Response of potatoes to fertilizer application and nutrient use efficiency in Bulgaria

I. Manolov, N. Shaban, S. Bistrichanov, M. Nikolova, B. Stalev, A. Yordanov
In the frame of an extensive research project entitled “Best agricultural practices for sustainable crop nutrition in Bulgaria”, supported by the International Plant Nutrition Institute (IPNI), the response of potatoes to nutrient fertilization was studied. The potato trials were carried out at the two most suitable locations for potato cultivation, Smolyan and Merdanya. The experiment was designed on the base of reduction plots (control, N, P, K, NP, NK, PK, NPK, NPKMg). The paper presents the effect of fertilization on potato yield by nutrient reduction (N, P, and K) and their combinations. Nutrient use efficiency (NUE), and partial factor productivity (PFP) and agronomic efficiency (AE) were calculated. On both sites, the primary limiting nutrient was nitrogen, followed by potassium. The NUE indicators outline significant specificity of the trials sites - while the PFP was almost equal, the AE for both locations show differences for the three nutrients. AE at Merdanya was lower than in Smolyan. High AE for magnesium was obtained in Smolyan because of low exchangeable Mg content. The nutrient reduction effects also differ on the two locations. In Smolyan, the highest reduction effect was nitrogen - almost 50%. In Merdanya, nitrogen and potassium had a more significant reduction effect than in Smolyan, 60 and 38%, respectively. However, phosphorus reduction did not influence the yield significantly. Thus, fertilizer recommendations for potatoes should be location-specific.
Manolov, I., Shaban, N., Bistrichanov, S., Nikolova, M., Stalev, B. and Yordanov, A. (2021). Response of potatoes to fertilizer application and nutrient use efficiency in Bulgaria. Acta Hortic. 1326, 153-158
DOI: 10.17660/ActaHortic.2021.1326.20
effects of nutrients, NUE, partial factor productivity, agronomic efficiency

Acta Horticulturae