干物质和氮素累积
N and dry matter accumulation
营养物质转化规律
law of transformation of nutrients
营养物质组成
composition of nutritive substance
nutrient composition
有毒有害物质
Hazardous chemicals
Hazardous and Noxious Substance
hazardous and noxious substances
Toxic and harmful substances
toxic and noxious contaminant
Toxic and harmful material
deleterious substance
Nocuousness substances
有关物质和含量测定
Determine assay and related