Long-Term Fertilizer Experiments in Red and Lateritic Soils: Practical Lessons on Sustainable Agriculture

摘要

Indiscriminate exploitation of natural resources without taking into account their carrying capacity and injudicious use of nutrient inputs over the years to realise higher crop yields pose serious threats to sustenance of crop productivity and soil health. Impact of continuous cropping, fertilizer, manure and lime application on crop productivity, profitability and soil health was studied for two on-going permanent experiments viz., Permanent Manurial Trial (PMT) with maize-wheat sequence (in progress since 1956) and ICAR-A11 India Coordinated Research Project (AICRP) on Long Term Fertilizer Experiment (LTFE) with soybean-wheat sequence (in progress since 1972) under a set of different nutrient management practices. About half century sustained research has shown that the carrying capacity of the red and lateritic soils is low, but these can sustain around 6 to 8 t ha~(-1) yr~(-1) of wheat equivalent grain yield (WEY) under best nutrient and crop management practices. This is 50 to 100% higher than the current level of crop production. The present paper collates the results of detailed soil and crop based analysis for the past five to six decades of research on the subject and brings out the salient conclusions. Results suggest that sustainable higher crop yields in these soils without any adverse effect on soil quality are possible by supplementing lime and organic manures with periodic soil test-based balanced nutrient use.