Soil chemical attributes, technological quality and yields of sugar cane submitted to organic and mineral fertilizers

摘要

The experiment was carried out to evaluate the effects of organic and mineral fertilizers on soil chemical properties, technological quality and yield of sugar cane, performed in a field experiment in the city of Dracena, Sao Paulo, Brazil. The experimental design was a randomized block with four replications. For the treatments two compounds were produced. Compound 1: sugar cane bagasse (70%) + ashes (10%) + byproduct of tanning (20%) + decomposing microorganisms; Composite 2: sugar cane bagasse (70%) + ashes (10 %) + byproduct of frigorific (20%) + decomposing microorganisms. The evaluated treatments were the following: 1) 275 kg/ha (half dose) of mineral fertilizer 5 25 25; 2) 10 t/ha of compost 1 + treatment 1, 3) 15 t/ha of Compound 1 + 1 treatment; 4) 20 t/ha of compost 1 + treatment 1,5) 10 t/ha of compost 2 + treatment 1,6) 15 t/ha of compost 2 + treatment 1, 7) 20 t/ha of compost 2 + treatment 1. There was a change among the sources in calcium content in the soil only for the application of 15 t/ha of compost, however, all values are considered low. There was no difference in the phosphorus in the soil between the doses of compounds. The concentration of P in soil is directly proportional to the doses of organic compost. The pH, organic matter, K, Mg, S-SO_4~(-2), Al, B, Cu, Mn, Fe and Zn in soil were not affected by the doses of organic compost. The dose of 15 t/ha of organic compound associated with 275 kg/ha of mineral fertilizer (5 25 25) gave the best response in the production of stems of sugar cane. The average doses of organic compost with the byproduct of frigorific showed higher cane yield. Technical quality was not affected by the treatments.