The Influence of Fertilizer Application of N, P, K, Mg, and Planting Spacing on Soil Chemical Properties and Production of Long Bean (Vigna sinensis L.).

Abstract

This study aims to examine the effect of fertilizer doses of N, P, K, Mg based on production targets and determination of plant spacing on the chemical properties of Ultisol soil and the production of long beans (Vigna sinensis L.). This research was conducted on a plantation area with Ultisol soil type located in Gang Bulang, Simalingkar B, Medan Tuntungan District. Soil and plant analysis were carried out at the Research and Technology Laboratory, Faculty of Agriculture, the University of North Sumatra, and PT Socfin Indonesia Laboratory, North Sumatra. The research was conducted from September 2021 to March 2022. This research design used a Factorial Completely Randomized Design (CRD) consisting of 2 factors, namely the administration of fertilizer doses based on the production target consisting of P0 = 0 tons/ha (Control); P1 = 10 tons/ha; P2 = 20 tons/ha; P3 = 30 tons/ha, and the plant spacing factor consisting of T1 (30 cm x 40 cm); T2 (40 cm x 40 cm) and T3 (50 cm x 40 cm). Each treatment was repeated 3 times. Parameters observed included parameters of soil chemical properties (pH, CEC, N, P, K, Mg) and plant parameters (pod weight and pod length).

The results showed that the dose of fertilizer based on the production target affected soil H₂O pH, N-total, soil Mg-dd, and plant pod weight. The interaction between fertilizer application based on production targets and plant spacing affected the Mg-dd value of the soil, pod length, and pod weight. Treatment of fertilizer application was according to the production target of 10 tons/ha (Urea 351.6g/plot; SP36 146.3g/plot; KCl 235.1g/plot; Dolomite 166.7g/plot) and spacing of 30 cm x 40 cm showed the best results in long bean cultivation.