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1	Evaluation of technology aimed to improve nitrogen use efficiency for delayedlood rice (Oryza sativa L.) production Satterfield, Jason Morris 02 May 2009 (has links) Improving nitrogen (N) use efficiency is crucial for maximizing growth and yield in rice production. Tools to determine precise midseason N rates as well as knowledge of the effects of starter fertilizer N applications on rice growth and yield are lacking. Field experiments were conducted in 2007 and 2008 at the Delta Research and Extension Center to evaluate canopy reflectance as a means for determining yield and N nutrition at midseason and to assess agronomic effects and N recovery efficiency of starter fertilizer N. Measurable in-season parameters were significantly related to grain yield. Grain yield and measured parameters were related to canopy reflectance. The results of this study support the continued research of canopy reflectance for predicting N nutrition indicators and yield. Minimal growth responses were observed when starter N was applied to seedling rice. Nitrogen recovery increased significantly throughout the growing season; however, less than 20% recovery was obtained. starter nitrogen remote sensing
2	INVESTIGATION OF CORN YIELD IMPROVEMENT FOLLOWING CEREAL RYE USING STARTER NITROGEN FERTILIZER Houston L Miller (7830965) 20 November 2019 (has links) Cereal rye (CR), the most common and effective nitrogen (N) scavenging cover crop option in the Midwest, is often utilized in cropping systems to reduce nitrate loss for environmental benefits. To increase environmental efficiency in Midwest corn cropping systems, we must increase the overall adoption of CR. However, due to the yield reduction potential (6%) for corn planted after CR termination, CR is primarily recommended before soybean. To increase CR adoption, we must develop adaptive fertilizer management practices that achieve competitive grain yields relative to cropping systems where CR is not adopted. Therefore, the objectives of this study are to determine (1) the effect of CR and starter nitrogen rate on corn growth and nitrogen content. (2) the optimum starter nitrogen rate to achieve agronomic optimum corn yield following CR. (3) the impact of phosphorus (P) at starter on plant growth, nitrogen content, and yield with the inclusion of CR. For our study, five starter N rates were applied in a 5x5 cm band to both CR and non-CR plots, concentrations ranged from 0-84 kg N ha<sup>-1 </sup>in 28 kg N ha<sup>-1</sup> intervals. Total N applied was the same for each treatment, relative to its location, and was split between starter N at planting and sidedress applied at growth stage V6 relatively. Although CR termination took place at least two weeks before planting, CR decreased corn grain yield at one of three locations by an average of 8%, nitrogen recovery efficiency (NRE) by 27%, and R6 total N content by 23%, relative to the conventional control (non-CR 0N), when no starter N was applied. At one of three locations, starter N rates of 56 kg N ha<sup>-1</sup>, 56 kg N ha<sup>-1 </sup>plus 17 kg P ha<sup>-1</sup>, and 84 kg N ha<sup>-1</sup> increased corn grain yield, in CR plots, and 56 kg N ha<sup>-1</sup> plus 17 kg P ha<sup>-1</sup> increased corn grain yield in non-CR plots. Phosphorus increased corn grain N content at growth stage R6 in one of three locations and did not impact corn grain yield at all locations. We conclude that the inclusion of starter N at planting has the potential to increase agronomic productivity in CR corn cropping systems in soil environments with a high capacity to mineralize soil N. However, further research is required to refine our starter N results to find an optimum starter N rate to apply before planting corn following CR. Agronomy cereal rye corn starter nitrogen cover crop soil inorganic nitrogen biomass nitrogen content carbon content conservation cereal rye disease cereal rye impact on corn grain yield phosphorus corn 5x5 band 2x2 band sidedress UAN corn yield rye rye growth corn growth stage corn development nitrogen uptake corn biomass grain moisture stalk nitrate contrasts corn population cereal rye biomass nitrate reduction corn following cereal rye starter urea ammonium nitrate nutrient reduction strategy no-till no till nitrogen reduction management practices spring soil enviornment

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Evaluation of technology aimed to improve nitrogen use efficiency for delayedlood rice (Oryza sativa L.) production

INVESTIGATION OF CORN YIELD IMPROVEMENT FOLLOWING CEREAL RYE USING STARTER NITROGEN FERTILIZER