FLOOR CROP NUTRITION ON MICROBIAL INTERACTIONS IN COCONUT BASED MULTITIER CROPPING SYSTEM*Namitha V.V., Sheeja K. Raj, Anith K.N., Shalini Pillai P. and Jacob D.
To assess the importance of maintaining and improving the soil quality, an understanding of microbial population is of great importance. With the objective to assess the effect of different coconut-based crop combinations and floor crop nutrition on soil quality a study was conducted at Coconut Research Station, Balalaramapuram. Enumeration of bacteria, fungi and actinomycetes from the soils of different coconutbased cropping system under 75 per cent and 100 per cent RDF for the floor crop revealed significant differences in microbial population among the crop combinations and floor crop nutrition. Among the different crop combinations, the bacterial and actinomycetes population was significantly higher (16.7 x106 CFU g-1 wet soil and 6.7 x104 CFU g-1 wet soil respectively) for coconut + banana + turmeric system and the fungal population was higher (2.6 x103 CFU g-1 wet soil) for coconut + banana + ginger system. Results clearly revealed that, compared to papaya, treatments, involving banana resulted in higher population of bacteria, actinomycetes and fungi. Application of 75 per cent recommended dose of fertilizers (RDF) for the floor crop resulted in higher microbial population. Interaction effect was also significant and coconut + banana + turmeric system with 75 per cent RDF for the floor crop turmeric (c1n2) recorded significantly higher bacterial (18.0 x106 CFU g-1 wet soil) and actinomycetes (7.0 x104 CFU g-1 wet soil) population while fungal population (3.1 x103 CFU g-1 wet soil) was higher for coconut + banana + ginger system with 75 per cent RDF for the floor crop ginger (c2n2). It can be concluded that, 75 per cent RDF for the floor crop was sufficient for maintaining the soil microbial population in high density multiple cropping system in coconut.