Forms of nitrogen fertilization on soybean in the northern of Mato Grosso State, Brazil

This study aimed to verify the effects of soil and foliar application of N in different growth stages of two soybean cultivars in the Northern of Mato Grosso State, Brazil. The experimental design was randomized complete block design with four replications in factorial scheme 2 x 7. The soybean cultivars were: TMG 132 and TMG 1179. The treatments were: control (without N fertilizer), 20 kg of N applied in the furrow at sowing, 20 kg of N applied on the soil surface at sowing time, 20 kg of side dress N applied in V2 on the soil, 20 kg of side dress N applied in V4 on the soil; 20 kg of N applied via foliar in V2 and lastly 20 kg of N applied via foliar in V4. The N in the soil, even at sowing, reduces nodulation of soybean plants, generating small gains in productivity. The application of 20 kg N ha-1 starting in V2 stage increases vegetative growth, nodulation and soybean yields. Foliar application of N at a dose of 20 kg ha-1 in V2 or V4 stages is the most efficient way to increase soybean productivity