Humic acid and fulvic acid, also commonly referred to as “black gold of agriculture”, as they are a major component of organic matter and play an important role in soil fertility and plant nutrition. Plants grown on soil with adequate humate acid and fulvic acid face less stress and grow healthier and produce higher yield. Moreover foods grown on soil rich in humic/fulvic acid produce superior quality food and feeds.
There has been much hype about N P K fertilizers in agricultural communities from the time it is discovered that they stimulate plant growth. Prolonged use of these acidic fertilisers in the absence of adequate humic substance in the soil can result in serious sustainablility problems. Scientist and farmers are realising the need to reconsider their approach towards the use of fertilisation techniques that will place more priority on soil humus. The sense of urgency today in emphasising the importance of humic substances and their value as a fertilizer ingredient was never been seen before. Increasingly soil scientist and agronomist are recognising the importance of humic substance in healthy and fertile soil.
Humus is a brown to black complex variable of carbon containing compounds. Humic substances are component of humus and are high molecular weight compounds. They give the soil the structure, porosity, anion exchange, water holding capacity and cation. They also play an active role in chelation of mineral elements. Naturally occurring humic acid (HAs) readily forms a salt with inorganic trace mineral elements. There are over 60 different mineral elements bond to humic acid in a form that can be readily utilised by various living organisms. This helps humic acid function as an important ion exchange and chelating system. Uptake of major plant nutrients that is N, P and K is mediated by humic substances. Studies have shown that adequate presence of humic substance results in reduced requirement for N, P and K fertilizers.
Fulvic acids on the other hand are relatively smaller than humic acid and are mixture of weak aliphatic and aromatic organic acids readily soluble in water. Fulvates acids have twice oxygen content of humic acids and hence they are more chemically reactive. Because of the relatively smaller size of fulvic they can readily enter plant root, stem and leaves. This enables them to carry and transport trace minerals to plant tissues.
Humic substances commonly occur within soil water and compost etc. Most of the soil and water contains some humic substance. Over past several years, the concentration of humic substance in agricultural soil has reached low levels.
Solution: Purchasing fulvic acid and humic acid will never supply even a small percentage of the amount required so are a waste of money. They are also extremely expensive and often sold by snake oil salesman. Humic substance forms naturally if soil is managed properly by adopting certain production practices such as crop rotation, use of a balanced fertilisation program, growing legumes, using green manures, increased use of compost application (contains 60% humic acid and 20% fulvic acid (by dry weight), minimum tillage practice, etc are the only real honest ways to increase these important compounds in the soil.