以往研究表明:腐植物质可直接和间接地影响植物的生长。其间接作用归因子它对土壤物理,化学和生物条件的改变;从直接意义上看,腐植酸可通过加速呼吸过程,增强细胞渗透性以及激素效应来影响植株的生长。但以往这些研究仅局限于对种子萌发、幼苗生长以及根系伸长等方面。最近的试验证据表明:腐植酸还能影响作物的营养吸收及干物质生产。从上述讨论可以看到,土壤有机化台物(例如腐植质)对作物生长是有利的,如土壤腐植质可以增加大豆、花生以及其它豆科作物的生长并改善生物氮的固定,这后者可 Previous studies have shown that humic substances can directly and indirectly affect plant growth. Its indirect effect is attributed to its change in soil physical, chemical and biological conditions; in a direct sense, humic acid can affect plant growth by accelerating the process of respiration, enhancing cell permeability, and hormonal effects. However, these studies in the past were limited to germination, seedling growth and root elongation. Recent experimental evidence shows that humic acid can also affect nutrient uptake and dry matter production in crops. It can be seen from the above discussion that soil organic compounds (such as humus) are beneficial for crop growth. For example, soil humus can increase the growth of soybean, peanut and other leguminous crops and improve the fixation of biological nitrogen. The latter can