Reconstruction of Crop Development Model with Its Simulation Test Based on Sugarcane

Crop growth model describes the development and growth process of crop. Development process is the physiological age of crops, which is related to the morphological changes of crops, and is a landmark stage of crop growth to achieve qualitative change. Development process is the time indicator of crop growth model. Reasonable description of the crop development process is the premise of high accuracy of crop growth model. At present, although different crop development models have been developed and widely used in crop growth models, their simulation ability can hardly meet the needs of crop growth simulation. These models only focus on the impact of meteorological conditions in a certain period (day), but do not particularly consider the period of crop development, which may be an important factor for the low accuracy of model simulation.It is assumed that the development rate of a crop on a certain day is not only related to the meteorological conditions of that day, but also related to its development stage. The development stage of crop is represented by the date, so that the temperature-day (TAd) and development unit-day (CHUd) models are constructed. In addition, according to the principle of heat unit corrected by temperature model (THUa), the development unit corrected by temperature model (CHUa) is constructed. Based on the principle of response-adaptation of temperature model (RAM), the response-adaptation of development unit model (CHUr) is established.The adaptability of the development model for sugarcane is analyzed by using the field data of 30 agrometeorological stations in China from 1980 to 2019, and the advantages and disadvantages between the traditional development model and the reconstructed model are compared. The results show that CHUd and TAd model have better adaptability to simulate the development process of sugarcane, especially in the later stage of the development process when the temperature is decreasing. Compared with the original model (CHU), the adaptive ability of CHUa model for sugarcane decreases from seedling emergence to stem elongation but increases from stem elongation to maturity. The theoretical description of CHUr model is not tenable. Sorted by simulation ability, the order of development models is as follows: CHUd, TAd, RAM, CHU, CHUa and the heat unit (THU) model, and their simulation ability values (SCV) calculated by root mean square difference are 4.3, 3.9, 3.7, 3.3, 3.0 and 2.8, respectively.The reconstruction of the development model will further improve the CAMM and promote the development of crop growth simulation theory.