风化煤用量下覆膜和AM真菌对玉米生长和土壤微环境的影响

Effect of film mulching and AM fungi inoculation on maize growth and rhizosphere soil properties with the addition of weathered coal

为缓解我国东部贫瘠土壤,以风化煤与覆膜为切入点,通过室内盆栽试验,研究两种覆膜方式(无覆膜和覆薄膜)和两个供试土壤基质(砂土基质和砂煤混合基质)下接种AM真菌对干旱胁迫时玉米生长特性、水分利用效率与土壤性状的影响。结果表明:两个覆膜方式下,砂煤混合基质相比砂土基质提高了接种AM真菌处理的玉米根系侵染率和土壤根外菌丝密度,但无明显差异;同时土壤总球囊霉素和易提取球囊霉素含量分别显著提高了80.0%~106.5%和55.0%~73.3%(P<0.05)。同一覆膜方式下,砂煤混合基质接种AM真菌和CK处理的土壤有机碳、全氮与速效磷含量分别显著高于砂土基质下相应处理,但降低了土壤速效钾含量。砂煤混合基质下覆薄膜与接种AM真菌联合对玉米株高、生物量、叶片SPAD值及水分利用效率的促进效果最好;同时砂煤混合基质接种AM真菌处理提高了无覆膜下土壤蔗糖酶和全覆膜下过氧化氢酶和碱性磷酸酶含量,分别比砂土基质下处理显著提高了46.8%~59.8%、37.9%~70.0%与57.8%~87.5%(P<0.05)。研究表明施加一定量风化煤时,接种AM真菌和覆薄膜能够促进水分胁迫下的植物生长发育,改善水分利用效率和提高土壤肥力。

Owing to the heavy evaporation in the spring-autumn period and cold climate,coal exploitation in the Eastern Prairie of China disturbs the soil structure,accelerates soil desertification,and lowers soil fertility,thus hindering crop growth in the mined regions.In order to solve the issues of poor soil nutrients,a pot experiment was conducted with two film mulching patterns,i.e.,non-film mulching and film mulching;two soil substrate types,i.e.,sandy soil and a mixed substrate of sand and weathered coal;and two levels of microbial inoculation,i.e.,arbuscular mycorrhizal(AM)fungi inoculation and no inoculation,namely the control(CK).The aim of this study was to evaluate the effects of AM fungi inoculation on plant growth,water use efficiency,and rhizosphere soil properties under water stress conditions using dif ferent soil substrate types and film mulching patterns.Results showed that the inoculated,mixed-substrate system improved maize root colo nization and soil external hyphal length compared to those of the inoculated,sandy-substrate system utilizing the two film mulching pat terns,but not significantly.In addition,soil total glomalin and easily extractable glomalin contents with the mixed substrate were significantly higher by 80.0%~106.5%and 55.0%~73.3%than with the sandy substrate(P<0.05).With the same mulching pattern,both the AM fun gi and CK treatments utilizing the mixed substrate significantly improved the soil SOC,TN,and Olsen-P contents compared to those utiliz ing the sandy soil(P<0.05),but reduced the soil available K content.The combination of film mulching and AM fungi inoculation positively affected plant height and biomass,leaf SPAD value,and water use efficiency with the mixed substrate.Compared to the sandy soil,the inoc ulated soil invertase activity with non-film mulching and the soil catalase and alkaline phosphatase activities with film mulching of the mixed substrate significantly increased by 46.8%~59.8%,37.9%~70.0%,and 57.8%~87.5%(P<0.05),respectively.Our results indicate that the combination of film mulching and AM fungi inoculation can improve plant growth,water use efficiency,and soil fertility with the ad dition of weathered coal.