Qualidade da silagem de híbridos de milho em diferentes densidades de semeadura

Abstract

The objective was to evaluate the qualitative characteristics of the silage of corn hybrids with different sowing densities under no-tillage system. The experimental design used was completely randomized with the treatments in a 3x4 factorial arrangement (three corn hybrids and four plant densities), using five replications (experimental silos) in two agricultural years. The evaluated hybrids were: B2688, B2433 and B2410. The plant densities evaluated were: 60,000, 80,000, 100,000 and 120,000 plants ha-1. The basic fertilization consisted of 670 kg ha-1 of chemical fertilizer (NPK: 5-25-15). The cover fertilization was 140 kg ha-1 of N, divided into two applications (V4 and V8). After 60 days of silage, five silos from each treatment were used to determine aerobic stability and dry matter losses, and another five silos were used to assess water activity, electrical conductivity, pH, crude protein, neutral detergent fiber (NDF) and acid (FDA). The electrical conductivity and the water activity were superior for the silage of the hybrid B2410 in relation to the others, which did not differ among themselves. The other characteristics of the evaluated silage were not influenced by the hybrids. The pH and aerobic stability of the silage decreased with increasing plant density. The electrical conductivity, NDF and FDA of the silage increased with the increase in plant density. The crude protein content and dry matter losses varied quadratically with the increase in plant density, with the highest values for densities of 80,000 and 100,000 plants ha-1, respectively. The increase in the density of corn plants increases the fiber content of the silage, reducing aerobic stability. The silage quality of hybrids B2688, B2433 and B2410 does not differ.