连续炭基肥替代化肥对菜园土壤性质和细菌群落结构的影响

Effects of Continuous Biochar-based Fertilizer Replacement on Soil Properties and Bacterial Community Structure in Vegetable Garden

为了解生物炭基肥替代化肥减量施用的田间长期效应,利用定位试验研究连续5 a炭基肥替代化肥对蔬菜产量、土壤理化性质和细菌群落结构的影响。结果表明,连续5 a实施炭基有机肥替代化肥,土壤pH提高了0.13~0.25,土壤有机质、碱解氮和有效磷含量也分别提高了2.1%~62.2%、5.8%~86.0%和0.4%~103.1%,炭基肥替代化肥处理的荠菜(Capsella bursapastoris)产量提高了4.0%~14.8%,但75%替代处理较50%替代处理有所降低。炭基肥替代化肥处理的土壤菌群Sobs、Shannon、Ace和Chao指数均高于单施化肥处理,且均以75%替代处理最高。炭基肥替代化肥显著降低了土壤中硝化菌属(Nitrolancea)、拟无枝酸菌属(Amycolatopsis)、芽单胞菌属(Gemmatimonas)等的丰度,增加了纤维素降解菌菌群(Planifilum、Saccharomono-spora)的丰度。芽单胞菌属、Ilumatobacteraceae、Methyloligellaceae等的丰度与土壤全氮、全磷、有机质间具有显著的相关性。可见,连续炭基肥替代化肥明显改善了菜地土壤的理化性质,从而影响了土壤细菌群落结构和多样性,适量替代可以提高蔬菜产量,但应注意长期连续施用对土壤pH、碳/氮的影响,避免过量施用抑制作物对养分的吸收利用。

In order to understand the field long-term effect of biochar-based fertilizer instead of chemical fertilizer,the vegetable yield,soil physical and chemical properties and bacterial community structure with biochar-based fertilizer replacement for 5 consecutive years were studied by localization experiment.The results showed that soil pH increased 0.13-0.25 after 5 years,and the contents of organic matter,alkali-hydrolyzable nitrogen and available phosphorus in soils increased 2.1%-62.2%,5.8%-86.0% and 0.4%-103.1%,respectively.The yield of Capsella bursa-pastoris with biochar-based fertilizers increased by 4.0%-14.8%than that of the control,but the yield under 75%replacement was lower than that of 50%replacement.The indexes of Sobs,Shannon,Ace and Chao of soil bacteria with biochar-based fertilizer were higher than those of chemical fertilizer,and those under 75%replacement were the highest.Compared to chemical fertilizer,the abundances of Nitrolancea,Amycola-topsis and Gemmatimonas with biochar-based fertilizer decreased significantly,and the abundances of cellulose-degrading bacterial increased,such as Planifilum and Saccharimonadales.There were significant correlations between the abundances of Gemmatimonas,Ilumatobacteraceae,Methyloligellaceae,and soil total nitrogen,total phosphorus,organic matter.Therefore,the replacement of continuous biochar-based fertilizer significantly improved soil physical and chemical properties,and caused the changes in bacterial community structure and diversity.Appropriate replacement of biochar-based fertilizers could increase vegetable yield,but the effect of long-term continuous application on soil pH and C/N should be paid attentions,so as to avoid excessive application inhibiting nutrients uptake and utilization by crops.