有机肥对我国酸性和碱性土壤pH的影响差异及原因

Differences and reasons for the effects of organic fertilizer on the pH of acidic and alkaline soils in China

施用有机肥对改善土壤pH及提高作物产量稳定性具有重要作用;研究全国不同气候类型、土壤性质和农田管理措施下,施用有机肥对酸性和碱性土壤pH影响的差异及原因,可为有效提升土壤肥力、优化农田管理措施提供科学依据.共收集2002-2022年间发表的103篇文献(308组相对独立的涉及pH的数据),采用整合分析(Meta-analysis)方法从气候、土壤pH水平、有机肥类型、施肥量、施肥年限等多个方面定量分析施用有机肥对我国农田土壤pH的影响.结果表明,酸性(pH<7)土壤条件下,年均温≤8℃、降雨量400-600 mm时,施用有机肥对土壤pH提升幅度最大;在有机肥施用下,低有机质土壤pH增幅为8.07%,高量有机肥增幅为6.42%,粪肥增幅最显著,为7.14%,中、长期施肥对土壤pH的提升幅度显著高于短期施肥.碱性(pH>7)土壤条件下,年均温≤8℃、降雨量400-600 mm时,施用有机肥对土壤pH降幅最大;有机肥施用显著降低了低有机质土壤pH(4.07%);粪肥与商品有机肥对土壤pH降幅比生物有机肥高约3.60倍;随着有机肥施用量的增加,土壤pH下降幅度增加;中、长期施肥对土壤pH降低幅度最为显著(11.41%和7.82%).在酸性土壤中有机肥施用年限是影响pH的主控因素,而碱性土壤则是年均温.总之,有机肥施用对不同酸碱度土壤pH的影响不同,低温且降雨量适中区在有机质含量较低的酸性土壤中长期施用高量粪肥可显著提高土壤pH,有效缓解土壤酸化效应,而碱性土壤中长期施用高量粪肥和商品有机肥均可有效降低土壤pH.上述结果可为有机肥的合理施用和土壤肥力提升提供科学依据.

The application of organic fertilizers plays an important role in improving soil pH and crop yield stability.Investigating the effects of organic fertilizers on the pH of acidic and alkaline soils under different climate types,soil properties,and farmland management practices in China could provide a scientific basis for effectively improving soil fertility and optimizing farmland management.In this study,we collected 103 articles(308 groups of relatively independent pH data)published from 2002-2022,and a meta-analysis was used to quantitatively analyze the effects of organic fertilizer application on soil pH in farmlands in China from many aspects,such as climate,soil pH level,organic fertilizer type,fertilizer amount,and fertilization period.Under acidic soil(pH<7)conditions,the average annual temperature was≤8℃and rainfall was 400-600 mm;the application of organic fertilizer had the largest increase in soil pH.Under the application of organic fertilizer,the pH of soil with low organic matter,high amount of organic fertilizer,and manure increased by 8.07%,6.42%,and 7.14%,respectively.Medium-and long-term fertilization significantly increased the soil pH compared to short-term fertilization.The increases in soil pH with medium-and long-term fertilization were significantly higher than that with short-term fertilization.Under alkaline soil(pH>7),the average annual temperature was≤8℃and rainfall was 400-600 mm;the application of organic fertilizer had the most significant decrease in soil pH.Organic fertilizer significantly reduced the pH of soil with low organic matter content by 4.07%.The decrease in the soil pH of manure and commercial organic fertilizer was 3.60 times higher than that of the bio-organic fertilizer.With an increase in the amount of organic fertilizer,the decrease in soil pH also increased.The most significant decrease in soil pH was caused by medium-and long-term fertilization(11.41%and 7.82%,respectively).The years of organic fertilizer application were the main factors affecting pH in acidic soils,whereas the average annual temperature was the main factor in alkaline soil.Overall,the application of organic fertilizers had different effects on soil pH at different pH levels.At low temperatures and moderate rainfall areas,medium-and long-term application of high amounts of manure in acidic soils with low organic matter content can significantly improve soil pH and alleviate soil acidification,whereas long-term application of high amounts of manure and commercial organic fertilizer in alkaline soil can effectively reduce soil pH.The present study provides a scientific basis for the rational application of organic fertilizer for improvement in soil fertility.