The study looked at how different levels of nitrogen and potassium affect the soil nutrient status for growing fennel seeds. They tested various combinations of nitrogen and potassium levels in the soil and found that using 120 kg of nitrogen per hectare along with 60 kg of potassium per hectare resulted in the best soil nutrient status for fennel seed production. This combination led to the highest levels of available nitrogen, phosphorus, and potassium in the soil, as well as increased nitrogen and potassium uptake by the fennel plants.