地面覆盖对盐渍土水热盐运动及作物生长的影响

利用田间小区试验研究了山东省莱州半干旱海水入侵地区不同覆盖措施对土壤水盐热运动及作物生长的影响,试验结果表明,①塑膜覆盖对盐渍土有很好的保温增温效果和一定的保水抑盐作用;②秸秆覆盖能拦蓄雨水、减少地面径流和地表蒸发,对盐渍土有非常明显的保持土壤水分、抑制地表返盐、促进降雨淋盐的作用,且其作用随覆盖厚度的增加而增强,③秸秆覆盖的隔热性及其对土壤热容量的提高,缓和了土壤温度的日变化;④5cm厚秸秆覆盖的土壤含盐量变化幅度较小,说明秸秆覆盖提高了土壤对盐分的缓冲性;⑤随着油葵的生长,增加了地面的植被覆盖度,削弱了覆盖措施对土壤水盐热运动的影响;⑥5cm秸秆覆盖下的油葵生长状况及其产量均优于其他处理。由此可见,秸秆覆盖是改良利用盐渍土非常有效的一项措施。

Effects of Different Ground Covers on Soil Physical Properties and Crop Growth on Saline-alkaline Soil

Field experiments were conducted to study the effects of different ground covers on the physical properties of soil and crop growth on saline-alkaline soil in semi-arid region of Shandong province, China. The results revealed that plastic film cover could not only raise greatly the temperature, but also could help the soil maintain high water content and low salt. Results also showed that straw cover could retain rainwater, hinder the run off and evaporation of water, prevent the soil from secondary salinization and promote the leaching of salts by rainwater. Moreover, straw cover could hinder the exchange of heat and enlarge the heat capacity of soil,resulting in less difference of temperature of soil than other ground covers. Sunflower under the cover of 5cm straw grew better and showed a higher yield than other treatments. As a result, straw cover was the best way in the utilization of saline soil.