Efeito do teor de água do solo e da carga aplicada pela roda compactadora na velocidade de emergência da soja - DOI: 10.4025/actasciagron.v29i5.713

The aim of this work is to study the effects of soil water contents combined with press wheel loads of a seed drill on the emergence velocity index of soybean plants, in direct drilling systems. The experiment was a subdivided design where each unit corresponded to a different soil water content (U1, U2 e U3): 0.27; 0.31 and 0.36 kg kg -1 , and the sub-portions stood four charge levels applied by the press wheel (C1, C2, C3 e C4): 0, 50, 90 and 140 N, respectively, in a randomized block design with four repetitions. Parameters evaluated were: pondered medium diameter of the aggregates in the planted line, percentage of thin ones < 2.0 mm, plants velocity emergence index. The combination between the charges applied by the press wheel and the soil water contents did not influenced the thin percentage < 2.0 mm. The soybean plants emergence velocity was affected by the applied charges and the water contents. The maximum charge of 140 N applied by the press wheel on the seed caused a superficial incrusting of the soil.