Improving the Water Retention Characteristics of Sandy Soil using Food Waste Compost Amendment and Indigenous Microorganisms

Abstract

The ability of soil to promote plant development is mostly governed by its hydraulic properties, namely its water retention capacity. Sandy soils are the least fertile because of their poor moisture capacity, high water permeability, and low nutrient concentration. Adding food waste (FW) compost to sandy soil can improve its water retention capacity. The FW compost can enhance soil organic matter, which improves water and nutrient retention in sandy soils for plant growth and health. This study aims to identify the best composition amendment for FW compost to enhance soil water retention in sandy soil (sand 76 %, silt 8 %, clay 10 %, pH 4.8, and EC 142.4 dS/m). Indigenous microorganisms (IMOs) collected from bamboo leaves (Gigantochloa albociliata) were added to the FW compost to supply nutrients and stimulate plant growth. Five treatments were applied experimentally, with FW compost amendment rates of (5,15, 25, 35 and 100) % w/w, compared to unamended sandy soil as the control. 100 % FW compost provided the largest increase (169 %) in the amount of readily accessible water in sandy soil, raised total porosity to 6 % and reduced bulk density by 64 %. The FW compost with 25 % w/w compost significantly increased the seed germination of Dwarf Pak Choy (Brassica campestris sp. chinensis) to 125 %. This short-term study highlights the benefits of using FW compost and its potential to improve water retention when a low amendment rate (25%) is used.