摘要
为明确土壤干湿交替环境下保水剂与土壤颗粒之间的作用方式及保水剂对土壤结构和水分有效性的影响。通过土柱模拟试验,研究连续失水—复水条件下,不同粒径(>0.85,0.6~0.85,0.30~0.45 mm)保水剂对土壤水分特性、土壤团聚体分布和结构稳定性的作用,以及保水剂—土壤混合体价键结构的微观变化特征。结果表明:第1次(T1)和第2次(T2)失水取样阶段,除T2阶段的最小粒径处理外,其余各粒径保水剂促使土壤相对含水量较对照显著增加72.9%以上(P<0.05)。保水剂粒径大小和土壤水分状况均会影响保水剂对土壤供水能力的作用效果,粒径最小的保水剂改变土壤持续吸水和供水的能力较差,促进土壤水稳性大团聚体组成和团聚结构稳定的性能最优。在连续的干湿交替影响下,保水剂与土壤的作用加剧,壤土中的Si-O-Si键、-OH、蒙脱石和石英等矿物胶体会进入到保水剂网状结构中,反应的剧烈程度会影响土壤水稳性大团聚体的形成和稳定性。初步分析认为,随着反复失水—复水进程,更多黏粒矿物对保水剂分子结构的破坏,是减弱保水剂吸持水性能的主要因素之一。
To clarify the interaction between super-absorbent polymers(SAPs)and soil particles,and the influences of SAPs on soil structure and soil moisture availability under alternating dry and wet conditions,the soil column simulation experiments were carried out to study the effects of SAPs with different particle sizes(>0.85,0.6~0.85,0.30~0.45 mm)on soil moisture characteristics,soil aggregate distribution and soil structure stability,and the microscopic changes of the valence bonds of SAPs and soil mixtures.The results showed that,compared with the control,the SAPs’treatments significantly increased the relative soil moisture content by more than 72.9%in the first(T1)and second(T2)sampling stages(P<0.05),except for the minimum particle size treatment in T2 stage.The particle size of SAPs and soil moisture condition would affect the SAPs’application effect on soil water supply capacity.The SAPs with the smallest particle size had the poor ability to change the continuous soil water absorption and supply,but it had the most beneficial to promote the composition of soil water-stable macro-aggregates and the stability of soil aggregates.The interactions between SAPs and soil particles were intensified during continual soil wetting and drying cycles.The mineral colloids such as Si-O-Si bond,-OH,montmorillonite and quartz in the loam soil would enter into the network structure of SAPs,and the reaction intensity might affect the formation and stability of soil water-stable macro-aggregates.It was preliminarily analyzed that more soil clay minerals would destroy the molecular structure of SAPs during the process of repeated water loss and rehydration,which resulted in the decreases of the water absorption and holding capacities of SAPs.
作者
纪冰祎
赵驰鹏
吴玥
吕国华
宋吉青
白文波
JI Bingyi;ZHAO Chipeng;WU Yue;Lü Guohua;SONG Jiqing;BAI Wenbo(Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081;Liaoning Province Modern Agricultural Production Base and Construction Engineering Center,Shenyang 110032)
出处
《水土保持学报》
CSCD
北大核心
2021年第5期375-383,共9页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(41601226)
国家重点研发计划项目(2017YFD0300408)。
关键词
保水剂
粒径
土壤结构
土壤水分
干湿交替
super-absorbent polymer
particle size
soil structure
soil moisture
wetting and drying cycle
