Use of Remote Sensing to Monitor Crop Residue Coverage and Tillage Intensity

Satellite imagery was used as a rapid and spatially explicit method to delineate crop residue cover and to estimate the use and intensity of conservation tillage. The potential of multispectral high spatial resolution of WorldView-2 local data was evaluated using 11 satellite spectral indices and linear spectral unmixing analysis (LSUA). Experimental plots were examined; residue cover was measured at each location using the line transect method and recorded as ground control. The output of the indices and LSUA were individually correlated to the control and R2 was calculated. Results indicate that crop residue cover was related to IPVI, RVI1 and GNDVI spectral indices and satisfactory correlations were established (.084 - 0.85). The crop residue cover estimated using LSUA correlated with the ground residue data (0.76). The infrared percentage vegetation index (IPVI) and ratio vegetation index (RVI) had maximum R2 values and were considered appropriate for classification of tillage intensity. Classification accuracy of the IPVI and RVI indices under different conditions varied from 83% to 100%, indicating they were in good agreement with ground measurement, observations and field records.