垄沟覆地布对晋西旱塬梨园土壤墒情及导水特性的影响

Effects of Ridge-furrow Polypropylene Film Mulching on Soil Moisture and Hydraulic Conductivity in a Pear Orchard in Dryland Highland of Western Shanxi

以黄土高原丘陵沟壑区18a生酥梨为试材,探究全生育期裸地和起垄开沟覆地布的梨园,距树干不同距离(70cm和140cm)、不同土层(0~160cm)土壤含水量的时空变化,以农田为参照计算不同土壤管理措施下梨园各土层的土壤水分相对亏缺指数,并分析土壤和叶片的导水特性,以探求起垄开沟覆地布的土壤管理措施对梨园蓄水保墒的作用。结果表明,在果树生育期内经垄沟覆地布的梨园土壤含水量均高于裸地,但随着梨树的生长发育,二者土壤含水量间的差距逐渐缩小;与大田相比,梨园土壤水分表现出不同程度的亏缺状态,其中裸地梨园土壤水分在80~160cm的土层表现出亏缺现象,而经垄沟覆地布处理后的梨园水分亏缺的土层下移至120~160cm;同时,垄沟覆地布后果园土壤饱和导水率、枝条叶比导水率和叶片相对含水量分别较裸地提高2.24倍、40.59%和4.91%,且垄沟覆地布的土壤管理措施可显著提高果树的净光合速率、气孔导度、蒸腾速率和水分利用效率。可见,垄沟覆地布可改善土壤水分入渗状况,并有效缓解黄土高原丘陵沟壑区梨园土壤水分亏缺现象,增强梨树光合作用,进而促进梨树的生长发育。

In this paper,we used 18 a‘Suli＇trees as test material to study the effect of nudation and ridge-furrow polypropylene film mulching（RFM）on the dynamic changes of the moisture content at different soil layers（0-160 cm）of different distances（70 and 140 cm）from the tree trunks in a pear orchard during the growth period in the hilly and gully region of Loess Plateau.The soil water deficit index at the different layers of the pear orchard was calculated from field data.The soil saturated hydraulic conductivity of the pear orchard,stem and leaf area specific conductance and gas exchange parameters of the pear trees were measured.The results showed that compared with nudation,RFM increased soil moisture content more greatly throughout whole growth period,however,with pear growth and development,the difference of soil moisture content under nudation and RFM gradually decreased;compared with the field soil moisture of pear orchard,it showed varying degrees deficit,the soil layers from 80 cm to 160 cm,120 cm to 160 cm were water deficit in nudation and RFM respectively;compared with nudation,the RFM increased soil saturated hydraulic conductivity,leaf area specific conductance and relative water content of the leaves by 2.24,40.59% and 4.91% respectively.RFM also significantly improved the net photosynthetic rate,transpiration rate,stomatal conductance and water use efficiency in the pear trees simultaneously.Therefore,RFM could be an effective agronomic measure to improve soil water infiltration and may effectively alleviate soil water deficit of pear orchards in the hilly and gully regions in the Loess Plateau,and ultimately promoted the growth and development of pear trees.