不同覆草量苹果园土壤水温效应及对树体生长的影响

将麦草覆盖应用于果园,研究不同覆盖用量22 000 kg·hm-2(T1)、33 000 kg·hm-2(T2)、44 000 kg·hm-2(T3)和清耕(CK)在整个生长期对19年生长富2号苹果园0~100 cm土壤水分、5~25 cm土壤温度、树体生长量及果实品质的影响。结果表明:在旱情较重的4—7月,3种覆草处理的平均含水量随覆草量的增加而增大,其中T2和T3处理极显著(P0.01)高于CK,高出8.98%~27.09%;且3种覆草处理0~20、20~40 cm土层的含水量极显著(P0.01)高于CK,高出9.36%~73.77%;4—8月3种覆草处理的各深度地温低于CK,4—6月份极显著(P0.01)低于CK,低出2.11℃~8.02℃;相反,9—11月份高于CK。覆草处理5~20 cm深度土温日变幅极显著(P0.01)低于CK,低出0.39℃~3.63℃。果实单果重和产量以T2处理最高,3种覆草处理每公顷产量较CK极显著(P0.01)提高,高出10.70%~20.83%;产量水分利用效率覆草处理较CK极显著(P0.01)增高,高出9.87%~20.87%。覆草对树体生长量、枝类比例影响不大。综合各种效应及投入产出比,陇东黄土高原苹果园覆草量以22 000~33 000 kg·hm-2较经济适宜。

Effects of wheat straw-mulching on soil moisture and soil temperature and tree growth in apple orchard

The wheat straw mulching with different amounts (22 000 kg·hm-2(T1),33 000 kg·hm-2(T2)and 44 000 kg·hm-2(T3))and clean tillage(CK)were used in orchards to study its influence on the soil moisture in 0~100 cm soil depth,the soil temperature in 5~25 cm soil depth,tree growth and fruit quality during the whole growth period of 19-year-old Nagafu No .2 tree .Results showed that from April to July the average soil moisture in the depth of 0~100 cm of corresponding three treatments increased with the increase of wheat straw amounts;the average moisture con-tents of T2 and T3 were significantly (P<0.01)higher than that of CK in same period,increased by 8.98%~27 .09%,and the soil moisture contents in 0~20 cm and 20~40 cm two soil layers of three wheat straw mulching treat-ments were also significantly (P<0 .01)higher than that of CK in the same soil layer,increased by 9 .36%~73 .77%. From April to August the soil temperature in 5~25 cm soil depth in three wheat straw mulching treatments was lower than that in CK,significantly (P<0 .01)from April to June,decreased by 2 .1 1℃~8 .02℃.But it was higher than that in CK from September to November .Daily amplitude in 5~20 cm soil depth in wheat straw mulching treatments was very significantly (P<0 .01)lower than that in CK,decreased by 0 .39℃~3 .63℃.The single fruit weight and yield of T2 were all the highest in four treatments,the yields of three wheat straw mulching treatments were significantly (P<0 .01) higher than CK,increased by 10 .70%~20 .83%.Water use efficiency of fresh yield of wheat straw mulching treat-ments was significantly (P<0 .01)higher than CK,increased by 9 .87%~20 .87%.Wheat straw mulching treatments had little effect on tree growth and shoot ratio .In view of comprehensive effects and input and output ratio,it was suit-able for apple orchard to apply wheat straw mulching with 22 000~33 000 kg·hm-2 in this area .