Are Nitrogen Fertilizers Deleterious to Soil Organic Matterand Soil Health?

摘要

Honourable past Presidents of the Indian Society of Soil Science, my respected teachers, esteemed colleagues, dear students, ladies and gentlemen; it is an honour and proud privilege to be asked to deliver a lecture in the memory of late Dr. Radha Raman Agarwal, who was President of the Indian Society of Soil Science during 1962-63. It was in 1971 when as a student of soil science I came across the book 'Soil Fertility in India' by Dr. R.R. Agarwal. It was among the very few text books available at that time which dealt the subject of soil fertility in the Indian context. The book was published 50 years ago in 1965 but it contains information which is still very relevant. Dr. Agarwal was a chemist by training, but as described by Dr. J.S.P. Yadav who was his student and delivered the first lecture in his memory, he adapted exceptionally well to soil science, mainly due to his outstanding scientific competence, brilliant intelligence, great devotion, hard work, critical observations, remarkable grasping capacity, and prudent application of research advancements to the local specific situations (Yadav 2003). Both as Agricultural Chemist and Director of Agriculture of the erstwhile undivided state of Uttar Pradesh, he richly contributed in making anaccurate inventory of soil resources consistent with methodologies and concepts of soil survey and soil classification, management practices with special reference to soil fertility, and proper diagnosisas well as amelioration of the degraded lands, particularly salt-affected areas.