Abstract:
Producing chickpea on Vertisol without fertilizer application leads to low yields because of low soil nutrient availability. Hence, a field experiment was conducted in 2017/2018 in Ada’a-Liban District of East Shoa Zone, Ethiopia, to assess the effect of rates of blended NPSZnB and DAP fertilizer on yield components and yield of chickpea varieties. Treatments consisting of four levels of blended NPSZnB fertilizer (0, 64.4, 129 and 193 kg ha-1) and four chickpea varieties (Natoli, Dalota, Arerti, and Dhera), including a standard check fertilizer rate (100 kg DAP ha-1), were laid out in Randomized Complete Block Design in a factorial arrangement and replicated three times per treatment. The main effect of chickpea variety significantly affected all parameters except seed yield. Chickpea variety Dhera had the highest aboveground biomass yield (6754 kg ha-1),grain crude protein content (16.56%), total N uptake (85.02 kg N ha-1) and total P uptake (19.69 kg P ha-1). The main effect of rates of blended NPSZnB fertilizers also significantly affected all parameters except days to emergence, number of secondary branches, number of seeds per pod, hundred seed weight, harvest index and grain crude protein. The highest aboveground biomass (6494 kg ha-1), seed yield (3187 kg ha-1), N uptake by grain (79.93 kg N ha-1) and P uptake by straw (6.91 kg P ha-1) were obtained for application of 193 kg NPSZnB ha-1 though statistically in parity with different rates of blended NPSZnB and standard check (100 kg DAP ha-1). Moreover, the highest number of pods (41.32 plant-1) and P uptake by grain (10.93 kg P ha-1) were obtained from application of 129 kg NPSZnB ha-1 and 64.4 kg NPSZnB ha-1, respectively though statistically similar with 100 kg DAP ha-1 and rates of NPSZnB fertilizer. Interaction effect of chickpea variety and rates of blended NPSZnB significantly affected numbers of effective nodules, N uptake by straw, S and Zn uptake by grain, straw and total uptake. The interaction of Dhera variety with the rate of 129 kg NPSZnB ha-1 led to the production of the highest number of effective nodules (20.67 plant-1), while the highest S uptake by grain (7.95 kg ha-1) was recorded for interaction of Dhera variety with 64.4 kg NPSZnB ha-1. Moreover, interaction of 64.4 kg NPSZnB ha-1 with Arerti variety resulted in the highest total uptake of Zn (2484 g ha-1).Treatment combination of Natoli with 129 kg NPSZnB ha-1, Dalota with 64.4 kg NPSZnB ha-1 and Arerti with all rates of blended NPSZnB and standard check were utilized the lowest rate of N efficiently to produced the highest seed yield (AE > 30 kg kg-1). Alternatively, Dalota and Arerti varieties with 64.4 kg NPSZnB ha-1 and Arerti with 129 kg NPSZnB ha-1 produced the highest seed yield with low rate of P applied (AE > 20 kg kg-1). Economically, Arerti was found to be the most responsive variety to 193 kg NPSZnB ha-1 with the highest net benefit of 55997 birr ha-1and 195.9% marginal rate of return. Thus it can be concluded that application of 193 kg NPSZnB ha-1 with varieties Arerti and Dhera were found to be superior and can be used for chickpea production in Ada’a Liban District East Shoa Zone. However, since the experiment conducted in one season and one location, the experiment should repeat over seasons and locations to reach a conclusive recommendation.