This paper deals with three patterns of
nutrient utilization in rice field.Under the experi-mental condition,in the pattern
of applying only chemical fertilizer one kilogram(kg)of nutri-ents added 6.09 kg of rice grain to the output.The ratio of output to input was 1.79:1.Thispattern was not beneficial to the improvement of soil ecology. In the pattern of growing wintergreen manure crop- milk vetch(Astragalus sinicus L. )and returning the early
rice straw tothe field combined with proper amount of chemical fertitizers,one kg of nutrients added 6.18kg of rice grain to the output.The ratio of output to input was 1.82: 1.This pattern savedalmost half of the amount of chemical fertilizers,increased soil fertility and has certain ecologialefficiency. In the pattern of concurrent using of winter green manure crop both as fertilizer andas feed-fermenting pig manure to generate biogas-applying the biogas fertilizer(biogas fer-mented manure)to the field,one kg of
nutrient added 6.61 kg of rice grain to the output and2/3 of chemical fertilizers was saved.Meanwhile every 74.3 kg of ensilaged milk vetchused asfeed added one kg of pig weight,and one kg of dry milk vetch generated 0.4m￣3 of biogas indi-rectly, the N,P and K reclaimed from the biogas fertilizer were 32.8%, 72.9%and 39.1%respectively. The overall ratio of output to input was 4:1, making a nutrient cycling and uti-lizing pattern with high performance and high efficiency.