(i)

It is a low cost and easy technique, and can be used by small and marginal farmers.

(ii)

It is free from pollution hazards and increase soil fertility.

(iii)

On application of algal biofertilizers increase in rice yields ranges between 10-45 per cent and about 40-50 Kg N is left over in the soil which in turn is used for the subsequent crops (Venkataraman, 1972). Moreover, benefits from algalization is about 25-30 Kg N/ ha/cropping season in rice fields (Subba Rao, 1992). After 3-4 consequent years, the algal effects become consistent and there is no need of using this practice. The parental inoculum is sufficient for growth and multiplication.

(iv)

Cyanobacteria secrete growth promoting substances like IAA, IBA, NAA, aminoacids, proteins, vitamins, etc. They add sufficient amount of organic matter in soil.

(v)

Cyanobacteria can grow and multiply under wide pH range of 6.5-8.5. Therefore, they can be used as the possible tool to reclaim saline or alkaline soil because of their ameliorating effect on the physico-chemical properties of the soil.

(vi)

Rhizobial biofertilizer can fix 50-150 kg N/ha/annum.

(vii)

Azotobacter and Azospirillum, besides supplying N to soil, secrete antibiotics which act as pesticides.