Effects Of Biochar On Soil Properties And Crop Growth

Biochar used as a soil amendment could greatly reduce the emissions of carbon dioxideand other greenhouse gases. Biochar could alleviate the greenhouse effect, improved soilphysical and chemical properties as well as biological traits and reduced the bioavailability ofsoil pollutants and thus reduce its toxicity. Therefore the soil application of biochar catchedmore and more attention in recent years. But there were many contradictory findings inbiochar application effects which might be related to soil type and the properties of biochar.Therefore, this study intended to explore the effects of different types of biochar on differentsoils, to reveal factors affecting effects of biochar application and provide instructions for theapplication of biochar in practice. The main findings are as follows:1. Biochar could affect soil physical properties significantly. It could effectively reducesoil bulk density and density, increase soil total porosity, capillary porosity and aerationporosity and effectively keep m oisture in the soil. Different results were found in soils withdifferent texture.2. Biochar application could increase soil pH. When the application level was morethan2:3, volume ratio of the amount of rice husk biochar, the pH of brown soil and cinnamonsoil all increased by0.44and0.3pH unit relatively.3. The adsorption properties of biochar made of different raw materials were different.The adsorption amout of copper decresed in the following order: straw biochar>cow dungbiochar> rice husk biochar. The higher the pH value was, the stronger the adsorption capacityof biochar was.4. The pH and conductivity of soil leaching liquor increased with the increasing amountof biochar. Biochar application did not inhibit the leaching of soil potassium. The effects ofbiochar on ammonium nitrogen leaching in soils with different texture were different. Biochardid not significantly inhibit the leaching of ammonium nitrogen in sandy soil, while in sandyloam soil it effectively reduced the amount of ammonium nitrogen leaching when theapplication level reached5%(in weight).. Similarly, the effects of biochar on phosphorusleaching were different due to different soil texture. Biochar application did not inhibited theleaching of phosphorus in sandy soil, while it effectively inhibited the leaching of phosphorusin the sandy loam soil.5. Biochar could effectively promote the growth of ryegrass and Chinese pakchoi. With the increase in the amount of biochar, the fresh weight of ryegrass and Chinese pakchoi firstlyincreased and then reduced. Different soil showed different results. Biochar increased theplant height of ryegrass by24%in maximum and weight yield by66%in maximum. Thebiomass of Chinese pakchoi were increased by65%.