Whatever the cropping system adopted, bioclimatic conditions as sun radiation, temperature and rainfall, (spatial and temporal variability ) are soundly affecting crop photosynthetic activity and biomass production. With the climate change already emerging in south east Asia ( see El Nino impacts ), there is a necessity for looking at new agricultural practices in the view of adaptation to these new situations that farmers are going to face. This communication is dealing with the main agroclimatic and ecophysiological process that are involved in the biomass production in the case of the practice of no-till mulch based cropping systems DMC as already diffused with farmers by millions of ha in the world and beeing up to now under participative experimentation in south east Asia, mainly in Laos, Cambodia, Thailand and Vietnam in order to meet small farmers expectations. Main objective of this paper will be putting in evidence that sustaining high biomass production may be obtained by farmers through a fine tuned integrated management of the crop's biological microenvironment.