Zinc indexing in wheat grains and associated soils of Southern Punjab

Journal Article

Hussain, Muhammad A Maqsood, Shahid Hussain, Tariq Aziz, Munir Ahmad, A Naeem, Hammad R Ahmad, Shamsa Kanwal, Makhdoom . 2014

• Publication Online URL: Zinc indexing in wheat grains and associated soils of Southern Punjab
• Magazine \ Newspaper: Pak. J. Agri. Sci.,
• Issue Number: 2
• Volume Number: 51
• Pages: 1-8

Publication Abstract

Higher grain Zn concentration is desirable to combat human Zn deficiency. A total of 58 farmers’ fields from were surveyed from districts of Multan and Lodhran to represent cotton-wheat rotation zone of Punjab. Soils were sampled separately from the surface (0–15 cm depth) and subsurface (15–30 cm depth) layers. Within 5 m2 of soil sample, about 100 spikes from mature tillers of wheat were also collected. Nearly all subsurface and 76% of the collected surface soil samples were deficient in plant available Zn resulting in grain Zn concentration of 20 µg g−1, on average. The inherent capacity of subsurface soil layer to supply Zn positively correlated with grain Zn concentration (r=0.33, n=58; P=0.01). Organic matter content (r=0.32, n=58; P=0.02) in subsurface layer and soil salinity (ECe) of both layers (r=−0.53, n=58; P<0.01 for ECe of both layers) were the other major soil characteristics that significantly correlated with grain Zn concentration. Zinc bioavailability in wheat grains, estimated by [phytate]:[Zn] ratios and trivariate model of Zn absorption, was low. Present study indicated a need to reduce current grain [phytate]:[Zn] ratio (46, on average) and to increase the current trivariate model based estimated Zn bioavailability (1.5 mg Zn for 300 g flour, on average) by about 2-folds. Conclusively, Zn fertilization strategy for southern Punjab was suggested as a solution to human Zn deficiency and low grain yields. Keywords: Biofortification; Calcareous soils; Southern Punjab; Wheat; Zinc