Effect of predicted climate change on growth and yield performance of wheat under varied nitrogen and zinc supply

Abstract

Sustainable crop production is crucial to address global food security and requires a solid input of chemical fertilizers containing macro (e.g. nitrogen: N) and micro (e.g. zinc: Zn) nutrients. However, climatic factors beyond farmers’ management capabilities determine the final crop yields, and world’s climate has been changing more rapidly than ever due to human activities such as industrialization and deforestation. This study evaluates the interactive effects of predicted climate change and N and Zn supply on performance of bread wheat as a model staple food crop. Bread wheat (T. aestivum cv. Ceyhan-99) was cultivated in soil fertilized with adequate or low N and Zn in pots under ambient climate (ambient CO2 and temperature) or predicted climate (700 μmol mol−1 CO2 and 3 °C temperature rise) conditions in dedicated plant growth chambers. Plants were harvested at full maturity and grain yield, and yield attributes along with Zn and N status of grains were determined. Predicted climate (PC) treatment significantly accelerated plant growth rate resulting in early onset of successive growth stages and maturity. In both PC and ambient climate (AC) conditions, adequate supply of N and Zn significantly increased straw and grain yield by increasing number of spikes per plant and number of grains per spike, whereas PC significantly reduced straw and grain yield through reducing number of spikes per plant, particularly in plants supplied with adequate N. Effect of adequate Zn or PC treatments were significant only under adequate N supply. Adequate N not only increased grain protein concentration but also grain Zn, particularly under adequate Zn application. In general, PC tended to increase grain Zn concentration, but the effect was non-significant. PC had no effect on grain protein concentration, whereas it significantly reduced grain protein yield (i.e. total mass of protein in whole grains of a single plant). The future climate with elevated CO2 and raised temperature can dramatically reduce duration of time to complete successive growth stages in wheat. Plants cultured under PC conditions had significantly lower straw and grain yield, although supplied with ample fertilization. Whereas the PC and adequate Zn treatments enhanced main spike gain yield and number of grains per spike, PC declined overall grain yield, particularly due to severe reduction in number of spikes per plant. We conclude that sustaining a higher number of spikes per plant along with adequate nutrition with N and Zn are key factors to benefit from an elevated CO2 atmosphere and to minimize adverse effects of rising temperatures on wheat yield and quality.