Feng Di, Hao Qing-Ju, Zhang Kai-Li, Shi Jiang-Lai, Shi Xiao-Jun, Jiang Chang-Sheng
Key Laboratory of Eco-environments in Three Gorges Reservoir Region of Ministry of Education, College of Resources and Environment, Southwest University, Chongqing 400715, China.
National Monitoring Station of Soil Fertility and Fertilizer Efficiency on Purple Soils, Chongqing 400715, China.
Huan Jing Ke Xue. 2017 Oct 8;38(10):4380-4389. doi: 10.13227/j.hjkx.201702002.
Considering the common cropping system (chili-radish rotation) in Southwest China, the objective of this study is to explore the effect of plastic film mulching on NO flux, NO concentrations in the soil profile, soil temperature, and humidity from a vegetable field. The method of the static opaque chamber was used and the experimental period lasted for one year. The results showed that the average flux of NO was 1000.0 μg·(m·h) in the conventional treatment and 400.6 μg·(m·h) in the film mulching treatment during the chili growing period. The NO flux of the film mulching treatment was significantly lower than that of conventional treatment (<0.05). However, in the radish growing season, the NO flux of the film mulching treatment was higher than that of conventional treatment, but the difference between the two treatments was not significant (>0.05). NO concentrations in the soil profile of the two treatments both increased with the increase in soil depth. The NO concentrations showed significant correlations among the different soil profiles of each treatment; meanwhile, there was also a significant correlation between soil NO concentrations at the same soil depth in different treatments. There was a significant positive correlation between the NO concentration in different profiles and NO fluxes in surface soils in the conventional treatment, but the NO flux under the plastic mulching film treatment was only positively correlated with the NO concentrations of 30 cm deep soil. The soil moisture and temperature observations showed that the effect of plastic film mulching on soil temperature was more significant in summer and the soil moisture was more prominent in autumn and winter. However, the results of the correlation analysis and principal component analysis showed that NO emissions were mainly determined by the distribution of nitrogen in the soil and were affected by the change in soil total nitrogen content in the conventional treatment but NO emissions were more sensitive to the variation in soil inorganic nitrogen in the film mulching treatment.
考虑到中国西南部常见的种植制度（辣椒 - 萝卜轮作），本研究的目的是探讨地膜覆盖对菜地一氧化氮通量、土壤剖面中一氧化氮浓度、土壤温度和湿度的影响。采用静态不透明箱法，实验期持续一年。结果表明，在辣椒生长期间，常规处理下一氧化氮的平均通量为1000.0μg·(m²·h)，地膜覆盖处理下为400.6μg·(m²·h)。地膜覆盖处理的一氧化氮通量显著低于常规处理（<0.05）。然而，在萝卜生长季节，地膜覆盖处理的一氧化氮通量高于常规处理，但两种处理之间的差异不显著（>0.05）。两种处理的土壤剖面中一氧化氮浓度均随土壤深度增加而升高。各处理不同土壤剖面间的一氧化氮浓度呈现显著相关性；同时，不同处理相同土壤深度处的土壤一氧化氮浓度之间也存在显著相关性。常规处理中不同剖面的一氧化氮浓度与表层土壤中的一氧化氮通量之间存在显著正相关，但地膜覆盖处理下的一氧化氮通量仅与30 cm深度土壤的一氧化氮浓度呈正相关。土壤湿度和温度观测表明，地膜覆盖对土壤温度的影响在夏季更为显著，对土壤湿度的影响在秋冬更为突出。然而，相关性分析和主成分分析结果表明，一氧化氮排放主要由土壤中氮的分布决定，在常规处理中受土壤总氮含量变化的影响，但在地膜覆盖处理中一氧化氮排放对土壤无机氮的变化更为敏感。
