Efecto del sistema de cultivo sobre propiedades físicas del suelo y su relación con el rendimiento de maíz y soja

Uruguayan farming systems have been constantly changing since the 1950s. At first, the system was basically monoculture under plow tillage where the most important cash crop was the wheat during winter. Then, the system turned into a system based on crop - pasture rotation. At the beginning this system used plow tillage, but then, in the 2000s were done with no tillage. Nowadays, the predominant farming system is based on continuous cropping with neither tillage nor pasture. Even though it is expected that this kind of farming system generate less soil loss through erosion, in order not to jeopardize soil ́s chemical and physical properties, this system must follow some requisites. Among others, managing the system in a way that the beneficial effect of the pasture (which is not included) is replicated. Within this context, appears the present study which has to main objectives: 1) To detect the effects of different no till farming systems over the soil's physical properties and soil organic carbón (SOC); 2) To quantify the response of maize and soybean crop to the changes in soil ́s properties due to the different farming systems. The study was done in a long term experiment site in Paysandú department, Uruguay, most precisely in the “Estación Experimental Mario Alberto Cassinoni” of UDELAR ́s Facultad de Agronomía. The experimental design used was randomized complete blocks design with four treatments with four repetitions each. SOC and its stratification showed significant differences among the different farming systems as well as the infiltration rate and the visual evaluation of soil structure. However, there was not a significant response of either crop in terms of yield. Significant difference was detected in the number of ears per plant in R3-R4 stage, while in soybean there were no differences in the yield components