Investigating the performance and physiological characteristics of wheat cultivars under the influence of nitrapyrin application in different tillage conditions

The use of nitrification inhibitor nitrapyrin is vital for the long-term maintenance of urea fertilizer in the soil and preventing its leaching. Therefore, this study was carried out to investigate the yield and physiological characteristics of different wheat cultivars under different levels of fertilization and tillage systems. This study was performed as a split-split plot based on a randomized complete block design with three replicates in Karaj during two cropping seasons (2019-21). The experimental treatments included two tillage levels (no-tillage and conventional tillage) in the main plot and three fertilizer levels (urea, nitrapyrin + urea combination and control (main plot), and two cultivars (Rokshan and Pishgam) in the secondary plot. The results of the composite analysis showed that the highest yield of wheat grain was obtained in Rakhshan cultivar with 8331 kg/ha and the level of urea + nitrapyrin fertilizer was obtained in no-tillage, which was 6.15% superior to the level of urea. Also, in both tillage systems, the highest amount of leaf area index and nitrogen productivity index was obtained in the same treatment, so compared to the treatment of urea application, 6.1%, 2.7% in no-tillage and 0.8% and 1.3% in Cultivation was more common. In general, nitrapyrin improved wheat yield in both tillage levels. In addition to improving plant performance, the use of nitrapyrin can also be effective in reducing environmental hazards caused by the use of chemical fertilizers such as urea.