Nutrient Uptake by Soybean Plants in Succession of Cover Crops in Northeast of Brazil

Abstract

ABSTRACT This study aimed to estimate the nutrient absorption rate in soybean plants cultivated in succession to cover crops and under soil management systems. We performed two experiments with soybean grown on the remaining straw of Crotalaria spectabilis and Pennisetum glaucum (millet), under no-tillage (NT) and minimum tillage (MT), over the cropping years 2016/2017 and 2017/2018, in the Cerrado of Piauí state. The experimental design was a randomized blocks, arranged in split-plots. Plots corresponded to soil management systems and subplots to days after emergence (DAE) of soybean, with 3 replications. Nutrients contents were evaluated at 31, 38, 45, 52, 59, 66, 73, 80, 87, 94, 101, 108 and 115 DAE. Higher soybean dry matter (DM) production occurred in MT compared to no tillage. Crotalaria spectabilis enhanced accumulation of DM and N until stage R2. Accumulation of nutrients and DM in soybean cultivated on the straw of millet and C. spectabilis were similar across soil management systems. The phase of highest accumulation of nutrients and DM in soybean occurs between stages R5 and R7. All the nutrients, except Ca and Mn, are allocated to the grains during physiological maturity, in proportions higher than 50% of the total amount accumulated in soybean plants.