Response of Coffee (Coffea arabica L.) Seedlings to Lime and Phosphorus Mineral Fertilizer at Jimma, Southwestern Ethiopia

Abstract

Pot experiment was conducted at Jimma Agricultural Research Center, southwestern Ethiopia, to investigate the effects of lime and P mineral fertilizer on shoot (stem + leaf) and root (tap and lateral root) growth of Arabica coffee seedlings and establish optimum combination of these agricultural inputs that enhance the growth of the crop under nursery condition. Six lime rates [0, 2.31, 4.62, 6.93, 9.24 and 11.55 g/2.5 kg soil (pot)] and four P rates (0, 250, 500 and 750 mg P/ pot) were factorially combined and laid out in randomized complete block design with three replications. Results depicted that lime and P rates significantly (P ≤ 0.01) affected plant height, stem diameter, leaf number and area, tap and lateral root length, stem, leaf and root dry matter and shoot to root ratio of coffee seedlings. The highest value of these parameters was recorded on pots treated with 2.31 g lime and 750 mg P/pot. Similarly, the interaction of lime and P rates significantly (P ≤ 0.01) affected plant height, stem diameter, leaf number and area and stem, leaf and root dry matter of coffee seedlings. The highest and non-significant shoot and root growth was observed on pots treated with a combination of 0 g lime and 750 mg P/pot and 2.31 g lime and 250 mg P/pot. In conclusion, vigorous Arabica coffee seedlings for field planting could be produced by applying P at a rate of 750 mg P/pot or a combination of low lime (2.31 g lime/pot) and low P (250 mg P/pot) rate. However, the scenario might be quite different after planting coffee seedlings in the field. Thus, further investigation should be continued under field condition to evaluate growth and yield response of coffee trees and row and cup quality of green beans to varying levels of lime and P fertilizer and establish profitable levels of these agricultural inputs for sustainable production of the crop in the country.

Keywords: Acid soil, coffee seedlings, lime, phosphorus mineral fertilizer, shoot and root growth