Beneficial Nutrient Management Practice for Improving Maize (<em>Zea mays</em>) Yield in a Tropical Entisol

Abstract

Beneficial nutrient management practices could increase maize yield via improving soil fertility. A study was conducted in the mid country wet zone of Sri Lanka (WM2b) on Typic Troporthents aiming to formulate a site specific fertilizer (SF) recommendation and to identify beneficial organic soil amendments (OA) to improve the fertility and productivity of soils for maize cultivation. The SF recommendation was developed using modified missing element technique. Incubated mixture of cattle manure and sawdust at 2:1 wet weight basis (CS-i) and biochar (BC) derived from sawdust were selected as OAs. Four treatments, (i) un-amended control (S), (ii) soil amended with SF (SSF), (iii) cattle manure-sawdust CS-i (2.2 Mg ha-1) with SF (CSi+SF) and (iv) biochar (1.1 Mg ha - 1) with SF (BC+SF) were tested in the field for two consecutive growing seasons (Yala 2013 and Maha 2013/14) for maize. According to missing element technique, soil was deficient in K, Mg, P and Zn nutrients and resulted in 38%, 35%, 27% and 24% relative dry-matter reductions, respectively. Addition of OA+SF significantly improved soil organic carbon content compared to SSF. Green cob yield ranged from 7.9 to 16.5 Mg ha-1 in Yala and 5.4 to 12.4 Mg ha -1 in Maha increasing yield significantly in CS-i+SF, BC+SF and SSF over the un-amended control in both seasons. Soil fertility and maize yield were sustained or improved under combined application of site specific fertilizer and organic amendments. Moreover, cut down of K fertilizer is possible with application of BC and CS-i OAs. Hence, SF recommendation along with biochar or cattle manure-sawdust mixture OAs is a beneficial nutrient management practice for cultivating maize.