Potentially recyclable nutrients are largely in the form of the organic materials-night soil, animal manure, sewage sludge, composts, slaughter house wastes, and crop residues. There are some who believe that only naturally derived organic material should be used as fertilizer. Organic fertilizers do, indeed, have valuable properties as soil amendments. In particular, their humus content enhances the efficiency of mineral fertilizer, improves soil structure, increases water retention by soil, and decreases soil erosion. Vegetation like all living things requires certain foods for its survival and growth. For this purpose fertilizers or manure are the materials to be added to the soil and sometimes to foliage to supply nutrients to sustain plants and promote their abundant and fruitful growth. The elements that constitute these plants foods are divided into three classes. â€¢ Primary Nitrogen (N), phosphorus (usually expressed as P2O5), and potassium (expressed as K2O) â€¢ Secondary - calcium (Ca), magnesium (Mg) and Sulphur (S) â€¢ And Minor or so called micro nutrients Iron (Fe), Manganese (Mn), Copper (Cu) Zinc(Zn), Boron(B) and Molybdenum. In addition to their role as nutrients calcium and magnesium are important in adjusting the pH and filth of the soil. In the modern age the trend is more towards the Biofertilizers by virtue of their multifold superiority in soil replenishment with essential minerals, essential nutrients to the plant tissue, easy assimilation and above all greater economy. Mention may be made here of a very significant factor which is brought into play that bio-fertilizers are highly, Salubrious, resulting in healthiest possible growth of various parts of the plants. So any new entrants can venture in to this industry. Few Indian Major Players are as under:- Agro Extracts Ltd. Fertilisers & Chemicals, Travancore Ltd. Good Value Mktg. Co. Ltd. Jupiter Biotech Ltd. Madras Fertilizers Ltd. Nava Bharath Fertilizers Ltd. Navkisan Bio Plaantec Ltd. Vrundavan Agro Inds. Ltd.