Different micronutrient management practices showed a significant effect on the yield components of lentil during 2016-17 at Gazipur and Jessore. The plant height of the lentil ranged from 23.9-28.1 cm at Gazipur and 30.6-35.6 cm at Jessore. The highest plant height was recorded from the treatment T8 which was significantly higher over the other treatments at Gazipur and Jessore but at Jessore it was statistically identical to T7, T6 and T4 treatment. The highest number of branches per plant was recorded from the treatment T8 at both Gazipur and Jessore. The lowest values were obtained from the treatment T1. The maximum number of pods per plant was recorded from the treatment T8 at Gazipur and Jessore which was significantly different from the other treatments, but statistically identical to T7 at Jessore while it was lowest in T1 treatment (Table 1). The number of seeds per pod showed significant variation due to different treatments. The highest number of seeds per pod was observed in T8 followed by T5 and the lowest value in T1 treatment. Like other yield contributing parameters, the highest 1000 seed weight was also recorded in the treatment T8 followed by T5 only in Gazipur and the lowest 1000 seed weight was recorded in the control treatment. The seed yield of lentil was influenced significantly by the different micronutrient management practices during the period from 2016-17 at Gazipur and Jessore (Table 2). The highest seed yield was found in the treatment T8. This was significantly higher than the other treatments, except the treatment T7 in Jessore which was statistically identical per T7. The lowest yield was recorded from T1 treatment. In the case of stover yield of lentil showed also the highest in the T8 treatment which was significantly different over the other treatments but statistically identical to T7, T6 and T5 in both locations. The lowest stover yield was also recorded from T1 treatment.
From the three years study, different micronutrient management practices contributed positive and significant influenced to increase the yields of lentil in both Gazipur and Jessore of Bangladesh. The highest significant yield increased of lentil in T8 treatment in every year at both the locations except in the first year at Gazipur where the highest yield increase was found in T5 treatment (Appendix 1 and Figures 1 & 2). The three years average yields due to different micronutrient treatment ranged from 824-1236 kg ha-1 at Gazipur and 1253-1807 kg ha-1 at Jessore (Appendix 1 and Figure 3). Comparison the mean seed yield of lentil due to different micronutrient treatments between Gazipur and Jessore presented in the Figure 3. The yield of lentil at Gazipur was observed lower than that of Jessore yield. This yield variation might be associated with the adhephic factor and pest infestation. The Gazipur soil brings low pH and lower organic matter than Jessore, because the soil of Jessore under calcareous soil. The calcareous soils consists high CaCO3. On the other hand, foot rot disease infestation at Gazipur was ouccured.
Nodulation of lentil in different date were influenced significantly due to different micronutrient treatment during Rabi season of 2016-17. In 32 days after sowing, the numbers of nodules per plant varied from 7.78-11.5 at Gazipur and 40.4-54.0 at Jessore, in 47 DAS, ranged from 19.4-29.5 at Gazipur and 116-156 at Jessore, in 62 DAS, ranged from 25.3-38.4 at Gazipur and 138-181 at Jessore and in 77 DAS, it was varied from 18.3-22.9 at Gazipur and 67.7-84.0 at Jessore, respectively (Table 3). The maximum numbers of nodules were recorded from the treatment T8 in all the nodules collection dates which was significantly higher over the other treatment at Gazipur except nodule collection date 77 DAS it was highest in T4 treatment at Jessore. In both the locations, the lowest nodule values were obtained from the control treatment which was significantly inferior to all other treatment (Table 3). These findings were supported by Kurdali et al. (2002). From the results of different dates, nodule formations was less in 32 DAS and in 77 DAS but, the formation were maximum between the date of 47 and 62 DAS in both the locations. It seems that the maximum nodules formation were occured during early to mid flowering. After flowering, nodule efficiency might be reduced and began shut down. Soil samples were collected from each treated plot for analyzing different soil properties viz. soil pH, organic matter, total N and available P, K, S, Ca, Mg, Zn and B. The results are presented in Table 4. Initially the soil pH was 6.6 at Gazipur and 8.2 was at Jessore, but after completion of experiments, the soil pH remained unchanged although minor variation existed. A minor change in soil fertility occurred from initial status due to different micronutrients management practices. The combinend application of Zn, B and Mo (T8) tended to maintain the initial fertility or increased slightly (Table 4). Potasium (K), S and Mg slightly decreased in all plots over the initial status. The available Zn and B content of the soil slightly decreased when they were not applied, but remained almost static or increase when applied (Table 4). Regarding the cost and return analysis, the highest net return TK. 64520 ha-1 at Gazipur and Tk. 101960 ha-1 was obtained from the treatment T8 at Jessore. The highest benefit cost ratio 2.86 and 3.83 were recorded from the treatment T5 at Gazipur and Jessore, respectively. Similar result was reported by Mondal et al. (1995). The lowest net return was calculated from control (T1) treatment at both the location and the lowest benefit cost ratio was counted from the control treatment at Gazipur and Jessore (Table 5).
From the aforesaid results, it may be concluded that the micronutrient management practice of Zn2.0B1.5Mo1.0 and Zn2.0B1.5 with a blanket dose of N15 P20 K30 S10 kg ha-1 economically sound and suitable for lentil yield maximization in terrace and calcareous soils of Bangladesh.