The Effect of Natural Biochar Application on Nitrogen Fertilizer Productivity in Spinach

Current research was carried out as a pot experiment in order to investigate the effect of different biochar levels (zero (Bi0), one (Bi1) and two (Bi2) percent of soil mass) and nitrogen fertilizer (from the urea source) (zero (F0), 150 (F150) and 300 (F300) kg/ha) on spinach (cv. Viroflay) yield and fertilizer productivity. The experiment was done from September 2021 to January 2022 as a factorial experiment based on randomized complete blocks design with four replications in the research greenhouse of agricultural faculty of Zanjan University. Fertilizing was done as fertigation in three splits with an interval of 10 days. Results showed, using one and two percent biochar were significantly increased means of leaf chlorophyll index 15% and 34% (respectively) and leaf area 14% and 34% (respectively) compared to the control treatment. In F150 and F300 treatments compared to F0, means of leaf chlorophyll index increased 64% and 110% (respectively) and leaf area increased 30% and 58% (respectively). Based on the results of interaction effects, maximum mean of petiole length, fresh and dry mass of plant and fertilizer productivity were achieved in Bi2-F300 treatment (respectively 6.1 cm, 10.1 gr and 24.0 kg/kg). Based on the research results, biochar application in soil is suggested to increase fertilizer productivity which reduces the harmful effects of using chemical fertilizers on the environment.