Site Specific Nutrient Management for Low Productive Soils from Two Agro-Ecological Zones of Sri Lanka

Abstract

Soils and their management options are considered as location and situation specific. An experiment was conducted to identify beneficial nutrient management practices to improve soil fertility for selected low productive fields. Two sites were selected from Mahailluppallama (MI) at Dry zone Low country, (D Llb) and Kundasale (KS) at Intermediate zone Mid country (IM3) agro-ecological zones. Soil samples were analysed for initial soil properties such as pH, electrical conductivity (EC), soil organic matter (OM), CEC and texture by standard methods. Treatments for MI were site specific fertilizer (SF), biochar applied at 0.5% by weight with SF (BC+SF), rock powder applied at 5% by weight .i with SF (RP+SF), and a soil only control (C) while for KS, SF, BC+SF, incubated cattle manure and saw dust applied at 1% by weight with SF (CS+F,) and C were the treatments. The experiment was a complete randomized design with four treatments conducted under greenhouse conditions. For MI and KS, pH 7.1 and 5.6, texture sandy clay loam and sandy loam, CEC i 6 and 13.5 cmolst/kg, OM 1.5 and 1.3%, and EC 0.12 and 0.10 dS/m, respectively. Plant height and plant dry weights were highest in BC+F and RP+F treatments than control and SF treatm ent for MI soil. For KS all the amended treatments showed significantly higher growth parameters than the control, but no significant difference among the amended treatments. This study showed that biochar and rock powder with site specific fertilizers are valuable amendments for improving soil fertility in MI soils while site specific fertilizer alone improves soil fertility in KS soils.