Question

Why do producers always occupy first trophic level on every food chain?

Answer 1

The first trophic level of the food chain is always occupied by green plants which are termed to be producers. This is because producers absorb sunlight, abiotic factor and fix it into food chain. This energy is transferred to organisms in other trophic levels of the food chain. 
Food chains describe the feeding relationship between the organisms of an ecosystem.The successive levels in the food chains of a community are called as trophic levels. Various trophic levels in a food chain include producers, primary consumers, secondary consumers and tertiary consumers.

Answer 2

Producers are the one which make food for themselves and for other animals also and other animals consume it. eg plants