The aftermath of World War II saw a dramatic rise in national initiatives for self-sufficiency across the world . Tank manufacturers started building tractors , and the chemical industry shifted its focus onto pesticides and fertilizers , in a drive to enable farmers to grow more food with greater efficiencies than before . In the UK , the government increased its agriculture budgets to bolster these new objectives , but unfortunately , took things too far . It wasn ’ t long before farmers were harvesting four tons of grain per acre , as opposed to the previous one and a half . Landowners took to tearing out hedges and trees to maximize their farmable areas , ultimately , leading to farming against our environment .