This study was destined to investigate the efficacy of improved insitu mulch rows in improving and sustaining plantain yields up to the 4th crop cycle. The trial was conducted at the Rivers State University of Science and Technology Training and Research Farm, Portharcourt, Nigeria using six different banana and plantain clones/cultivars and improved life mulch rows incorporated on the three meter inter-rows and were cut back periodically. The In-situ Mulch rows were planted with selected grasses and legumes. Of all the tested 13 agronomic and yield parameters, the manure from the In-situ Mulch rows significantly increased and sustained yields up to the 4th crop cycle at (p0.005) level of significance other than in the circumference at the last finger. This seemed to be genetically controlled. On the growth parameters, there was also a significant difference amongst the clones in plant height, number of leaves and sucker production in all the crop cycles with the triploids scoring higher owing to their increased number of chromosomes and cell sizes. Bunch weights were found to be independent of bunch hand but increased with increase in finger number and size.