NITROFIX - B.
• Benefits the next crop also due to its residual effect. 
• Encourages better root development 
• Enhances soil health and soil fertility 
• Secretes growth hormones to increase crop productivity 
• Synthesizes biologically active substances like vitamins, nicotinic acid, indole acetic acid, gibberellins etc and helps in better germination and good growth of the crop.

Recommended for Chillies, Cotton, vegetables, Medicinal, Aromatic plants and all Horticulture crops.

BIO PHOSPHOROUS SOLUBILISING FERTILISERS:
PHOSPHORUS
Phosphorus plays an indispensable biochemical role in photosynthesis, early root formation, seed formation, respiration, energy storage and transfer, cell division, cell enlargement, and several other processes in the living plant. 
It is an important structural constituent of nucleic acids, phytin and phospholipids.
It helps plants to survive winter rigors and also contributes to increase in the disease resistance ability in some plants. 

ROCK PHOSPHATE (RP)
Among the alternative Phosphorus sources, the most important are locally available Rock Phosphate (RP) resources.
(Rajan et al., 1996).

CHEMICAL COMPOSITION OF ROCK PHOSPHATE
Element Composition %
Fe 0.32-0.55
K 0.15-0.19
Ca 28-35
P2O5 25-35

ASSIMILATION OF ROCK PHOSPHATE AND OTHER CHEMICAL P FERTILISERS
Efficiency of assimilation of such Rock Phosphate minerals depends much on the following factors.
• Chemical and physical structures of the soil, especially pH and P fixing capacities 
• Grain size and surface area;
• Management practices
• Reactivity/ Solubility Chemistry of the rock phosphate that is used;
• Type of Target crops and their nutritional requirements;

When fertilizers like SSP, TSP, DAP are applied in fields, the immediately adsorbed phosphate and the easily dissolved compounds of phosphate form more complex insoluble compounds like Di Calcium Phosphate, Octo Calcium Phosphate, Amorphous Aluminum and Ferrous Phosphates and Hydroxyl Apatite; that cause the phosphate to become fixed and unavailable which results in a decrease in solubility and availability of phosphate. Reactions that reduce P availability occur in all ranges of soil pH.

Percentage dissolution of rock phosphate with varying soil pH

pH	4	4.3	5.1	6.1	6.7
Dissolution (%)	0.42	0.39	0.31	0.27	0.21
pH	3.6	3.9	4.7	5.2	6.3
Dissolution (%)	1.32	1	0.91	0.88	0.77
pH	3.7	3.9	4.6	5.27	6.5
Dissolution (%)	1.16	0.94	0.68	0.51	0.45
pH	3.9	4.6	4.9	5.7	7.1
Dissolution (%)	0.63	0.51	0.4	0.32	0.21
pH	3.6	3.8	4	5.2	6.9
Dissolution (%)	1.26	1.23	1	0.73	0.51

ROLE OF MICROORGANISMS IN SOLUBILISING PHOSPHORUS
The release of inorganic phosphate from organic phosphates is called mineralization and is caused by microorganisms breaking down organic compounds. The activity of microorganisms is highly influenced by soil temperature and soil moisture. The process is most rapid when soils are warm and moist but well drained. 
By increasing soil microbial activities, bioavailability of P in a bioactive soil was remarkedly enhanced. 
(Thien and Myers, 1992).
It is generally recognized that organic acids solubilize RP through protonation and / or chelation reactions 
(Sagoe et al., 1998). 
Filamentous fungi are widely used as producers of organic acids 
(Matty, 1992)
The ability of low molecular weight organic acids to release P from ores or rocks, related to their ability to form stable metal complexes is well established 
(Mattey, 1992).
The principal mechanism for organic phosphate solubilization is acid phosphatase activity (McGrath et al., 1995).
Besides the acid strength, the type and position of the ligand determine the effectiveness of the organic acid in the solubilization process 
(Kpomblekou and Tabatabai, 1994)
The principal underlying mechanism of action of chelators is formation of unionized association compounds with Ca++, Fe++, Al+++ and thus, increasing soluble phosphate concentration by scavenging phosphate from mineral phosphates.
Narsian and Patel (2000) studied the influence of chelators on phosphate solubilization by Aspergillus aculeatus, a rhizosphere isolate of gram. They concluded that different test chelators had differential behaviors in relation to phosphate solubilization. The chelator nitrilotriacetic acid (NTA) increased RP solubilization at 2mg/ml while diethylenetriaminepentaacetic acid (DTPA) enhanced PS only at 6 mg/ml while ethylenediaminetetraacetic acid (EDTA), aluminon and oxine inhibited PS at all concentrations tested. They also found that the highest PS activity, in presence of RP, was up to 50 mg P2O5. Higher concentrations (ie. 100-250 mg P2O5) reduced fungal activity. Although higher concentrations of P were not effective for PS activity, growth, however, increased successively.

The limiting level of Pi in most soils provides the ecophysiological basis for positioning associations between plant roots and mineral phosphate solubilizing (MPS) and/or organic phosphate solubilizing microorganisms(OPS). These associations are assumed to play an important role in phosphorus nutrition in many natural and agro-ecosystems. 

SPECIFIC MICROBES THAT HELP IN P SOLUBILISING
Following micro organisms are reknown to solubilize the cheaper sources of phosphorus such as mineral rock phosphate.
1. Aspergillus awamori 
2. B.megaterium 
3. Bacillus polymyxa, 
4. Penicillium bilaii
5. Penicillium cf. fuscum
6. Pseudomonas striata 

Aspergillus niger and some Penicillium species have been tested in fermentation system or inoculated directly into soil in order to solubilize rock phosphate 
(Kucey, 1987 and Vassilev et al., 1995)
Reddy et al., (2002) found that all the isolates of Aspergillus tubingensis and A.
niger isolated from rhizospheric soils were found to be capable of solubilizing all
the natural forms of rock phosphates.
Arbuscular Mycorrhiza (AM) can make use of organic phosphate (Balaz and Vosatka, 1997) and are able to acidify the environment, which facilitates inorganic P dissolution (Bago et al., 1996).
Asea, Kucey & Stewart (1988) found that Penicillium billai and P. cf. fuscum increased total plant phosphorus uptake by 14% and wheat dry matter yield by 16%. In Canada, the use of a commercial formulation of P. billai spores to increase the availability of phosphate to wheat has been documented.
(Cunningham & Kuiack, 1992).