不同粒径组合对植物栽培基质容重及孔性和水吸力的影响

研究粒径对栽培基质容重、孔性和水吸力的影响，以便为空间植物培养提供栽培基质。采用4种基质，即Profile基质（P）、黑陶粒（B）、白陶粒（W）和蛭石（V），各基质按照不同粒径（< 1 mm，1~2 mm，2~3 mm）组成设置了10种组合（体积百分比），研究测试不同粒径组合基质的基本理化特性、容重、孔性和水吸力。P和B基质的容重约0.70 g·cm–3。P基质含有较多矿质养分离子；增加小粒径基质颗粒占比，不同组合基质的容重、总孔隙度和持水孔隙度均显著增加，但通气孔隙度下降；在10种不同基质组合中，P7（40-60-0）、B8（10-70-20）和W4（10-60-30）分别具有最高的总孔隙度，P8（10-70-20），B1（20-50-30）和W8（10-70-20）具有最高的气水比，P3（50-50-0），B3（50-50-0）和W3（50-50-0）具有最高吸附水量；4种基质的平均总孔隙度和吸水量大小顺序为V>P>B>W。因此，P3（50-50-0）基质和B7（40-60-0）基质具有适中的容重、良好的孔性和较高的水吸力，适用于空间植物栽培。 

Effects of Different Particle Sizes on the Bulk Density,Porosity Character,Water Suction of Substrates

To study the effects of different particle sizes on the bulk density, porosity character, water suction of substrates and select suitable substrate combinations for higher plants cultivation in space. Four substrates including profile particle (P), black ceramic particle (B), white ceramic particle (W), and vermiculite (V) were selected, and 10 kinds of particle size combinations (volume percent) are set, in which basic physicochemical character, bulk density, porosity character and water suction were tested. The bulk density of P and B substrates was 0.70 g·cm–3 and there were many minerals in P substrate. The bulk density, Total Porosity (TP) and Water Holding Porosity (WHP) of different substrate combinations increased significantly (p < 0.05) with the increase of proportion of < 1 mm particle size of substrates, but not for Air Porosity (AP). In the 10 kinds of substrate combinations, there were the highest total porosity for P7 (40-60-0) , B8 (10-70-20) and W4 (10-60-30), the highest water air ratio for P8 (10-70-20), B1 (20-50-30) and W8 (10-70-20), the highest adsorption water volume for P3 (50-50-0), B3 (50-50-0) and W3 (50-50-0). The order of average total porosities of 4 kinds of substrates was V> P> B> W. There are moderate bulk density, good porosity character and higher water suction for the P3(50-50-0) and B7 (40-60-0) substrates, which are suitable for plants cultivation in space.