不同施肥方式对设施土壤氨挥发特征的影响

有机肥与改良剂施入土壤是改善土壤结构、增加土壤有机质含量和培肥地力的重要措施，但也会影响土壤的氨挥发，探索不同施肥方式对土壤氨挥发的影响，对于减少氮素损失和保护生态环境具有重要意义.基于设施番茄微区试验，采用LGR915-0016超便携NH₃分析仪观测不同施肥方式50%化肥N+50%有机肥N+改良剂组（HYG）、50%化肥N+50%有机肥N组（HY）、100%有机肥N组（Y）、100%化肥N组（H）和不施肥处理组（CK）]下土壤氨的排放特征.结果表明:在番茄生育期内，不同施肥方式下设施土壤氨挥发通量的变化趋势基本一致.在土壤氨累积挥发量方面，与CK处理相比，H和HY处理下土壤中氨累积挥发量分别增加了11.76%和12.03%；Y和HYG处理则显著降低了土壤中氨累积挥发量，分别下降了24.31%和15.20%.就单因素模型而言，不同施肥处理下土壤氨挥发通量与0~10 cm土壤温度呈线性回归关系，且各处理均达到显著水平（P均小于0.05）；不同施肥处理下土壤氨挥发通量与0~10 cm土壤含水量均呈显著二次回归关系（P均小于0.05）；与单因素相比，0~10 cm土壤含水量和土壤温度的双因素复合模型（R2为0.700 6~0.849 7）可以更好地解释土壤氨挥发通量的变化情况.相关分析显示，土壤氨累积挥发量与0~20 cm土层土壤铵态氮含量、硝态氮含量、pH及土壤孔隙度均呈极显著相关（P均小于0.01），与0~20 cm土层土壤容重呈显著相关（P < 0.05）.采用PCA分析提取的2个主成分的累积贡献率为83.09%.研究显示，不同施肥方式会影响设施土壤氨挥发通量，综合考虑土壤氨累积挥发量及其影响因素，100%有机肥N组在降低土壤氨挥发方面显著优于其他处理组. 

Effects of Different Fertilization Treatments on Soil Ammonia Emission in Greenhouse

Applying organic fertilizers and amendments to soil is an important measure to improve soil structure, increase soil organic matter content and improve soil fertility. However, how the application of organic fertilizers and amendments affects soil ammonia (NH₃) emissions remains unknown. Exploring the effects of different fertilization treatments on soil NH₃ emissions is of great significance to reducing nitrogen (N) loss and protecting the ecological environment. Based on a micro-plot experiment of tomato greenhouse, a LGR915-0016 ultra-portable NH₃ analyzer was used to observe the characteristics of soil NH₃ emission under different fertilization treatments (50% chemical fertilizer N + 50% organic fertilizer N + amendment, HYG; 50% chemical fertilizer N + 50% organic fertilizer N, HY; 100% organic fertilizer N, Y; 100% chemical fertilizer N, H; and no fertilizer, CK). The results showed that the change trend of NH₃ emission flux of greenhouse soil under different fertilization treatments was basically the same during the growth period of tomato. Compared with the CK treatment, the H and HY treatments increased the cumulative NH₃ emission by 11.76% and 12.03%, respectively. The Y and HYG treatments significantly reduced the cumulative NH₃ emission by 24.31% and 15.20% relative to the CK treatment, respectively. Linear regression analysis revealed that soil NH₃ emission flux under different fertilization treatments was significantly related (P < 0.05) with soil temperature at 0-10 cm depths. There was a significant quadratic regression relationship (P < 0.05) between NH₃ emission flux and soil moisture content at 0-10 cm depth under different fertilization treatments. Compared with the single factor model, the two-factor model of soil moisture and temperature at 0-10 cm depth (R2 was 0.7006-0.8497) better explained the changes in soil NH₃ emission flux. The total amount of NH₃ emission was extremely significantly (P < 0.01) correlated with soil NH₄+-N content, nitrate N content, pH and soil porosity at 0-20 cm soil depth, and was significantly correlated with soil bulk density at 0-20 cm soil depth. The cumulative contribution rate of the two principal components extracted by PCA analysis was 83.09%. Therefore, NH₃ emission in greenhouse soil was affected by different fertilization treatments. Considering soil NH₃ emission and its influencing factors, it is recommended to apply 100% organic fertilizer to reduce NH₃ emission of greenhouse soil.