3种土壤灌溉后通气小白菜的水分及养分利用特性

选取3种河南省典型土壤(郑州黏土、洛阳粉壤土和驻马店砂壤土),以小白菜为供试作物,采用地下滴灌供水,设置常规灌溉为对照组(CK)、灌溉后通气(MV)为试验组开展盆栽试验,研究灌溉后通气对小白菜水分和养分利用的影响.结果表明,与CK相比,处理MV显著地提高了3种土壤小白菜根系活力、根干质量和净光合速率.处理MV显著提高了小白菜蒸腾速率,其中,黏土、粉壤土的分别提高了20.61%和15.98%.黏土在处理MV时,小白菜产量和水分利用效率分别提高了38.08%和52.70%;小白菜氮、磷、钾吸收效率分别增大了61.65%,66.54%,104.83%.粉壤土在处理MV时,小白菜磷、钾吸收效率分别增大了50.60%,73.65%.砂壤土在处理MV时,小白菜磷、钾吸收效率分别增大了40.84%,26.19%.以上差异均具有统计学意义(P<0.05).综上,黏土灌溉后通气处理对小白菜水分、养分利用及产量的提高效果最为显著.

Effects of post-irrigation aeration on pakchoi water use efficiency and nutrient uptake characteristics in three kinds of soil

Post-irrigation aeration can improve anoxic environment of crop root rhizosphere and increase crop yield. Hence investigating into effects of post-irrigation aeration on crop growth and nutrient absorption characteristics can provide a scientific guidance for application of aerobic irrigation technique. Three typical soils(clay soil in Zhengzhou, silty loam soil in Luoyang and sandy loam soil in Zhumadian)in Henan Province were collected and pakchoi was selected as experimental crop. Two groups, namely post-irrigation aeration(MV)and control(CK), were established in pot experiments under subsurface trickle irrigation conditions in a greenhouse, and then the crop water use efficiency and nutrient absorption characteristics were studied. Results showed that the crop root activity, root dry weight and net photosynthetic rate in MV group were significantly improved compared with those in CK group. The transpiration rate in MV group was increased by 20.61%, 15.98% and 33.33% in the clay, silty loam and sandy loam soils, respectively. The yield and water use efficiency were increased by 38.08% and 52.70%, and the absorption efficiency of nitrogen, phosphorus and potassium were increased by 61.65%, 66.54%, and 104.83% in the clay soil. In the sandy loam soil, the absorption efficiency of phosphorus and potassium were increased by 50.60% and 73.65% and the absorption efficiency of phosphorus and potassium were increased by 40.84% and 26.19%. These differences in the parameters between MV and CK groups are all of statistical significance(P<0.05). As such post-irrigation aeration can improve both water and nutrient use efficiencies and yield of pakchoi in the clay soil significantly. 