长期连续施用生物质炭对土壤肥力、小麦产量和微生物群落结构的影响

Effects of Long-Term Successive Biochar Amendment on Soil Fertility,Wheat Production and Microbial Community Structure

基于长期田间试验,研究了6 t/(hm^(2)·a)玉米秸秆还田(Straw)以及2.4、6和12 t/(hm^(2)·a)玉米秸秆生物质炭添加(分别记为BC1、BC3、BC5)对土壤肥力、小麦产量和微生物群落结构的影响。结果表明:与不添加玉米秸秆及其生物质炭的处理(CK)相比,BC5处理显著提高了2021年小麦产量,且3个剂量生物质炭处理2021年小麦产量平均提高15%。经过11 a的连续添加,土壤容重从CK的1.06 g/cm^(3)降低至BC5处理的0.73 g/cm^(3),全碳从CK的14.9 g/kg增加至BC5处理的83.8 g/kg。土壤碱解氮、有效磷和速效钾均随生物质炭施用量增加而增加,表现为BC5>BC3>BC1>Straw≥CK。本研究中,长期连续施用玉米秸秆及其生物质炭没有显著改变细菌群落多样性,而BC5处理略增加真菌群落多样性。PICRUSt2功能预测表明生物质炭处理显著提高了碳固定相关功能基因丰度,而降低碳降解相关功能基因丰度。

A field experiment started in 2010 was conducted to examine the effects of successive maize straw and its biochar amendment on soil fertility,wheat production and microbial community structure.There were 5 treatments:CK(no straw and no biochar),6 t/(hm^(2)·a)maize straw(Straw),2.4 t/(hm^(2)·a)biochar(BC1),6 t/(hm^(2)·a)biochar(BC3),and 12 t/(hm^(2)·a)biochar(BC5).The results showed that BC5 significantly increased wheat yields in 2021,compared with CK,wheat yields with biochars averagely increased by 15%.After 11 years of continuous addition,soil bulk density decreased from 1.06 g/cm^(3)(CK)to 0.73 g/cm^(3)(BC5),and total carbon increased from 14.9 g/kg(CK)to 83.8 g/kg(BC5).Soil available nitrogen,available phosphorus and available potassium increased with the application rates,following the order of BC5>BC3>BC1>Straw≥CK.No significant change was found in the diversity of bacterial communities under different treatments,while BC5 slightly increased fungal diversity.PICRUSt2 results showed that biochar addition significantly increased the abundance of C-fixation related functional genes,while decreased the abundance of C-degradation related functional genes.