Variability in soil properties influencing pigeonpea ( Cajanus cajana L.) yield: a multivariate statistical analysis

Aims: The aim of the study was to reveal the variability in soil properties influencing pigeonpea ( Cajanus cajana L.) seed yield under semi-arid rainfed condition. Methods: Soils were initially classified into series level and further these series were divided into soil-phase units. For two site years viz., 2018-19 and 2019-20, surface soil samples from each soil-phase unit were collected before sowing of pigeonpea and subsequently crop growth parameters at critical stages were recorded. Results: The principal component analysis with varimax rotation resulted in seven components for both the site years, having eigenvalues greater than one, explained more than 80% of the variability. The step wise linear regression analysis showed that the pigeonpea seed yield was linearly correlated with PC3 ( p<0.01), PC4 ( p<0.01) and PC7 ( p<0.05) of soil properties with R (2) = 0.679, during 2018-19. Whereas, during 2019-20, the seed yield was linearly correlated with PC1 ( p<0.01), PC3 ( p<0.01) and PC6 ( p<0.05) with R (2) = 0.677. In site year 1, the available P (2)O (5), Fe, Zn, S, Cu, number of pods, surface soil moisture determined the yield. In site year 2, the available K (2)O, P (2)O (5), Fe, Zn, S, clay, CEC and available water content determined the yield. All these variables together explain variability in yield.