Carbon management for sustainability of an intensively managed rice-based cropping system uri icon

abstract

  • Integration of a crop between the dry and wet season is known to capture nitrate-N which otherwise is lost upon flooding. Often a transition crop is of short duration and its biomass is incorporated into the soil as green manure. Although N dynamics as influenced by transition crop have been studied, not much is known about carbon dynamics and its residue management. Experiments conducted in four farmers' fields in the Philippines utilizing a rice- (Oryza sativa L.) sweet pepper (Capsicum annuum L.) system aimed to determine the effects of different transition crops like indigo (Indigofera tinctoria L.), indigo plus mungbean (Vigna radiata L.) and corn (Zea mays L.) grown during the dry-to-wet (DTW) transition on total and labile C pools. The decrease in labile C with cropping ranged from 6% to 21% and increase with residue incorporation ranged from 18% to 37% at different sites, but total C remained unchanged. The labile C balance indicated a loss of up to 1,438 kg halt due to farming practices and a gain of up to 3,077 kg ha(-1) with residue addition. Catch crop residue management in intensive rice-based cropping systems can play a role in maintaining soil health, as indicated by the improvement in labile C. Labile C is sensitive to soil management practices, and thus provides a better measurement of C dynamics in the short to medium term than total C alone.

publication date

  • 2002
  • 2002
  • 2002