Progression of drip irrigation and fertigation in cotton across the globe and its future perspectives for sustainable agriculture: an overview

Sustainable use and efficient management of water as an agricultural input have become a major global challenge. Agriculture consumes 70% of global freshwater sources, of which cotton alone is consuming 11%, and thus necessitates for appropriate water and fertilizer savvy strategies such as drip irrigation and fertigation. Drip irrigation has slowly progressed from being a novelty in 1960s to be now an accepted method among farmers. However, documented information on progress of drip fertigation in cotton over the last two decades is little available. In this global review, we have summarized a total of 124 studies not only from developed countries like China, USA but also from developing countries like India, and the Middle East showcasing the adoption and practice of drip fertigation in major cotton growing regions over the last 20 years, besides its role in improving productivity and rational resource use in a sustainable manner. Present findings reveal that drip fertigation could save 20-30% fertilizer and around 50-60% of water besides improving cotton yield. However, despite distinguished advantages, its adoption is limited in most of developing countries with the main impediment being the high initial investment. The area in India alone can be increased 15 folds as compared to present acreage under drip, which can translate into huge saving of water and fertilizer resources. Since, the long-term benefits can help to compensate for the initial cost, farmer friendly policies are required to popularize this technology. While providing quantitative evidence of the significant water and fertilizer savings achieved through drip fertigation, this study could significantly contribute to the existing body of knowledge besides helping to reduce water footprint of cotton across the globe.