具有不变的化学性状，自己不含有害成份，不使营养液发生转变。基质的化学性状首要指以下几方面： ph值：反映基质的酸碱度，很是主要。它会影响营养液的ph值及成份转变。ph＝6－7被认为是幻想的基质。
With constant chemical properties, it does not contain harmful ingredients and does not change the nutrient solution. The chemical properties of matrix mainly refer to the following aspects: pH value: it reflects the pH of matrix, which is very important. It will affect the pH value and composition change of nutrient solution. The matrix of pH = 7 is considered as fantasy.
电导度(ec)：反应已电离的盐类溶液浓度，直接影响营养液的成份和作物根系对各类元素的接收。 缓冲能力：反应基对肥料敏捷改变ph值的缓冲能力，要求缓冲能力越强越好。
Conductivity (EC): the concentration of ionized salt solution directly affects the composition of nutrient solution and the reception of various elements by crop roots. Buffering capacity: the buffering capacity of the reaction base to quickly change the pH value of the fertilizer. The stronger the buffering capacity, the better.
盐基代换量：是指在ph＝7时测定的可替代的阳离子含量。一般有机机质如树皮、锯未、草炭等可代换的物质多；无机基质中蛭石可代换物质较多，而其它惰性基质则可代换物质就很少。
Base substitution amount: refers to the replaceable cation content measured at pH = 7. Generally, there are many replaceable organic substances, such as bark, sawdust, peat and so on; Vermiculite has more replaceable substances in inorganic matrix, while there are few replaceable substances in other inert matrix.