Abstract: Grain security is a key issue having been concerned with all over the world. To understand the crop growth status in other countries and regions timely and accurately is of significance for China’s grain trade and grain macro-control. In this paper, a case study was made on the corn and winter wheat production in  USA. Based on the analysis of the spatial distribution and growth periods of the crops, the information of non-cultivated land was eliminated from land-use and land-cover data, making the extracted NDVI could objectively reflect the growth status of the crops. After analyzing the relations between actual crop yields and ten--day-composite NDVI in 1998-2007 based on the data from SPOT VEGETATION, the variables of dynamic yield estimation models for the cropsweredetermined, and the models were established. The comparison of the crop yields estimated by the models and the actual crop yields showed that the relative errors of estimated yields were mostly within 3%, illustrating that the established dynamic crop yield estimation models had a high accuracy, being feasible and practicable.

Key words: Soil salt, Water content, Taxodium distichum