MICROBIAL POPULATION ECOLOGY UNDER TEAK (TECTONA GRANDIS LINN. F.) FERTIGATION RESEARCH TRIAL IN FARM CONDITIONS OF WESTERN TAMIL NADU.

A field study was established in farmer's field at Coimbatore district of Tamil Nadu to study the impact of fertigation on growth and productivity of teak (Tectona grandis Linn. f.). The irrigation treatments were scheduled according to the crop water requirement based on climatological approach and the fertigation treatments are imposed as per the reference fertilizer dosage of 150:100:100 kg NPK/ha. The chemical fertilizers applied may have an impact of the physiobiochemical properties on the soil. Based on these assumptions the current study deals with the comparison of microbial populations under different fertigation regimes recorded terms of Total Bacterial Count (TBC), Total Fungal Count (TFC) and Total Actinoimycetes Count (TAC) in two-year-old teak plantations. The maximum value for TBC (6.69 cfu g-1), TFC (3.60 cfu g-1) and TAC (5.19 cfu g-1) is observed in I1F2 (50% PE 100% RDF). The karl Pearsons correlation analysis and canonical correlation analysis conducted infers correlation between soil physiochemical factors such as pH, electrical conductivity, organic carbon, total nitrogen and carbon:nitrogen(C:N) with soil microbial populations. The current study regsitered a decrease in microbial count at higher fertilizer levels with altered soil parameters corresponding to the microbial population. [ABSTRACT FROM AUTHOR]