Yield and Quality Parameters of Winter Wheat in a Wheat–Pea Mixed Cropping System

Modern agriculture is based on plant specialization, where the decrease in biodiversity makes vulnerable of our cultivated crops against climate change and the fluctuated market demands. Mixed cropping is a planned diversity in space, which is a powerful tool to conserving soil fertility. Our experiment was carried out in three growing seasons (2020/2021, 2021/2022, 2022/2023) with the combination of three winter wheat varieties (GK Szilárd, Cellule, GK Csillag) and a winter pea variety (Aviron) in four repeats and three seeding rates to determine yield and quality parameters (protein, gluten, Zeleny index, W-value) of wheat. Yield varied every year: The highest value was provided by the 50:100 mixture of GK Csillag/Aviron in 2021 (pure stands + 24%), then it gradually decreased in the following years. In terms of protein, Zeleny index and W-value, the Cellule/Aviron 50:100 achieved outstanding values, while in 2022 was preferred GK Szilárd/Aviron 50:100 combination. We verified a statistical difference between the wheat varieties in the case of gluten (in each year) in favor of GK Csillag/Cellule/GK Csillag and for the W-value (in 2021) in favor of Cellule. Plant density and seeding rate determined the final crop proportion within the mixture and indirectly affected yield quantity and quality.