Dados do Trabalho

Título

SHORT-TERM EFFECTS OF VERTICAL MOVEMENT OF CATIONS IN CLAYEY SOIL AFTER KCL FERTILIZATION

Resumo

Nutrient losses in the soil are indeed one of the major concerns for fertilizer management. Rates, sources, time, and form of application are decisive and can change the chemical properties of the soil and yield, with possible effects on nutrient leaching. In the present work, the movement of K, Ca and Mg was evaluated in clayey soil under field conditions after the application of increasing doses of KCl by broadcast after a soybean crop. The soybean was cultivated for 120 days. The treatments were arranged in a randomized blocks scheme with 5 treatments (0, 40, 80, 120 and 160 kg ha-1) with 8 replications. The soybean production components were evaluated, as well as the nutritional status of the crop and the soil that was sampled at depths of 0-5, 5-10, 10-20, 20-40 and 40-60 cm deep for analysis of K, Ca and Mg exchangeable. Accumulated rainfall in the experimental period was more than 1200 mm and was sufficient for the full development of the crop and fertilizer in the soil. The intensity of K movement in the soil deeper layers was proportional to the applied dose, so that significant movement was observed up to the 10-20 cm depth layer only for the highest applied dose. Among technicians and farmers, this intense and possible leaching of potassium is much discussed, although for clayey soils with more than 50%, even at high doses, this effect was not observed in a period of approximately 150 days with high levels of rain.

Palavras-chave

potassium; leaching; MOP;