柠条秸秆和地膜覆盖对土壤水分和玉米产量的影响

为了探讨北方农牧交错带不同保墒措施下旱地玉米的土壤水分特征及其对产量的影响,以甘农118为试验材料,监测了单膜(SFP)、双膜(DFP)、柠条秸秆沟埋(CPDP)和裸地(CK)4种不同处理下0~100 cm土壤水分季节变化、垂直变化及年际变化,测定了玉米产量和水分利用效率。结果表明:SFP和DFP处理明显改善0~40 cm土层土壤体积含水率,较CK处理保墒效果提高35.65%~47.91%,但随着玉米生育期的推进,由于玉米生长耗水和土壤蒸发作用,建植后土壤体积含水率均接近或低于萎蔫系数(7.20%)。连续2 a种植玉米4种处理土壤贮水量均有不同程度的减少,CPDP和CK处理土壤贮水量分别减少了68.42和68.07 mm,其次为SFP(53.49 mm),DFP减少最小(48.98 mm),说明研究区内玉米生长需要消耗大量土壤水分。SFP和DFP能够增加玉米对降雨和土壤水的利用,不同年份产量水分利用效率较CK处理分别提高12.55%~35.71%和25.11%~54.70%。SFP和DFP耗水量、产量和水分利用效率均无显著差异(P0.05),因此建议在研究区种植玉米时可以采取SFP措施,而CPDP耗水量较高、产量和水分利用效率相对较低,不宜采取此种保墒措施。

Effects of mulching with Caragana powder and plastic film on soil water and maize yield

Abstract: How to effectively use water and steadily increase crop productivity in arid and semi-arid region has become the focus of attention. It is well known that soil evaporation does little effect on the formation of crop biomass and yield, so reducing soil evaporation is important for improving water use efficiency and agricultural water saving management. Plastic film mulching and straw mulching are effective drought-resistant practices to produce higher crop yield and improve water use efficiency in arid and semi-arid region (Yanchi country, Ningxia Province, China). However, their influences on inter-annual and seasonal dynamics of soil water and crop yield are not quite clear. In this paper, inter-annual and seasonal changes of soil water content in the 0-100 cm soil layer, maize yield, water use efficiency under different mulching methods were studied. At the same time, ecological effects of different mulching measures on cropland were evaluated. The experiment was carried out from May to October in 2013 and 2014 respectively. With the aim of revealing the beneficial effects of straw and plastic mulch on water storage and maize yield, four kinds of different treatments were designed with three replications respectively: whole field surface single film mulching planting (SFP), double film mulching planting (DFP), Caragana powder ditch buried mulching planting (CPDP) and uncovered and flat planting (CK), and the Gannong 118 was taken as an experimental material. Results revealed that the methods of SFP and DFP greatly improved soil water content by 35.65%-47.91% in 0-40 cm soil layer comparing flat planting (CK), especially when there was no rainfall and benefit for the growth of maize. But with the development of maize growth period, the soil water content was closer to or below the wilting coefficient (7.20%) owing to the water consumption of maize growth and soil evaporation. The soil water storage in four treatments all decreased to different degrees after two years of planting. The soil water storage of CPDP and CK were in largest decline (by 68.42 and 68.07 mm, respectively), followed by SFP (53.49 mm) and the least DFP (48.98 mm), which revealed that precipitation couldn't meet the needs of normal growth of maize in the study region. In terms of the effect on yield components, the 100-grain weight of SFP and DFP was significantly higher than CPDP and CK (P<0.05), and the kernel rows per ear in 2 years did not significantly different in four treatments (P>0.05). Excepting the numbers of kernel rows, bare tip length and panicle length of CPDP in 2013 had significant differences with the other three treatments (P<0.05), there were no significant differences between the other treatments (P>0.05). It revealed that the reason why the SFP and DFP treatments produced higher crop yield than the others were the increase of the 100-grain weight (P<0.05). SFP and DFP could increase the utilization of rainfall and soil water, and improved water use efficiency in different years by 12.55%-35.71% and 25.11%-54.70% respectively, comparing with CPDP and CK. There were no significant differences between SFP and DFP in water consumption, maize yield and water use efficiency (P>0.05). Therefore, SFP could be recommended as a suitable method when planting maize in this study area. And due to the lower maize yield, water use efficiency and the higher water consumption, CPDP were not recommended.