(1) 中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室

In order to investigate the function of,biochar and fulvic acid on improving coastal salty-alkalinity land, this paper adopted field corn planting experimental method in June 2015; and set up 6 treatments: CK,BC1,BC2, FA,BC1+FA,BC2+FA, applying biochar 7.5 t /hm~2(BC1),30 t /hm~2(BC2),fulvic acid 1.5 t /hm~2(FA) and their combinations; and studied the effects of additional materials on characteristic indexes of important soil sanilityalkalinity situation. The results indicated that BC2 treatment could reduce soil bulk density,but soil bulk density was not reduced under treatment of low biochar application quantity (BC1),and soil in research area showed a gradual degradation state of natural hardening. With the increase of biochar applying quantity,soil water holding capacity showed a degeneration tendency. Applycation of biochar and fulvic acid significantly improved the organic matter contents in soil,which was the highest level under BC2+FA condition,reaching 6.31 g /kg. Among all treatment,the phenomenon of periodic desalting and accumulation of salt in the surface soil showed an identical rule,but the salt accumulation under BC1+FA and BC2+FA treatments was obviousely lower than that of the other treatments. The results indicated that applycation of biochar and fulvic acid could increase soil fertility,improve soil structure, restrain salt accumulation and was in favour of remoulding coastal beach saline-alkali land for rapid arable land utilization. The treatment of 30 t /hm~2 biochar combined with 1.5 t /hm~2 fulvic acid had the best result.