Reflectance characteristics of major Kharif crops of Madhya Pradesh and soil-canopy temperature characteristics of soybean

Abstract

The paper presents the results of field experiment carried out at Indore and Sehore districts of Madhya Pradesh during Kharif season of 1990 for the study of spectral separability of soybean from sorghum, red gram, castor and sunflower in ratio vegetation index (RVI) and normalized difference vegetation index (NDVI) data sets computed using spectral reflectance observations in red (R) and near infrared (NIR) bands of Indian remote' sensing satellite (IRS) LISS (Linear Imaging Self Scanning Sensor) system. The RVI has been found to be the better discriminator as compared to NDVI. The effect of date of sowing on the temporal profile of RVI and NDVI as a function of 'days after sowing' (DAS) has been studied for PK-472 variety of soybean sown on three different dates over the nearby seed breeding farms. The variability of RVI and NDVI between two different varieties of soybean (PK-472 and MACS-58), sown in the adjacent farms nearly at the same time, has also been discussed. It has been found that RVI is more sensitive than NDVI during initial vegetative and senescence stages. The variability of RVI and NDVI for the observations at 0930, 1030, 1330 and 1430 hrs LT as a function of DAS has been discussed. The paper also presents the results of radiant temperatures variability between the soybean canopy and the soil as a function of DAS.