Produção de sorgo com adubação orgânica em sistema agroecológico

Abstract

The management and use of the soil directly reflect on forage and livestock production in our country. Over the years, with the intensification of inappropriate agricultural practices in Brazilian soils, damages have been occurring at different intensities of degradation, such as in the Cerrado/Amazon ecotone region. Thus, changes in this reality have been demanded for sustainable production. Observing these facts, the objective of this work is to study agronomic characteristics and soil health indicators in an agroecological system cultivated with sorghum culture submitted to organic fertilization. The experiment was carried out at the School of Veterinary Medicine and Animal Science of the Federal University of Northern Tocantins (EMVZ/UFNT) located in the Municipality of Araguaína - TO. The study proceeded with evaluations of the agronomic characteristics of the Ponta Negra sorghum crop, intended for animal feeding in an experimental structure designed in randomized blocks, with four treatments and four replications. The treatments used were: Sheep Manure, Crotalaria, Sheep Manure + Crotalaria and the control (without any type of organic fertilization). Initially, the chemical evaluation and soil correction of the experimental area was carried out, followed by the planting of sunn hemp according to treatments with or without sheep manure. The legume was then cut and incorporated into the soil when the plants were in the flowering stage. After a periodof nine days of rest of the sunn hemp in the soil, the sorghum crop was implanted. After the crop was harvested, agronomic attributes were evaluated, such as height and number of plants per area, dry mass production, stem/leaf/panicle ratio, among others. The fertilization with Sheep Manure + Crotalaria was the one that stood out the most and provided the best results for most of the attributes evaluated, except forpercentage of leaves, panicle and dead matter. Dry matter production ranged from 2.52 t ha-1 to 10.31 t ha-1, with the first value referring to the control treatment and the second to the Sheep Manure + Crotalaria treatment. All treatments improved soil chemical conditions, and soil moisture varied throughout the crop cycle for all treatments, except for the Crotalaria treatment, which had no moisture variation inthe implantation and crop cycle phases.