Biomass and Yield Estimation of MR219 and MR220 of Paddy Varieties using Terrestrial Laser Scanning Data

Abstract

Rice (Oryza Sativa L.) is the main food source in Malaysia. Thus, to fulfill the needs, continuous rice production is required. Appropriate amount of nitrogen (N) fertilizer is needed to ensure high production of rice. In this research, the effect of N to plant height, SPAD reading, biomass and yield were firstly studied. It was later followed by the estimation of biomass and yield using Terrestrial Laser Scanning (TLS) data. Different amount of N i.e. 0 kg/ha, 85 kg/ha, 170 kg/ha and 250 kg/ha were applied to MR 219 and MR 220 paddy. The 2-way ANOVA results showed that all parameters were significantly different at each N level. The highest reading was achieved at 250 kg/ha of N level; 70.46 cm (plant height), 39.13 (SPAD reading), 927.29 g/m2 (biomass) and 830.99 g/m2 (grain yield) respectively. Therefore, these parameters can be used to indicate the level of input nitrogen at the plant. Later, the plant height calculated using developed Crop Surface Model (CSM) of the Terrestrial Laser Scanning (TLS) data was used to evaluate the biomass and grain yield of paddy. Results has shown that high correlations and regression were accomplished for CSM plant height and biomass (R2 = 0.809). However, the results between CSM plant height and grain were lower (R2 = 0.582). In accordance with the outcome, biomass and yield were best estimated at 94 Day After Sowing (DAS). An estimation model for biomass and grain yield using linear equation was developed. Then a t-test was done to test the estimated and measured biomass and grain yield. The outcome showed that there was no significance difference between measured and estimated values. The values for both parameters were 1 (p≥0.05). Thus, it can be said that CSM plant height can be used to estimate biomass and grain yield.