Definition of DMC (direct seeding mulch-based cropping systems : SCV in French) DMc are based on 3 principles: i) Continuous minimum mechanical soil disturbance, ii) Per-manent organic soil cover, iii) Diversified crop rotations in the case of annual crops or plant associations in case of perennial crops. The permanent cover can come from i) ex situ mulch, ii) insitu produced mulch, iii) in situ live mulch iv) in situ residual mulch. The suppression of ploughing creates an en-vironment favourable to the development of the biological ground activity, prevents the de-velopment of weeds, limits evaporation, limits runoff. The sharp cover allows a physical soil reorganization via its root system and plays the role of a biological pump: just as in the agroforestry systems. No tillage and limited weeds decrease labour requirements and in-crease return to labour. A farming system modelling (FSM) ap-proach linked to a farming system refe-rence monitoring network (FSRMN) to assist in decision making processes for de-velopment projects supporting Direct see-ding, Mulch-based Cropping systems (DMC) in Madagascar.