Nutrient Use Efficiency in Yacon Potato Under Varying NPK Fertilization Rates

This study aimed to determine the nutrient use efficiency of the yacon potato under NPK fertilization at different rates. The experiment followed a randomized block design with four replications and a split-plot arrangement. The main plots consisted of three fertilization levels (60%, 100%, and 140% of the reference dose—50:80:60 kg ha−1 of NPK), with subplots to data collection intervals, performed every 30 days, for a total of 7 collections, generating 21 treatments. The dry biomass of whole plants and tuberous roots was determined. Samples were taken to determine the content of N, P, K, Ca, Mg, Cu, Fe, Mn, and Zn. The biological utilization coefficient (BUC) was calculated by dividing the mean values of dry biomass in kilograms of plant parts by the kilogram of nutrient found in that biomass. The application of 100% of the reference dose led to the highest use efficiency of P, K, Ca, and Mg, and intermediate efficiency for N in yacon tuberous roots and total biomass production throughout the cycle, provides a significant contribution to fertilization planning for this crop. The amount applied which was 100% of the reference dose was 17, 80, and 20 kg ha−1 of N, P2O5, and K2O, respectively, at planting, supplemented with 33 and 40 kg ha−1 of N and K2O as topdressing.