Impacts of wood vinegar on enzyme activity in saline alkaline soil
Liu Min, Geng Yuqing, Cong Richun, Liu Duo
1. College of Forestry, Beijing Forestry University, 100083, Beijing, China;2. Institute of Desertification Research, Chinese Academy of Forestry, 100091, Beijing, China
Abstract：Salt toxicity is one of the major edaphic factors limiting crop production and eco-environmentalquality in salinized and/or sodic soils throughout the world. Application of organic fertilizer to salinealkaline soil is considered as a good practice for soil remediation. Wood vinegar, as a new kind of liquidorganic fertilizer, plays an important role in reducing soil pH and salt content, increasing soil organic matter content and promoting plant growth in saline alkaline soil. Soil enzyme stimulates the decomposition of organic matter and the transformation of nutrient substances, can reflect the function of soil microbe, and is regarded as a potential index for monitoring soil quality in a short time.Nevertheless, the impacts of wood vinegar on enzyme activity in saline alkaline soil remain unknown. The objectives of the present study were to investigate the impacts of different wood vinegar contents onenzyme activity in saline and alkaline soil. In our study, five treatments with different contents of woodvinegar, namely 100% (not diluted), 20% (diluted 5 times), 10% (diluted 10 times), 5% (diluted20 times) and 0 (CK) were mixed with soil at a wood vinegar liquid (mL)- to- soil (g) ratio of 1:4,respectively. The soil chemical properties, such as the dissolved organic carbon, phenol, and sever alkinds of hydrolases and oxido reductase activity were measured after 20 days indoor culture. In addition, the relationship between the soil chemical properties and soil enzyme activities was analyzed by the linear regression analysis. The results showed that all the different contents of wood vinegar could significantly decrease soil pH, and increase the content of soil dissolved phenol, soil readily oxidizable carbon, soil dissolved carbon and nitrogen, NH+4and NO-3. However, the change of soil available phosphorus content was not significant. The activities of soil glycosidase and urease were inhibited at 100% wood vinegar.For soil glycosidase activity, it was decreased with the decline of wood vinegar content at the rate below 20%. The urease activities at 20% and 10% wood vinegar were significantly higher than that at 5% and CK. The activities of soil acid phosphatase and phenol oxidase were enhanced with the increasing woodvinegar content. However, alkaline phosphatase activity was significantly decreased at 20% and 10% wood vinegar. These results demonstrated the changes of soil readily oxidizable carbon and NO-3-N werepositively related to the activity of soil glycosidase. The changes of soil pH and available phosphorus hada significantly negative correlation with soil acid phosphatase activity, but a significantly positive correlation with alkaline phosphatase activity. On the other hand, the change of soil dissolved phenol hada significantly positive correlation with phenol oxidase activity. In conclusion, the application of woodvinegar in the saline alkaline soil can stimulate enzyme activity. The long-term impacts of the application of wood vinegar on soil enzyme activities should be concerned in the future since our conclusion isobtained by a short indoor culture manipulation.
2015, Vol. 13 
