BIO-ORGANIC NUTRIENT MANAGEMENT ENHANCES SOIL PLANT SYSTEM FUNCTIONING AND VARIETAL YIELD RESPONSE OF SHARBATI WHEAT IN VERTISOLS: A PRINCIPAL COMPONENT ANALYSIS APPROACH

Abstract

Bio-organic nutrient management is increasingly promoted as a sustainable alternative to conventional fertilization; however, its system-level effects on soil health, crop functional traits, and varietal yield realization remain inadequately quantified, particularly in Vertisol-based wheat systems. This study evaluated the integrated response of soil chemical and biological properties, nutrient uptake, grain quality, and yield of sharbati wheat (Triticum aestivum L.) under bio-organic management using a multivariate analytical framework. A field experiment was conducted during two consecutive rabi seasons (2015-16 and 2016-17) on Vertisols of central India under a rice-wheat cropping system. Seven bio-organic treatments involving vermicompost, biodynamic preparations (BD-500 and BD-501), and Panchagavya were tested across four wheat varieties. Soil organic carbon, available nutrients, microbial populations, nutrient uptake, grain quality parameters, and grain and straw yield were analyzed. Principal component analysis (PCA) was applied to integrate correlated variables and identify dominant soil-plant system functioning gradients. The soil chemical-biological PCA revealed a dominant integrated fertility-biological axis explaining 78.3% of the total variance, clearly separating integrated bio-organic treatments from the control. A second PCA showed strong coupling between nutrient uptake and grain quality, with the first component explaining 92.9% of the total variability. Grain yield exhibited a strong positive rank-based association with PCA-derived system functioning, while straw yield responded more directly to enhanced system performance. Varietal responses differed significantly, with JW-3020 and C-306 achieving the highest yield gains under high system-functioning conditions.