Dados do Trabalho

Título

TIMES AND DOSES OF ALTERNATIVE POTASSIUM’ SOURCES IN SOYBEAN CROP IN THE CERRADO

Resumo

With the increase in cultivated area and soybean production, there are concerns about adequate plant nutrition so that they reach the maximum potential of cultivars and bring greater return to the producer. In Brazil, there are several silicate rocks that can be used as sources of K when ground, that can reduce the production cost in the agriculture. The present study aimed to verify the effect of application times and doses of alternative sources of potassium (Potasil "phonolite" or Ekosil "Hydrothermalized phonolite/Potassic Rock"), in the soybean crop in no-tillage system in the Cerrado. The experiment with the soybean crop was conducted at the UNESP Teaching, Research and Extension Farm, Ilha Solteira Campus, in Selvíria-MS. The soil in the experimental area is classified as Oxisol with clayey texture. The experimental design was carried out in randomized blocks, in a 2x4x3 factorial scheme, as follows: two application times (30 days before the sowing and in the sowing), four potassium doses (0, 40, 80 and 120 kg ha-1 of K2O) and three sources of potassium (KCl, Potasil “Phonolite” and Ekosil “Hydrothermalized Phonolite/Potassic Rock”), with four repetitions. The treatments with potassium fertilization were applied by broadcast and without incorporation into the soil. There was a higher roots dry mass using KCl and Potasil in relation to Ekosil at the dose of 40 kg ha-1 of K2O. The dose of 80 kg ha-1 of K2O as Ekosil provided greater dry mass of the roots in relation to the others; increased the insertion height of the first pod; The highest estimated soybean grain yield was 3262 kg ha-1 at the estimated dose of 78 kg ha-1 of K2O, being the most suitable for soybean cultivation in dryland under no-tillage system in clayey Red Latosol. Early supply of Ekosil increased nodule mass and soybean agronomic efficiency. The highest agronomic efficiency and dry mass of the roots occurred with doses of 40 and 80 kg ha-1 of K2O using Ekosil.

Palavras-chave

Glycine max; potassium silicate; grain yield; nodules' mass.

Instituição financiadora

Fundação de Ensino, Pesquisa e Extensão de Ilha Solteira