CYCLING OF NITROGEN IN THE PADOY SOIL-CROPS-DOMESTIC ANIMALS SYSTEM
稻田土壤－作物－家畜系统中氮的循环研究

This paper deals with the use of N15-labelled rice straw and green manure to study the cycle of N in the crops-domestic animal-paddy soil system.When a N15-labelled rice straw was used to feed goats. the total N recovery was 65.14%, including 31. 16%in bodies,28. 26%in feces and 5.72% in goat urine.Then the goat feces and urine were retuned topaddy field and 4.82% N15 was recovered in whole rice plants ,inciuding 3. 19%in ricegrain,19.0% of N remained in soil ,and 10.14%of N was lost.In the two pro...