Contrasting rice management systems – Site-specific effects on soil parameters
Conventional rice production systems (CRPS) with continuous flooding demand much water. While population growth increases the demand for rice and, consequently, water consumption, agricultural production needs to reduce its water demand. The System of Rice Intensification (SRI) is promoted as an alternative cropland management strategy to sustainably maintain rice yields while optimizing water use. Here, we aimed at investigating whether different management translates into differences in soil parameters. To this end, the two contrasting rice production systems were compared on the same soil types, at four different study sites of D.I. Yogyakarta Province, Indonesia. Crop yields were estimated, and soils were analysed for soil total soil organic carbon (TOC), total nitrogen (TN), dissolved organic carbon (DOC), macro-aggregate stability, and a fungal biomarker (ergosterol) indicative of oxidative soil conditions. Rice yields in the study area were between 6.7 and 9 t ha-1. For TOC, the combined effect of management and site was significant; in particular, in Kulonprogo and Bantul, SRI significantly exceeded CRPS’ TOC values. However, a significant management effect was observed for ergosterol and DOC concentrations. Significantly higher ergosterol concentrations in SRI vs CRPS were found in Sleman and Bantul. DOC was significantly higher under SRI compared to CRPS only in Sleman. DOC and ergosterol were most responsive to management and were improved in SRI systems. The observed site-specific effects suggest the importance to consider the prevailing site conditions for adapting management strategies.