advantage for either corn or soybeans for any tillage system, which appears to be related to environmental conditions experienced during the season.

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and machine learning (ML) algorithms for utilizing soil and weather information for improving corn N recommendation tools. Eight algorithms [stepwise, ridge regression, least absolute shrinkage and selection operator (Lasso), elastic net regression, principal component regression (PCR), partial least squares regression (PLSR), decision tree, and random forest] were evaluated using a dataset …