Applicability of Conventionally Recommended Fertilizer Rates for Potato Cultivated in Saemangeum Reclaimed Land in the Fall Season

Abstract

It is important to increase the area of potato cultivation in the fall season for a stable year-round supply system in Korea. Saemangeum reclaimed land has the potential to extension of potato cultivation area with appropriate practices. This study was performed to test applicability of fertilizer recommendation in southern coastal area to the Saemangeum area. Two experiments were conducted: one experiment compared the yield response of potato between standard rates of N-P-K (SR) and recommendation rates of N-P-K based on soil test (STR) and the other experiment analyzed yield response to 4 different levels of N, P, K, respectively. The potato yield in SR was 6.05 Mg ha-1 on average and varied from 1.68 Mg ha-1 to 11.80 Mg ha-1. The potato yield in STR, meanwhile, ranged from 8.13 Mg ha-1 to 12.17 Mg ha-1 with a mean value of 9.65 Mg ha-1. Potato yield was increased linearly with N fertilization rates but P and K fertilization did not have any significant effect on potato growth. The N fertilization rate (NFR) and the soil available phosphate content (Av. P2O5) had significant positive corelation with potato yield (p < 0.01). Based on stepwise multiple regression analysis, partial regression coefficient was 0.30 for NFR and 0.08 for Av. P2O5; Y = 19.6 X1 + 34.9 X2 + 1,410, where Y, X1, and X2 mean potato yield, NFR, and Av. P2O5, respectively. Conclusively, STR was strongly recommended for potato in the Saemangeum reclaimed land and the conventional standard fertilization rate was hardly applicable to the area, especially for nitrogen. Potato product by fertilization rates in the fall season. The standard rates were 120, 106, and 156 kg ha-1 for N, P2O5, and K2O. The other two were provided as the standard rates.