DETECTING THE EFFECT OF IRRIGATION WATER QUALITIES ON THE HETEROGENEITY OF CLOVER BIOMASS USING GEOGRAPHIC INFORMATION SYSTEMS (GIS) AND PASSIVE REFLECTANCE SENSOR

Heterogeneous biomasses stands of cultivars require maximize the efficiency of crop inputs within small areas of the farm field. However, its determination via classical measurements to cover full area of site is tedious and time-consuming. The precision agriculture technologies based on the passive reflectance sensor and GIS tools have the potential for fast and non-destructive measurements for different parameters. In the present study, the performance of GIS maps based on two spectral reflectance indices (R780/R740 and R780/R700) for assessing the heterogeneity in vegetation Clover biomass under fresh, drainage and mixed water was tested. The results showed that there were significant variations in spectral index (R780/R740) values, spectral index (R780/R700) values and Clover biomass weights under fresh water, drainage water and mixed water. There were a more pronounced strong negative relationships between spectral index (R780/R740) and Clover biomass and the coefficients of determination varied between (0.92*** to 0.93***) under three water qualities. As well as there were a more pronounced strong positive relationships between spectral index (R780/R700) and Clover biomass and the coefficients of determination varied between (0.88** to 0.96**) under three water qualities. In conclusion, the GIS maps based on two spectral reflectance indices (R780/R740 and R780/R700) were useful to describe the heterogeneity in vegetation Clover biomass under three water qualities.