Soils recovery by means of the incorporation of green manure in agricultural systems

Recent alluvial soils have borne intensive agriculture couple with the corresponding abuse of agricultural machinery for soil preparation produce losses in its productivity .the present work raises as hypothesis using green manure to restore soil fertility and productivity as well as crop productivity. It was selected a productive corn farm in the Aria ri alluvial plain with soil physical and chemical problems; in the a/95 semester it was sown to corn as monocultures and associated to vitabosa (Stizolobium deeringianum) and canavalia (Cannavalia ensiformis) and three N levels: 0,80 y 100 kg/ha; in the B/95 semester it was sown to corn as monocultures to look at residual effects of green manure. A randomised block design with three replications was applied. In the first harvest a non-significant response (Tukey 0.05) to N application was observed, obtaining the major yield of 1.71 and 1.47 ton/ha in monocultures and associated in the 100-kg/ha levels. The incorporated material to the soil caused by the association (2.8 to 5.3 ton/ha) was higher than the monocultures; likewise the nutrient content; vitabosa yield higher N, P and Mg than canavalia and the latter one higher K and Ca, obtaining greater production of maize 1.18 to 2.16 ton/ha. For the third harvested though it was observed in the soil equal organic matter content and a slight increase of P, Ca and Mg corn yield was low (0.52 to 1.5 ton/ha) and similar to the first crop, which indicates a rapid benefit in the soil as a nutrient liberator and slow effect on soil physical properties, observing decreasing in resistance values but high values of bulk density and slow basic infiltration