Fertigation of wheat (Triticum aestivum L.) cultivars with zinc leads to enhanced yield and marginal rate of return in silty loamy soils

This study was aimed to understand the role of Zn fertilizer (ZnSO4·7H2O) applied through soil media, foliar spray and in combination for enhancing yield and marginal rate of return of wheat crop in filed conditions. Four wheat cultivars; Anaj-2017; Akbaer-2019; FSD-2008 and Zincol-2016 were sown in randomized complete block design in field. The Zn fertilizer was applied as soil media, foliar spray and in combination of soil + foliar media. A significant enhancement in plant height (18.2 %), leaf area index (28 %), heat unit efficiency (25.1 %) and SPAD (23 %) value was observed in wheat cultivars with Zn fertilization. However, the impact of soil + foliar media (T4) Zn application (15 kg ZnSO4 ha−1 (soil) + 1 % ZnSO4 foliar spray solution) was higher than soil media or foliar spray. The protein, ash, fat and phytate contents were enhanced to 13.38 %, 2 %, 0.57 % and 27 % respectively while significant decrease in α-amylase (−29 %) and was recorded after Zn fertilization. At T4 considerable enhancement in grain yield (4.2 tons ha−1), harvest index (55.3 %), internal use efficiency and partial nutrient budget was recorded. It was observed that uptake K, N, Zn and Fe were enhanced while that of P were reduced after Zn fertigation especially at T4 in wheat cultivars. The value cost ratio (VCR) and marginal rate of return (MRR) to farmers was better at T4 as compared to T1-T3 in all wheat cultivars. Finally, Zn applied as soil + foliar spray was most effect while among cultivars Zincol-2016 and Akbar-2019 showed more yield potential than Anaj-2017 and FSD-2008. It has been established that the soil–plant-mineral nutrition nexus is the road leading to fetching higher income, sequestration of carbon dioxide from the air and also ensuring food and nutrition security.