认识腐植酸对作物生长和土壤健康的作用

Understanding the Role of Humic Acids on Crop Performance and Soil Health

腐植酸(HA)是有机分子,在改善土壤性质、植物农艺性状和生长方面发挥着重要作用。HA的来源包括煤、褐煤、土壤和有机材料。近年来,为了保证农业生产的可持续性,以HA为原料的产品已广泛应用于农作物生产中。相关研究表明,HA对土壤的物理、化学和生物学性质都有积极的影响,包括土壤质地、结构、持水量、阳离子交换容量(CEC)、pH、土壤碳氮循环、酶活性和养分有效性等等。本文着重介绍了HA对作物生长、激素分泌、养分吸收和同化、产量和蛋白质合成的影响。HA对土壤性质和作物的影响受HA类型、HA施用量、HA施用方式、土壤类型、溶解度、分子大小和官能团的影响。本文还指出了HA领域亟待研究的一些知识空白。在不同轮作体系、氮肥形态、地点和气候条件下,HA及其施用量的相关田间试验研究还比较有限。此外,HA的化学和分子结构、水溶和碱溶组分也缺少田间试验验证以评估其对作物产量、品质和土壤健康的影响。施用HA后土壤-植物养分有效性与植物养分吸收之间的关系也有待进一步研究。

Humic acids(HA)are organic molecules that play essential roles in improving soil properties,plant growth,and agronomic parameters.The sources of HA include coal,lignite,soils,and organic materials.Humic acid-based products have been used in crop production in recent years to ensure the sustainability of agriculture production.Reviewed literature shows that HA can positively affect soil physical,chemical,and biological characteristics,including texture,structure,water holding capacity,cation exchange capacity,pH,soil carbon,enzymes,nitrogen cycling,and nutrient availability.This review highlights the relevance of HA on crop growth,plant hormone production,nutrient uptake and assimilation,yield,and protein synthesis.The effect of HA on soil properties and crops is influenced by the HA type,HA application rate,HA application mode,soil type,solubility,molecular size,and functional group.This review also identifies some knowledge gaps in HA studies.HA and its application rate have not been tested in field experiments under different crops in rotation,nitrogen fertilizer forms,sites and climatic conditions.Furthermore,HA chemical and molecular structures,their water and alkaline soluble fractions have not been tested under field experiments to evaluate their effects on crop yield,quality,and soil health.The relationship between soil-plant nutrient availability and plant nutrient uptake following HA application should also be further studied.