Volume 37, Number 4, 2013

Where the level of agricultural technology is higher, common bean cultivars with a higher yield potential possibly require greater amounts of micronutrients. In Brazil however, there is a lack of information about the micronutrient extraction and exportation by the main grown cultivars. The objective of this study was to evaluate micronutrient (B, Cu, Fe, Mn, and Zn) extraction and exportation by common bean cultivars Pérola and IAC Alvorada, under different levels of NPK fertilization, on a dystroferric Red Nitosol, in […]

Nitrogen fertilization is a major component of the cost of agricultural production, due to the high cost and low efficiency of fertilizers. In the case of urea, the low efficiency is mainly due to losses by volatilization, which are more pronounced in cultivation systems in which plant residues are left on the soil. The objective of this work was to compare the influence of urea coated with sulfur or boric acid and copper sulfate with conventional N fertilizers on N […]

The substitution of the native vegetation of marshlands in Paraiba, initially by sugarcane and more recently by pastures, in a strongly undulated relief, has caused serious problems of soil degradation. Currently, some of these pastures are being replaced by plantations of sabiá (Mimosa caesalpiniaefolia Benth). The objective was to analyze the effect of these changes on the soil physical and chemical properties and root development. The experiment was conducted in Areia-PB, in a dystrophic Ultisol. The three treatments were represented […]

Unplanned urbanization along the Jacarecica river basin in Maceió (AL), causes major environmental issues. The substitution of vegetated by urban areas reinforces these impacts. However, the potential effect of these changes on the sediment yield is unknown. In this work, we evaluated changes in the sediment yield of the Jacarecica river basin in 2010, caused by changes in the soil cover due to urbanization using mathematical modeling. The results showed that the month with the highest production yielded more than […]

Forestry companies have become increasingly concerned about the adoption of practices based on the conservation of soil and water. Thus, this study aimed to assess the impact of crop residue management, tillage and the use of industrial wastes on soil fertility and productivity of eucalyptus. The experiment started after clear-cutting of a commercial plantation of Eucalyptus grandis and the harvest residues were managed differently (removal of all residues; removal of bark and branches with diameter > 3.0 cm; and maintenance […]

Erosion has been recognized as the main cause of soil degradation and is accelerated by human intervention in watersheds, causing losses to the agricultural sector and damaging the environment. To estimate the impacts caused by land use or climate changes on hydrosedimentological processes, physically-based distributed models have been shown to be quite effective. In this study, the SWAT model was calibrated and validated for two subwatersheds of the Japaratuba Mirim river watershed, one located upstream of the Fazenda Pão de […]

Considering the importance of knowledge of the spatial distribution of soil properties, the purpose of this study was to evaluate the spatial variability of physical properties in a Cambisolunder different land uses in the southern Amazon region. The study was conducted on three farms with cassava, sugarcane, and agroforestry, in the region of Humaitá, in the south of the State of Amazonas. In these areas, 70 x 70 m grids were established, with a regular spacing of 10 x 10 […]