Potato intercropping systems with maize and faba bean
The effects of different row spacings and plant densities on production of potatoes/maize intercrops were studied at Yusipang (2700 m alt.) and Kangma (1900 m), Bhutan, and the effects of different row spacings on potatoes/faba beans intercrops were studied at Yusipang. Potato yields were reduced by 0-21% depending on year (1989 or 1990) and site, and were unaffected by planting geometry. The land equivalent ratio was 1.03-1.06 for faba beans and 1.11-1.49 for maize intercropping systems. Maize yields were reduced by up to 60% by intercropping, and economic returns from the potatoes/maize intercrops were no greater than from sole-cropped potatoes at Yusipang, but at Kangma maize plant density of 2.8/m increased returns by 12-15% in 1990. Yields of faba beans were low both in sole crops and intercrops, due to fungal disease, and economic returns from potatoes/faba beans intercrops were >10% less than from sole-cropped potatoes. It is suggested that in normal farm conditions, with lower potato yields, there would be more benefit from intercropping and that intercrops may reduce the risks from environmental and market fluctuations.