O.A. Folorunso¹, J.O. Ohu² and K.B. Adeoye³
1. Department of Soil Science, University of Maiduguri, Maidurguri, Nigeria2. Department of Agricultural Engineering University of Maidurguri, Maidurguri, Nigeria
3. Department of Soil Science Ahmadu Bello University, Zaria, Nigeria
A greenhouse study was conducted to investigate the effects of irrigation water quality and quantity on soil properties and on the straw yield of wheat in a sodic Vertisol of northeast Nigeria. Five kilogrammes of the sodic soil were weighed into each of 36 small plastic buckets (pots). Wheat seeds were uniformly sown in these pots after wetting the soil to a predetermined "field capacity". Four rates of irrigation water corresponding to a total growing season application of 100, 200, 400 and 600 mm, and three water qualities having electrical conductivities (ECiw) of 0.5, 4.5 and 9.0 dS m-1, were applied in a completely randomised design with three replications. The irrigation water had an SAR value of 3.5. The plants were grown for 8 weeks.
The different grades of saline, non-sodic irrigation waters significantly reduced the exchangeable sodium percentage (ESP) of the soil, but increased the electro-conductivity of the saturation extract (ECe). The greatest reclamation effect was achieved with water having an electro-conductivity (ECiw) of 0.5 dS m-1, which not only reduced the ESP of the soil by 34-48%, but also kept the ECe within tolerable limits.
Significant differences in wheat straw yield were observed with different quantities of irrigation water applied, the greatest yield occurring with a total application of 400 mm over the growing season. However, application of the different grades of the saline, non-sodic irrigation waters did not result in any significant difference in straw yield. No interactive effect of water quality and quantity on straw yield was observed.
