تأثير عصاره هاي كودي آلي متفاوت بر قابليت جذب آهن در يك خاك آهكي تحت كشت ذرت

Iron deficiency in calcareous soils is one of the most serious nutritional challenges in agriculture, particularly in crops such as corn that are highly sensitive to iron unavailability. In these soils, iron mainly precipitates into insoluble forms, leading to chlorosis, reduced photosynthetic efficiency, an‎d yield decline. Conventional practices to address this problem include the use of composts an‎d commercial iron fertilizers such as Fe-EDDHA an‎d iron sulfate, which, despite their effectiveness, suffer from drawbacks such as high cost, limited persistence, an‎d potential environmental impacts. Accordingly, this study was conducted to examine whether organic fertilizer extracts can provide greater benefits than composts an‎d commercial fertilizers in improving iron availability in soil an‎d enhancing the nutritional an‎d growth status of corn plants. A greenhouse experiment was carried out in a completely ran‎domized design with seven treatments an‎d three replications in a calcareous soil, under both planted an‎d unplanted conditions. Treatments included composts an‎d their corresponding extracts prepared from cow, sheep, an‎d poultry manures, as well as kitchen food waste, along with Fe-EDDHA, iron sulfate, an‎d an untreated control. Soil chemical properties (pH, EC, organic carbon, an‎d macro- an‎d micronutrient concentrations), plant nutrient concemtration an‎d uptake, an‎d morphological an‎d physiological traits (leaf number, plant height, shoot dry weight, pigments, an‎d greenness indices) were measured an‎d statistically analyzed. The results showed that organic fertilizer extracts, particularly the kitchen food waste compost extract, had the most pronounced effects on reducing soil pH an‎d increasing available iron, which directly led to a significant increase in plant iron uptake. Composts also improved iron availability, although their effect was generally less than that of the extracts. Compared with commercial fertilizers, the extract treatments demonstrated greater efficiency not only in enhancing iron uptake but also in improving the nutritional status of plants with respect to other micronutrients (zinc, manganese, an‎d copper). In addition, extract treatments enhanced plant physiological an‎d growth traits such as leaf number, plant height, shoot biomass, an‎d chlorophyll content, thereby improving overall corn performance. In conclusion, the findings indicate that compost extracts can not only compete with, but in many cases surpass composts an‎d commercial iron fertilizers in improving iron availability an‎d plant growth in calcareous soils. Among the tested sources, the kitchen food waste extract exhibited the highest potential as a sustainable, low-cost, an‎d environmentally friendly strategy for managing iron deficiency in corn cultivation.

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