ot experiments
were carried out to study the effect of combining applicationof organic manure(silkworm
manure)and
inorganic fertilizer(urea and ammoniumbicarbonate)on the biomass-N and
N-supplying characteristics of coastal slightlysaline soil.The results obtained showed
that(1)application of both organic andinorganic
fertilizers could significantly increase the soil
biomass-C and biomass-Nand the
combining application of silkworm manure and inorganic
fertilizer mightcause a more increase of biomass-N than single application of silkworm manure
orinorganic fertilizer;(2)soil biomass-N was an important link in soil nitrogen tran-sformation
and a major part of available N in soil,(3 )there was a significantlyclose relationship between
the changes of soil biomass-Nand soil N-supplying cha-racteristics,thus a strong
immobilization of N fertilizer by microorganisms wasalways followed by a net N mineralization,
which was most favourable for the gro-wth and development of barley plant,and(4)silkworm
manure was helpful in rai-sing fertilizer utilization efficiency,especially for ammonium
bicarbonate which canvolatilize violently in coastal saline soil because of its higher pH,and it
would bean efficient way to raise N utilization efficiency by combining application of
variousorganic manures and inorganic fertilizers.