| ABSTRACT The implementation of conservationist systems of cultivation, with less soil turning and a greater deposition of plant residue, has increased the stocks of C and N in soil and humic substances, but may reduce the quality of the organic matter (SOM). The aim of this study was to evaluate the storage of carbon and nitrogen in plant residue, humic substances and soil at three depths (0-0.2, 0.2-0.4 and 0.4-0.6 m) and under five systems of cultivation: an old banana plantation (14 years cultivation), renovated banana plantation (renewed 1.5 years earlier), sugarcane plantation (two years cultivation), pasture (three-year-old Colonial grass), crotalaria juncea (cultivated yearly for five years) and native forest, as a reference of a natural semi-arid... |
