Plant productivity and nutrient uptake as affected by tillage and site‐position in furrow‐irrigated rice

Abstract

AbstractFurrow‐irrigated rice (Oryza sativa L.) is a relatively new production system that has been shown to have increased water‐use efficiency and reduced operational costs. However, due to spatial variations in soil moisture, field studies are necessary to evaluate potential resulting variations in rice growth and yield in the furrow‐irrigated production system. This study was conducted to evaluate the effects of tillage practice (conventional tillage, CT; no‐tillage, NT) and site position (up‐, mid‐, and down‐slope) on aboveground biomass, yield, and plant nutrient uptake from rice grown in a silt‐loam soil in a direct‐seeded, furrow‐irrigated production system in eastern Arkansas. Field research was conducted from May to September during the 2018 and 2019 rice growing seasons. Total aboveground dry matter, vegetative dry matter, and yield were unaffected (P > .05) by tillage treatment or site position in either growing season. Vegetative tissue nutrient concentrations and uptake were generally at least 10% greater (P < .05) under CT than NT but did not substantially differ by site position during the drier growing season (2018). During the wetter growing season (2019), vegetative tissue nutrient concentrations and uptake were generally at least 20% greater (P < .05) at the up‐ than at the mid‐ or down‐slope positions. Results suggest that different approaches, in terms of soil and nutrient management per site position, in combination with tillage practices, may need to be considered for implementation to maximize nutrient uptake and reduce losses, thus improving the agronomic suitability of the furrow‐irrigated rice production system.