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Effect Of Natural And Artificial Fertilization Of Biochar On Humus Carbon And Black Carbon In Soils

Posted on:2016-08-20Degree:DoctorType:Dissertation
Country:ChinaCandidate:G ZhangFull Text:PDF
GTID:1223330503452118Subject:Soil science
Abstract/Summary:PDF Full Text Request
Biochar is a part of the stability pool of soil organic carbon. The most important source of black carbon in nature soil is from forest and grassland fires or fire plow. Nowadays, application of biochar to soil has became an important way to response the change of global climate. Black carbon not only can improve the content of carbon in soil, promote the formation of soil aggregates and increase soil nutrients, and promote plant growth, increase productivity and stimulate microbial activity, but also play an important role in global carbon recycle, and greenhouse gas emissions and environmental pollution remediation. Currently there are little reseach on the effect on humus carbon and soil black carbon of application of biochar to soil, especially,there is no study about the comparision btween the two condition of that nature and artificial. So, this paper take soil black carbon and humus carbon as object, applied the thermo-chemical oxidation, elemental composition analysis, IR spectroscopy, differential thermal and thermal gravimetric analysis, nuclear magnetic resonance spectroscopy, isotope ratio mass spectrometry and other techniques, under two conditions of the natural(forest fires) and artificially application of biochar(culture experiments, pot experiments, embedded experiments and field experiments) systematic, study the effect on the content of humus carbon and soil black carbon,and the distribution of biochar in the soil organic carbon and black carbon.The resultare as follows:(1) The existence of the more obvious differences between maize straw biochar carbon and soil carbon black, maize straw biochar have features that with high content of C element and great condensation. The C elemental content of maize straw biochar was 797.0g ? kg-1, and the C elements content of the soil black carbon was between 350.0 and 716.5g ? kg-1; compared with the soil black carbon, the content of maize straw biochar carbon chain aliphatic hydrocarbons and carboxyl was less, and the content of aromatic carbon content was high, Condensation degree was larger.(2) Application of biochar had some influence on the soil properties and crop yield. Under natural conditions, application of biochar had little effect on soil pH, but decreased the soil organic matter content, mainly forest fires(severe fire) directly consumed soil organic carbon, severely damaged the vegetation and microbial communities of forest ecosystems, destroyed the soil C cycle systems; Under artificial conditions, application of biochar significantly increased soil pH and content of organic matter. In addition, according to add proportion 48 t ? ha-1 Maize straw biochar, no positive effect on rice yield, wheat yield to a certain extent, but the effect is not obvious.(3) Application of biochar had some influence on soil carbon content of composition of soil humusand HA degree of condensation. In the natural condition, soil carbon content of composition of soil humus and PQ values reduced;In the artificial condition, soil carbon content of composition of soil humusand PQ values increased. Furthermore,And compared to CK(no application of biochar),after application of biochar to soil,content of C elemental and degree of condensation of HA increased,content of chain aliphatic hydrocarbons and carboxyl of HA reduced, aromatic carbon content of HA increased.(4) After application of biochar, the content of soil BC(black carbon) and condensation degree of BC increased.Compared with the CK(no application of biochar), with the increase of application of time and quantities, the content of soil BC increased, the content of soil BC in field experiment increased from 3.54 g·kg-1 to 14.71 g·kg-1increase the sharpest; Through the study of soil carbon black structure characteristics found that:compared with the CK(no application of biochar),the content of C elements of soil black carbon and condensation degree increased, content of chain aliphatic hydrocarbons and carboxyl of BC reduced, aromatic carbon content of BC increased, hydrophobic increased, the molecular structure became complex, enhanced stability.(5) After application of biochar, the δ13C value of soil organic carbon and carbon black increased; With the increase of application of time and quantities, the content and updated proportion of soil organic carbon and black carbon that derived from the C4 plants increased,the content of soil organic carbon and black carbon that derived from the C3 plants didn’t cut,but,the updated proportion of soil organic carbon and black carbon that derived from the C3 plants reduced;The turnover of soil organic carbon was slower than the black carbon’s; the rate of Annual turnover of soil organic carbon and black carbon that derived from the C3 plants were 0.1221% and 0.2775% respectively.
Keywords/Search Tags:Forest Fire, Maize Straw Biochar, Humus Carbon, Black Carbon, Turnover
PDF Full Text Request
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