Interactive effects of partial liming and fertilizer regimes on growth, yield, and multivariate trait relationships of mustard in acidic sandy loam soils

Soil acidity is a major constraint to mustard cultivation in eastern India, resulting in nutrient imbalances, reduced fertilizer-use efficiency, and poor crop productivity in sandy loam soils. Although liming is widely recommended to ameliorate soil acidity, its interactive effects with fertilizer regimes on yield performance and trait interrelationships in mustard remain insufficiently documented. To address this, a rooftop pot culture experiment was conducted during the Rabi season of 2024 at Dhanbad, Jharkhand, using Brassica rapa var. yellow sarson (cv. ‘Benoy-9’). The experiment was laid out in a Completely Randomized Design with ten treatments and four replications, comprising two fertilizer regimes (no fertilizer and recommended dose of fertilizer, RDF: 50:25:25:20 kg ha-¹ N:P:K:S) combined with four graded lime levels (0.1, 0.2, 0.3, and 0.4 lime requirement, LR), along with an untreated control. Observations were recorded on vegetative traits, yield attributes, seed and stover yield, and oil content. The combined application of RDF with lime significantly enhanced growth, yield components, seed yield, and oil productivity compared to unfertilized and unlimed treatments. RDF with 40% LR (210 kg ha-¹ CaCO₃) produced the highest seed yield, oil yield, and oil content, followed closely by RDF with 30% LR, while the absolute control exhibited the poorest performance. Principal Component Analysis revealed that the first two principal components explained 78.3% of the total variability, with yield-related traits such as seed yield, biological yield, oil yield, and harvest index contributing most to overall variation and clearly discriminating superior lime–fertilizer combinations. PCA biplots further confirmed the strong positive association of higher lime levels combined with RDF with productivity-enhancing traits. Overall, the study demonstrates that partial liming in conjunction with recommended fertilization effectively improves mustard productivity and fertilizer efficiency in acidic sandy loam soils, providing a robust statistical basis for optimizing lime–fertilizer management strategies under similar agro-ecological conditions.