Effects Of Biochar On Soil Quality And Kinggrass's Yield And Quality

Due to the characteristics of highly physical, chemical, biological stability, biochar plays a significant role in increasing soil carbon storage, improving soil fertility, and maintaining the balance of the soil ecosystem. In this thesis, the key components, traits and processes of soil quality, the relationship between biochar and soil aggregates, were investigated in a field experiment, to reveal the effects of biochar on soil quality and Kinggrass's yield and quality, as well as the distribution and migration of biochar in latosol. Providing technical and theoretical support for the reduction of the CO2emission by human activities and application of biochar on grass and other crop production in large scale. The main results of this thesis are as follows:(1) Bulk density, natural moisture content, steady infiltration rate, capillary water capacity, total porosity and penetration resistance were investigated in this study. The results showed that the biochar had no significant effect on those6soil physical indexes in Kinggrass field. However, biochar significantly changed some of those indexes in stylo field, such as the total porosity of0.5%biochar treatment increased by5.68%in the third sampling, compared to the control; and for the1.0%biochar treatment, compared to the control, its total porosity increased by7.27%in the first sampling, its steady infiltration rate decreased by62.96%in the third sampling, its capillary water capacity increased by20.52%in the fourth sampling.Influence of biochar on total nitrogen, available phosphorus (P) and available potassium (K) were investigated. The results showed that biochar significantly affected the total nitrogen in the first sampling of stylo field and the forth sampling of Kinggrass field; and biochar had a significant effect on Kinggrass field's available P, but no effect on stylo field's; biochar improved the available K of stylo field significantly, such as the1.0%biochar treatment increased the available K of stylo field by38.50%,90.90%,110.76%from the first sampling to the third sampling, respectively, but no significant effect on Kinggrass field.(2) Results showed that biochar treatments had an indistinctive decreasing trend on the yield of Kinggrass. Biochar decreased the whole nutrient qualities of Kinggrass. Compared to the control, the treatment of0.1%significantly decreased the content of nitrogen-free extract by13.95%in the third mowing; the treatments of0.5%and1.0%significantly increased the content of crude ash by22.15%and17.69%in the sixth mowing, respectively; and the treatment of0.1%significantly increased the content of acid detergent fiber in the sixth mowing. Through analyzing the data of yield and nutrient by grey relational grade analysis, results show that control had the largest average grey relational grade in all treatments. Especially, the average grey relational grade of0.5%treatment was significantly smaller than control. The results also indicated that the treatment of0.5%decreased the yield and nutrient qualities of Kinggrass.(3) The results showed that, compared with the control, the biochar treatments of0.5%and1.0%significantly increased GMD of water-stable aggregates by15.64%and10.80%, and the contents of>5mm water-stable aggregates by98.75%and88.37%, respectively; compared with the control, the biochar treatment of1.0%increased the total carbon of3-5mm,2-3mm and0.5-1mm water-stable aggregates by32.24%,39.31%and306.36%respectively, and increased the distribution proportion of total carbon in>5mm water-stable aggregates by90.44%. For that, incorporation of biochar was beneficial for latosol to improve soil structure and increase soil total carbon.