Inoculação com azospirillum brasilense, manejo de pastejo e nitrogênio em integração lavoura-pecuária

Abstract

This thesis presents results of an experiment with crop-livestock integration in two growing seasons (2012/2013 and 2013/2014). In cold seasons was used pasture formed by the mixture of black and annual ryegrass grazed sheep on a three-factor experiment (Grazing management, nitrogen fertilization level and seed inoculation) in experimental design of randomized blocks. For Grazing management factor to pasture was managed as follows: (i) conventional grazing (PC), where the animals remained in the pasture throughout the trial without a control of the grass height, (II, III and IV) - stubble height of 10, 20 and 30 cm and a witness without grazing (SP). Nitrogen rates were three (0, 50 and 100 kg nitrogen ha-1), and seeds of oat and ryegrass inoculated or not with bacteria Azospirillum brasilense. In herbage mass of pasture collected at the entrance and exit of animals, botany separation of the components (leaf, stem, senescent material, inflorescence) was carried out and was obtained total biomass production in the different treatments. It was found that the biomass production of black and annual ryegrass increased with the application of 100 kg nitrogen ha-1 and the Azospirillum brasilense inoculation and the proportion of structural components varied according to the different grazing managements, doses nitrogen and inoculation with Azospirillum brasilense. Above straw of black and annual ryegrass were introduced corn and soybeans in no-till system, which were inoculated or not with bacteria Azospirillum brasilense. In maize, higher plant height was checked when it is grown under straw oat and ryegrass in the absence of grazing, which also favors the crop yield. In conditions of drought nitrogen applied on grassland favors the development of corn, increasing plant height, insertion height of spike and stem diameter. In maize yield this effect is pronounced in areas where it had a larger mass of waste fodder. Inoculation with Azospirillum brasilense has a positive effect on the components of income and productivity of independent corn growing season and hybrid used. The soybean crop has the best yield in crop-livestock integration system as established under black and annual ryegrass pasture managed with heights between 20 and 30 cm. Inoculation with Azospirillum brasilense should not be used alone in the soybean crop.