Optimization of Within-Row Plant Spacing Increases Nutritional Status and Corn Yield: A Comparative Study.

Uniform within-row plant spacing is a key crop management strategy to achieve high corn (Zea mays L.) yield. A new precision planting concept is emerging based on the use of modern devices in planters. The objective of this study was to investigate the impact of optimizing within-row plant spacing to enhance plant nutritional status and corn yield. The treatments investigated were (a) traditional planter with mechanical horizontal plate metering system (TP), (b) precision planter with vSet (Precision Planting, Tremont, IL) vacuum meter system (PP) and (c) PP pulled by a tractor equipped with an real time kinematic (RTK)-based auto-steering system (APP). The experimental design was a randomized block with three replications, and the plant evaluations were determined based on a main plot and a plant-to-plant study. Two types of vegetation indexes (VI and normalized diff erence, NDVI) were used for assessing plant nutritional status. A high standard of uniform plant spacing (CV < 10%) was required to achieve the highest corn yield. Optimizing the within-row plant spacing resulted in higher VI and NDVI. Based on the average of two experiments, PP improved the uniformity of plant spacing (CV = 22.5%) compared to TP (CV = 38.7%). This optimization of within-row plant spacing increased the corn yield by 10.7%. Only in the year with higher corn yield potential did APP result in a yield increase of 6.9% in relation to PP. Although the precision planters investigated had decreased the error in plant distribution, no one reached the plant spacing uniformity required to achieve higher corn yields. [ABSTRACT FROM AUTHOR]