Asad Sarwar Qureshi

Sustaining Asia’s groundwater boom: An overview of issues and evidence

This article suggests that Asia’s groundwater socio-ecology is at an impasse. Rapid growth in groundwater irrigation in South Asia and the North China plains during the period 1970‐1995 has been the main driver of the agrarian boom in these regions. India, Pakistan, Bangladesh and China account for the bulk of the world’s use of groundwater in agriculture. On the plus side, groundwater development has provided sustenance to agrarian economies and millions of rural livelihoods. On the downside, it has created chronic problems of resource depletion and quality deterioration. While problems of groundwater depletion, pollution and quality deterioration are indeed serious, so are the consequences of the degradation of the resource for those that have come to precariously depend upon groundwater irrigation. Three problems currently afflict groundwater use: depletion due to overdraft; water logging and salinization; and pollution due to agricultural, industrial and other human activity. The pathology of the decline in groundwater socioecology reflects a remarkably similar pattern across regions. The critical issue for Asia now is: what might be done to sustain and revive these groundwater socio-ecologies vital to the region’s economy? This article reviews a variety of technoinstitutional approaches. However, transposing lessons from the industrialized world uncritically in the Asian context may not work. A more nuanced understanding of the peculiarities of Asia’s groundwater socio-ecology is needed.

The Indus and the Ganges: river basins under extreme pressure

The basins of the Indus and Ganges rivers cover 2.20 million km2 and are inhabited by more than a billion people. The region is under extreme pressures of population and poverty, unregulated utilization of the resources and low levels of productivity. The needs are: (1) development policies that are regionally differentiated to ensure resource sustainability and high productivity; (2) immediate development and implementation of policies for sound groundwater management and energy use; (3) improvement of the fragile food security and to broaden its base; and (4) policy changes to address land fragmentation and improved infrastructure. Meeting these needs will help to improve productivity, reduce rural poverty and improve overall human development.

Amelioration and nutrient management strategies for sodic and alkali soils

Sodic and alkali soils are characterized by the occurrence of excess sodium (Na + ) to levels that can adversely affect soil structure and disturb the availability of nutrients for plant growth. Structural problems in these soils are created by certain physical processes (slaking, swelling and dispersion of clay minerals) and specific conditions (surface crusting and hardsetting), which affect water and air movement, seedling emergence, root penetration, runoff and erosion, as well as tillage and sowing operations. Such changes ultimately impact choice of crops, and crop growth and yield, which are also affected by osmotic and ion-specific effects in these soils. Of the salt-affected soils worldwide, about 60% are sodic and alkali soils, warranting attention for efficient, inexpensive and environmentally feasible amelioration. Sodic and alkali soil amelioration primarily involves increasing calcium (Ca 2+ ) on the cation exchange complex at the expense of Na + . The replaced Na + is removed from the root zone through infiltrating water resulting from excessive irrigation(s). Several approaches aiming at amelioration of these soils have been used, which include application of water, crop, chemical amendment, electric current and tillage as amelioration tools. In addition, management of plant nutrient elements in these soils has been addressed as a crucial factor in improving crop productivity and soil fertility. While the principles and technologies aiming at the amelioration of sodic and alkali soils are fairly well understood, their adoption in poor and developing countries is very slow because the majority of the affected lands are in the possession of resource-poor communities or form part of the common property resources of the villages. This paper reviews various amelioration and nutrient management approaches as well as constraints to large-scale adoption of the amelioration approaches. This information will assist researchers and farm advisers in choosing appropriate management practices to achieve maximum benefits from these soils while considering the participation of the farmers in the planning and setting of the amelioration programmes.