| 摘要 | 第8-10页 |
| Abstract | 第10-11页 |
| 1 INTRODUCTION | 第12-25页 |
| 1.1 Background | 第12-14页 |
| 1.1.1 Problem statement | 第14页 |
| 1.2 Soil CO_2 efflux | 第14-22页 |
| 1.2.1 Soil as Source and Sink of Greenhouse gases | 第15-16页 |
| 1.2.2 Carbon in soils | 第16页 |
| 1.2.3 Soil Carbon pools and Carbon fractions | 第16-17页 |
| 1.2.4 Microbial Biomass Carbon (MBC) / Microbial Biomass Nitrogen (MBN) | 第17-19页 |
| 1.2.5 Soil NH_4~+-N and NO_3~--N | 第19页 |
| 1.2.6 Total N in Agricultural soils | 第19-20页 |
| 1.2.7 Soil Aggregation and Aggregate Stability | 第20-21页 |
| 1.2.8 Soil Water Holding Capacity / Soil Water Retention | 第21-22页 |
| 1.3 Biochar | 第22-25页 |
| 1.3.1 Origin | 第22-23页 |
| 1.3.2 Production | 第23-24页 |
| 1.3.3 Uses | 第24-25页 |
| 2 MATERIALS AND METHODS | 第25-33页 |
| 2.1 Experiment 1 (Soil Incubation) | 第25页 |
| 2.2 Experimental design and treatment | 第25页 |
| 2.3 Experimental materials | 第25-27页 |
| 2.3.1 Physical and chemical properties of materials used for the experiment | 第26页 |
| 2.3.2 Soil preparation | 第26页 |
| 2.3.3 Soil incubation | 第26-27页 |
| 2.4 Gas measurements | 第27页 |
| 2.5 Soil Microbial Biomass Carbon and Nitrogen fumigation, extraction, and measurements | 第27-28页 |
| 2.6 Nitrogen mineralization | 第28页 |
| 2.7 Statistical Analysis | 第28页 |
| 2.8 Experiment 2 (Field study) | 第28页 |
| 2.9 Experimental design and treatment | 第28-30页 |
| 2.9.1 Land Preparation | 第28页 |
| 2.9.2 Sowing of corn seeds | 第28-29页 |
| 2.9.3 Soil Sampling and Analysis | 第29-30页 |
| 2.10 Methods | 第30-32页 |
| 2.10.1 Plant growth analysis | 第30页 |
| 2.10.2 Soil Water Holding Capacity and Bulk Density | 第30-31页 |
| 2.10.3 Soil Total Porosity | 第31页 |
| 2.10.4 Soil Aggregate Stability | 第31-32页 |
| 2.11 Statistical Analysis | 第32-33页 |
| 3 RESULTS AND ANALYSIS | 第33-71页 |
| 3.1 Effects of biochar and straw on soil respiration | 第33-35页 |
| 3.2 Effects of biochar and straw on N mineralization | 第35-37页 |
| 3.3 Effects of biochar and straw on soil microbial biomass carbon (SMBC) | 第37-39页 |
| 3.4 Effects of biochar and straw on soil microbial biomass nitrogen (SMBN) | 第39-44页 |
| 3.5 Effects of biochar and straw on soil Total N | 第44-45页 |
| 3.6 Effects of biochar, manure and straw on soil organic carbon (SOC) | 第45-48页 |
| 3.7 Effects of biochar, manure and straw on soil microbial biomass carbon (SMBC) | 第48-51页 |
| 3.8 Effects of biochar, manure and straw on soil pH | 第51-53页 |
| 3.9 Effects of biochar, manure and straw on soil bulk density (BD) | 第53-56页 |
| 3.10 Effects of biochar, manure and straw on soil water holding capacity (WHC) | 第56-58页 |
| 3.11 Effects of biochar, manure and straw on soil total porosity | 第58-59页 |
| 3.12 Effects of biochar, manure and straw on aggregates mean weight diameter (MWD) | 第59-62页 |
| 3.13 Effects of different treatments on aggregate-size distribution | 第62-67页 |
| 3.14 Total organic carbon (TOC) content at top soil from soil treatments of differentaggregate size fractions following wet sieving | 第67-69页 |
| 3.15 Effect of different soil treatments on Com yield (Zea mays) | 第69-71页 |
| 4 DISCUSSION | 第71-78页 |
| 4.1 Effects of biochar and straw on soil respiration | 第71页 |
| 4.2 Effects of biochar and straw on N-mineralization | 第71-72页 |
| 4.3 Effects of biochar and straw on soil MBC and MBN | 第72页 |
| 4.4 Effects of biochar and straw on soil total nitrogen | 第72-73页 |
| 4.5 Effects of biochar, straw and manure on SOC | 第73-74页 |
| 4.6 Effects of biochar, straw and manure on SMBC | 第74页 |
| 4.7 Effects of biochar, straw and manure on soil pH | 第74页 |
| 4.8 Effects of biochar, straw and manure on soil bulk density and total porosity | 第74-75页 |
| 4.9 Effects of biochar, straw and manure on soil WHC | 第75-76页 |
| 4.10 Effects of different treatments on aggregate-size distribution | 第76页 |
| 4.11 Total organic carbon content in different aggregate-size fractions | 第76-78页 |
| 5 CONCLUSIONS | 第78-80页 |
| ACKNOWLEDGEMENT | 第80-81页 |
| REFERENCES | 第81-97页 |
| Paper published in the period of Ph.D. education | 第97页 |
