AN ANALYSIS OF NATIONAL-STATE-DISTRICT LEVEL ACREAGE AND PRODUCTION ESTIMATES OF RABI SORGHUM UNDER FASAL PROJECT
Sorghum (Sorghum vulgare Pers.) popularly known as jowar is the most important food and fodder crop of dry land agriculture. It is generally grown in both Kharif and Rabi season, with sown area of 25.3 and 38.3 lakh ha, respectively, at National level. The major states contributing to national sorghum acreage are Karnataka and Maharashtra. Crop acreage and yield estimation is of great significance to develop food policies and economic plans for a country. In this regard, under FASAL project, Sorghum production estimation is being carried out since 2013-14. Data from December to January is used for classification considering the peak season of crop. The satellite data used for classification has been gradually changed from Resourcesat 2 LISS III/ Landsat 8 OLI to Sentinel 2. Ground Truth has played major role to support the classification methodology. Total 1,409 GT points have been collected so far for both the states, with the help of state agriculture departments. NDVI based Crop Cutting Experiment (CCE) points are also generated and given to State for conducting the experiments at ground level. District level Sorghum crop yield is estimated using two procedures - i) Agro-meteorological regression models, ii) Remote sensing index based empirical models. The state and district level estimates were compared with government estimates. At state level the RMSE was found ranging from 6.5% to 34.7% and correlation (r) was found ranging from 071 to 0.87. At district level, the correlation between FASAL project estimates and government estimates ranged between 0.80 to 0.95. Overall, the paper discusses, the experience gained from the Rabi sorghum production estimation, in last 5 years, under FASAL project and the scope of improvement.