गोबां फुंखानिफ्राय मिथिनाय जादों दि आबादनि सिङाव थानाय बांद्राय गुदुं हा बाहागोनि हासारा थाबैनो खमायलांदों ।
It is known through various sources that there has been steep depreciation in the fertility of tropical soil under cultivation .