Pak. J. Bot., 38(2): 249-266, 2006. | Back to Contents | ||||
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Updated: 09-07-09 | ||||
GROWTH RESPONSE OF RICE AND WHEAT CROPS DURING RECLAMATION OF SALINE-SODIC SOILS M. H. ZIA, A. GHAFOOR, G. MURTAZA, SAIFULLAH AND S.M.A. BASRA*
Abstract: Productivity and internal drainage of saline-sodic soils can be restored
by better management practices like combination of physical and chemical
treatments. A field experiment was carried out for 3 years at two saline-sodic
sites, in Punjab-Pakistan to improve soil physical/chemical properties
and increase wheat and rice yields. The site 1 was highly deteriorated
(bulk density 1.77-1.86 Mg m-3) followed by site 2 (bulk
density 1.6-1.7 Mg m-3). Due to a very low infiltration rate
at both sites, vertical drainage through auger holes that extend down
to a permeable soil layer was suggested to flush down excess saline
water thus minimizing temporary waterlogging and associated hypoxia.
Gypsum as a source of calcium was applied @ 3.8-7.2 t ha-1 at
site 1 and 3.6-11.4 t ha-1 at site 2, to all vertical drainage
treatments to replace excess sodium on soil exchanger and decrease dispersion.
Saline-sodic tube well water, used to irrigate rice and wheat crops,
also helped attain a significant decrease in soil salinity and sodicity
within a reasonable time period. After harvesting the final wheat crop
(6th in sequence), non-significant differences were observed between
the vertical drainage/gypsum treatments and the control treatments regarding
the final electrical conductivity, sodium adsorption ratio, and yields
of crops. Detailed economic analysis indicated that at site 1, combination
of gypsum and vertical drainage technique was the best, with benefit
cost ratio of 8.0 while at site 2, the vertical drainage + gypsum treatments
did not work. As the study was carried out with farmers' participation
approach, there seems a need to educate and train the farmers, as well
as supply them with quality inputs, in time and space, to maximize the
benefits from the projects dealing with the management of saline-sodic
groundwater resources and saline-sodic soils. Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad. Department of Crop Physiology, University of Agriculture, Faisalabad, Pakistan. |
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