Long-Term Cropping Pattern Management in Relation to Cabbage Yields in the Highlands of Lembang, West Java']Java

Intensive crop management practices for vegetable production are widely practiced by farmers of the Lembang Highlands in West Java, Indonesia. Cabbage is one of the preferred vegetables of the region and plays an important role as a cash crop. However, the continuous planting of cabbage without rotation in the Highlands has been associated with increasing incidences of club root (Plasmidiophora brassicae Wor.). Although the application of manure is able to increase the nutrient value of the soil, in-organic fertilizers still play a significant role in vegetable production. A long-term field experiment has been implemented by the Indonesian Vegetables Research Institute (IVEGRI) in Lembang. Its goals are to evaluate the effects of nutrients and crop management on the yield and quality of cabbage, as well as the rate of club root infestation. Secondly, the study sought to find the best soil and crop management practices for tackling the problem of cabbage production in the Highlands of Lembang. The results showed that: (a) crop rotation of cabbage - lettuce - Mucuna sp. was an efficient crop management system for reducing club root infestation and maintaining cabbage productivity; (b) the application of half dosages of the recommended NPK fertilization did not decrease cabbage yield, while increased N content in the soil of the 4th and 7th planting seasons contributed to the cabbage yields; and (c) the soil organic carbon (SOC) content fluctuated during the experiments. Further observation is necessary to determine the impacts of field management on the SOC.