Crop field as an Agroecosystem

a. Abiotic Components:

• Abiotic components are carbon dioxide, oxygen and free nitrogen present in the air and the soil containing water, combined nitrogen, phosphorus, potassium, calcium, iron, magnesium, etc.
• Organic substances like humic acid and amino acids. Inorganic fertilizers are added to enrich the soil in mineral nutrients and organic manure is added to improve the texture of the soil.

b. Biotic components:

• The primary producers are the green plants of the cultivated crop and weeds growing in association with the crop plants and in some cases the hedge plants planted as enclosure around the field.
• The consumers of the first order are the herbivorous insects like the thrips, aphids, ants etc., rats, rabbits and man.
• Carnivores are the insectivorous insects, frogs and birds, which constitute the consumers of the second order.
• The snake and predatory birds like the kite and hawk are the top carnivorous and constitute consumers of the third order.
• Saprotrophs (decomposers) are the saprophytic soil fungi and bacteria, which are aided by the protozoa and other detritivorous animals on and in the soil. These obtain their food from all the tropic levels described above.