Differences in productivity and soil properties in rice-based cropping systems under long-term organic, integrated and conventional production

Abstract

ABSTRACT This study investigated the effects of four rice-based cropping systems (rice-vegetable pea + coriander; rice-chickpea + coriander; rice-potato and rice-wheat) cultivated in long-term organic, integrated and conventional production systems on system productivity (SP), soil organic carbon (SOC) sequestration and soil properties. The experiment was laid out in a split plot design with the production system assigned to the main plots and the cropping system to sub-plots. The results revealed that SP, SOC content and SOC sequestration in the organic system were significantly higher than in the conventional counterpart (17.1%, 59.4% and 165.9% higher, respectively). The fractions of total organic carbon followed the order: very labile carbon > non-labile carbon > labile carbon > less labile carbon. The soil in the organic system had, in general, the most improved physical (water holding capacity, bulk density), chemical (available N, P, K and S, and DTPA-extractable Fe, Mn, Cu and Zn) and biological properties (dehydrogenase and acid and alkaline phosphatase activity), especially when compared with the conventional system. The legume-based cropping systems (rice-chickpea + coriander and rice-vegetable pea + coriander) enhanced the SP, SOC content and SOC sequestration by 22.6% and 46.5%, 16.3% and 11.9% and 47.5% and 29.4%, respectively, compared with the rice-wheat cropping system, with improvements also in different physical, chemical and biological soil properties. Thus, organic system with legume-based cropping (rice-chickpea + coriander and/or rice-vegetable pea + coriander) was concluded to sustain crop productivity and have greater soil carbon sequestration potential in the longer term.