Study on Cover Crop Potential in Arabica Coffee

Abstract

Effect of cover crop species on plant growth and soil condition were studied on red kidney bean (Phaseolus vulgaris L.), black bean (Vigna unguiculata), lab lab bean (Phaseolus lima) and Centrosema pubescens Benth. All cover crops were grown in plantation of arabica coffee mixed with perennial fruit trees at Chiang Mai. The result showed that; after 2 years experimental period, coffee with black bean performed maximum growth i.e. height increment, no. of primary branches and canopy diameter which was better than coffee-lab lab bean plot. They were significantly higher than control in which pure standing of coffee was used without ground coverage. Concerning physiological effect : lab lab bean resulted in maximum chlorophyll and nitrogen content of coffee leaves. However, average leaf area of coffee in coffee-black bean was the highest and significantly different from control.

Considering growth of cover crop; black bean shows maximum ratio of fresh and dry weight per unit area. Soil structure in plots with cover crops had better performance in erosion prevention and soil moisture content comparing with plot in absence of coverage. Although soil organic matter content showed tendency to increase but the difference was statistically insignificant.