Influence of mycorrhizae and inorganic fertilizer on plant growth and yield components of two Sri Lankan traditional rice accessions (<em>Oryza sativa</em> L)

Abstract

A greenhouse experiment was conducted to determine the influence of mycorrhizae as a substitute for inorganic fertilizer on growth and yield of two traditional rice (Oryza sativa L.) varieties namely,“Bathkiriel” and “Sinnanayam”, and on soil microbial activity. The experiment was conducted in pots (30cmx 30cmx 45 cm) filled with paddy soil treated separatelywith four doses of inorganic fertilizers,i.e. the recommended dose of basal ferti-lizer UREA:TSP:MOPat 50:62.5:50kg/ha and top dressing Ureaat87.5kg/ha,½ and ¼ of the recommend doses of inorganic fertilizers, and no inorganic fertilizer. In addition commercially available mycorrhizae (diluted at2g of mycorrhizae mixture /5L water) was added to all pots except those received the total dose of inorganic fertilizers. The above four treatments were replicated four times in a Completely Randomized Design (CRD) with four repli-cates. The experiment revealed that there was no significant difference in all growth parameters in plants treated with recommended dose and those treated with 1/2 of recommended dose of inorganic fertilizer with standard dose of mycorrhizae. The highest soil microbial activity was recorded in soil treated with standard dose of mycor-rhizae without inorganic fertilizer (5,660 CO2mgkg-1of soil)as compared to those treated only with inorganic ferti-lizer (4,662 CO2 mgkg-1of soil). Mycorrhizaefound to increase soil microbial activity significantly and complemen-tary to inorganic fertilizer.Itwas concluded that 1/2 of the recommended dose of inorganic fertilizer with standard dose of mycorrhizae was the best fertilizer mixture out of the tested mixtures for traditional rice varieties “Bathkiriel” and “Sinnanayam”.