| 冉艳玲,王益权,张润霞,祝飞华,刘金.保水剂对土壤持水特性的作用机理研究[J].干旱地区农业研究,2015,33(5):101~107 |
| 保水剂对土壤持水特性的作用机理研究 |
| Research on the mechanism of super absorbent polymer to soil water-holding characteristic |
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| DOI：10.7606/j.issn.1000-7601.2015.05.19 |
| 中文关键词: 保水剂 风沙土 水分特征曲线 Van Genuchten模型 |
| 英文关键词:super absorbent polymer aeolian sandy soil water characteristic curve Van Genuchten model |
| 基金项目:渭北果园土壤钙素退化（K332021312） |
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| 中文摘要: |
| 分别将B1（北京华瑞祥科技有限公司高吸水树脂保水剂）、B2（广东东莞市安信保水有限公司农林保水剂）、B3（唐山博亚科技工业开发有限责任公司的高能抗旱保水剂）3种保水剂以不同用量（0.05%、0.10%和0.50%）施入无团聚体孔隙的风沙土中，测定各处理土壤在不同吸力时的含水量，并用V-G模型拟合各土壤水分特性曲线，获得各处理土壤的水分特性曲线参数和主要水分常数等结果，以期揭示使用保水剂在改善土壤持水性方面的作用特征和机理。结果表明：①使用保水剂后，除土壤无效水部分无显著变化外，各处理土壤饱和含水量、田间持水量、重力水和有效水部分均显著增加，保水剂用量为0.50%时处理土壤的田间持水量比对照高3～4.7倍，使用保水剂显著改善了土壤中、低水吸力段的持水容量，即土壤的“孔隙”持水部分。②各处理土壤的水分特征曲线右移，各吸力段的持水容量明显增加，n值均小于对照，表明使用保水剂显著增大了在失水过程中土壤的持水能力。③ 使用保水剂后，各处理土壤增加的吸水量主要来源于重力水和有效水，保水剂用量为0.05%时，各处理土壤重力水所占比重高于60%，随着保水剂用量增加，重力水所占比重下降，有效水分所占比重提高，表明保水剂对土壤持水特性的作用机理主要体现为增加了土壤的“毛管孔隙”持水比例，即在低使用量时显著改善土壤重力水部分，随着保水剂使用量的增加则显著增加土壤有效水部分。④综合比较保水剂类型和对土壤持水能力的改善作用，B3型保水剂在使用量为0.5%时的改善效果最好。由此得出，化学保水剂尽管是一种具有很强分子吸水能力的基质，却在土壤中能够极大地改变土壤“孔隙”持水性，增加土壤有效水贮量，应当受到应有的重视和广泛使用。 |
| 英文摘要: |
| In order to explore the function and mechanism by using the super absorbent polymer to improve soil water-holding characteristic, put three types of super absorbent polymers with different dosages (0.05%, 0.10% and 0.50%) into sand soil without aggregate pore, to measure the soil moisture content of each treatment under different suctions, successfully fitted soil water characteristic curve by V-G model, and acquired the results of the soil water characteristic curve parameter and main water constants for each treatment. The results indicate that: (1) After using the super absorbent polymer, except the soil unavailable water had no significant change, the saturated soil water content, field capacity, gravity water and available soil water in all treatments had significantly increased. When we used 0.50% super absorbent polymer, the field capacity in this treatment was 3～4.7 times higher than the control group. Using the super absorbent polymer, the water-holding capacity in middle and low water suction segment was significantly improved, that was the soil pore for holding water. (2) The soil water characteristic curve for each treatment was moved to the right, the water-holding capacity in each suction section was increased. The n value was total less than the control group, which indicated that super absorbent polymer can significantly improve the soil water-holding capacity in the dehydration process. (3) After using the super absorbent polymer, the soil added absorbent water mainly derived from gravity water and available water. When we use 0.05% of the super absorbent polymer, the proportion of the gravity water in each treatment was high than 60%. With the dosages increasing, the proportion of the gravity water was decreased and the available water was increased. It indicated that mechanism of super absorbent polymer to the soil water-holding characteristic was mainly embodied the increase of the proportion of water held by capillary pore. When use low dosage, the soil gravity water can be significantly improved, but with the increase of the dosage, the soil available water was significantly improved. (4) Comprehensively compared the improving effect of the super absorbent polymer type, the B3 with 0.50% dosage was the best improvement effect. From this, even though the super absorbent polymer was a kind of substrate with strong ability of moisture-absorbing by molecule, it can be greatly changed the water-holding capacity by soil pore and increase available soil water capacity. So it should be given great attention and widely used. |
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