Mr. Yechezkel Harroch

As for today, we know citrus trees’ seasonal mineral requirements and can correct fertilization annually by leaf analyses. Yet, precise fertilization relies on matching fertilization to frequent phenological shifts in citrus trees’ nutrient uptake. Hence, we set to monitor trees’ daily water and nutrient uptake. We needed a large apparatus that could support numerous trees for multiple years. Therefore, instead of traditional lysimeters, we designed a serial drainage collector that sequentially measures the mass, EC, and pH of 75 citrus trees by a single combination of a vacuum pump, load cell, and chemical electrodes.  The serial lysimeter enabled us to investigate the effects of variable nitrogen, phosphorus, potassium, and fruit loads on citrus trees’ performances and to optimize irrigation and fertilization for field conditions.