Heavy metals, soil salinity/sodicity and soil fertility status of soils and plants of some sewage-irrigated farms

Khan, M.A.; Naeem, M.A.; Ahmad, M.

Heavy metals, soil salinity/sodicity and soil fertility status of soils and plants of some sewage-irrigated farms

2002

Khan, M.A. | Naeem, M.A. | Ahmad, M. (University of Arid Agriculture, Rawalpindi (Pakistan))

Utilization of municipal and industrial waste (sewage) for the purpose of irrigation is a common practice among the farmers holding lands nearby towns and industrial areas. Sewage is quite rich in plant nutrients and organic matter. Its application to farmland results in higher crop production and benefit to the farmers especially when it is available free of cost. However, since sewage may also contain excess of soluble salts and heavy metals, it may cause soil pollution and health hazards. The present study was, therefore, undertaken to check the levels of heavy metals in soils and plants, soil salinity/sodicity hazard, and c) soil fertility status of seventeen sewage-irrigated farms located around Rawalpindi, Gujar Khan, Haripur, Attock, and Fateh Jang. It was revealed that soils of the sewage-irrigated farms, in general, had higher levels of heavy metals and soluble salts as compared to rain-fed soils of the region. Some plant samples contained Cu, Ni, and Cr in the toxicity range. High level of soil fertility was found in these soils: available P ranged from 9-42 mg kg-1 showing medium to high level; majority of the soils had high levels of K and organic matter-around 200 mg kg-1 and 1%, respectively. These investigations indicate that sewage irrigation may be good for improving crop yields through increased soil fertility, yet it could cause soil pollution and health hazards. Monitoring of soil pollution of sewage-irrigated farms, at regular interval, is therefore recommended.

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