Dissertations and Theses

Summary

The surface runoff of the water causes the transport of the nutrients from the soil, when it is with the unprotected cover surface. The present work had as objective to evaluate the possible relations between relief positions, erosion in entresulcos and their reflexes in the losses of soil, organic matter and nutrients in an area cultivated with the sugar cane crop submitted to the mechanized harvest. Experimental plots were subjected to a simulated rainfall of 60 mm h-1 for 65 minutes. Analyzes of the eroded sediment were made to determine soil, organic matter and nutrient losses. There were higher losses of soil, organic matter and nutrients in the sediment of the plots with 0% and 25% coverage by sugarcane straw. On average, losses in the eroded sediment were significantly reduced in the plots with 75% and 100% coverage by residues of sugarcane straw. In the loss of water, it was observed that there were statistical differences between the averages of coverage levels 0% and 25% in relation to the others (50%, 75% and 100%) in all the positions of the slope. At the top, the difference of the highest value (168,600 L ha-1) for the lowest value (120,300 L ha-1) was 48,300 L ha-1. The results allow to conclude that over 50% of straw cover in the studied area reduces the loss of soil and organic matter, and nutrient concentration in the eroded sediment.