دوماهنامه
نوع مقاله : مقالات پژوهشی
نویسندگان
1 دانشیار گروه علوم و مهندسی خاک، دانشگاه رازی، کرمانشاه، ایران
2 استادیار گروه مهندسی تولید و ژنتیک گیاهی، دانشکده علوم و مهندسی کشاورزی، دانشگاه رازی، کرمانشاه، ایران
کلیدواژهها
عنوان مقاله English
نویسندگان English
Introduction
Tillage management is one of the main factors affecting soil quality and the sustainability of agricultural systems. Intensive conventional tillage can weaken soil structure, accelerate organic matter decomposition, and alter microbial activity due to continuous mechanical disturbance of the soil. In contrast, conservation tillage systems such as reduced tillage and no‑tillage minimize soil disturbance and often retain crop residues on the soil surface, which can improve soil aggregation, enhance soil organic carbon storage, and increase nutrient retention. These systems also help reduce soil erosion, improve water infiltration, and create more favorable conditions for soil microorganisms. In semi‑arid regions, where soil moisture is limited and soil degradation can occur rapidly, maintaining soil structure and fertility is particularly important for crop production. Durum wheat is an important cereal crop in many semi‑arid areas, and its productivity is closely related to soil health and nutrient availability. Therefore, understanding how different tillage systems influence soil properties is essential for developing sustainable management strategies. This study was conducted to evaluate the effects of different tillage systems and crop presence on selected physical, chemical, and biological properties of soil.
Materials and Methods
The experiment was conducted as a split-split-plot arrangement within a randomized complete block design (RCBD) with three replications. The treatments consisted of three tillage systems, including conventional tillage (CT), reduced tillage (RT), and no-tillage (NT), assigned to the main plots. The subsoiling treatments, including subsoiling and no-subsoiling, were allocated to the subplots, and two crop treatments, including control (uncultivated soil) and durum wheat (Triticum durum), were assigned to the sub-subplots. Soil samples were collected after the crop growing period from the experimental plots and prepared for laboratory analysis. A set of soil quality indicators representing physical, chemical, and biological aspects of soil functioning was measured. Physical and chemical assessments included pH, electrical conductivity (EC), water dispersible clay (WDC), and mean weight diameter (MWD) of aggregates, which were used to evaluate salinity condition and aggregate stability. Chemical analyses included soil organic matter (SOM), soil organic carbon (SOC), total nitrogen (TN), available phosphorus (P), and available potassium (K) as the main indicators of soil fertility and nutrient status. Biological properties were determined through basal soil respiration (BR) and substrate induced respiration (SIR), in order to estimate microbial activity and the potential metabolic response of soil microorganisms to an added substrate. In addition, microbial biomass carbon was considered in the interpretation of biological responses where relevant. The collected data were statistically analyzed using analysis of variance (ANOVA) to test the significance of the main effects of tillage and crop treatment as well as their interaction effects on soil properties. Mean comparisons were performed using appropriate post hoc tests at the selected probability level.
Results and Discussion
The results showed that tillage management significantly influenced the measured soil properties. Conventional tillage generally resulted in higher EC and water dispersible clay, indicating weaker structural stability, whereas no tillage improved aggregation and produced the highest mean weight diameter of soil aggregates. These results confirm that reduced soil disturbance promotes aggregate formation and protects soil structure. Soil organic matter and soil organic carbon increased as tillage intensity decreased, with the highest values observed under no tillage. This trend indicates that conservation systems reduce oxidation of organic materials and favor carbon accumulation within stable aggregates. Nutrient availability also improved under conservation practices, particularly in the no tillage treatment, where nitrogen, phosphorus, and potassium values were generally higher than in conventional tillage. Crop treatment had a positive effect on several soil properties. Soils under durum wheat showed higher soil organic matter, soil organic carbon, and nutrient concentrations than uncultivated control soils, probably because of root residues, rhizosphere activity, and enhanced microbial interactions. Biological indicators also responded significantly to management practices. Basal respiration was greater under conventional tillage, suggesting more rapid decomposition of soil organic matter under intensive disturbance. In contrast, lower respiration values under no tillage reflected greater stabilization of organic carbon. Substrate induced respiration was significantly affected by tillage, crop treatment, and their interaction, indicating that microbial activity was highly sensitive to both soil disturbance and plant presence.
Conclusions
The findings demonstrate that tillage management has an important role in controlling soil quality in durum wheat systems. Conservation practices, especially no tillage, improved soil structure, increased soil organic carbon and organic matter, and enhanced nutrient availability compared with conventional tillage. Durum wheat cultivation also contributed positively to soil improvement through rhizosphere effects and organic inputs. Overall, the combination of no tillage and durum wheat cultivation appears to be a suitable management strategy for improving soil quality and supporting sustainable production in semi arid conditions.
کلیدواژهها English
