| This study was carried on platform of modern agricultural peanut industry technology system fertilizer long-term experiment established by Shenyang Agricultural University in 2011.There were five treatments: no fertilizer(CK),low level of biochar(C15;250 kg·hm-2),high level of biochar(C50;750 kg·hm-2),chemical fertilization(NPK;N:75.0 kg·hm-2,P2O5: 97.5 kg·hm-2,K2O: 97.5 kg·hm-2)and biochar-based fertilization(BBF;750 kg·hm-2).Soil and plant samples collected after peanut harvest in 2018.Determination of basic physical and chemical properties of soil,soil total organic carbon and its components content,soil aggregates structure and stability,soil microbial characteristics,soil aggregates bacterial abundance and community structure,peanuts nutrient accumulation and yield under different fertilization conditions.This study was helpful to reveal the interaction between soil nutrient elements,soil structure and soil microorganisms.It was the deepen research direction of the carbon sequestration mechanism of farmland soil.It had great significance for formulate reasonable nutrient management measures and increase yield and efficiency in continuous cropping peanuts soil.The experiments results showed that:(1)Long-term application of biochar and biochar-based fertilization alleviated soil acidification.The contents of nitrogen,phosphorus and potassium in application of biochar and biochar-based fertilization treatments were higher than that in CK treatment 69.5%~91.0%,74.3%~523.0% and 24.3%~60.5%,respectively.The biochar-based fertilization treatment had the best results.(2)Long-term application of biochar and biochar-based fertilization significantly improved the content of soil total organic carbon(TOC)5.8%~10.2% compared with application of no fertilization.The soil free particulate organic carbon(f POC),coarse organic carbon(c POC)and physical protected intra-microaggregate particulate organic carbon(i POC)content in BBF treatment significantly increased by 21.2%~34.7%,50.0%~123.3% and 7.5%~115.1% compared with that in CK treatment.The soil mineral-associated organic carbon(m SOC)in BBF treatment significantly decreased by 3.3%~19.5% compared with that in CK treatment.Soil TOC,f POC,c POC and i POC in BBF treatment was the highest,and they were obviously higher than in NPK treatment 6.2%,23.3%,131.0% and 39.0%,respectively.Soil m SOC in BBF treatment was the lowest and it significantly decreased by 13.4% compared with that in NPK treatment.(3)Long-term application of biochar and biochar-based fertilization significantly increased the proportion and organic carbon of > 0.25 mm large soil aggregates,contribution rate of > 0.25 mm large soil aggregates to soil total organic carbon and enhanced the soil aggregates stability.The ratio of >1mm and 1~0.25 mm soil aggregates,the content of soil organic carbon content in >1mm aggregates,the >1mm and 1~0.25 mm aggregates organic carbon contribution rate to the soil total organic carbon,the value of Mean weight diameter(MWD)and geometric mean diameter(GWD)in BBF treatment significantly increased by 18.5% and 33.7%,23.8%,34.6% and 23.6%,23.3% and 37.5%,respectively,compared with that in NPK treatment.The fractal dimension(D)of BBF treatment was significantly decreased by 4.0% compared with that in NPK treatment.The organic carbon content of >1mm soil aggregates and its contribution rate to soil total organic carbon of C50 treatment was significantly increased by 50.9% and 31.0% compared with that in C15 treatment.(4)Long-term application of biochar and biochar-based fertilization significantly increased the content of soil microbial carbon,the soil microbial community diversity,richness index and Pielou index by 164.8%~383.8%,12.1%,11.2% and 10.1% respectively,compared with application of no fertilization.Long-term application of biochar and biochar-based fertilization also increased the capacity of different carbon-source utilization.The capacity of different carbon-source utilization in BBF treatment was higher than that in NPK treatment,especially the use of carboxylic acids and amine carbon sources.(5)Long-term application of biochar and biochar-based fertilization significantly increased the large aggregates bacterial abundance,community diversity and abundance.The biochar and biochar-based fertilization treatments bacterial 16 Sr RNA gene copies of >1mm and 1~0.25 mm aggregates were increased by 12.9%~97.9% and 29.2%~80.2%,the shannon index increased by 8.4%~11.7% and 3.7~6.4% and simpson index decreased by 4.2%~38.9% and 10.5%~16.7% compared with that in CK treatment.The biochar and biochar-based fertilization treatments ace and chao index of >1mm soil aggregates significantly increased by 25.2%~40.4% and 10.1%~22.8% compared with that in CK treatment.Application of biochar-based fertilization had the best results.The proportion of Proteobacteria,Actinobacteria,Acidobacter and Chloroflexi phylum in aggregates were higher.Application of biochar and biochar-based fertilization increased the relative abundance of Proteobacteria and Actinobacteria phyla,and reduced the relative abundance of Acidobacteria and Chloroflexi phylain in large soil aggregates.Proteobacteria was significantly positively correlated with the organic carbon content in the aggregates(r=0.323).Acidobacteria showed a significant negative correlation with the aggregate organic carbon content(r=-0.275).(6)Long-term application of biochar and biochar-based fertilization significantly increased the accumulation of nitrogen,phosphorus and potassium,the pod distribution coefficient in different parts of peanut plants compared with application of no fetilization.With the increase of biochar input,nutrient accumulation,nitrogen and phosphorus pod distribution coefficient increased.Application of biochar and biochar-based fertilization significantly increased the peanut yield by 30.7%~38.2% compared with application of no fertilization.The BBF treatment peanuts yield reached 4183.9 kg·hm-2,which was the highest.The soil organic carbon,stability index of aggregates and soil microbial diversity were significantly correlated with peanut yield. |
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