Humate-Silica as an ameliorant to decrease Fe toxicity and increase rice yields on acid sulfate soils

National Research and Innovation Agency Republic of Indonesia, Research Center for Food Crops, Jl. Raya Jakarta-Bogor Km 46, Cibinong, Bogor 16911, West Java, Indonesia

^* Corresponding author: enim002@brin.go.id

Abstract

Iron toxicity is a major problem in increasing rice production in acid-sulfate soils. Humate materials and Silica ions can interact with Fe ions to form chelates so that they can decrease Fe toxicity and increase rice yields. This research aimed to study the effect of humate-silica soil on decreasing Fe toxicity and increasing rice yields in acid-sulfate soils. The research employed a simple randomized block design incorporating treatments F0=100% lime, F1=30% humate manufacturer+30% rice husk ash+40% lime, F2=30% water hyacinth humate+30% rice husk ash+40% lime, F3=30% water hyacinth humate+30% rice husk biochar + 40% lime, F4=30% humate manufacturer+30% rice husk biochar+40% lime, and control=without ameliorant. Each treatment was repeated 4 times. Observations of soil characteristics were carried out at the end vegetative stage including pH and Fe, while at the end of the research, observed including panicle length, 100g weight, and grain weight per pot. The findings indicated that F1 was able to increase pH and decrease Fe²⁺ concentration and wasn’t significantly different from F3. Ameliorant F3 was able to decrease Fe toxicity and increase rice yields. The application of this formula resulted in a decrease in the usage of agricultural lime while enhancing rice productivity in tidal soil.