Effect of Nano-chelate Nitrogen and Urea Fertilizers on Nitrate Leaching and Its Distribution in Soil Profile and Potato Plant

Excessive use of chemical fertilizers causes soil, surface water and groundwater pollution. The purpose of the present investigation was to study nano-chelate nitrogen effect on nitrate concentration variations in soil, water and potato tuber (Solanum tuberosum L.) in comparison to the urea fertilizer. A factorial experiment in CRD with 3 replications and factors of urea fertilizer and nano-chelate nitrogen was conducted. In each factor three levels of 46, 92 and 138 kg N/ ha were used. The results showed that the highest soil nitrate (100.5 mg/kg soil) and the highest nitrate leaching concentration (629.2 mg/L) belonged to the third level of the urea treatment. The results of the yield measurements showed that with increase of the urea fertilizer from the first level (46 kg N/ha) to the third level (46 kg N/ha), the yield decreased 2.6%, while similar increasing in the amount of nano-chelate nitrogen fertilizer, increased the yield by 20.7%. Furthermore, the difference between the average tuber yields in the urea treatment (42.8 t/ha) and nano- chelate nitrogen treatment (73.3 t/ha) was significant at 5% probability level. The results showed that the leaf nitrogen in the nano- chelate nitrogen treatment was significantly more than that in the urea treatment. The results of the accumulated nitrogen measurement in the tubers as one of the quality indicators showed that the tuber nitrate concentration in the nano-chelate nitrogen treatment was 121.2 mg/kg and in the urea treatment was 154.2 mg/kg. Therefore, according to the results of this experiment, the use of 138 kg N/ha nano-chelate nitrogen in order to achieve the highest yield, noting the lower nitrate accumulation in potato tubers (Agria cv.) in greenhouse conditions, can be recommended.