Maintenance of surface straw and its effect on soil attributes and yield sugarcane.

Abstract

The maintenance of straw on the soil surface results in increased soil carbon stocks, reducing total emissions of greenhouse gases, improving the soil physical and chemical attributes, increasing soil biological activity and increased infiltration and storage soil water. Moreover, the sugarcane industry is positioning itself towards using part of straw for energy and 2nd generation ethanol. Thus, it is important to assess how much straw should be kept on the ground aiming at sustainability of sugarcane. Therefore, the aim of this project is to assess the maintenance of different quantities of straw on the soil surface and its effects on the physical, chemical, soil carbon stocks and productivity of sugarcane. The experiments will be conducted at the plants Iracema (very clayey Oxisol) and Porto das Águas (Oxisol clay), located in the municipalities of Iracemápolis-SP and Plain of Heaven-GO, respectively. The experiments will be assembled considering a randomized block design with four replications. Each plot will consist of 10 rows of sugarcane, with spacing of 1.5 m and 10 m in length. Annually will be the monitoring of the physical, chemical and soil carbon in order to assess the effect of maintaining distinct quantities of straw on the soil surface at depths of 0.00 to 0.10, 0.10-0.20, 0.20 to 0.40, 0.40 to 0.60 and 0.60 to 1.00 m. The physical quality of the soil will be evaluated through the optimal water and tensile strength of the aggregate. Is studied the decomposition of straw, the growth of shoots and roots of the culture of sugarcane. Expected to get results indicating the effects of maintaining different amounts of straw on the soil surface in different climatic conditions, to assist in the scientific answer to the question: How much straw sugarcane can be removed from sugarcane for industrial use without compromising the sustainability of production of sugarcane.