Sat Pal Saini* SM and. Evaluation of Nutrient Index using Manganese as a Measure of Fertility Status of Soils under Different Cropping Systems of Punjab in North-Western India. JISSS. 2021;68(4). Accessed October 20, 2025. https://epubs.icar.org.in/index.php/JISSS/article/view/110853