不同保水剂及用量对砂培黄瓜幼苗生长和水分利用效率的影响

以砂子作为育苗基质,以黄瓜为供试作物,研究不同种类、不同用量的保水剂对砂子孔隙状况、持水性能和黄瓜幼苗生长和水分利用效率的影响。结果表明:聚丙烯酰胺型和聚丙烯酸钠型保水剂,在一定范围内,随着保水剂用量的增加,砂子总孔隙度增加,但大小空隙比逐渐减小,通气作用降低,水分日蒸发量和累积失水量减少,鲜重增加,水分利用率提高;但保水剂用量过高,虽持水、保水作用增加,且可延长植株萎蔫时间,由于通气孔隙减少,不利于幼苗生长。从整体上看,聚丙烯酰胺型的效果要优于聚丙烯酸钠型保水剂。

Effect of Different Water Retaining Agents and Their Application Rates on the Growth and WUE of Cucumber Seeding in Sand Substrate

Using cucumber as the test plants and sand as substrate to study the effect of different water retaining agents(WRA) and their application rates on the growth and water use efficiency of the plant, the porosity, the water retention and properties of the substrate. The results showed that, for both copolymer of polyacrylamide and polyacrylate and polyacrylate , the total porosity, wet weight of the seeding and water use efficiency(WUE) were significantly increased along with the increase of WAR application rates, while the big and small pore space ratio, aeration capacity, amount of water evaporation per day, cumulated amount of water loss reduced. Higher rates of application, however, with a strong water retaining capacity and effect on prolonging the wilting time of the seeding, did not benefit the seeding because of the decrease of aeration pore space. Considering the whole results, copolymer of polyacrylamide and polyacrylate had better effect than polyacrylate.