Abstract:
Objective The effect of different fertilization patterns on soil CO2 emission characteristics and carbon (C) balance were discussed, which provided data support for C sequestration and emission reduction of greenhouse soil and reasonable fertilization.
Method "fentailang" tomato as the tested material, the emission characteristics of soil CO2 under different fertilization patterns 50% chemical fertilizer N + 50% organic fertilizer N + modifier group (HYG), 50% chemical fertilizer N + 50% organic fertilizer N group (HY), 100% organic fertilizer N group (Y), 100% chemical fertilizer N group (H) and no fertilization treatment group (CK) were observed with LI-8100A automatic soil C flux tester based on the facility micro zone test. The effects of soil water content, temperature , pH, total nitrogen, microbial biomass carbon (MBC), soil porosity and soil organic matter (SOM) on CO2 emission were discussed.
Result The results showed that the CO2 emission rate of greenhouse soil increased first and then decreased under different fertilization patterns at the initial stage and after fertilization of tomato. In terms of soil CO2 emission accumulation, there were significant differences among different fertilization patterns (P < 0.05). Compared with CK treatment, the cumulative CO2 emission of H, Y, HY and HYG treatments increased by 26.7%, 83.2%, 47.3% and 44.2% respectively. The two factors composite model of soil water content and soil temperature could explain the change of soil CO2 emission rate of 76.0% (P < 0.01), indicating that the change of soil hydrothermal environment under different fertilization patterns would significantly affect the soil CO2 emission rate. Correlation analysis showed that the cumulative amount of soil CO2 emission had a very significant positive correlation with soil pH, total nitrogen, MBC and soil porosity (P < 0.01), and a significant positive correlation with SOM (P < 0.05). Compared with other fertilization treatments, HYG treatment could significantly improve tomato yield and total biomass by 9.4% - 38.2% and 9.0% - 32.9% respectively. Compared with the current main fertilization patterns of greenhouse soil (HY treatment), HYG treatment could significantly reduce the total soil C release and crop C emission efficiency by 2.2% and 10.9%, and HYG treatment could also increase the ecosystem C sequestration potential by 11.5%.
Conclusion From the perspective of C sequestration and emission reduction, 50% chemical fertilizer N + 50% organic fertilizer N + modifier treatment is a better fertilization pattern for greenhouse cultivation of "fentailang" tomato in Liaoning Province.