The normalized difference vegetation index value of volcanic paddy soils of Mt. Talang using Landsat 8 image

Abstract

Abstract Accurate and up-to date information on the spatial distribution of paddy fields in volcanic soils is important. The volcanic soil in West Sumatra covers an area about 602.500 ha. Soils of volcanic origin are considered fertile and productive soils. They are widely used to grow annual and perennial crops. Paddy cultivation in volcanic soils is commonly practiced in West Sumatra. Remote sensing data can be used to observe the condition of rice plants in volcanic soils from by calculating the vegetation index value through the NDVI (Normalized Difference Vegetation Index). This study aims to determine the vegetation index of paddy grows in Mt. Talang by using Landsat 8 satellite imagery and correlate the index value with the total carbon and fractions content. Soil samples were collected using the 1x1 km interval grid method from 5099,78 ha of volcanic paddy fields. Soil samples were collected undisturbed and disturbed condition. The undisturbed soil samples were used to analyze bulk density (BD). The disturbed soil samples were dried and sieved with a 2-mm sieve and then analyzed for soil pH (H20 and KCl), Organic C, Labile C, and Very Labile C. All of soil samples have low bulk density (0.76-0.89 Mg/m3). Soil pH is considered neutral (6.50 to 6.93). The average vegetation index value was high, with a maximum value of 0.60 and a minimum value of 0.39. The results of the regression analysis showed that there was no relationship between NDVI and soil chemical properties. Determination of the vegetation index during the growing period of paddy is very useful to improve the accuracy of paddy identification sites at the regional scale and to predict the potential paddy production in due time.