聚丙烯酰胺型保水剂对基质持水性和菜心生长的影响

在砂、炉渣、锯木屑三种基质中加入不同用量的保水剂并进行菜心育苗和盆栽试验，研究保水剂对基质的持水特性、容重和菜心出苗、生长的影响。结果表明：随着保水剂用量的增加，3种基质的持水量和锯木屑的湿容重显著增加，而砂、炉渣的湿容重趋于降低；保水剂可提高菜心出苗率，随着保水剂用量的增加，菜心幼苗萎蔫天数、植株高度和生物量也显著增加；菜心水分利用效率在一定范围内随保水剂用量的增加而增加，但保水剂用量超过一定水平，菜心水分利用效率反而下降。

Effects of Water Retaining Agent on Water Retention Properties of Substrates and Growth of Flowering Chinese Cabbage

Three substrates, sand, cinder and sawdust with different rates of water retaining agent(WRA) application, and flowering Chinese cabbage as tested crop were used to study the effect of WRA on the water retention properties and bulk density of the substrates as well as the emergence and growth of the crop seedling. The results showed that the water holding capacity of the three substrates and the wet bulk density of sawdust were significantly increased along with the increase of WAR application rate, but the wet bulk density of sand and cinder were trended to decrease. WRA also could enhance the rate of emergence. As the increase of WAR application rate, the wilting time of the seedling was markedly prolonged and the plant height and biomass of the seedling were obviously increased. The water use efficiency of the crop increased only with the increase of WRA application rate under a certain level. However, when the rate overran the level the water use efficiency would decline.