Fertilizer Recommendation: Correlation and Calibration Study of Soil P Test for Yard Long Bean (Vigna unguilata L) on Ultisols in Nanggung-Bogor

Proper fertilization of a crop is knowing the crop nutrient requirement for production of maximum yield and the potential level of nutrient availability from the soil. In addition to yield obtained, quality of the commodity is an important factor of profit and shelf-life for high-value crops. Nitrogen, phosphorous, and potassium availability are the most limiting factors for maximum growth and yield. Yard Long Bean (Vigna unguilata L.) were grown to evaluate optimum rate of N, P, and K fertilizer in Ultisol Jasinga soil with low pH (5.5), low C-Organic (1.54%), very low N-total (0.12 %), low K content (0.29 me/100 g), but very high soil P2O5 concentration (19.2 ppm) to evaluate the best crop management practices with starter solution.