On-farm verification of dolomite lime and soil test based fertilizer on tuber yield of potato (solanum tuberosum) in acidic soils under surma‐kushiyara floodplain of Bangladesh

On-farm verification trial was conducted with lime and soil test based fertilizer application for improving the yield of potato in acidic soils under the Surma‐Kushiyara Floodplain soil of Bangladesh. The trials were laid out in a factorial randomized complete block design with six dispersed replications. The treatments were, M1: soil test based (STB) recommended fertilizer and M2: farmers practice (FP) and dolomite levels (L0: 0 t ha-1, L1: 1 t ha-1 and L2: 2 t ha-1). The result showed that average yield of tuber (24.04t ha-1) was higher in STB fertilizer (M1). Lime application gave significantly superior tuber yields of potato in all three years. The average tuber yield of potato increased in treatments L1 and L2 by 6.73 and 19.75%, respectively over non- lime control. The STB fertilizer dose (N151 P29 K116 S14 Zn1 kg ha-1) along with 2 t ha-1 of dolomite (M1L2) performed better and produced the highest average tuber yield (25.46 t ha-1) of potato. Economic analysis revealed that maximum gross return (Tk. 305520 ha-1) and gross margin (Tk.170852 ha-1) was obtained from treatment combination M1L2 followed by M2L1 (N160 P50 K130 S0 Zn0 kg ha-1 and 1 t ha-1 of dolomite lime). The maximum marginal benefit cost ratio (MBCR) 9.06 over non-lime control was also observed in treatment combination M2L1. Considering the results, the fertilizer nutrients practice by farmers (N160 P50 K130 S0 Zn0 Kg ha-1) with 1 t ha-1 of dolomite lime was found more profitable and viable among the treatments for cultivating potato under strongly acidic soil of Sylhet in Bangladesh.