Background: Under intensive fertilization systems such as soilless cultures, a surplus nutrient supply could result in the excessive discharge of fertilizers. However, very few studies have developed nitrate absorption indicators for plants that can be used for decision-making under these systems. This study was conducted to develop indicators related to the absorption of nitrate that can be applied in online systems utilizing the monitored irrigation and drainage amount data, electrical conductivity (EC), and the nutrient analysis data of irrigation and drainage.
Results: In the simulation, a stochastic change was generated for the nutrient absorption rate. The theoretical prediction was verified by the cultivation experiment and a higher correlation of tomato yield with the nitrate absorption indicator was confirmed than with the nitrate supply amount.
Conclusions: The results of the simulation and cultivation experiments showed that the indicators related to nitrate absorption provide useful information regarding decision-making for efficient resource management through online monitoring.