Development of precision farming calls urgently for remote sensing techniques capable of providing timely accu rate ground information.Estimation of soil moisture from reflectance measurements in the solar spectral domain (400~2 500 nm) was investigated.For this purpose,18 soils representing a large range of permanent characteristics were gathered for the test.Reflectance data were measured in the laboratory during the soil drying process with a high spectral resolution spectroradiometer.Five approaches were compared.The first one was based on single-band reflectance and on calibration of the reflectance data by the reflectance of the corresponding soil under dry conditions,the second and the third approaches on either reflectance deriva tives or absorbance derivatives and the fourth and fifth approaches on differences between reflectance and absorbance observed in two non consecutive bands.In the first step,the relationships were calibrated over half the dataset (nine soils) with emphasis on selection of the most pertinent spectral bands.Results showed that,for the first approach,the bands corresponding to the highest water absorption ca pacities (1 944 nm) yielded the best soil moisture retrieval performance.For the second and third approaches,the bands corre sponding to sharp edges of the water absorption features performed better (1 834 nm for the reflectance derivatives and 1 622 nm for the absorbance derivatives).The fourth and fifth approaches could be considered as a generalization of the derivative approach when bands were no longer consecutive.The best performance was achieved when the bands were not too far apart.The best overall retrieval performances were achieved with the absorbance derivatives and the absorbance difference,confirming the non linear character of the relationship between soil moisture and reflectance.