Starch-Lignin Biocomposite Soil Amendment

Food Grade Starch (85% min, moisture 13% max, ash 0.2%, pH 5–7, Ghobee IMM manufacturer, Sdn. Bhd. Malaysia). Lignin Indulin AT (Kraft alkaline lignin, water-insoluble, Sigma-Aldrich, USA). Starch and Lignin were supplied and used in dry powder form after drying at 105 °C for 12–24 h. Commercial grade granular urea fertilizer with 47% nitrogen was accessed directly from farmers. All chemicals used were of high purity and used as received without any prior treatment. Loamy sand soil samples were collected from the Titi Gentang rice field (Perak, Malaysia). Soil sampling and physicochemical properties are already described in our earlier publications [14 ].