Levels of straw in the soil physical attributes and sugar cane production in different seasons

Resumo

Conservation management practices are beneficial to the physical quality of the soil and agricultural sustainability. The objective of this work was to evaluate the influence of remaining straw levels (0; 5; 10 and 15 Mg ha_-1) on soil physical attributes and sugarcane productivity components (third cut), in three seasons - 1 ( variety RB 855156), 2 (variety RB 835486) and 3 (variety RB 835054). For physical analyses of density, macroporosity, microporosity, and total porosity, soil samples were collected in 0.00-0.05; 0.05-0.10; 0.10-0.15, and 0.15-0.20 m layers. The soil resistance to penetration (RP) was evaluated up to 0.40 m deep, at the experimental setting up (third cut), and after 12 months, following the fourth cut. The number of stems ha^-1, total recoverable sugar (TRS), the productivity of industrializable stalks (ISP), and sugar (TAH) were evaluated. At the end of the sugarcane harvest (first season), a reduction was found in the density and an increase in total porosity up to 0.20 m, an increase in macropores, in the 0.00-0.05 and 0.10-0.15 m layers, and RP reduction, in the 0.00-0.10 m layer. At the end of the second and third harvest seasons, RP increases of up to 0.30 m stand out. Straw levels did not influence stalk and sugar productivity in the first and second seasons, and in the third harvest season, maximum stalk and sugar productivity was obtained by maintaining 5 Mg ha^-1 of straw.