自制林木废弃物再生型保水剂在林业生产中的应用潜力评价

Evaluation of Application Potential of Two Non-commercial Super Absorbent Polymers Made from Chinese Fir and Bamboo Sawdust in Forestry

以商品保水剂聚丙烯酸钾为参照,通过比较分析保水剂的保水能力以及土壤的物理、化学、微生物学指标,评估杉木屑和竹屑2种林木废弃物再生型保水剂的应用前景和生态环境风险,旨在筛选出保水性能好、价格低廉的环保型保水剂。结果表明:2种自制再生型保水剂在纯水中的吸水能力不如聚丙烯酸钾强,但与土壤(1∶200)混合后,保水能力表现为杉木屑保水剂(88.60%)>竹屑保水剂(86.50%)>聚丙烯酸钾(84.00%)。施入0.50%,0.25%杉木屑和竹屑保水剂后,土壤田间持水量依次表现为杉木屑73.80%和58.80%,聚丙烯酸钾67.80%和49.30%,竹屑58.40%和46.50%,明显高于对照(35.80%)。施入0.25%保水剂的70d田间水分动态监测表明,杉木屑保水剂、竹屑保水剂、聚丙烯酸钾的最高含水量分别为43.21%,40.57%和38.58%,高于对照(35.69%),但大部时间聚丙烯酸钾与对照的保水能力没有差异。随着时间的推移,自制保水剂的优势逐渐下降,70d时基本消失。保水剂能提高土壤pH和速效钾含量,对土壤细菌和真菌均没有不利影响,相反自制保水剂对细菌有积极作用。综合评价得出结论:自制保水剂有较强保水能力且有利于土壤微生物活动,在林业生产上具有推广应用价值,建议用量为1∶200(0.50%)。

This objective of paper was to evaluate the application potential and environmental risks of two super absorbent polymers(SPS)respectively made from Chinese fir(CF-SAP)and bamboo sawdust(BB-SAP) by contrast with commercial SAP:Potassium Polyacrylate(PP-SAP)by means of measurement of water absorption capacity of different types of SAPs and their effects on soil physiochemical and biological properties.It was found that CF-SAP and BB-SAP had lower capacity of water absorption in pure water compared with PP-SAP,while the opposite was true when SAPs mixed with soil(1∶200),the maximum capacity of water absorption of soil were ranged as:CF-SAP(88.60%)>BB-SAP(86.50%)>PP-SAP(84.00%).When 0.50%,0.25%of CF-SAP and BB-SAP were applied into soil,soil field capacity were 73.81%and 58.80% for CF-SAP,67.80%and 49.30%for PP-SAP,58.40%and 46.50%for BB-SAP,respectively,which were significantly higher than that for CK(35.80%)(with no any SAP).The results revealed from dynamics of soil(mixed with 0.25% of SAP)water content during 70days observation that the maximum moisture content with respective 43.21%,40.57% and 38.58% for CF-SAP,BB-SAP,PP-SAP were higher(P< 0.05)than CK(35.59%),while PP-SAP and CK were at similar level in most of time.The advantage of CFSAP and BB-SAP in water absorption was decreased with the time and almost disappeared in 70days.Soil pH was improved by three SAPs,while the contents of soil available N,P and K were observed no change except available K in PP-SAP treatment.There were no adverse effects on soil bacteria and fungi being detected.On the contrast,CF-SAP and BB-SAP had a positive effect on bacteria instead.In conclusion,CFSAP and BB-SAP exhibited better influence on both water retention and soil microbial activity,and had a good potential to be applied in forest in southern China.The recommended CF-SAP or BB-SAP dose was 0.50% based on dry soil weight.