荒漠旱区梨园秸秆覆盖的节水效应及对梨树生长结果的影响

Effect of Straw Mulching on Water Saving and Pear Growth in Arid Desert Areas

1996～ 1998年对干旱荒漠地区梨树覆盖秸秆后的节水效应研究表明 :覆秸秆后能从整体上提高 0～ 6 0 cm土层土壤含水率 1.8%～ 3.6 % ,提高最大幅度出现在该区旱季 ,此时覆盖树土壤含水率为 10 .3%～ 13.6 % ,而对照已处轻中度水分亏缺状态。根系因此生长加速 ,总根量增加 6 6～ 88条 / m2 ,树体水分状况得到相应改善 ,发育枝的含水率与水势分别提高 0 .87%～ 1.33%和 0 .2 6～ 0 .35 MPa;叶片含水率与水势分别提高 1.2 8%～ 2 .0 7%和0 .31～ 0 .4 2 MPa;叶绿素含量增加 19.4 % ,光合速率提高 18.1%。果实生长加速 ,果实纵径和横径平均日生长量增加 0 .0 7mm和 0 .0 5 8mm,果实纵径快速生长期延长 15 d左右 ,单果质量增加 17～ 2 4 g,在覆秸秆树挂果数不超过对照树 12 %时 。

Straw mulching as one of the important water saving measures was adopted in this experiment of pear tree in arid desert area during 1996 to 1998. The results showed that soil water content (SWC) in a depth of 0 to 60 cm was increased by 1.8% to 3.6% with straw mulching. The highest increased SWC occurred in drought season, with its range from 10.3% to 13.6% for treatment while that for CK was under water deficiency. Roots grew strongly and increased to 66 to 88 items/m 2. The corresponding water content was increased by 1.28% to 2.07% and 0.87% to 1.33%, and water potential by 0.31 MPa to 0.42 MPa and 0.26 MPa to 0.35 MPa in blade and vegetative shoot, respectively. Both chlorophyll content and photosynthetic rate increased by 19.4% and 18.1%, respectively. As a result, fruit growth enhanced and average increment of both fruit length and width increased by 0.07 mm and 0.058 mm respectively. Single fruit weight increased by 17 to 24 g, and the fruit size increased when the number of fruit per tree did not exceed 12% compared with that without straw mulching.