The year after his father died, Ponnamalaiah sprayed his 10-acre field with pesticides and added chemical fertilisers to cotton, paddy and vegetables. The results were impressive. The first summer and winter harvests saw more cotton and paddy than his father had ever managed to achieve. The second year’s harvest, however, dipped. In the third year, the results were poorer than those without chemical pesticides and fertilisers. When I meet him about 20 years later, Ponnamalaiah is t