翻耕法对土壤斥水性改良效果

Amelioration effect of water repellency by tillage

为了消除土壤斥水性对农业生产的不利影响,对以色列具有强斥水性的2种土壤(黏性土、砂质土)、4种不同深度的翻耕处理(0～2.5,0～10,0～20,0～30 cm)和种植与否(种植、不种植)共进行16个处理,研究翻耕法对土壤斥水性的改良效果.对于种植的处理,每隔4个月重新进行翻耕处理一次,对于不种植的处理,在试验过程中不再进行翻耕处理,以1年时间为试验期,在每个阶段开始和结束时测定土壤斥水持续时间,最后对各试验在不同阶段土壤斥水持续时间进行比较分析.结果表明:对斥水性土壤进行翻耕处理的物理方法可以暂时消除土壤的斥水性,但斥水性又会在灌溉一段时间后重新出现,经过多次翻耕可有效地消除土壤的斥水性,消除效果随翻耕次数、时长和翻耕深度呈显著的正相关关系.翻耕法对黏性土壤的改良效果明显好于砂质土壤.研究结果可为物理方法进行土壤改良提供理论依据.

In order to eliminate the negative influence of soil water repellency on agricultural produc- tion, two kinds of strong water-repellent soils （ clay and sand） collected from Israel was used to inves- tigate the amelioration effect of tillage on water repellency of soil. Sixteen treatments in total, including four depths （0 -2.5 cm, 0 -10 cm, 0 -20 cm, 0 -30 cm） of tillage, planting （cabbage） or not, were set in experimental pots. The treatments with planting were tilled in every 4 months and those without planting weren ＂t tilled during the experiment for one year. Water Drop Penetration Time （WDPT） of soil was measured before and after each tillage applied for every treatment. After analyzed and compared the WDPT, the results show that tillage can eliminate the repellency for a while, but the repellency reoccurs after irrigation for a period of time. The water repellency disappears after the soils experiences many times of tillage; moreover the amelioration effect of repellency shows a significant positive correlation to number, duration and depth of tillage. The amelioration effect of tillage on clay soils is more obvious than on sand ones. The results can provide the evidence that a physics method can improve the water repellencv of a soil.