INTENSIVE AND EXTENSIVE CULTIVATION TECHNIQUES IN NORTH VIETNAM
ARMY BIOLOGICAL LABS FREDERICK MD
Cultivation can be intensified by expanding the plantation of crops and increasing the yield for each crop season. In some areas, it is easier to expand vegetable crops. Two vegetable crops are planted in fields which have been used for only one crop. The ninth-month rice is planted as usual after the winter-autumn vegetables are harvested. This is the two vegetables-one rice formula.
Trans. of Khoa Hoc Ky Thuat Nong Nghiep (North Vietnam) p2-5, 15 Jan, 1965.