Fertigation regime impacting productivity, moisture and nutrient distribution in mango under subtropical condition

A fertigation experiment was conducted to assess the spatio-temporal variation in soil water content, productivity, fruit quality and nutrient distribution in drip irrigated mango cv Dashehari under subtropical environment. Temporal variations in soil water content in the orchard was mainly governed by climatic factors particularly rainfall while the spatial variability was influenced by the hydrological properties of existing soil layer. Higher moisture content was recorded in the surface layer (0–15 cm) and it decreased down the depth. Higher moisture retention was observed in the treatment where fertigation was applied from September to second week of May which coincided with the crop phenological stages including fruit development. Lower moisture content (9–10%) was observed during flowering which is a pre-requisite for flowering in mango. The highest fruit yield (5.44 t ha⁻¹) was obtained in fertigation with N, PandKfrom the beginning of September to second week of May (T₅) as compared to 3.58 t ha ⁻¹ in basin application (T₁). Nutrient distribution in soil and leaf tissues showed better nutrient levels in all the treatments as compared to the control. Soil organic carbon (SOC) content ranged between 0.27–0.57%, available P between 11.7–18.93 mg kg⁻¹ and K between 92.23–181.83 mg kg⁻¹ across different treatments; however, the highest availability of these nutrients was recorded in T₅ treatment as compared to control (T₁). Available micronutrients (Fe, Mn, Cu and Zn) had showed improvement in T₅ over T₁ with highest values as Zn (0.75 mg kg⁻¹), Cu (3.63 mg kg⁻¹), Mn (8.53 mg kg⁻¹) and Fe (11.07 mg kg⁻¹). Leaf tissues were found in optimum range with the highest content as 0.25% P, 0.94% K, 29.67 mg kg ⁻¹ Zn, 35.33 mg kg⁻¹ Cu, 68.33 mg kg⁻¹ Mn and 262.33 mg kg⁻¹ Fe. Correlation analysis showed yield is positively correlated with SOC content (r = 0.994**) and soil micronutrients (r = 0.898* to 0.994**). In contrast, TSS was non-significantly correlated with these parameters. Available soil K and P were positively and significantly correlated with yield and acidity as well as ascorbic acid content (r = 0.865* to 0.921**). Soil micronutrients were also significantly correlated with acidity and ascorbic acid content (r = 0.892* to 1.00**). Moreover, it was inferred that leaf micronutrients were positively correlated with yield yet mostly non-significantly correlated with quality parameters.