Abstract: Conflict between soil nutrient supply and crop demand is one of the technical bottlenecks influencing organic crop production. In this study, certain nutrients were monitored during crop growth in soil samples from conventional paddy fields, transformed paddy fields and organic duck-rice farming fields. Based on the study, organic matter, alkali-hydrolysis N, available P and available K contents in organic duck-rice farming fields are relatively stable. Available K is much higher in organic duck-rice farming fields than in conventional paddy fields at panicle stage, while alkali-hydrolysis N, available P and available K contents are much higher in organic duck-rice farming fields at mature stage. Organic rice yield is lower than conventional rice whereas the price of organic rice is much higher than conventional rice - which has a considerable economic benefit. Based on the study, integrated organic duck-rice farming should be promoted.