Maintaining soil organic matter (SOM) in low input smallholder rice cropping systems worldwide is of
paramount importance to maintaining livelihoods and food security. A long term rainfed lowland rice
experiment tested the hypothesis that applying small (1.5 t/ha dry matter) annual additions of slowly
decomposable plant materials which were grown offsite and applied prior to land preparation, could result in
increased soil organic carbon, crop yield and improve the recovery of nutrients compared with plant materials
of higher quality or straw retention alone. Annual leaf litter applications over 9 seasons resulted in significant
increases in SOC of 39% (from 3.5 to 4.9 mg/g) in the leaf litter treatments compared to only 13 % in the noleaf
litter control. In terms of rice grain production and nutrient use efficiency, leaf litter quality was an
important driver. Apparent nutrient recovery of nitrogen and sulfur reflected the decomposition rate of the
added residues. Sustainable farming systems will require that crop yields are stable through the maintenance
of soil fertility and the balanced use of nutrients in the system. The results of this study are therefore highly
significant and provide evidence that low rate, long term residue management can have profound effects
