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

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.

KEYWORDS:

• Organic farming
• Oryza sativa
• rice-based cropping systems
• soil organic carbon sequestration
• system productivity

Acknowledgements

The first author is thankful to Indian Council of Agricultural Research, New Delhi, India for providing ICAR-Senior Research Fellowship for his Ph.D. programme. The help received from scientists and technical staff of Department of Agronomy, College of Agriculture, G. B. Pant University of Agriculture and Technology, Pantnagar in the laboratory during the experimentation is duly acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).