Does sewage sludge application increase micronutrients uptake and yield of mung bean (Vigna radiata L.) under semi-arid conditions?

Sewage sludge, a residual, semi-solid organic matter material obtained from wastewater treatment were beneficially used as soil additives/valuable soil conditioner and as fertilizer being nutrient rich which are naturally occurring and are needed by plants. The sewage sludge application effect on micronutrient uptake and yield of mung bean (Vigna radiata L.) in semi-arid conditions of Northwestern India had been studied during Kharif 2021-22 with three replications based on completely randomized design. The seven treatments of sewage sludge i.e., 0, 2.5, 5, 7.5, 10, 15 and 20 t ha-1 were imposed. Grain yield was increased 44.9 % over control (no sewage sludge) after application of the sewage sludge at 20 t ha-1. The maximum grain and straw yield of mung bean recorded with the application of sewage sludge at 20 t ha-1. The uptake of diethylenetriaminepentaacetic acid (DTPA)-extractable micronutrients (zinc, copper, iron and manganese) increased significantly with the increasing rates of sewage sludge application over control. The highest availability of DTPA-extractable micronutrients in soil and their maximum uptake was found in T7 where 20 t ha-1 sewage sludge applied. The results showed that yield of the mung bean, micronutrients content in soil and their uptake by mung bean increased significantly with the increasing rates of sewage sludge in the semi-arid regions of Northwestern India. The principal component analysis revealed that soil pH, Fe and straw yield were the most influential and reliable factors for evaluating soil quality and mung bean crop performance. Two principal components accounted for 88.87 % of the total variance in original data set.