The input and decomposition of plant remains in agroecosystems of Central Siberia

The input and decomposition of plant remains in agroecosystems have been st udied in the Krasnoyarsk region, Central Siberia. The annual input of plant remains into the plow layer of chernozems varies from 3 to 8 t/ha under ce real crops (wheat) and from 8 to 15 t/ha under perennial grasses. From 15 t o 55% of this amount gets into the soil during the growing season before ha rvest. The synthesis of new humic substances compensates for nitrogen uptak e by plants from labile organic compounds and ensures the accumulation of n itrogen in the humus pool of soils.