Effect of adding Anti-salinity and enriching organic fertilizer with nano-compound fertilizer NPK on the growth of sour orange seedlings

• mariam kareem Basem rahem bader

  Author

The experiment was conducted in the fields of the College of Agriculture, University of Diyala, located at 44°45' East longitude and 33°17'41" North latitude, during the 2025-2026 growing season in sandy-clay-loamy soil. The aim was to study the effect of adding Anti-salinity and enriching organic fertilizer with NPK nano-compound fertilizer on the growth of sour orange seedlings. The experiment was carried out according to a randomized complete block design (RCBD) using a split-plot design with three replications. The experiment included 36 experimental units as a two-factor experiment: three levels of Anti-salinity treatments placed in the main plots, and four levels of sheep manure and NPK nano-compound fertilizer placed in the subplots. Anti-salinity treatments were a control factor of 10 and 20 ml.L^-1 per seedling, and the concentrations of sheep manure were 0% (no addition) and 5% (sheep manure). Based on volume and enrichment (5% sheep manure + 5 kg.ha⁻¹ compound nano-fertilizer) and 5 kg.ha⁻¹ compound nano-fertilizer.4 The results were statistically analyzed and the arithmetic means were compared using Duncan's multiple range test at a probability level of 0.05. The results showed the following:

1- The 5% sheep manure treatment outperformed the no-add O1 level for the following traits: nitrogen, phosphorus, potassium, plant height, and chlorophyll content. The treatment means were (2.4933%, 0.64444%, 2.4978%, 137.111 cm, and 58.867 mg.g⁻¹), respectively. The leaf proline concentration was 1.514 mg.g⁻¹ fresh weight.

2- The fourth level of NPK O4 nano-fertilizer achieved the highest means for the following traits. Nitrogen, phosphorus, and potassium averaged (2.753%, 0.7200%, and 2.873%), respectively, compared to the level without O1 addition. The average proline concentration was 1.50444 mg.g⁻¹ fresh weight.

3- The dual interaction between sheep manure and NPK nano-fertilizer at levels two and three for both sheep manure and nano-fertilizer (+) achieved the highest averages for nitrogen, phosphorus, and potassium in the leaves and plant height, with average values ​​for level O3 of (3.48330%, 0.864%, 4.888%, and 143.444 cm), respectively (mg.kg⁻¹ and 411.78 mg.kg⁻¹). The proline concentration in the leaves at the interaction was 1.51000 mg.g⁻¹ fresh weight.

4-  The triple interaction (W3O3) of sheep manure, nano-fertilizer, and Anti-salinity achieved the highest average concentrations of nutrients (nitrogen, phosphorus, and potassium, with averages of 3.536%, 0.960%, and 5.183%, respectively) in the plant. This interaction also resulted in the highest plant height, reaching 162.00 cm, while the proline concentration in the leaves reached 1.50667 mg.g-1 fresh weight. Fertilization with the Anti-salinity at a level of 20 ml L⁻¹ per seedling (W3) led to significant effects on most of the studied traits, including total chlorophyll concentrations, which reached 56.542 mg.g-1, and plant height, which reached 142.667 cm. The same treatment also

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