Efecto de los plaguicidas sobre la calidad química y biológica del suelo en sistemas de producción de hortalizas del semiárido venezolano.

[摘要] The aim of this work was to evaluate the effect of the pesticides and the different systems of crop rotation on the chemical and biological properties of the soil in the Sector Guarabal, Falcon State.Two sites were chosen using different systems of crop rotation, 1) alternated tomato-paprika-onion (T-P-O) and monoculture of tomato (T-T-T). A non-altered natural forest, was selected as a reference soil. Samples were taken at two depths: 0-10 cm and 10-20 cm. The soil properties evaluated were pH, electrical conductivity (EC), organic carbon (OC), soil basal respiration (BR), soil carbon microbial biomass (C-BM), metabolic quotient (qCO2) and the relation (C-BM/CO *100). The CE's highest values (1,4 and 1,5 ds/m) were reported in monoculture system, possibly showing a process of salinization of the soils. The RB ranged between 35,70 to 36,35 µg C-CO2 g-1 day for the alternated system and between 74,40 µg C-CO2 g-1 day to 75,90 µg C-CO2 g-1for the monoculture system. The values of carbon of the microbial biomass for the monoculture system, were lower than those reported in agricultural systems of semiarid zones. In contrast, data from alternated system (398,40 - 421,11 µg C-CO2 g-1) was similar to that previously reported for soils of semiarid zones. Higher values of qCO2 were reported in the monoculture system (0,58 - 0,39 µg C-CO2 µg-1 Cmic.) in comparison with alternated culture. The highest percentages of the relation C-BM/CO *100 in the studied soils, were found in the alternated system culture (3,43 - 3,53 %) in comparison with the monoculture (1,15-1,73 %).These biological properties of the soil, turned out to be sensitive indicators to observe the effects of the different systems of crops rotations and the use of pesticides on the soils of the Sector Guarabal, Federación. The monoculture system showed the mayor problems of biological degradation of the soil.

[学科分类] 生物技术

[关键词] settlement strategies;climate fluctuations;Neolithic;Eneolithic;Central Europe;Slovakia