Comparative analysis of nutrient absorption in rice cultivation: Aerobic versus anaerobic conditions in furrow-irrigated rice

Rice (Oryza sativa L.) production in the Mid-Southern United States has traditionally been under conventional flood (CF) production, namely, direct-seeded and delayed-flood production. However, furrow-irrigated rice (FIR) has grown to comprise over 15% of Arkansas' and 30% of Missouri's rice hectarage. The uptake of several nutrients, including phosphorus (P), potassium (K), and zinc (Zn), has been shown to differ between aerobic and flooded rice production. Hence, a nutrient uptake survey was conducted from 2018 to 2020 in FIR fields to determine the difference in nutrient uptake (macro- and micronutrients) between the upper generally aerobic environment at the top of the field and the bottom of the field, where a generally anaerobic or flooded environment existed from R1 to maturity. Aboveground biomass samples were taken at R3 from four nitrogen (N) treatments at the top and bottom of five sites on a clayey soil texture and four sites on a loamy soil texture. Results suggest that there is significantly lower P, K, sodium (Na), and manganese (Mn) uptake at the top of the field compared to the bottom of the field on both soil textures. Additionally, the N treatments that yielded the highest biomass generally led to the greatest uptake of all nutrients examined. The decrease in P and K uptake in the aerobic portion of an FIR field suggests that they may require altered fertilizer recommendations compared to the traditional CF rice system. P and K uptake are inhibited in the upper, aerobic portion of a furrow-irrigated rice production field. Increased biomass leads to increased uptake of P, K, Ca, Mg, S, Na, Fe, Mn, Zn, Cu, and B. Decreased P and K uptake under upland conditions may require fertility program adjustments.