نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction
Global food demand is rising, and by 2050 the world population is expected to reach about 9 billion. To meet this demand under increasing environmental pressures, improving the efficiency of production factors through sustainable agricultural practices is essential. Conventional tillage and sole-cropping systems often suffer from limited ground cover and associated soil degradation. Intercropping systems, especially mixtures of cereals and legumes, can enhance resource use efficiency, improve soil quality via biological nitrogen fixation, and reduce soil erosion while maintaining or increasing forage yield and quality. This study focuses on the performance of intercropping two forage crops, vetch (Vicia sativa L.) and triticale (×Triticosecale Wittmack), under different tillage regimes, aiming to identify combinations that optimize forage quality under dryland conditions in Kurdistan, Iran.
Materials and Methods
The field experiment was conducted during the 2019–2020 growing season at the Kurdistan University experimental farm. The trial employed a split-plot based on a randomized complete block design with three replicates. The main plots consisted of three tillage treatments: conventional tillage (plough-back, disc, and harrow), reduced tillage (chisels), and no-tillage. Subplots represented six sowing patterns: (I1v) pure vetch, (I1t) pure triticale, (I2) 80% triticale+20% vetch, (I3) 60% triticale+40% vetch, (I4) 40% triticale+60% vetch, and (I5) 20% triticale+80% vetch. Subplot dimensions and spacings were standardized, with three 5 m by 1.5 m main plots per replicate. Quality parameters of the forage were assessed at anthesis by harvesting excluding edge effects. The laboratory analyses included crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and ash content, following standard procedures. Plant height and dry matter (DM) yield were also recorded. Data were analyzed using SAS 9.1. Means were compared with LSD at 5% probability. Figures were produced in Excel.
Results and Discussion
Analysis of variance showed significant interactions between tillage and intercropping on several forage quality traits in both species. Specifically, the interaction affected the acid detergent fiber (ADF) and crude protein (CP) of vetch forage at the 1% level, and also influenced the neutral detergent fiber (NDF) and CP of vetch and triticale in different contexts. Overall, ADF and ash contents, and CP of vetch, were sensitive to tillage × intercropping, whereas NDF showed pronounced responses to tillage and intercropping independently in many treatment combinations. Crude protein was higher in vetch pure stands and generally increased under no-tillage compared with conventional tillage. In the intercropping setups, CP of triticale tended to rise as vetch proportion increased, indicating a positive effect of legume association on the protein content of the cereal component, likely due to better nitrogen availability and improved canopy light capture under mixed stands. The content of ADF (and thus digestibility potential) and NDF was notably affected by tillage and intercropping. Pure cropping with conventional tillage tended to exhibit higher NDF and ADF values compared with no-till and mixed stands, suggesting lower forage digestibility in traditional systems. Intercropping, especially with favorable cereal-legume ratios, reduced fiber concentrations in some treatments, aligning with improved forage quality reported in other cereal-legume mixtures. Ash content was mainly driven by intercropping. Among the treatments, pure vetch exhibited the highest ash content, while pure triticale had the lowest, with mixed patterns showing intermediate values. This pattern reflects changes in mineral content and tissue composition influenced by species mix and resource availability. Dry matter did not show significant differences among tillage systems in this study. The land equivalent ratio (LER) analysis demonstrated that intercropping, particularly at ratios of triticale 80% + vetch 20% improved LER across all tillage treatments, with the highest LER observed under conservation tillage systems.
Conclusion
The study demonstrates that tillage systems and intercropping patterns significantly influence the quality of forage from vetch and triticale under dry Mediterranean conditions. Intercropping, particularly with balanced cereal–legume ratios, improved forage quality by modulating Crude Protein and fiber fractions (Acid Detergent Fiber and Natural Detergent Fiber), and reduced ash content relative to pure stands under some tillage regimes. No-tillage tended to enhance CP for vetch, and under intercropping, CP of the cereal component increased, suggesting improved nitrogen use efficiency and forage nutritive value in conservative farming systems. Intercropping, especially at an 80:20 ratio, improved LER, particularly under conservation tillage systems. Practically, adopting conservation or reduced tillage in combination with carefully designed vetch–triticale mixtures can enhance forage quality and soil health in semi-arid environments.
کلیدواژهها English
Authors retain the copyright. This is an open access article distributed under Creative Commons Attribution 4.0 International License (CC BY 4.0)
