Response of Potato (Solanum tuberosum L.) Varieties to Different Levels of Nitrogen under Agroclimatic Conditions of Meghalaya

Nitrogen (N) is a very dynamic yield-limiting plant nutrient and excessive N fertilization beyond crops demand has led to soil acidification and major environmental issues. Nitrogen use efficiency of potato cultivars is vary widely and Nitrogen use efficiency was found to be very low for some cultivars. We investigated the response of potato varieties (Kufri Girdhari and Kufri Himalini) to different levels of nitrogen (0, 70, 140,1 75 kg N ha⁻¹) under Meghalaya conditions. The results of the two-year experiment indicated that total tuber yield was significantlyinfluenced by both potato variety and N fertilizer treatment. Compared to Kufri Girdhari, Kufri Himalini recorded 26 percent higher tuber yield than its counterparts. Regardless of variety, the application of 175 kg N ha⁻¹ with RDP and RDK resulted in the highest total potato tuber yield (21.84 t ha⁻¹). The agronomic nitrogen use efficiency decreased linearly as N doses increased. Kufri Himalini was more responsive to nitrogen fertilizer than Kufri Girdhari as it recorded higher Nitrogen use efficiency and Partial factor productivity in all nitrogen levels. Being more responsive to fertilizer nitrogen, Kufri Himalini is cultivated with 175 kg N ha⁻¹ to produce the highest net return.