Acúmulo de matéria seca e balanço de nutrientes no sorgo volumax, cultivado em sistema de alta tecnologia

Abstract

ABSTRACT

Sorghum, together with corn, have been the most used plants in forage production for medium to high productivity animals. However, due to its characteristics of easy cultivation, rusticity, good adaptation to different edaphoclimatic environments and good bromatological value, high yield potential, sorghum has been a good substitute for corn silage in ruminant feed. Currently, there are several sorghum hybrids, with high productive potential, responsive to the improvement of the physical, chemical and biological properties of the soil, with a large participation of panicles in the total dry matter of plants. One of these sorghum hybrids is Volumax, present in most competition studies of sorghum hybrids destined for ensiling. Knowing that one of the factors that most burden animal production is food, the aim of this study was to evaluate the nutritional status, dry matter accumulation and nutrient balance in the soil-plant system, in the first cut and in regrowth of Volumax, cultivated in a high productivity system. Sorghum was cultivated in medium to high fertility soil, and sowing was carried out in the first week of October, beginning of the rainy season. Fertilization was carried out based on expected yield, applying N-P-K fertilization in sorghum sowing and N and K regrowth in order to replenish the nutrients removed by the future harvest. It was concluded in this study that Volumax sorghum is a forage with high productive potential; that the adopted production system adequately supplied nutrients to the plants; that the removal of nutrients by the harvest of Volumax was high and that one should be aware of the replacement of nutrients and soil acidification, both by the use of nitrogen fertilizers and by the removal of soil bases. Thus, it can also be seen that the application of cattle manure in areas destined for silage will contribute to reducing production costs and improving the physical, chemical and biological properties of the soil. Key-words: Agricultural management, productivity, sorghum hybrids, animil production, forage sorghum.