Evaluation of Stomata in Vetch-Barley Intercropping and Its Relationship with Forage Production in Rainfed Conditions, Under the Influence of Biofertilizer and Superabsorbent

Abstract

Considering the role of stomata in photosynthesis and dry matter production, an experiment was performed to investigate the stomata in vetch-barley intercropping and its relationship with dry forage production under rainfed conditions as influenced by biofertilizer azotobarvar‑1 and superabsorbent in two cropping years (2018 and 2019). One factor was intercropping with an alternative method (100% vetch, 100% barley, 75% vetch +25% barley, 50% vetch +50% barley, and 25% vetch +75% barley). Another factor included the application of biofertilizer and superabsorbent (Azotobarvar‑1, superabsorbent, superabsorbent+Azotobarvar‑1, and non-application of them). The results showed that stomata density and dimensions, net photosynthesis, dry forage yield, and the percentage and yield of crude protein in vetch and barley were affected by intercropping, Azotobarvar‑1, and superabsorbent in both years. In both years, increasing the density of intercrop component caused a decrement of stomata density and an increment of stomata dimensions in both plants. Intercropping increased net photosynthesis of vetch and barley and total dry forage yield compared to the monocropping. In different culture patterns, the application of superabsorbent+Azotobarvar‑1 raised photosynthesis. The highest total dry forage yield (3799 Kg ha−1) was related to the application of superabsorbent+Azotobarvar-1 at 50% vetch +50% barley in year 2019. The highest total forage crude protein yield in year 2018 (436 Kg ha−1) and in year 2019 (569 Kg ha−1) was related to the application of superabsorbent at the vetch monocropping system. In terms of total dry forage yield, the intercropping of 50% vetch +50% barley can be recommended as a suitable treatment. In total, Azotobarvar‑1 in line with the goals of sustainable agriculture and superabsorbent in order to store rainwater can increase the dry forage yield of vetch and barley and total forage crude protein yield.