聚丙烯酸钠对3种土壤持水能力及作物产量的影响

在离心机模拟不同水吸力条件下,研究了聚丙烯酸钠(sodium polyacrylate记作SP)5种使用浓度(占干土质量0,0.01%,0.08%,0.2%与1%)对3种土壤(砂土、壤土、黏土)持水能力的影响;采用大田试验研究了地表撒施2 g/m2SP对冬小麦与下季玉米产量及WUE影响。结果表明:3种土壤在0.01 MPa至1.5 MPa水吸力下的持水能力随着SP用量的增加而增加,砂土的作用效果较壤土、黏土更显著;3种土壤适宜浓度为0.08%~0.2%,最佳用量为0.2%,此用量条件下砂土、壤土、黏土的最大毛管持水量分别较对照增加了138.61%,7.22%,62.70%;不灌水条件下,SP处理较不施用SP冬小麦增产4%,WUE增加5.7%,灌浆期灌水28.5 mm条件下SP处理较不施用SP增产1%,WUE降低1%;SP处理的玉米产量较对照降低0.5%,WUE提高3%,效果明显低于对冬小麦效果。

Influence of Sodium Polyacrylate on Water-holding Capacity of Three Different Soils and Effects on Yield of Crop

The effects of sodium polyacrylate(SP) on soil,water-holding capacity at different suctions of sand,silt and clay were evaluated by using centrifugal Method.Five rates of SP,0.0%,0.01%,0.08%,0.2%,and 1%(on dry weight basis),were added to these three soils.The effects of SP on yield and WUE of winter wheat and the following maize were studied.SP was dusted on the upper layer with 2gm/m2after the wheat was sown and the maize was planted on the field without any treatments after the wheat was harvest.The results show that the amount of water retained by the soil at each suction over the range of 0.01MPa to 1.5 MPa significantly increased with increase of SP;The effects on sand were more obviously than silt and clay;It is suggested the concentrations of SP be controlled from 0.08% to 0.2% by weight and the best rate is 0.2% of each soil.Then the capillary prosity of sand,silt and clay were increased 138.61%,37.22%,62.70% respectively compared to the CK.Without added irrigation,the yield and WUE of SP treated wheat were increased 4% and 5.7% respectively compared to the CK while increased 1% and-1% respectively with added 28.5mm irrigation at filling stage.The yield and WUE of the maize planted on the SP treated plot were increased-0.5% and 3% respectively compared to CK.The effect of SP on the yield and WUE of maize was less obviously than on the wheat.