The amount of biomass or organic matter produced by plants by photosynthesis per unit area and over a period of time is called primary productivity. It is divided into gross and net primary productivity. The rate of production of organic matter by plants through photosynthesis is called gross primary productivity and the net primary productivity is the availability of biomass for consumption by heterotrophs. The rate at which the new organic matter is produced by consumers is called secondary productivity. Here fowl or chicken is a consumer.