Precision farming for optimised nutrient use efficiency and yield of Capsicum annuum L. in southern coastal plain of Kerala

Modern agriculture has driven significant yield increase but also led to widespread chemical fertiliser use, causing soil health deterioration and multiple nutrient deficiencies. In India, studies evaluating optimal nutrient management strategies for high-value crops like chilli in nutrient-deficient sandy coastal soils using precision farming techniques are limited. To address this knowledge gap, a field experiment was conducted in nutrient-deficient sandy coastal soils of Kerala during 2023–2024 using a split plot design to evaluate balanced nutrition strategies combining fertigation and foliar application of nutrients in Capsicum annuum L. For that, 75, 100 and 125 % of 210:46:276 nitrogen, phosphorus and potassium (NPK) kg ha-1, were applied through fertigation and were indicated as F1, F2 and F3 respectively. It was compared against fertigation dosage of 75:40:25 NPK kg ha-1 (F4). Secondary and micronutrient effects were studied using soil application of sulphur (25 kg ha-1) S1, foliar nutrition of 0.5 % Sampoorna (S2), foliar nutrition of 0.25 % (S3) and 0.5 % (S4) of customised multinutrient mixtures with water spray (S5) as control. Results demonstrated that the treatment F3S2 recorded maximum fruit weight (8.2 g) and total nutrient uptake of potassium (312.12 kg ha-1), sulphur (37.19 kg ha-1) and zinc (434.02 g ha-1), while F2S2 exhibited highest uptake of calcium (128.04 kg ha-1) and iron (15.74 kg ha-1). Maximum magnesium uptake (111.99 kg ha-1) was observed in F3S4 substantially outperforming F4S5. Hence, 263:60:345 NPK kg ha-1 with foliar nutrition of Sampoorna optimised balanced nutrition and productivity of chilli in sandy coastal soils.