论文部分内容阅读
根据砂田不同耕作年份实地取样,并进行粒径分析,结果表明,砂层中混入的土含量随着砂田耕作年限增加而逐步增加;参照实地取样后粒径分析,以砂层混入土的不同重量百分比梯度设置处理T1-5%、T2-10%、T3-20%、T4-25%、T5-30%、T6-40%,并设对照CK1(纯砂砾覆盖)和CK2(无覆盖裸地),进行温度变化和蒸发效应的模拟研究。结果表明,5cm、10cm的土壤温度在8:00和20:00均随着退化程度的加重而降低,而在中午则呈横置S状;与对照纯砂砾覆盖CK1相比日高温延时性随退化程度加重而逐步减弱,日积温减小且昼夜温差增大;蒸发强度随着砂田退化程度的加重而逐渐增强,无覆盖处理蒸发量约是纯砂砾覆盖蒸发量的3倍,而严重退化的处理T5、T6分别是纯砾石覆盖的2倍,即严重退化砂田年蒸发量要比CK1多110mm。
According to field sampling in different tillage years and grain size analysis, the results show that the content of soil mixed with sand gradually increases with the increase of tillage time; with reference to the particle size analysis after field sampling, the sand is mixed with different weight of soil The percentage gradient was set at T1-5%, T2-10%, T3-20%, T4-25%, T5-30%, T6-40% and control CK1 (pure gravel covered) and CK2 ), A simulation study of temperature changes and evaporation effects. The results showed that the soil temperature at 5 cm and 10 cm decreased with the degree of degradation at 8:00 and 20:00, and traverse S at noon. Compared with CK1, With the increasing degree of degradation, it gradually weakened, the daily accumulated temperature decreased and the temperature difference between day and night increased. The evaporation intensity gradually increased with the degradation degree of sandy soils. The evaporation without covering treatment was about three times of the evaporation with pure gravel, T5 and T6 are twice as large as those covered by pure gravel, respectively, that is, the annual evaporation of severe degraded sands is 110mm more than that of CK1.