生物质炭和植物促生菌添加对矿井废水灌溉下小麦产量及土壤环境的影响

Effects of Adding Biochar and Plant Growth Promoting Bacteria on Wheat Yield and Soil Environment under Mine Wastewater Irrigation

以中国农业大学小麦新品系农大136为供试对象,采用盆栽方式,研究矿井废水灌溉下土壤添加5%、10%、15%生物质炭以及各含量生物质炭+植物促生菌(PGPB)处理对小麦产量以及土壤环境的影响。结果表明,与普通井水浇灌相比,矿井废水灌溉下土壤酶活性减弱,微生物量碳、微生物量氮含量降低;小麦根系活力下降,在各生育时期表现为拔节期最高,开花期次之,抽穗期最低;小麦各生育时期株高、单茎干物质质量及成熟期实际产量和生物产量均表现为下降趋势。而添加各含量生物质炭以及PGPB处理有利于改善土壤环境,促进小麦生长和增产。与矿井废水浇灌对照处理相比,矿井废水浇灌下添加10%生物质炭+PGPB处理的土壤过氧化氢酶、蔗糖酶、多酚氧化酶、酸性磷酸酶以及脱氢酶活性分别增加90.6%、37.5%、60.3%、55.7%、69.2%,土壤pH值、全氮、速效钾含量分别提高11.1%、185.4%、63.9%;小麦抽穗期10%生物质炭+PGPB处理的土壤微生物量氮含量最高达139.1 mg/kg,微生物量碳含量最高达253.4 mg/kg;成熟期小麦生物产量和实际产量分别提高24.4%、24.0%。综上所述,添加不同含量生物质炭和PGPB处理均能够提高矿井废水灌溉下土壤酶活性以及微生物量碳、微生物量氮含量,显著改善土壤理化性质,提高小麦各生育时期相对叶绿素含量、净光合速率和根系活力,增加株高和单茎干物质质量及小麦成熟期产量,其中以10%生物质炭+PGPB处理小麦增产效果最佳。

Using the new wheat line of China Agricultural University,Nongda 136,as the experimental object,a pot planting method was used to study the effects of adding 5%,10%,15%biochar and various concentrations of biochar+plant growth promoting bacteria(PGPB)to soil under mine wastewater irrigation on wheat yield and soil environment.The results showed that compared with ordinary well water irrigation,soil enzyme activity was weakened and microbial carbon and nitrogen content was reduced under mine wastewater irrigation;The vitality of wheat root system decreased,with the highest performance at the jointing stage,followed by the flowering stage,and the lowest at the heading stage;The plant height,single stem dry matter weight,actual yield and biomass yield of wheat at different growth stages showed a decreasing trend.However,adding various concentrations of biomass charcoal and PGPB treatment was beneficial for improving soil environment,promoting wheat growth and yield increase.Compared with the control treatment,the soil catalase,sucrase,polyphenol oxidase,acid phosphatase,and dehydrogenase activities increased by 90.6%,37.5%,60.3%,55.7%,and 69.2%respectively when treated with 10%biomass charcoal+PGPB under mine wastewater irrigation;The soil pH value,total nitrogen,and available potassium content increased by 11.1%,185.4%and 63.9%,respectively;The soil microbial biomass nitrogen content reached 139.1 mg/kg and microbial biomass carbon content reached 253.4 mg/kg during the wheat heading stage treated with 10%biomass charcoal+PGPB;The biological yield and actual yield of mature wheat increased by 24.4%and 24.0%,respectively.In summary,the addition of different concentrations of biomass charcoal and PGPB treatment can improve soil enzyme activity,microbial carbon and nitrogen content under mine wastewater irrigation,significantly improve soil physicochemical properties,increase relative chlorophyll content,net photosynthetic rate and root vitality of wheat at different growth stages,increase plant height,single stem dry weight and yield at maturity.Among them,the best yield increase effect is achieved under the treatment of 10%biomass charcoal+PGPB.