Availability of water and biomass input under different fallow strategies

Abstract

The objective of this work was to evaluate the effect of different fallow strategies on the gravimetric moisture of the soil and the availability of useful water for the successor crop and to analyze the biomass contribution of the cover crops. In the Experimental Station J. Hirschhorn, Facultad de Ciencias Agrarias y Forestales, Univesidad Nacional de La Plata, Argentina, on an Argiudol typical soil. Field trials were started in 2011 in which different agricultural sequences were compared: S1: wheat / soybean 2nd corn-soybean-wheat; S2: barley / soybean 2nd corn-soybean-wheat; S3: oats / soybean 2nd corn-sunflower-wheat; S4: rapeseed / soybean 2nd maize-sorghum-wheat; under two forms of production, an average technological level and a high technological level. In 2016, between the 2nd soybean harvest and the corn sowing, on the average technological level, three types of fallow were made: chemical fallow, compost application and inclusion of cover crops. On the high technological level, cover crop was cultivated. Compost and cover crop were higher to chemical fallow in the conservation of water useful for the successor crop. The biomass provided by the cover crop resulted in an average of 3,397.91 kg/ha and presented statistically significant differences for the different sequences, being higher for S4 and lower on S1. In turn, the higher biomass production of the cover crop in S4 corresponded to a higher consumptive use and lower final useful water. Considering the technological level, the cover crop resulted in a higher volume of waste at the high technological level, which implied an improvement in water use efficiency.