FA旱地龙
FA
FA yellow-humic acid drought resistance agent
FA handinong
FA handilong
fulvic acid
半干旱地区生态系统
Semi-arid land ecosystems
半干旱和半湿润易旱地区
the semi-arid area and semi-moist area which incline to be arid
北方旱地农业
Dry Land Agriculture in North China
风沙半干旱地区
Sandy and semi-drought area