论文部分内容阅读
[目的]为了探求宁夏中部干旱地区最适宜的硒砂瓜覆砂厚度。[方法]采用蒸发器整体称重法,以宁夏中卫南山台地区天然砂石为试材,研究了不同厚度砾石覆盖对土壤蒸发的影响。[结果]砾石覆盖处理的土壤日蒸发量的大小顺序为CK>H1(5 cm)>H2(8cm)>H3(10 cm)>H4(15 cm)。同时,随着试验天数的增加,H3(10 cm)和H4(15 cm)处理的累积蒸发量的差别逐渐减小。土壤总蒸发量随碎石覆盖厚度的增加呈现幂函数减少的变化趋势,拟合曲线的决定系数达到0.925 5。[结论]随着砂石覆盖厚度的增加,土壤日蒸发量逐渐减少,土壤含水量逐渐增加。覆盖可以有效减小蒸发,且覆盖厚度越厚,对蒸发的抑制效果越明显。在实施砾石覆盖处理时,应该适量增加覆盖厚度,阻止大量水分因蒸发而造成的水分损失。当砾石覆盖厚度达10 cm以上时,砾石抑制蒸发的效果差别不大,因此10 cm的砾石覆盖厚度最适宜当地区域的自然条件。幂函数方程Y=atb可以用来模拟土壤总蒸发量随碎石覆盖厚度的变化。
[Objective] The aim was to find the most suitable sand thickness of selenium sand cake in the arid area of central Ningxia. [Method] The natural gravel of Nanshantai of Zhongwei in Ningxia was used as sample to study the influence of gravel covering with different thickness on soil evaporation. [Result] The order of soil daily evaporation of gravel covering was CK> H1 (5 cm)> H2 (8 cm)> H3 (10 cm)> H4 (15 cm). At the same time, with the increase of test days, the differences of cumulative evaporation of H3 (10 cm) and H4 (15 cm) decreased gradually. The total soil evaporation showed a decreasing trend with the increase of gravel thickness, and the coefficient of determination of the fitted curve reached 0.925 5. [Conclusion] With the increase of sand cover thickness, soil daily evapotranspiration gradually decreased and soil moisture content increased gradually. Covering can effectively reduce the evaporation, and the thicker the cover, the more obvious the effect of inhibiting evaporation. Gravel coverage should be applied to increase the thickness of the cover, to prevent the loss of moisture due to evaporation of large amounts of water. When the gravel coverage is more than 10 cm, the effect of the gravel in suppressing evaporation is not so different. Therefore, the gravel thickness of 10 cm is most suitable for the natural conditions in the local area. Power function equation Y = atb can be used to simulate the total soil evaporation with the gravel thickness changes.