Modelling Soil Water Dynamics

The International Society of Precision Agriculture defined precision agriculture as follows: ‘Precision Agriculture is a management strategy that gathers, processes and analyzes temporal, spatial and individual data and combines it with other information to support management decisions according to estimated variability for improved resource use efficiency, productivity, quality, profitability and sustainability of agricultural production’ ( www.ispag.org ). Bouma (2007; https://doi.org/10.1002/9780470515419.ch2 ) stated more concisely that precision agriculture aims at adjusting and fine-tuning land and crop management to the needs of plants within heterogeneous fields. Besides a reactive approach, using yield maps and sensors, Bouma (2007) also promotes the proactive approach in which simulation models for plant growth and soil processes can be used to predict optimal timing of management practices. The attention required for crop modelling is evident, as high yields of good quality mean a good profit for the farmers. This profit can be increased if the use of resources, such as fertilizers, land management practices and irrigation water, is minimized. Minimizing the use of resources means that we are at the cutting edge. For example, we are balancing between adding too much or too little water and fertilizers. This requires good knowledge on the interaction of soil–water–plant–atmosphere processes. Crop modelling is discussed in chapter “ Process Based Modelling of Soil–Crop Interactions for Site Specific Decision Support in Crop Management ” of this book, and here we will focus on modelling the dynamics of water in soils. Modelling nutrient dynamics in soils is discussed in chapter “ Process-Based Models and Simulation of Nitrogen Dynamics ” of this book.