Harvesting Management for Protein Rich Biomass Production from Azolla (Azolla caroliniana)

A study was conducted to assess the effect of daily harvesting rates on Azolla (Azolla caroliniana) biomass production from poly-lined culture pits under climatic conditions of Punjab. The results showed that up to 250 g of Azolla could be sustainably harvested daily per m² of culture pit without affecting the growth and nutritive value of the Azolla mat. Although, Azolla harvesting @ 125, 187.5 and 250 g/m² did not affect the water quality (pH, temperature, NH₃-N, NO₃-N and ortho-phosphate) but a higher level of CP was recorded when Azolla was harvested @ 250 g/m²/d compared to Azolla harvested @ 125 g/m²/d (25.71 to 30.89% vs. 24.42 to 28.97%). Furthermore, cost of 1.0 kg Azolla protein production decreased by 56.40% with increase in the daily harvesting rate from 125 to 250 g/m²/d without any additional nutrient input and labour cost.