cFertigUAL: A fertigation management app for greenhouse vegetable crops

The fertigation process is the most common method employed to supply water and nutrients to soil or soilless cultures in greenhouses in Almería. The main objective of this work is to develop a mobile application (app), using Android Studio software, that helps to calculate the amounts of fertilizers and irrigation to be supplied to the most important crop types as well as to choose between the different crop growing systems and the variety of fertigation technologies. The use of this mobile app will allow agricultural engineers, farmers and students to better use the existing resources thus ensuring the appropriate application of water and nutrients. The development of this platform has been divided into two parts: (1) Determining the amount of water lost by transpiration by means of virtual sensors that monitor the external greenhouse conditions - this estimates the energy cost and establishes the irrigation requirements, and (2) Determining the fertilizers that need to be applied per liter of water in the fertigation tanks (kg/l). Once the system configuration data have been obtained, the app operates automatically using certain optimization algorithms to provide a final solution, in which the estimated equilibrium meets the crop's nutrient requirements. In addition, it is possible to operate the app manually following the instructions so as to achieve better fertigation management control and, in many cases, to learn about the fertilizer calculations as a function of the system profile. This platform provides the supply loads of the various fertilizers as well as the electrical conductivity and pH, the possible presence of precipitation in the final solution, and a drainage or soil analysis to help optimize the nutrient strategy. As a result, the developed application will work both as a learning system and as a decision-making tool for fertigation systems, making it easier to access the methodology used to determine the optimal fertigation parameters within any crop system.