Wheat Response to Increasing Levels of Residual Alkalinity in Irrigation Water in a Semi-Arid Region

Abstract

Response of wheat (Triticum aestivum L. emend. Fiori & Paol.) cultivars to irrigation with sodic waters having high residual alkalinity is not well known. The objective of this field investigation (2006–07 to 2008–09) was to study the response of three wheat cultivars (PBW 343, PBW 502, and PBW 550) to four levels of residual sodium carbonate (RSC) in irrigation water: 0, 3, 6.5, and 10 mmolc L−1 at Ludhiana. Another field study (2004–05 to 2006–07) involving PBW 343 and PBW 502 was carried out using tubewell water irrigation (RSC of 5.5 mmolc L−1) at Bathinda. Increase in RSC significantly increased soil pH and exchangeable sodium percentage and decreased grain yield of all three cultivars at Ludhiana. The three cultivars responded differentially to RSC levels. Data pooled across three years at Ludhiana revealed that at 3 mmolc L−1 RSC, yields of PBW 343 and PBW 502 were similar, but cultivar PBW 343 produced higher yield than PBW 502 and PBW 550 when irrigated with water containing 6.5 and 10 mmolc L−1 RSC. Cultivar PBW 550 had the lowest grain yields at all levels of RSC. Grain yield at 10 mmolc L−1 RSC was 3.9, 3.3, and 2.9 Mg ha−1 for PBW 343, PBW 502, and PBW 550, respectively. No significant effect of RSC of irrigation water on any grain quality parameter of cultivars was observed. At Bathinda, cultivar PBW 343 produced 11% higher grain yield than PBW 502 under tubewell irrigation. At both the locations, cultivar PBW 343 performed better with respect to yield than the other cultivar/s and, therefore, should be preferred on soils irrigated with waters containing RSC higher than 5 mmolc L−1.