تاثير نيتروژن و منگنز بر قابليت استفاده برخي عناصر غذايي خاك تحت كشت گياهان مختلف

Nitrogen is usually the most limiting nutrient for crop production. Thus, N fertilizer is widely used by farmers. Moreover, Mn deficiency in some calcareous soils of Iran with high pH has been reported. Therefore, the addition of nitrogen and manganese to achieve the optimum yield is necessary. The objective of this study was to evaluate the effect of N and Mn applications on the availability of some soil nutrients under wheat (Triticum aestivum L.), corn (Zea mays L.), and spinach (Spinacia oleracea L.) plants in greenhouse conditions. In a factorial test, five levels of N (0, 50, 100, 200 and 400 mg/kg soil as NH4NO,) and three levels of Mn (0, l5 and 30 mg/kg soil as MnSO4) in a completely randomized design with four replication were applied. Corn, wheat and spinach varieties were Sc704 Falat and Spinacea spp, respectively. After eight weeks, total N content and DTPA-extractable Mn, Fe, zn and cu of soil were measured. The results indicated that N and Mn aplications increased Mn-extractable of soil in three cultures but didnʹt affect the soil total N. Nitrogen application in corn increased available Fe in soil. Mn application decreased extractable Zn and Cu of soil in wheat and soil extractable Cu in corn.