RESEARCH & INNOVATION

NOVELGRO TERRA FULVIC ACID HAS DUAL FUNCTION IN AVAILABILITY OF FIXED PHOSPHORUS

Prof. G. A. Wattimena

I. Function of Phosphorus

Phosphorus is a very important macronutrient in plant structure and metabolism. Phosphorus is a structural component of nucleic acid (DNA, RNA), sugar phosphate, nucleotide (ATP, CTP, UTP, GTP, TTP), coenzymes and phospholipids. Phosphorus is also important in metabolic process in plant including: photosynthesis, respiration, cell division, regulating starch-sugar in vegetative and reproductive organ (flower, fruit, seeds).

II. Available of Phosphorus

Eventhough phosphorus is a very important macronutrient it is the least available to plant due to:

(1)    Fixation at the soil level as inorganic phosphorus

In soil the available of phosphorus is pH dependence. At high pH phosphorus is fixed by cationic Ca⁺⁺, Mg⁺⁺, and at low pH by cationic Al⁺⁺⁺ and Fe⁺⁺. The high available is at pH 5,5 - 7,0

(2)    Fixation at the soil level as organic phosphorus (phytic acid = myoinositol hexaphosphoric acid = IP₆)

Phosphorus in plant dry matter is about 0,1 – 0,4%. Phosphorus is high in seed in fixed form as phytic acid and phytate (salt of phytic acid with macro and micro cation especially as Ca²⁺, Mg²⁺, K⁺, Fe²⁺, Mn²⁺, Zn²⁺). The percentage of phytate in seeds average from 1- 8%, where 90% of phytate is fixed phosphorus.

(3)    Novelgro TERRA Fulvic acid and available phosphorus

Novelgro TERRA Fulvic acid (FA) is an organic acid with high activity group of COOH, OH, and C=O with act as cation exchange and anion exchange. According to Stevenson (1991), the functional group of fulvic acid has a range of: COOH (520-1120 cmol kg^-1), OH (290-1520 cmol kg^-1), and C=O (120-420 cmol kg^-1). Fulvate is a salt of fulvic acid with macro and micro cations and is soluble in water. Novelgro TERRA Fulvate/fulvic acid has functions to increase the available of phosphorus to plant.

(a)    Exchangeable cation of fixed phosphorus in soil.

Fixed phosphorus in soil is in the complex of exchangeable cation of Ca²⁺, Mg²⁺, Fe²⁺, Al³⁺. Novelgro TERRA Fulvic acid exchanges these cations with functional group of fulvic acid and release fixed phosphorus.

(b)    Exchange of phosphorus in plant

Novelgro TERRA Fulvic acid is absorb by plant and translocated to all plant parts. Novelgro TERRA Fulvic acid degradate phytate by exchange the micro and macro cation to phytic acid. Novelgro TERRA Fulvic acid seems also to induce phytase. Phytase hydrolize phytic acid to myoinositol and phosphorus (IP₆ --- Phytase---> myo-inositol + 6 Pi).’

References

1. Marshner, H. 1986. Mineral nutrition of higher plants. Academic Press, New York.
2. Mengel, K. Krickby. 1980. Principles of plant nutrition 3^rd, International Potash Institute, Bern.
3. Stevenson, F.J. 1991. Organic matter-micronutrients reaction in soil. In Mortvedt J.J. Cox FR, Shuman LM, Welch RM, Micronutrients in Agriculture 2^nd. Soil Science Society of America, Madison, Wisconsin.