| The EM38 conductivity gauge can be applied to observe soil salt content in the fields rapidly and easily. With the increase of its distance above the ground, the electromagnatism induction sensitivity of the gauge is reduced. The EMv and EMh values measured by EM38 are related more greatly to the salt contents in 515 cm and 1525 cm soil layer than to those in 05 cm soil layer. Using the EMh at the height of 20 cm and the EMv at the height of 100 cm, the measurement models of salt content are established, which can be used to survey the salt content in the plough layer. In order to raise the accuracy of the EM38 gauge, all environmental factors except for salt should be kept relatively consistent. |