Atributos físico-hídricos do solo em sistemas consorciados de milho com adubos verdes sob manejo orgânico

Abstract

The use of plants in intercropping has the purpose of increasing the diversity of species, producing a greater amount of dry matter, greater root exploration, inducing improvements in soil physical and hydraulic attributes. The objective of this work was to analyze the effects of Crotalaria spectabilis and Cajanus cajan on soil physical and hydraulic attributes. The experiment was conducted in the 2017/2018 harvest in the city of Araras - SP, in Nitisols (Nitossolo Vermelho), in a randomized complete block design, with four replications. The treatments consisted of three maize intercropping with: MC) Crotalaria spectabilis (5 plants m-1); MG) Cajanus cajan (5 plants m-1); MCG) Crotalaria spectabilis and Cajanus cajan (10 plants m-1, five plants of each green manure), planted in the corn row and three control treatments: M) corn; C) Crotalaria spectabilis and G) Cajanus cajan, singles for temperature and soil moisture, besides: CANA) conventional cane and MN) forest fragment, for the other attributes. Soil temperatures were measured at 8, 12 and 17 hours in the phenological stages V5, V8, VT, R2, R4 and R6 in the row and between row of sowing and soil moisture in the corn sowing row for all treatments. The depths of evaluation were 0-0.10, 0.10-0.20 and 0.20-0.40 m. Deformed and undisturbed soil samples were collected at the same depths. Time, depth and line / interline positions influenced soil temperature, while depths and phenological stages influenced soil moisture. The intercroop reduced the temperature of the soil, mainly MG. Also, the MG reduced the soil moisture between V8 and R2 of maize. The introduction of Cajanus cajan in the consortium reduced soil density (DS) in the 0,10-0,20 m layer while the introduction of C. spectabilis reduced in the 0.20-0.40 m layer, compared to the CANA. C. spectabilis increased the macroporosity (Mac) in the layer 0-0.10 and 0.10-0.20 m, whereas the Cajanus cajan increased Mac in the layer 0,10-0,20 m, in relation to M. The use of these species in intercropping did not cause significant differences for the soil resistance to penetration in any of the depths studied in relation to M.