数字化作物的 Crop modelling approach according to 建模方法来自 De Wit 的论文。

模型成立的条件是：System is a simplified description of reality: a homogeneous crop field, with defined thematic  boundaries, internal characteristics and external driving variables 系统是对现实的一个简化：假定它是一个均质的农田，具有明确的边界、内部特征和外部驱动变量

它是一个动态的过程 Dynamic: Rates of change per unit time as opposed to static. Integration over time 相对于静态单位时间的变化率。随着时间的推移不断地集成。

整个模型是由结构性 Hierarchical 分级模块组成。

1. Within a system: Cells – organs – plants- crop 系统的模块包括：细胞-器官-植物-作物。

2. Sequence in system complexity defined by a succession of theoretical production situations: potential, water-  limited, nutrient-limited, 顺序地实现系列理论生产情况定义的系统复杂性：潜在生产力、水分限制、营养限制。

3. State-variable based: Starting from gives initial state, each state is updated each time step, where  State = previous state + rate of change. Most basic crop states are expressed in dry weight of living  biomass and crop development stage (crop age) 基于状态变量的表示方式：从给定初始状态开始，每个状态在每个时间步长都会更新，其中：状态=先前状态+变化率。大多数基本作物状态以生物量干重和作物发育阶段（作物生长期时间长度 ）表示。

4. Explanatory: explicit quantitative description of bio-physicaL processes leading to change in system  state, by means of mathematical equations 原理解释定量化：通过数学方程对导致系统状态变化的生物物理过程进行明确的定量描述。

5. Deterministic: a given crop responds according to the rules, defined in the model (apparent absence  of uncertainty) 确定性规则：给定作物根据模型中定义的规则做出生理反应（明显不存在不确定性）。

6. Differences in crop growth processes between crops are due to  different model parameter values. 作物之间作物生长过程的差异是由于不同的模型参数值造成的。

7. A cereal crop is the basic reference for an annual field crop in the crop  model. 禾谷类作物是由一年生的大田作物的基础模型作为参考的模型。

8. Root crops, legumes, vegetables and grasses are forced into the  basic cereal model. 根茎作物、豆类、蔬菜和禾草被强制纳入基本谷物模式。