Potassium fertilization and sowing seasons on protein yield in soybean cultivars

Adubação potássica e épocas de semeadura no rendimento de proteína em cultivares de soja

ABSTRACT

The present study was conducted in order to determine the effects of potassium (K) fertilizer doses on the protein yield of different soybean cultivars, sown in two seasons, in the agricultural year 2013/14 (12/05/13 and 01/23/14), in Palmas-TO, Brazil. The experimental design, in each sowing season, was randomized blocks with 60 treatments and three replicates. The treatments were arranged in a 10 × 6 factorial scheme, represented by ten cultivars (BRS 325RR, M 9144RR, BRS 33871RR, TMG 1288RR, BRS 333RR, P 98Y70RR, TMG 1180RR, BRS 9090RR, M 8766RR and BRS 8990RR) and six doses of K fertilizer (0, 40, 80, 120, 160 and 200 kg ha^-1 K₂O). The late sowing decreased the protein yield. K fertilization increased the protein yield in soybean cultivars. The BRS 9090RR, BRS 33871RR and BRS 333RR cultivars, at high and low K doses, were the most promising for the protein yield, and their cultivation is strategic from the economic and environmental point of view.

Key words:
Glycine max; potassium; planting; industrial yield