Forage shrub production from saline and/or sodic soils in Pakistan

• Nuclear Institute for Agriculture and Biology, Pakistan
• University of Agriculture, Pakistan
• Pakistan Council for Research on Water Resources, Pakistan
• University of Karachi, Pakistan

Waterlogging and salinity have substantial adverse social and economic effects in Pakistan, causing deteriorating living standards, health hazards, the crumbling of houses and difficulties in transport, and forcing many people to migrate to other areas. Both these problems severely affect the country's major livestock industries - the raising of buffaloes, goats, sheep and cattle for milk, meat, wool and progeny. In addition, the horses, donkeys and camels used for transport have substantial forage needs. Revegetation of salt-affected land with productive forage thus has enormous economic and environmental implications.

Pakistan contains about 5.7 million hectares affected by salt, including 3.0 million ha of saline/sodic land, on which biosaline agriculture is currently being used to improve production since engineering approaches have often failed. An important recent advance in this work has been the development of Kallar grass - an ecotype of Leptochloa (syn. Diplachne) fusca - as a forage for salt-affected soils. Apart from its considerable value as forage for buffaloes, this grass has the major advantage that the roots ameliorate soil sodicity by exchanging calcium and sodium ions, enabling leaching of the sodium. However, D. fusca will not maintain goats in winter, nor will it grow in areas subject to extreme salinity.

In Western Australia, the Department of Agriculture has studied rehabilitation of salt-affected land for over 30 years. Selections of halophytic forage shrubs (especially Atriplex spp.) now in commercial use there are palatable and productive and grow well on saline/alkali and seasonally waterlogged soils.

The present project will evaluate the potential for using Atriplex spp. to revegetate salt-affected land in Pakistan. Detailed research in Australia will cover screening for waterlogging tolerance, nutrition of Atriplex spp. and the water and salt balance of Atriplex stands. The Department will publish a comprehensive bibliography and develop a computerised data-bank. An important new project here concerns development of an expert system for prescribing establishment methods from data on site characterisation and species requirement, and cooperation with the ACIAR project will extend its application.

In Pakistan, both the University of Faisalabad and the Nuclear Institute have grown Atriplex species in preliminary tests on their research farms, with promising results, and several species grown by the University of Karachi in field plots irrigated with saline water have performed well. The present project will expand this research to provide a sound basis for extensive use of halophytic forage shrubs in Pakistan.

Successful application of this work will allow reclamation of currently unproductive land. Moreover, the perennial halophytic shrubs will complement the summer-growing D. fusca to provide an improved year-round feed supply, which will stabilise animal production and improve reproduction capacity. Extensive plantings should also help to lower groundwater levels.

Within Australia, availability of the data-banks on germplasm and species adaptation and the bibliography will benefit research in several states, including a cooperative program planned by workers in South Australia, Victoria and New South Wales. The project should also provide selections with improved waterlogging tolerancea major factor limiting use of these speciesand assess the long-term viability of halophyte shrubs on soils with a shallow saline water table.

Spillover benefits should extend from this project to FAO programs on the rehabilitation of salt-affected rangelands of Iran and of those in Iraq, Syria and Egypt. It is planned to make the data-banks and bibliography common to all three projects.