Effect of nitrogen depot with saturated ammonium (NDSA) fertilization on the spacial distribution of corn root and N uptake .
饱和铵贮库施肥对玉米根系空间分布和氮素吸收的影响

Rhizobox experiments were carried out to study the effect of nitrogen depot with saturated ammonium (NDSA) fertilization on the spacial distribution of corn roots and N uptake . The results indicated that the growth of the roots and shoots of corn were significantly promoted by NDSA fertilization . The fresh mass of roots and shoots was increased by18% and37% respectively compared with that of the conventional fertilization . The corn roots distributed mainly in the soil layer away from the center of NDSA6 to8 cm and formed a root ball around the fertilized spot in NDSA treatment . N uptake of corn roots,stems and leaves was increased by43%,30%,31%,respectively,and apparent N utilization was increased by15% in NDSA treatment compared with that of the conventional fertilization treatment . The ammonium content of NDSA treatment was more than two times higher than that of conventional fertilization,while the nitrate decreased to a half,indicating that the NDSA inhibited the transformation of ammonium to nitrate . Therefore,it can be concluded that under NDSA fertilization,a root ball" formed by inducing root growth,altering its spacial distribution and architecture in the soil and inhibition to nitrification may refers to one of most important mechanisms for NDSA fertilization reducing nitrogen loss,increasing N utilization rate and promoting plant growth .