【摘要】 运用整合分析方法(meta-analysis)定量研究长期施用化肥对我国农田土壤pH的影响,以评估化学氮肥在土壤酸化中的作用,为合理施肥提供科学依据。通过搜集整理国内40篇已发表文献的数据,建立化肥用量和土壤pH数据库,比较分析长期施用化肥对中国农田土壤pH的整体影响及化肥的有利施用条件。结果表明:在平均施氮量为150 kg/hm~2的条件下,施用化肥可以显著降低土壤pH,降低了10.46%(95%CI,9.04%～11.95%),与不施肥相比,施用化肥使土壤p H在不同利用方式、种植制度和初始p H下均降低。其中,在旱地上降低的幅度比水田高5.82%;在一年一熟作物体系中降低的幅度分别比一年两熟和一年三熟作物体系高3.26%和2.79%;在酸性土壤(pH≤6.5)上降低幅度分别比中性土壤(pH 6.5～7.5)和碱性土壤(pH≥7.5)高3.71%和3.36%。同时,在施肥年限<10年或超过20年,农田土壤pH降低的幅度最小,分别为8.37%(95%CI,6.07%～10.62%)和6.68%(95%CI,6.07%～10.62%)。在施氮量为60～120 kg/hm~2的条件下,农田土壤pH降低的幅度最小,为5.48%(95%CI,1.86%～8.96%)。施用化肥可以显著降低农田土壤pH,其中在旱地上降低幅度最大,在施肥量为120～240 kg/hm~2、施肥年限为15～20年、一年一熟和初始pH≤6.5上降低幅度最大。更多还原

【Abstract】 The effects of long-term application of chemical fertilizer on soil pH were quantitatively studied by integrated analysis method(meta-analysis) to evaluate the role of chemical nitrogen fertilizer in soil acidification and provide scientificbasis for rational fertilization.Based on the data collected from 40 published papers in China,a database of fertilizer use and soil pH was established to compare the overall impact of long-term application of chemical fertilizer on soil pH of China’s farmland and the favorable application conditions of chemical fertilizer.Results show that under the condition of an average nitrogen application rate of 150 kg/hm2,the application of chemical fertilizer could significantly reduce soil pH,and the decrease rate was 10.46%(95% CI,9.04%-11.95%).Compared with no fertilization treatment,the application of chemical fertilizer reduced pH of soil under different utilization ways,planting systems and initial pH,among which,the reduction in dry land was significantly larger than that in paddy field by 5.82%,in the system of one crop per year,the decrease rate was respectively 3.26% and 2.79% larger than that in the system of two crops per year and three crops per year,and in the acid soil(pH≤6.5),the decrease rate was respectively 3.71% and 3.36% larger than that in the neutral soil(pH 6.5-7.5) and alkaline soil(pH≥7.5).At the same time,when the fertilization period was less than 10 years or more than 20 years,the decrease rate of soil pH was the smallest,which was 8.37%(95% CI,6.07%-10.62%) and 6.68%(95% CI,6.07%-10.62%),respectively.Under the condition of a nitrogen application rate of 60-120 kg/hm~2,the decrease rate of soil pH was the smallest,which was 5.48%(95% CI,1.86%-8.96%).The application of chemical fertilizer can significantly reduce the pH of farmland soil,especially in the dry land,which is the largest with a fertilization amount of 120-240 kg/hm~2,a fertilization period of 15-20 years,a year of ripeness,and an initial pH≤6.5.更多还原