覆膜滴灌对玉米光合特性、物质积累及水分利用效率的影响

采用田间试验方法,以雨养条件为对照,研究3种灌溉处理(滴灌、覆膜滴灌、覆膜限量补灌)对玉米相对叶绿素质量浓度(SPAD值)、光合特性及产量和水分利用效率的影响,探讨不同膜下滴灌节水增产的效果及内在机制。结果表明,覆膜增加玉米苗期叶绿素质量浓度,在拔节期覆膜的作用减弱,抽雄期SPAD值依次为覆膜限量补灌覆膜滴灌滴灌雨养。与对照相比,覆膜滴灌、覆膜限量补灌玉米地上部干物质重分别增加22.8%~52.8%和20.3%~48.0%;玉米产量增加1 261 kg/hm2和1 300 kg/hm2,增产12.7%和13.1%;提高水分利用效率0.83 kg/m3和1.23 kg/m3,提高水分生产效率0.30 kg/m3和0.36 kg/m3。覆膜限量补灌在不影响光合产物积累的基础上,比覆膜滴灌节水60%。

Effect of Drip Irrigation under Plastic Film Mulch on Photosynthetic,Dry Matter Accumulation and Water Use Efficiency

The effects of different irrigation methods(Rained farming, Drip irrigation, Drip irrigation under plastic film mulch, limited supplemental irrigation under plastic film mulch) on chlorophyll relative content(SPAD), photosynthetic characteristic, maize yield and water use efficiency were studied by the method of field experiments. The objective of this study was to discuss water-saving and increasing yield effects and internal mechanism of different drip irrigation under plastic mulch measures. The results showed that the method of plastic film mulch could increase SPAD value of maize leaves, the effects would be decreased in jointing stage. In tasseling stage, limited supplemental irrigation under plastic film mulch has highest SPAD value, and then drip irrigation under plastic film mulch, the third was drip irrigation, last was rained farming. Compare to rained farming, the treatments of drip irrigation under plastic film mulch and limited supplemental irrigation under plastic film mulch could increase dry matter weight of plant 22.5%-52.8% and 20.3%-48.0%; improve maize yield 1 261 kg/ha and 1 300 kg/ha; increase yield rate 12.7% and 13.1%, respectively. Drip irrigation under plastic film mulch and limited supplemental irrigation under plastic film mulch could improve water use efficiency 0.83 kg/m³ and 1.23 kg/m³, increase water production efficiency 0.30 kg/m³ and 0.36 kg/m³, respectively. Compared with drip irrigation under plastic film mulch, limited supplemental irrigation under plastic film mulch could keep higher dry matter accumulation and save water 60%.