NEW DELHI—Sri Lankan paddy fields this season became the plot for a geopolitical soft war between India and China as the island nation found its Chinese fertilizer samples highly contaminated and hastily requested India import a replacement. Rice is Sri Lanka’s staple food and is the second-largest crop in the country after tea. The country has also recently banned chemical fertilizers, aiming to become the world’s first 100 percent organic food producer. This turn to organic farming has been a topic of debate in the country’s media and politics. It has also brought Sri Lanka into an unexpected fiasco with China, which is investing in the country’s multi-billion dollar port projects and offering it other grants, loans, and freebies. Trouble started in the Sri Lanka-China kinship when the Department of Agriculture in Colombo found organic fertilizer samples supplied by Qingdao Seawin Biotech Group Co., Ltd., in August this year to be …