Water plays a vital role in agricultural intensification. In the past several decades, the concentration of inputs on high-value land has relieved pressure on land expansion, increased farm incomes and allowed an urbanizing global population a measure of food security. But it comes at a cost. Globally, agriculture water withdrawals (2,703 km3/yr) account for more than double the combined withdrawals for municipal and industrial use (468 km3/yr and 731 km3/yr, respectively). The application of agrochemicals and the accumulation of low quality surface and groundwater within and beyond irrigation schemes has degraded land and polluted watercourses, aquifers and coastal zones.
Current levels of demand is already stressing river basins and aquifers, with water scarcity driving the rapid rise in groundwater use in agriculture. And with rising populations, growing incomes and more unpredictable rainfall patterns, demand for water in agriculture is expected to grow.
Managing the global agricultural production risk in the face of producer price volatility, increasing temperatures, and more variable events will require both rainfed and irrigated agricultural systems to become much more responsive to climate shocks and much more flexible in approach while staying within environmental limits. Water scarcity can managed by more attention to river basin planning, transparent allocation of water among competing sectors and by better maintenance and operation of existing infrastructure in that basin. At the farm level, farmers can switch to less water intensive crops, and different farming techniques to generate more value from the water and other inputs at their disposal.