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Full-Text Articles in Life Sciences
The Effect Of Preflood Nitrogen And Flood Establishment Timing On Rice Development, Nitrogen Uptake And Grain Yield, Tyler Richmond
The Effect Of Preflood Nitrogen And Flood Establishment Timing On Rice Development, Nitrogen Uptake And Grain Yield, Tyler Richmond
Graduate Theses and Dissertations
Urea-N fertilizer is typically applied at the 5-leaf stage to rice (Oryza sativa L.) grown in a dry-seeded, delayed-flood production system. How long the preflood-N can be delayed without adverse effects on yield potential is poorly understood. The research objective was to determine the effects of preflood-N application and flood establishment timing on aboveground-N content, 50% heading, yield components, and grain yield. Trials were established on silt loam soils at the Pine Tree Research Station (PTRS) and Rice Research and Extension Center (RREC) during 2015 and 2016. Urea-N was applied at 0, 45, 90, 135, and 180 kg N ha-1 …
Rice Grain Yield And Nitrogen Uptake And Ammonia Volatilization From Urea As Affected By Urea Amendment And Simulated Rainfall, Randy Dempsey
Rice Grain Yield And Nitrogen Uptake And Ammonia Volatilization From Urea As Affected By Urea Amendment And Simulated Rainfall, Randy Dempsey
Graduate Theses and Dissertations
The effect of rainfall between urea application and flood establishment on N loss and grain yield of rice (Oryza sativa L.) has not been studied. The first research objective was to compare the effects of simulated rainfall amounts and N-(n-butyl) thiophosphoric triamide (NBPT) urease inhibitor rate on NH3 volatilization and rice growth. Three field experiments were conducted and NH3 volatilization was measured in two experiments for 11 days after urea application (DAU) in semi-open chambers. Urea or NBPT-treated urea (NBPT-Urea) was subjected to six simulated rainfall amounts (0-25 mm) applied 5 to 15 h after urea application and flooded 7 …
Potential For Optical Sensor-Based Nitrogen Fertilization In Grain Sorghum (Sorghum Bicolor L. Moench) In Arkansas, Kamil H. Rosales Rodriguez
Potential For Optical Sensor-Based Nitrogen Fertilization In Grain Sorghum (Sorghum Bicolor L. Moench) In Arkansas, Kamil H. Rosales Rodriguez
Graduate Theses and Dissertations
Ground-based active-optical (GBAO) crop sensors have become an effective tool to improve nitrogen (N) use efficiency and to predict yield early in the growing season, particularly for grass crops. Commercially available canopy sensors calculate the normalized difference vegetative index (NDVI) by emitting light in the red and near infrared range of the electromagnetic spectrum. The NDVI is used to evaluate vigor status and to estimate yield potential. However, few studies have been conducted to compare the performance of commercially available sensors. Therefore, a study was conducted using the most common crop canopy sensors: i) N-Tech's GreenSeekerTM (GS), ii) Holland …
Fertilizer Nitrogen Uptake Efficiency In Soft Red Winter Wheat And The Ability Of N-Star To Detect Alkaline Hydrolyzable Nitrogen In Crop Residues, Lana Aubrey Clark
Fertilizer Nitrogen Uptake Efficiency In Soft Red Winter Wheat And The Ability Of N-Star To Detect Alkaline Hydrolyzable Nitrogen In Crop Residues, Lana Aubrey Clark
Graduate Theses and Dissertations
Soil testing methods such as the Illinois Soil Nitrogen Test (ISNT) and Direct Steam Distillation (DSD) have been developed which measure alkaline hydrolyzable-N (AH-N) as a means of estimating potentially mineralizable-N. Crop residues play an important role in N cycling. However, the ability of the ISNT and DSD methods to determine AH-N within crop residues is unknown. Therefore, the first objective of this study was to determine the ability of the ISNT and DSD to quantify potentially mineralizable-N within five different crop residues common to Arkansas. Corn (Zea mays L.), soybean (Glycine max, L.), wheat, rice (Oryza sativa, L.), and …