The importance of soil organic matter (SOM) and their functions are known with and are addressed in the literature, however, the processes that involve the dynamics still need to be better understood, and the factors that affect the accumulation and quality of SOM. The objective of this study is to quantify and qualify the MOS according to different soil management and crop sequences conducted in No Till (NT) correlating to the supply and quality of the straw. In addition, the objective is to estimate the need for residue inputs for each crop succession to maintain or increase the C stock. The research will be conducted between the years 2013 and 2016, in a Nitossolo conducted on NT for 16 years, and the last ten years are maintained experimental treatments involving different crop sequences. The experimental area located at the Experimental Farm Lageado (FCA / UNESP, Botucatu). In the autumn-winter are cultivated sunflower and triticale, while the spring is cultivated sorghum, millet, sun hemp, or the area maintained in fallow, and soybeans grown in the summer. The experiment is conducted in split-plot arrangement with four replications. Will be sampled throughout the soil profile for analysis of the levels and total stocks C and N. In soil samples are also analyzed the levels of microbial C and N, as well as studying the degree of lability and humification of organic matter in the soil by chemical and physical fractionation. The plants will be chemically analyzed for the levels of C and N, and soluble and structural carbohydrates. The straw on the soil will be sampled to determine the mulch prior to sowing of the succeeding crops.. The CO2 emission will be determined and the index calculated carbon conservation. Finally, will be the mathematical modeling of soil organic matter and the results compaed with data obtained. The data will be submitted to analysis of variance and t test comparison of means at 5% probability of error. Will be performed Pearson correlation analysis between the variables studied, mainly to check the influence of the quantity and quality of plant residues in the accumulation of MOS and its fractions as well as in C-CO2 emission.
News published in Agência FAPESP Newsletter about the scholarship: