Synergistic effects of soil and foliar nano-biochar on growth, nitrogen metabolism and mineral uptake in wheat varieties

Abstract

Soil amendment and foliar application of nanobiochar (NBC: a unique nanomaterial) may enhance soil fertility which ensures that nutrients are available to plants, and increase crop production because it is a suitable source of macro- and micronutrients. From this study, NBC induced modification in two wheat varieties (Akbar, Zincol) yield, growth, physio-biochemical and ionic profiles have been studied. The soil application of nanobiochar was applied in four concentrations [control (0 %), S1 (1 %), S3 (3 %), and S5 (5 %)] at the sowing stage while after 30 days of germination, the foliar application of same NBC concentrations with surfactant (0.1 % Tween-20) was applied in the pots. Each treatment has three replications and experiment was arranged in a completely randomized design (CRD). Results indicated that growth attributes, physio-biochemical parameters and ion contents were significantly increased in both varieties than their respective controls with Akbar variety exhibiting better improvement in Akbar. However, the application of NBC increased the plant height, shoot–root dry biomass and shoot length at the S3F3 level (NBC in soil 5 % + NBC as foliar 3 %) while root length, plant and shoot fresh weight at the S5F5 level (NBC in soil 5 % + NBC as foliar 5 %) root fresh weight and plant dry weight S3F1 level (NBC in soil 3 % + NBC as foliar 1 %), leaf area at S3F3 level (NBC in soil 3 % + NBC as foliar 3 %), number of tillers at S1F5 level (NBC in soil 1 % + NBC as foliar 5 %). On the other hand, both methods of NBC applications significantly enhanced the photosynthetic pigments in both varieties but the Zincol variety showed the highest rate of pigments. Moreover, both applications of NBC significantly affect the primary metabolites (total soluble sugar, protein, and free amino acids), secondary metabolites (phenolic and flavonoid content), antioxidants (Catalase and peroxidase) and nitrogen metabolic enzyme (Nitrite and Nitrate) of both varieties with comparatively higher rate in the Akbar variety. In conclusion, these results showed that the combined applications of NBC as soil and foliar form could be used as a suitable source of fertilizer because of its beneficial effects and high nutritional content.