RESERACH ON TECHNICAL METHODS OF FERTILIZER AND PLANTING DENSITY ON THE GROWTH, YIELD AND ECONOMIC EFICIENCY IN THE PRODUCTION OF GREEN KERNEL BLACK BEAN (Vigna unguiculata subsp. Cylindrica (L.) verdc)

Abstract

Two technical methods including fertilizer rate and planting density were studied to determine the best integration of these two methods to the growth, yield and economic efficiency in the green kernel black bean production. The experiment consisted of two factors, 5 doses of organic fertilizer: 0 (control), 4, 8, 12, 16 tons/ha on foundation 30 kg N + 40 kg P₂O₅ + 40 kg K₂O/ha + 300 kg lime powder and 3 planting densities of 16, 12 and 8 plants/m², was arranged in a split-plot, with three replicates on the red-brown soil. The research targets were implemented in accordance with the collection of questionnaires, description and evaluation of the Center for Plant Resources. The results showed that two technical methods of fertilizer and planting density effected the growth, yield and economic efficiency of the green kernel black bean. The highest yield and economic efficiency were at the organic fertilizer application rate of 4 tons/ha and a planting density of 16 plants/m² (treatment P1M1). This the treatment, the actual yield is 15,17 quintals/ha/crop, the profit is 28,075,000 VND/ha/crop and the VCR is 12.12. From the research results, it is recommended to use an organic fertilizer rate of 4 tons/ha and a planting density of 16 plants/m² for green kernel black bean on red-brown soil in the summer - autumn crop in Quang Tri province.