ABSTRACT
Historically, the seeds for agricultural activity (agrosphere) were sown in the Indo-Gangetic region several centuries ago, beginning with the domestication o f important cereals (e.g. rice) and legumes by the local population. Natural savannas, scrubland, shrubs, tropical and subtropical jungles, and barren expanses along the major rivers Indus and Ganges, and their tributaries, gave way for a regular agricultural cropping ecosystem. Since then, the cropping systems in particular, and general agro-ecology has co-evolved with human population in these plains. Human ingenuity has played a dominant role in developing and maintaining the agroecosystem's equilibrium, particularly the nutrient dynamics and productivity equations. Driven by dense population pressure in recent times (beginning mid 20th century till date), this agroecosystem experienced drastic modifications towards intensification through high nutrient inputs, improved crop genetic stocks, and increased productivity. Presently, this 'emerald green belt' predominately grows two most important cerealsrice and wheat.
