Qingsong Jiang ^1* Yang Gao ² Lin Chang ¹ Mei Zeng ¹ Quanze Hu ¹ JiaoJiao Hui ¹

• ¹ College of Information Engineering, Tarim University, Alar, China
• ² Tarim University, Aral, Xinjiang Uyghur Region, China

Soil salinization seriously affects the efficiency of crops in absorbing soil nutrients, and the cotton production in southern Xinjiang accounts for more than 60% of China's total. Therefore, it is crucial to monitor the dynamic changes in the salinity of the soil profile in cotton fields in southern Xinjiang, understand the status of soil salinization, and implement effective prevention and control measures. The drip-irrigated cotton fields in Alaer Reclamation Area were taken as the research objects. The multivariate linear regression model was used to study the relationship between soil salinity and soil depth in different periods, and the Kalman filter algorithm was used to improve the model accuracy. The results showed that the month with the highest improvement in model accuracy was July, with the model accuracy R 2 increasing by 0.26 before and after calibration; followed by June and October, with the model accuracy R 2 increasing by 0.19 and 0.18 respectively; the lowest improvement was in March, which was only 0.01. The accumulation of soil salt in cotton fields showed a sawtooth fluctuation trend in all periods, and showed an obvious accumulation trend in units of 40-100 cm soil depth. After the model was calibrated by the Kalman filter algorithm, the fitting accuracy (R 2 ) between the predicted value and the actual value was as high as 0.79, and the corresponding RMSE was only 96.17 S cm -1 , and the measured value of soil salinity was consistent with the predicted value. Combined with the predicted conductivity data of each soil layer, the total yield of the study area was predicted to be 5,203-5,551 kg hm -2 , and the income was about 4,953-7,441 RMB hm -2 . Conclusion: Kalman filtering can significantly improve the prediction accuracy of the model. The results of this study can provide a theoretical basis for the study of soil salt migration mechanism in different periods of drip irrigation cotton fields, evaluate the potential relationship between cotton yield and deep soil salinity, and have important significance for guiding the efficient prevention and control of saline soil in cotton fields.