Cobertura del suelo, captura y uso de la radiación y el agua, por vicia y centeno como antecesores de soja

The agricultural expansion that the country went through in the first decade of the XXI century showed symptoms of its unsustainability in the long term. The frequent periods of winter fallow in the agricultural rotation demonstrated being the weakest point on these production systems. Cover crops appeared as an alternative in order to mitigate these unproductive periods and its consequent loss of physical-chemical properties of the soil. The magnitude of these effects strongly responses to the species used as cover crop and the biomass production achieved, so the objective of this thesis is to evaluate the differential performance of a grass and a legume that had been sown purely or in a mix and its residual effects on the soybean sowing. The species used were Vicia villosa and Secale cereale. Regarding the behavior of the cover crops, hairy vetch obtained a higher interception of radiation but a minor efficiency in the use of it. The mix and the rye did not show differences when talking about RUE, but since the mix achieved a higher radiation intereceptance, this cover crop overcame the other treatments referring to biomass production. They were observed differences in the weeding dynamics during the growth cycle, and also during the fallow period that occurred after the end up of their cycles. Linear regression models were adjusted for residuals nitrates levels when the sowing of soybean happened in function of the biomass production obtained by each cover crop, observing contrasting trends between treatments. The ground cover by the crop residues at the moment of the soybean sowing showed significant differences, but they did not affect the implantation of the crop.