Yang Ting, Xing Xu-Guang, Ma Xiao-Yi
College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China.
Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education, Northwest A&F University, Yangling 712100, Shaanxi, China.
Ying Yong Sheng Tai Xue Bao. 2022 Aug;33(8):2187-2195. doi: 10.13287/j.1001-9332.202208.020.
Water is one of the most important factors limiting vegetation recovery and agricultural development in arid and semi-arid areas. The reduction of ineffective soil evaporation can improve soil water use efficiency. As a kind of clay mineral, attapulgite (ATP) plays a critical role in limiting soil evaporation due to its hydrophilicity and adsorption. In this study, three typical soils with different textures (dark loessial soil, cultivated loess soil, and sandy soil) were selected from the arid and semi-arid area of the Loess Plateau, and five ATP additions (0%, 1%, 2%, 3% and 4%) were set for conducting soil evaporation experiments under natural conditions using micro-evaporators to investigate the effects of ATP addition on different soil evaporation processes and the characteristics of evaporation surface cracks. The results showed that the cumulative evaporation and evaporation loss ratio of the same soil decreased with the increases of ATP addition when the ATP addition was <3%. When ATP was added at 3%, the cumulative evaporation and evaporation loss ratio of dark loessial soil and sandy soil decreased, while those of cultivated loess soil increased. When ATP was added at 4%, the cumulative evaporation decreased and the evaporation loss ratio increased for dark loessial soil, the cumulative evaporation increased and the evaporation loss ratio decreased for sandy soil, and the cumulative evaporation and evaporation loss ratio decreased for cultivated loess soil. The average cumulative evaporation of different soils followed an order of dark loessial soil > cultivated loess soil > sandy soil. Soil water content of ATP treatment was consistently higher than that of control throughout the whole evaporation process in the same soil. Simulations of cumulative evaporation versus the square root of time indicated that the amount of water released from the ATP-treated soil samples at the end of evaporation was higher than that of the control. After the addition of ATP, the crack area density of dark loessial soil and cultivated loess soil increased significantly, and the crack area density of sandy soil increased with the increase of ATP addition. The crack area density of all three soils reached the maximum at 4% of ATP addition. In summary, ATP addition of 3% could minimize the ineffective evaporation of soil water.
水是限制干旱和半干旱地区植被恢复和农业发展的最重要因素之一。减少无效土壤蒸发可提高土壤水分利用效率。凹凸棒石（ATP）作为一种粘土矿物，因其亲水性和吸附性在限制土壤蒸发方面起着关键作用。本研究从黄土高原干旱和半干旱地区选取了三种质地不同的典型土壤（黑垆土、耕种黄土和砂土），设置了五个ATP添加量（0%、1%、2%、3%和4%），利用微型蒸发器在自然条件下进行土壤蒸发实验，以研究添加ATP对不同土壤蒸发过程及蒸发表面裂缝特征的影响。结果表明，当ATP添加量<3%时，同一土壤的累积蒸发量和蒸发损失率随ATP添加量的增加而降低。当ATP添加量为3%时，黑垆土和砂土的累积蒸发量和蒸发损失率降低，而耕种黄土的累积蒸发量和蒸发损失率增加。当ATP添加量为4%时，黑垆土的累积蒸发量降低而蒸发损失率增加，砂土的累积蒸发量增加而蒸发损失率降低，耕种黄土的累积蒸发量和蒸发损失率降低。不同土壤的平均累积蒸发量顺序为黑垆土>耕种黄土>砂土。在同一土壤的整个蒸发过程中，ATP处理的土壤含水量始终高于对照。累积蒸发量与时间平方根的模拟结果表明，蒸发结束时ATP处理土壤样品释放的水量高于对照。添加ATP后，黑垆土和耕种黄土的裂缝面积密度显著增加，砂土的裂缝面积密度随ATP添加量的增加而增加。三种土壤的裂缝面积密度在ATP添加量为4%时均达到最大值。综上所述，添加3%的ATP可将土壤水分的无效蒸发降至最低。
