Pengaruh Dosis Pupuk NPK dan Pupuk Kandang Sapi terhadap Pertumbuhan dan Produksi Tamanan Kacang Merah (Phaseolus vulgaris L.)

Ultisol has low pH value, nutrient content and organic matter content, high level of dissolved Al and Fe, and high soil density and low water holding capacity that limited the production of plants grown on it. To study the effect of NPK fertilizer and cow manure dosages and their interactions on the growth and production of red beans (Phaseolus vulgaris L.) on Simalingkar Ultisol, a research was carried out from February to April 2024 in Kota Medan. The research used a Factorial Randomized Block Design consisting of two factors, namely: NPK fertilizer dosage consisting of four levels, namely N0 = 0 g/plot equivalent to 0 kg/ha (control), N1 = 30 g/plot equivalent to 200 kg/ha, N2 = 60 g/plot equivalent to 400 kg/ha (recommended dose), and N3 = 90 g/plot equivalent to 600 kg/ha, and cow manure dosage consisting of four levels, namely S0 = 0 kg/plot equivalent to 0 ton/ha (control), S1 = 1.5 kg/plot equivalent to 10 tons/ha, S2 = 3 kg/plot equivalent to 20 tons/ha (recommended dose), and S3 = 4.5 kg/plot equivalent to 30 tons/ha. The research used three replications. The variables observed were: plant height, stem diameter, number of pods per plant, and dry seed production per hectare. The results showed that the dosage of NPK fertilizer, the dosage of cow manure and the interaction between the two of them had no significant effect on all variables.