Recuperação da qualidade de solo em pastagens degradadas por meio de sistemas integrados

• Autor(a) principal: Furquim, Leonnardo Cruvinel
• Data de Publicação: 2020
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/10902
• topic: Pastagem degradada; Sistemas integrados; Qualidade do solo; Sensoriamento remoto; Degraded pasture; Integrated systems; Soil quality; Remote sensing; CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO

Strategies to intensify livestock production in the Cerrado must consider improving the quality of the soil and the forage offered to animals. In addition, sustainability in meat and milk production is an international demand that will have a crucial impact on the continuity of rural properties. In this sense, integrated production systems, especially crop-livestock-forest integration and the use of technologies are highlighted. The objectives of the present work were to evaluate the soil quality and the current evapotranspiration in integrated in the recovery of degraded pastures. The experiment was implemented in Rio Verde - Goiás in November 2017, in a Red Latosol with a very clayey texture soil and composed of seven treatments, and from the third onwards there was soil tilling and fertilization in new forage and, from the fourth, production between eucalyptus rows: Degraded Pasture - 1.36 AU ha-1 with 507 days of grazing; Fertilized Pasture - 1.68 AU ha-1 with 507 days of grazing (fertilization in established pasture); Conventional - 2.05 AU ha-1 with 355 days of grazing; Lavoura-Floresta integration (production of vegetables and fruit); Livestock-Forest integration - 2.68 AU ha-1 with 507 days of grazing (immediate), Crop-Livestock-Forest hay integration - 4.15 AU ha-1 with 157 days of grazing after hay cutting and Crop-Livestock integration -Silage forest - 3.26 AU ha-1 with 157 days of grazing after cutting the consortium with forage sorghum. The forage planted was BRS RB331 Ipyporã, forage sorghum BRS655 and eucalyptus the clone AEC-2111. The lines were implanted with a simple line, 22 meters between lines and 2 meters between plants. After four months of planting, an evaluation of the chemical, physical and microbiological quality of the soil was carried out, in addition to the evaluation of evapotranspiration and biomass by remote sensing. The parameters soil density, total porosity, macropores, S index and soil aeration capacity did not differ statistically. Degraded pastures showed higher microporosity than other treatments. The indices indicate greater water retention in the pasture degraded by the greater amount of micropores due to the compaction processes. All treatments were below the critical S limit of 0.045, whose values below indicate soil structure degradation. Higher population density of fungi and bacteria was observed, as well as mycorrhizal fungi spores in treatment soils without soil disturbance. The results referring to soil fertility were responsive only in treatments where liming was performed. The remote sensing data were accurate in determining the current biomass and evapotranspiration in the treatments. At 24 months were determined of experiment, were determined the water infiltration speed curves and the respective basic infiltration speed values, the soil resistance to penetration, the current evapotranspiration of the cultures and the measurement of the chemical attributes in the treatments in response to the management of soil fertility. In the cultivation systems in which the soil was prepared, the basic infiltration speed tended to be higher, with emphasis on the livestock-forest integration system with eucalyptus cultivation intercropped with brachiaria for grazing and the planting of the brachiaria done with conventional tillage. The lesser resistance of the soil to the penetration was provided by the diversity of species in the silviagricultural systems. In the livestock-forest integration treatment, the highest mean ETa was observed (1.33 mm day-1) and, in the degraded pasture treatment, the lowest mean ETa (0.96 mm day-1) was observed. The integrated systems were adapted to the region's seasonality, suffering water stress in the dry season and with space-time heterogeneity in the wet season. There was an increase in organic matter, pH, potassium and base saturation and a decrease in aluminum saturation in conditions of non-revolving soil and replacement of nutrients through liming and fertilization. There was no effect of the forest component on soil attributes in relation to areas without eucalyptus in the period of 2 years. The fertilized treatments provided an increase in the stocking rate, showing viability in its implantation due to the nutrient cycling provided by the animals and plants.