. Sumarni, N., A. Hidayat, and E. Sumiati. 2006. The effect of cover crops and organic mulches on hot pepper yield and soil erosion. The main problem of hot pepper cultivation in dry upland with slope of >15° is the nutrient leaching and soil erosion due to run-off. One of the efforts to overcome this problem is by utilization of cover crops and organic mulches. The aim of the experiment was to determine the best cover crop and organic mulch in hot pepper cultivation. A strip plot design with 3 replications was used. The treatments were 4 kinds of cover crops (without cover crop, red bean, ground peanut, and sweet potato) and 3 kind of organic mulches (without mulch, rice straw, and plant residues). Cover crops and hot pepper were planted at the same time. Results of the experiment indicated that application of rice straw and plant residues mulches did not affect the yield of hot pepper, but increased the fruit number by 6.8% and 4% respectively, and decreased soil erosion by 34.82%. Using red bean and ground peanut as cover crops could increase hot pepper yield by 11.74 and 33.91%, and also decreased soil erosion by 22.41 and 39.65%, respectively. On the other hand, cover crop of sweet potato decreased the growth and yields of pepper, however, it was the most effective for decreasing soil erosion (41.38%). The best cover crop for cultivating hot pepper was ground peanut which gave the highest increased in yield of hot pepper (33.91%). Application of suitable cover crop and organic mulch can maintain soil productivity.