Abstract:
【Objective】 To study the effects of carbonization conditions of cotton stalk charcoal on the basic physiochemical properties and active organic carbon and nitrogen of ash desert soil in the hope of providing a theoretical basis for the improvement and application of cotton stalk biochar in ash desert soil in northwest China.
【Methods】 The effects of quantitative application of cotton stalk carbon on basic physiochemical properties and active organic carbon and nitrogen in ash desert soil were studied by indoor constant temperature culture method.
【Results】 Adding cotton stem carbon increased soil pH value, electrical conductivity and organic carbon content, which were increased by 1.48%-2.65%, 25.62%-39.61% and 54.99%-213.09% compared with CK, respectively. Soil microbial biomass nitrogen in some treatments (H
0, H
4 and T6H
2) was increased by 5.21%-95.49% compared with CK, and soil microbial biomass carbon and CEC (except T
4H
0)were decreased by 27.89-49.50% and 0.08%-5.12%, respectively.T
4H
1, T
6H
1 and T
6H
4 treatments increased the total soil soluble organic carbon content, while other treatments decreased the total soil soluble organic carbon content. With the increase of carbonization temperature and carbonization time, the soil pH value increased. The carbonization time was the same, the carbonization temperature increased, the soil CEC and organic carbon content decreased, and the soil microbial biomass nitrogen and soluble organic carbon content increased. The carbonization time was too short or too long (0.5 h, 4 h) between the carbonization treatments to increase the soil microbial biomass carbon. When the carbonization temperature was high (600℃), the carbonization time affected the soil pH value and organic carbon content.
【Conclusion】 Based on the comprehensive analysis, the cotton stalk charcoal prepared at low temperature for a short time (450℃, 1h) has a good effect on the physiochemical properties and the changes of active organic carbon and nitrogen of ash desert soil, and it is a more suitable carbonization treatment.