摘要
为了解决农业固体废弃物棉花秸秆还田后的快速降解问题,本研究以棉花秸秆在白腐真菌和噬热性侧孢霉复配下的微生物降解为研究内容,通过对白腐真菌和噬热性侧孢霉拮抗试验、白腐真菌和噬热性侧孢霉复配对棉花秸秆降解的最优条件组合筛选试验、白腐真菌与噬热性侧孢霉复配在田间降解秸秆的系列研究进行分析,结果表明:(1)白腐真菌和噬热性侧孢霉两种菌株共存时不相互抑制菌丝生长,菌株之间不发生拮抗反应,可以对两种菌株进行复配形成棉花秸秆降解菌群;(2)根据L9(34)正交试验结果,综合考虑温度、氮添加量、菌种类型和料水比这四种因素对棉花秸秆中木质素、纤维素和酸性洗涤纤维的降解效果,室内降解棉花秸秆在最优组合条件温度45℃、氮添加量3%、料水比1/2,复合菌群下的效果最好;(3)田间降解试验进一步验证了室内降解实验结果的可靠性,在冬季低温和降雪等情况下,为期50 d的田间试验中复配菌组对棉花秸秆降解率达到29.93%。后续实验需要在考虑实际土壤磷素含量情况下,确定适合于棉花秸秆降解的磷素补充量来促进棉花秸秆在田间快速降解。本研究对农业固体废弃物棉花秸秆在田间的快速降解提供了一种有效的方法,具有很好的实践意义。
Background, aim, and scope Straw is the mature crop stems and leaves（ear）, usually refers to cotton, wheat, corn, rice and other crops remaining after harvest seeds. Straw is rich in nitrogen, phosphorus, potassium and organic matter for more than 50% photosynthetic products exist in it. If these agricultural solid wastes can not be effectively used and processed, it will not only lead to waste of resources, but also cause environmental pollution and other issues. China is the world＇s largest cotton（Gossypium hirsutum L.） production country. Cotton acreage, cotton yield and cotton output are ranked first in the world, cotton production accounts for about 1/4 of the world＇s total output. Cotton straw returning to the field is still the main treatment method, but the cotton straw returned to the field could not be degraded quickly, which seriously affected the sowing and seedling emergence of cotton in the following year. How to deal with and quickly break down the cotton straw into the field has become an urgent problem to be solved. Based on previous research work, an antagonism test is used to test the possibility of culture compound between white rot fungi and Sporotrichum thermophile; then the optimal condition for compound inoculants degradation of cotton straw was selected by orthogonal pot experiment; and finally the effect of compound microorganism based on orthogonal experiment results was verified in a field test. Materials and methods The operation method of antagonism test is as following： the two strains were all picked a small colony in PDA culture medium plate, inoculated around 3 cm distance of the center point, cultured 5 d at 30℃, carefully observe the strains are mutually inhibited mycelial growth and spore formation and colony growth. When two strains of white rot fungi and Sporotrichum thermophile not mutually inhibit the mycelium growth, there was no antagonistic reaction between the strains. If the inoculated strains were separated and there was a clear gap between the two strains, this means these two kinds of microorganisms have the antagonistic phenomenon. L_9（34） orthogonal design was used to screening out the optimal experiment conditions of the degradation of cotton straw under different temperature, N content, microbial strain and water ratio conditions. Cellulose, lignin and acid detergent fiber（ADF） were analyzed after a 40 d degradation period to evaluate the cotton straw degradation degree. Based on the orthogonal experiment result, the actual effect of the compound white rot fungi and Sporotrichum thermophile in the field of cotton straw decomposition was studied at the optimal conditions. Cellulose, lignin and acid detergent fiber（ADF） were analyzed by the Van Soest method. Cotton straw degradation was tested by the difference weight method during the experimental period. Results The results showed as follows：（1） White rot fungi and Sporotrichum thermophile were not mutually inhibit the mycelium growth, there was no antagonistic reaction between the strains and the compound white rot fungi and Sporotrichum thermophilecould be used to degradation cotton stalk.（2） According to L_9（3~4） orthogonal test results, considering temperature, amount of N, strain type and ratio of material to water on cotton straw lignin, cellulose and acid detergent fiber degradation, the optimal combination of indoor conditions to degradation of cotton straw is temperature at 45℃, the amount of N at 3%, the ratio of material to water at 1/2 and compound white rot fungi and Sporotrichum thermophile.（3） The field degradation experiment verified the reliability of the indoor decomposition experiment results. The compound white rot fungi and Sporotrichum thermophile decomposed 29.93% cotton straw during a 50 d field experiment in the winter season and have an unsuitable environment condition such as snow and low temperatures. Discussion Straw returning is the most important treatment for agricultural solid wastes treatment. The lignin, cellulose and semicellulose in cotton stalk decomposition is slow under the natural environment, which influences the following crop germination and seedling emergence. The degradation efficient of compound microbial inoculants is higher than single microorganism. However, in this research, the effect of temperature on degradation effect of cotton straw is minimum than N content and water content. Therefore, the right cotton straw treatment in field should be carry out to maintain the agriculture production and sustainable development. Conclusions The results showed that the compound white rot fungi and Sporotrichum thermophile can degrade cotton straw quickly in field condition under 3% N addition and the ratio of material to water at 1/2. The effects of phosphorus on straw degradation is need to be considered in the subsequent experiments, and the amount of phosphorus added to promote the rapid decomposition of cotton straw in the field should determent by actual soil phosphorus content. Recommendations and perspectives This research provides a significant scientific basis for agricultural solid wastes treatment and an effective method for enhance soil quality. It is recommended that compound white rot fungi and Sporotrichum thermophile is an effective method to degrade cotton straw in field condition. Phosphorus fertilization should be considered in the cotton field management.
作者
王益
李春越
韩雅娇
杨宝和
马多
贾宏涛
WANG Yi;LI Chunyue;HAN Yajiao;YANG Baohe;MA Duo;JIA Hongtao(Institute of Earth Environment,Chinese Academy of Sciences,Xi＇an 710061,China;School of Geography and Tourism,Shaanxi Normal University,Xi＇an 710119,China;College of Grassland and Environmental Sciences,Xinjiang Agricultural University,Urumqi 830052,China)
出处
《地球环境学报》
CSCD
2018年第3期273-281,共9页
Journal of Earth Environment
基金
国家自然科学基金项目(41671269
41501255)
中国科学院"西部之光"项目
中央高校基本科研业务费专项基金项目(GK201603073)
国家重点研发计划项目(2017YFD0800500)~~
关键词
白腐真菌
嗜热性侧孢霉
降解
棉花秸秆
农业固体废弃物
white rot fungi
Sporotrichum thermophile
degradation
cotton straw
agricultural solid wastes
