Efeito da aplicação de biofertilizante na produção e qualidade de capim Piatã (Brachiaria Brizantha cv. Piatã) e nos atributos quimicos do solo

Abstract

Forage grasses are the main sources of food for cattle, since, in Brazil, animals are raised, for the most part, in an extensive system, however, tropical soils, in general, are collected and of low availability of nutrients, and this factor impairs plant development. To get around the situation, several alternatives of fertilization management are used, such as plastering, liming, chemical and organic fertilization. Among the organic fertilization there is the use of biofertilizer. Thus, the objective was to evaluate the effect of biofertilizer application on soil chemical attributes and forage production and quality. The study was carried out in the municipality of Jateí - MS, in an Oxisol cultivated with Brachiaria brizantha (Syn. Urochloa brizantha) cv. BRS Piatã. The experimental design used was randomized blocks, in a 2x2 factorial scheme (with and without biofertilizer), with four replications. The treatments were: A1 - pasture area that was at rest and receiving biofertilizer; A2 - pasture area under grazing, but with only three animals that received the biofertilizer; A3 - newly reformed area, without application of biofertilizer or any fertilizer being intercropped with the watermelon plantation under correction effect and A4 - pasture area under grazing, containing 155 animals, with degraded pasture. This area did not receive any type of fertilization and correction. The application of the biofertilizer was carried out with a tank. Three applications of the biofertilizer were carried out in areas A1 and A2, with an interval of 90 days. Samples of the treatments were analyzed to evaluate the production of dry mass and bromatological analyses. As purchased for the mass, a 0.25 m² ring was used to delimit the harvesting area. The forage was cut at ground level observing the periphery limits of the rim and harvested. After cutting, the forages were weighed for foreign fresh weight and, subsequently, the representative experiments were placed in a forced air circulation oven at 65°C until constant weight. The dry weight was determined and then the material was ground in a Wiley-type mill with a 2 mm sieve, for bromatological determinations: neutral detergent fiber (NDF), acid detergent fiber (ADF) and crude protein (CP). Soil samples were collected on October 1, 2022. For the chemical characterization of the soil, samples were taken, sampling five random subsamples of the total area, at depths 0 to 20 and 20 to 40 cm. The subsamples were then composed for each depth and homogenized, and then sent to the FCA/UFGD Soil Fertility Laboratory for chemical analysis. The results were examined using analysis of variance and Tukey's test was applied at 5% probability to compare the means of the indicators. In general, in all treatments the chemical attributes of the soil were below the range considered adequate for the growth and development of the forage. These factors led to low production of phytomass with low nutritional value.