Wang Hao, Hu Rong-Gui, Lin Shan, Gao Hong-Jun, Xu Ming-Gang, Zhang Wen-Ju, Wu Lei
National Key Laboratory of Efficient Utilization of Arid and Semi-arid Farmland in North China, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
College of Resources and Environment, Huazhong Agricultural University, Wuhan 430072, China.
Huan Jing Ke Xue. 2025 Apr 8;46(4):2621-2628. doi: 10.13227/j.hjkx.202401053.
As an important grain production area in China, the Northeast Black Soil Region has experienced many problems, such as soil degradation, fertility decline, and grain yield reduction, in recent years. Optimizing fertilizer management is an important measure to maintain and enhance soil fertility. However, improper fertilizer application could aggravate nutrient losses and greenhouse gas NO emissions, thus leading to soil degradation and environmental pollution. The objectives of the present study were to investigate the response of NO emission from black soil to long-term application of organic and chemical fertilizers and the key controlling factors. Soil samples (0-20 cm) were collected from a total of nine treatments, including organic fertilizer as the primary treatment (M- no organic fertilizer; M- low organic fertilizer; M- high organic fertilizer) and chemical fertilizer as the secondary treatment (CK- no fertilizer; N- chemical nitrogen fertilizer; NPK- chemical nitrogen, phosphorus, and potassium fertilizer), in a long-term experiment (32 years) on the black soil of Gongzhuling, Jilin Province. The soil samples were incubated at 25℃ with 65% field water holding capacity for 21 days, and NO emission and soil physico-chemical biological properties were determined. The results showed that long-term application of organic and chemical fertilizers notably increased NO emissions from black soil. Compared to those from the MCK treatment [(0.25±0.01) mg·kg, in terms of N, the same as below], the cumulative NO emissions from the only organic fertilizer treatment significantly increased by 361%-456% [(1.17±0.02) mg·kg and (1.41±0.02) mg·kg for the MCK and MCK treatments, respectively]. Furthermore, the NO emissions strongly increased with increasing organic fertilizer application amounts. Cumulative NO emissions were significantly higher in the chemical fertilizer treatments by 96%-236% [(0.49±0.01) mg·kg and (0.84±0.03) mg·kg for the MN and MNPK treatments, respectively] compared to those in the MCK treatments. Moreover, the increased NO emissions due to fertilizers application were significantly larger in the MNPK relative to MN treatments. The positive effects of chemical fertilizer application on NO emission decreased under organic fertilizer amendments (M and M), indicating that organic fertilizer application alleviated increased NO emission because of chemical fertilization. The application of organic fertilizers significantly increased bulk soil, aggregate organic carbon (SOC), total nitrogen (TN), and soil microbial carbon and nitrogen contents. The application of organic combined with chemical fertilizers further increased SOC and TN contents in bulk soil and aggregates. Pearson correlation and path model analyses showed that the NO emission was positively correlated with soil carbon and nitrogen fractions and microbial carbon and nitrogen contents among organic and chemical fertilizer treatments. Long-term application of organic and chemical fertilizers strongly regulated NO emissions via affecting the distribution of carbon and nitrogen contents in soil fractions and changing microbial biomass and substrate availability. In conclusion, the application of organic fertilizers could significantly facilitate NO emission by increasing the available soil carbon and nitrogen pools as well as microbial carbon and nitrogen contents. The application of organic fertilizers mitigated the positive effects of chemical fertilizers on NO emissions. Appropriate amounts of organic fertilizers should be used when applying chemical fertilizers, in order to balance the comprehensive effects of fertility improvement with nitrogen loss and greenhouse gas emissions.
作为中国重要的粮食产区,近年来东北黑土区出现了诸多问题,如土壤退化、肥力下降和粮食减产等。优化肥料管理是维持和提高土壤肥力的重要措施。然而,不当施肥会加剧养分流失和温室气体一氧化氮(NO)排放,进而导致土壤退化和环境污染。本研究的目的是探究黑土中NO排放对长期施用有机肥料和化学肥料的响应以及关键控制因素。在吉林省公主岭黑土的一项长期试验(32年)中,从总共九个处理中采集了土壤样本(0 - 20厘米),包括以有机肥为主处理(M - 不施有机肥;M - 低量有机肥;M - 高量有机肥)和以化肥为副处理(CK - 不施肥;N - 化学氮肥;NPK - 化学氮、磷、钾肥)。将土壤样本在25℃、田间持水量65%的条件下培养21天,测定NO排放以及土壤物理化学和生物学性质。结果表明,长期施用有机肥料和化学肥料显著增加了黑土中的NO排放。与MCK处理[(0.25±0.01)毫克·千克,以氮计,下同]相比,仅施用有机肥处理的累积NO排放量显著增加了361% - 456% [MCK处理为(1.17±0.02)毫克·千克,MCK处理为(1.41±0.02)毫克·千克]。此外,NO排放随着有机肥施用量的增加而大幅增加。与MCK处理相比,化肥处理的累积NO排放量显著高出96% - 236% [MN处理为(即0.49±0.01)毫克·千克,MNPK处理为(0.84±0.03)毫克·千克]。而且,相对于MN处理,MNPK处理中因施肥导致的NO排放增加量显著更大。在有机肥改良(M和M)下,施用化肥对NO排放的正向影响减弱,这表明施用有机肥缓解了因施用化肥导致的NO排放增加。施用有机肥显著增加了土壤总碳、团聚体有机碳(SOC)、全氮(TN)以及土壤微生物碳和氮含量。有机肥料与化学肥料配合施用进一步增加了土壤总碳和全氮含量以及团聚体中的含量。Pearson相关性和通径模型分析表明,在有机肥料和化学肥料处理中,NO排放与土壤碳氮组分以及微生物碳氮含量呈正相关。长期施用有机肥料和化学肥料通过影响土壤组分中碳氮含量的分布以及改变微生物生物量和底物有效性,强烈地调节了NO排放。总之,施用有机肥料通过增加土壤有效碳氮库以及微生物碳氮含量,能够显著促进NO排放。施用有机肥料减轻了化学肥料对NO排放的正向影响。施用化学肥料时应使用适量的有机肥料,以平衡提高土壤肥力与氮素损失和温室气体排放的综合效应。