摘要
【目的】研究农田微塑料影响水稻秸秆分解过程以及农田微塑料的分解情况。【方法】通过野外实验,设置PE(聚乙烯)、PP(聚丙烯)和PVC(聚氯乙烯)3种微塑料,1%和5%两种浓度,S(小粒径)、M(中粒径)和L(大粒径)3种粒径,对照组Control(不添加微塑料)。以水稻秸秆作为分解底物,分析水稻秸秆的失重率、微生物活性及残留微塑料的粒径分布范围。【结果】除PE之外,PP与PVC对水稻秸秆分解的促进作用效果均较为显著。微塑料的添加浓度越高,水稻秸秆的失重率越大;微塑料粒径增加导致秸秆失重率减少。在秸秆整个分解期内,微塑料对羧甲基纤维素酶(Cx酶)起到了促进作用,而对外切β-葡聚糖苷酶(C_(1)酶)却有抑制效应;在分解前期,微塑料对过氧化物酶活性起到了促进作用。另一个方面,大粒径的微塑料相较于小粒径的微塑料其分解程度更大,PP的分解程度大于PE,大粒径PE80%分解为更小颗粒,小粒径PE66%分解为更小颗粒,而大粒径PP91%分解为更小颗粒,小粒径PP70%分解为更小颗粒。【结论】农田土壤中的微塑料均对水稻秸秆分解起促进作用,但是对于微生物活性影响是不确定的,微塑料有大幅度分解为更小颗粒的趋势。
【Objective】The present paper aimed to study the effects of farmland microplastic on the decomposition of rice straw and the decomposition of farmland microplastic.【Method】In field experiments, 3 types of microplastic as PE(polyethylene), PP(polypropylene), PVC(polyvinyl chloride), 2 types of concentration( 1% and 5%), 3 types of partical size as S(small particle size), M( middle particle size), L(large particle size), and control group(no add microplastic) were used to set up experiments. Using rice straw as decomposition substrate, the weight loss rate, microbial activity and particle size distribution of residual microplastic were analyzed.【Result】Except for PE, both PP and PVC had significant effects on the decomposition of rice straw. The higher the concentration of microplastic added, the greater the mass loss rate of rice straw;The increase of the particle size of microplastic leaded to the decrease of mass loss rate. During the straw decomposition, microplastic promoted carboxymethyl cellulase(Cx enzyme), but inhibited Exo-1,4-β-glucanase(C;enzyme);In the early stage of straw decomposition, microplastic promoted peroxidase activity. On the other hand, the decomposition degree of microplastic with large particle size was larger than that of microplastic with small particle size, the decomposition degree of PP was greater than that of PE, large particle size PE were decomposed into smaller particles by 80%, small particle size PE were decomposed into smaller particles by 66%, large particle size PP were decomposed into smaller particles by 91%, small particle size PP were decomposed into smaller particles by 70%. 【Conclusion】Microplastic in the farmland soil can promote the decomposition of rice straw, but the influence on microbial activity is uncertain, microplastic have a tendency to break down substantially into smaller particles.
作者
秦宇辉
李芬
肖佳敏
林永慧
何兴兵
QIN Yu-hui;LI Fen;XIAO Jia-min;LIN Yong-hui;HE Xing-bing(College of Biology and Environmental Sciences,Jishou University,Jishou,Hunan 416000,China)
出处
《西南农业学报》
CSCD
北大核心
2022年第4期748-756,共9页
Southwest China Journal of Agricultural Sciences
基金
国家自然科学基金(31670624,32060332,31560205)。
关键词
微塑料
水稻秸秆
分解
酶活性
Microplastic
Rice straw
Decompostion
Enzyme activity
