The study looked at how using manure and chemical fertilizer affects potato growth and nitrate levels in Isfahan, Iran. They tested different amounts of manure and urea on potato plants in two regions. Increasing the amount of urea fertilizer generally led to higher potato yields and nitrate levels in the tubers. The best results were seen with 60 tons of manure and 525 kg of urea per hectare in the Faridan region. Using manure along with chemical fertilizer not only boosts potato yield but also helps protect the soil.