Agricultural water productivity improvements

Natural Capitalism

p 217: $1 block of gypsum inserted at root zone provides soil moisture readings and allows for 1/3 - 2/3 water savings with no change in crop yields... extrapolate in relation to:

p 218: "In CA, the world's largest water wholesaler, the Metropolitan Water District ofSouthern California, buys back "saved" water from its distributors; just one, the Imperial Irrigation District, has invested in water-saving technologies that have allowed it to sell back 32 billion previously wasted gallons a year [sic].

CHARTING OUR WATER FUTURE:

Agricultural productivity is a fundamental part of the solution. In all of the case studies, agricultural water productivity measures contribute towards closing the water gap, increasing “crop per drop” through a mix of improved efficiency of water application and the net water gains through crop yield enhancement. These include the familiar technologies of improved water application, such as increased drip and sprinkler irrigation. The full suite of crop productivity measures includes, among others, no-till farming and improved drainage, utilization of the best available germplasm or other seed development, optimizing fertilizer use, and application of crop stress management, including both improved practices (such as integrated pest management) and innovative crop protection technologies.

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In India, the least-cost set of levers—those on the left-hand side of the cost curve—is dominated by these agricultural measures, which can collectively close 80 percent of the gap and includes both irrigated and rain-fed crop production measures. In addition to the agricultural opportunity, lower-cost supply measures constitute the remaining 20 percent required to close the gap, delivered mostly through the rehabilitation of existing irrigation districts and the “lastmile” completion of earlier projects such as canals. The total annual cost for the combined set of supply and agricultural levers is approximately $6 billion per annum—just more than 0.1 percent of India’s projected 2030 GDP.

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In India, drip irrigation offers potential for lending and equity investments alike: our analysis implies that the penetration of this technology will grow by 11 percent per year through 2030, requiring increased manufacturing capacity and credit for farmers.