INFLUENCE OF HUMIC ACID AND NITROGEN ON GROWTH, YIELD AND ECONOMIC RETURN OF ONION

Abstract

A field experiment was conducted at Horticulture Farm of Sher-e-Bangla Agricultural University, Dhaka from September 2021 to January 2022 to find out the effect of different level of nitrogen and humic acid on growth, yield and economic return of onion. BARI Piaz-5 was used as test crop material. Three different doses of nitrogen viz., N 0 = 0 kg/ha, N 1 = 80 kg/ha, N 2 = 100 kg/ha and four different doses of humic acid; H 0 = 0 kg/ha, H 1 = 12 kg/ha, H 2 = 14kg/ha, H 3 =16 kg/ha were used to conduct this experiment in a two-factor Randomized Complete Block Design (RCBD) with three replications. Data on growth and yield parameters were gathered and experimental results revealed that different levels of nitrogen and humic acid significantly influenced the growth, yield and economic return of onion. From results it was found that the highest marketable bulb yield (14.60 t/ha) was obtained from N 2 (100 kg/ha nitrogen) treatment while the lowest marketable bulb yield (11.99 t/ha) was obtained from N 0 (0 kg/ha nitrogen). The highest marketable bulb yield (16.82 t/ha) was obtained from H 2

(14 kg/ha humic acid) treatment while the lowest marketable bulb yield (11.81 t/ha) was obtained from H 0 (0 kg/ha humic acid). The highest marketable bulb yield (17.91 t/ha) with the highest Benefit cost ratio (BCR) of 3.11 from N 2 H 2 (100 kg/ha Nitrogen; 14 kg/ha humic acid) treatment combination whereas the lowest marketable bulb yield (9.82 t/ha) with the lowest benefit cost ratio (BCR) of 1.75 from N 0 (0 kg/ha Nitrogen; 0 kg/ha humic acid) treatment combination. From economic point of view, it was apparent from the above results that the combination of N 2 H 2 (100 kg/ha Nitrogen; 14 kg/ha humic acid) treatment was more economically profitable. So, the cultivation of onion with N 2 H 2 (100 kg/ha Nitrogen; 14 kg/ha humic acid) treatment combination was the most suitable treatment combination which promoted the plant growth, yield and economic return.