The mix was then fermented anaerobically until removed from the pit in mid-June and applied to rice paddy fields immediately prior to plowing, flooding and puddling. By composting under anaerobic conditions, organic matter is reduced to ammonium, the ideal fertilizer for paddy rice, so that nutrients are made available to rice throughout the cropping season. Though making oufei compost was considered essential for rice production into the 1960s, the method has virtually disappeared in all wealthy areas of China. As a result, Tai Lake Region canals and waterways have filled with sediments, causing problems with transportation, irrigation and flood control. The disappearance of oufei results from development of a cheap replacement- chemical fertilizers, and because it requires copious amounts of strenuous labor.
Nutrient cycling is increased by composting and returning crop residues and manures to soils .
By harvesting sediments, aquatic systems are kept clear of sediment accretion while maintaining fertility in paddy land, managing nutrients across village landscapes . Related Publications .