The major challenge of today’s agriculture is to provide food security for a growing population while remaining sustainable. As a result, a paradigm shift toward conservation agriculture (CA) is urgently required. Lentil is one of the major pulse crops in West Bengal and its incorporation into the cropping system through CA will ensure soil health and production sustainability. The goal of this study was to find the dynamics of soil-borne disease development on two lentil cultivars in three different tillage systems (conventional tillage, reduced tillage and zero tillage) with five different doses of fertilizer and organic residue treatments: T₁= (0% Residue + 100% NPK), T₂= (0% Residue + 50% NPK), T₃=(100% Residue + 75% NPK), T₄=(50% Residue + 100% NPK) & T₅=(50% Residue + 75% NPK). Regardless of treatment, it was discovered that among the three different tillage practices, zero tillage and reduced tillage had the lowest disease incidence (%) and severity (%). Whereas, irrespective of tillage, the lowest disease incidence (%) and severity (%) were observed when residue and NPK were used at (100% +75%) and (50% +100%), respectively, indicating that disease suppression could be achieved through minimal soil disturbance and residue retention. Through correlation and regression analysis it was also found that weekly average of two weather factors viz., maximum and minimum temperatures and bright sunshine hour had the significant effect on both disease incidence and severity. The isolated pathogens from collar rot and wilt infected plants were confirmed as Sclerotium rolfsii & Fusarium oxysporum f.sp. lentis by studying its morphological characteristics.