Influência do uso e ocupação do solo na qualidade da água e no processo erosivo da bacia de captação do Rio Barro Preto, Coronel Vivida-PR

This study was developed in objecting to investigate the use and occupation of land in 1999, 2005, 2011 e 2015 and estimate soil degradation by laminar erosion and the relation with water quality in 2015 in the catchment basin of the Barro Preto river, Coronel Vivida – PR. For multitemporal analysis of use and occupation of land in the basin used in the Landsat 5, 7 and 8 images and Geographic Information System. The laminar erosion was estimated by the Universal Soil Loss Equation through the systematization of calculations of the factors that compose the equation in SPRING/INPE. The water quality of the studied river section was evaluated according to the Water Quality Idex and the Resolution CONAMA n. 357/2005. The multitemporal analysis of the use and occupation of land has demonstrated that basin is predominantly agricultural in all years studied, as well as the permanent preservation area presents it not regularized during the period in accordance with the Brazilian Forest Code in force. In relation the quantification of laminar soil erosion in the study period, the rainfall and runoff factor was estimated considering the rainfall data from 1986 to 2014 and resulted in a value of 11.573,47 MJ/ha.mm/a. The Dystrophic Red Latosol, Dystrophic Red Nitisol, Fluvisol and Leptosol soil erodibility factor were 0,0138, 0,0137, 0,0207, 0,0196 t.ha.h/ha.MJ.mm/a, respectively. The topographical factor has demonstrated that the catchment basin has the rough terrain because the moderate and moderate strong classes are dominant in the study area. The cover and management and support practice factors were estimated according to the multitemporal analysis of the use and occupation of land in the basin and the values ranged from 0,0006 to 0,0688. The soil losses by laminar erosion were simulated with agriculture areas with corn and soybeans in no-till. The soil losses with maize crop in no-till in 1999, 2005, 2011 and 2015 were 9.782,75, 10.592,71, 9.636,61 e 11.058,26 t/year, respectively, and soybeans crops in no-till were 15.140,01, 16.645,20, 14.662,14 e 17.049,85 t/year, respectively. In relation with water quality of the section studied river, the average of Water Quality Index during the season were 55,47, 53,09 and 49,72, for the first, second and third sample point, respectively. Indication a decrease in water quality since the source to the last sample point. It is concluded that the use and occupation of land in the catchment basin interferes in the water quality, as well as in soil degradation.

Atributos do solo sob modelos em estágio inicial de restauração de floresta subtropical

The replacement of native vegetation by other land uses is one of the main degrading ecosystem agents, being the most important component of terrestrial environments, natural or with different levels of human disturbance, besides being the main substrate used by plants to obtain conditions soil for its development. In this context, there is the need to adopt the use and sustainable management of land systems. The study aimed to evaluate what is forest restoration system more efficient degraded areas, based on the potential recovery of physical, chemical, carbon and biological activity in the soil. The work was conducted in a forest restoration area UTFPR- Campus two neighbors, whose experiment was established in October 2010. The experimental design is completely randomized, with four replications and experimental plot of 40 m wide by 54 m long ( 2160 m2) were collected and six sampling points per plot. The soil is classified as a Typic. The models evaluated are: 1 - natural or passive regeneration; 2 - Nucleation; 3 - Planting trees in the total area under lines fill and diversity (total planting); 4 - Reference area (forest). The collection of soil samples in layers of 0.0-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m was carried out in October 2013 and evaluated physical attributes of texture, bulk density, total porosity, microporosity and soil macroporosity and stability of water in households, chemical properties, and total organic carbon (TOC) and physical particle size fractionation and soil biological activity. To find the best forest restoration model, we designed a Restoration Quality Weighted Index for each variable analyzed. Natural regeneration and total plantation showed generally better soil aggregation over 0.10 m and nucleation volume of similar porosity the forest for these layers. There were no differences between the models below 0.10 m for the variables aggregation and soil porosity. The nucleation template had the lowest bulk density, but being greater than the density in the layer forest 0.05-0.10 m, however, was similar to below 0.10 m above the ground. The models had chemical properties similar to or greater than the forest. The forest had the highest stock of COT and carbon associated with minerals (CAM), but natural regeneration was similar to the particulate organic carbon (POC) in the superficial layers of the soil (0-0.10 m), below 0, 10 m, the forest showed higher stock of COT and COP on the ground. The highest peak of C-CO2 emissions occurred in the 28-35 day range where the total plantation was similar to forest. After four years of experiments, it was found that the effect of restoration methods on physical attributes and soil carbon restricted to 0.10 m deep.

Altura do pasto e adubação nitrogenada sobre a produção de forragem e eficiência no uso de nutrientes em sistema de integração lavoura-pecuária

The proper use of management strategies, such as grazing intensity and nitrogen fertilization are primordial to the success of integrated crop-livestock system. Several studies have demonstrated the influence of grazing intensity and nitrogen fertilization on dynamics of forage production and nutrient cycling. However, most this researches studying these strategies in isolation and little is known about the interaction of these factors in the management of an integrated crop-livestock system. In this context, the aim of this study is to determine the best management strategy involving sward height and nitrogen fertilization, permitting greater forage production and improved efficiency in the use of nitrogen soil by a black oat ‘BRS 139’ plus ryegrass ‘Barjumbo’ pasture in integrated crop-livestock system. The experiment was realized in Abelardo Luz – SC, in an area of 14 ha, where has been conducted an experiment in long term with integrated crop-livestock system under no-tillage since 2012. The experimental design is a randomized block design with three replications in a factorial design (2x2), the first factor was the grazing intensity (high and low), characterized by two sward height management (10 and 25 cm), and the second included the time factor application of N in the system: N applied on pasture (N-pasture) and N applied on the culture of grain (N-grain), at dose of 200 kg N ha stocking and variable stocking rate. The previous crop to pasture was corn. The nitrogen fertilization of pasture increased tiller density, forage density, participation of ryegrass ‘Barjumbo’ and percentage of ryegrass leaves in forage mass. Forage mass was less at low sward height on average, however the percentage of ryegrass ‘Barjumbo’ and rye leaves was greater and dead material was lower in this treatment. With nitrogen fertilization of pasture it was possible to double the amount of forage accumulated in periods with further development of ryegrass, furthermore, the total production of DM was increased in 38.4% and the shoot N concentration in 28.6%. When the nitrogen fertilization is applied in pasture, it is possible to keep black oat ‘BRS 139’ plus ryegrass ‘Barjumbo’ pasture with an average sward height of 11 cm. The residual effect of N applied at corn was not sufficient to meet the nutritional needs of pasture and the forage production was affected by periods with N deficiency, while a single application of 200 kg N ha was sufficient to meet the N requirements throughout the forage accumulation period. The black oat ‘BRS 139’ plus ryegrass ‘Barjumbo’ pasture is efficient in use and recovery of the nitrogen applied in both treatments of sward height.