Inspite of soil mapping being carried out by using satellite data for over last two decades several problems are encountered in delineation of sandy, saline, gypsiferous and gravelly soils because of similarity in their image characteristics. Intensive ground truth is required for mapping these soils. Therefore, present study has been carried out to determine the spectral reflectance characteristics of sandy soils with varying intensity of wind erosion and for associated gypsiferous soils. The study has been carried out in Bhikampur-Nachna area of Jaisalmer district where the area is highly dune complex with sandy soils and gypsum bearing inter dunes. The Hindivac Spectro Radiometer 101 was used for recording the spectral reflectance of soil in the field. The spectral reflectance characteristics of sandy soils showed range between 17.5 to 25 % with a mean value of 21.4% at wave length 450 nm. Between wave length range of 800 to l000 nm the reflectance was not in increasing trend.. Waterlogged soils have low reflectance than the normal sandy soils.

The present study was carried out to analyze the growth and instability in area, production and productivity of sesamum and acreage response to sesamum crop in arid zone of Rajasthan. The study was confined to six districts of arid zone having more than 10,000 ha area under sesamum cultivation during last decade. The data were collected for the period 1960-2003 and analyzed by using exponential production function and instability index. The results revealed that area and production have increased in the arid zone of Rajasthan but with high instability. The productivity registered lower but relatively more stable growth compared to area under production. The allocation of area to sesamum crop guided by rainfall during crop growing season, yield lagged by one year and also have positive response to lagged price in Bikaner and Jodhpur districts only.

The present study was carried out to analyze the growth and instability in area, production and productivity of chilli and acreage response to chilli crop in arid zone of Rajasthan. The study was confined to five districts of arid zone having more than 500 ha area under chilli cultivation during last decade. The data were collected for the period 1960-2007 and analyzed by using exponential production function and instability index. The results revealed that area and production have increased in the arid zone of Rajasthan but with high instability. The productivity registered lower but relatively more stable growth compared to area and production which indicates that chilli production can be increased by stabilizing and sustained increase in area under chilli cultivation by efficient use of irrigation water. The farmers of the arid zone of Rajasthan tend to divert more area towards cash crop if current irrigation facilities are adequate.