Mathematical Model for Rice (Oryza Sativa) Growth Analysis Under Green Fertilizer of Biogas Slurry

Abstract

The purposes of this study were to observe and measure the growth of rice plants against the application of biogas slurry fertilizer, to calculate the growth rate of rice plants with an appropriate mathematical model, and to recommend a dose of biogas slurry fertilizer for rice cultivation. This study was conducted in an experimental field using plant pots with 5 treatments of applying biogas slurry, namely without treatment/control (K), 60 Mg/ha of liquid slurry (C1), 30 Mg/ha of liquid slurry (C2), 60 Mg/ha of solid slurry (P1), and 30 Mg/ha of solid slurry (P2). Each treatment was repeated 2 times with each plant pot filled with 3 rice plants. The pots were set in randomized complete block design. The growth parameters observed were the number of leaves, plant height, number of tillers, crown weight, and plant root weight. Observations were made for 120 days. The analysis used in this study used one-way ANOVA analysis, linear regression and logistic equation for plant growth rates. The results showed that the P1 treatment had the best growth response. The coefficient value of plant growth rate (μ) on the number of leaves treatment parameters K, C1, C2, P1, and P2 were -0.044; -0.047; -0.0567; -0.0613; and -0.0547, respectively. Then, the plant height parameters were -0.0448; -0.0474; -0.0448; -0.0421; and -0.0458, respectively. The number of tillers in a row were -0.0408; -0.0405; -0.0432; -0.0447; and -0.0448, respectively. The ANOVA test showed that the application of biogas slurry fertilizer was significant (sign < 0.05) on plant growth rate, while it had no significant effect on wet and dry weight of shoots and plant roots (sign > 0.05). Logistic equation was excellent to describe rice growth under biogas slurry fertilizer. The dose of slurry biogas fertilizer that provides the most contact for plants was 60 Mg/ha.