The film "Double-cropping on Eastern Coast" introduces the achievements and experience gained by the Tongbong Co-op Farm in Hamju County, South Hamgyong Province, in raising two crops a year.

It deals with ways of increasing the fertility of farmland and selecting high-yield strains of grain, and advanced farming methods.

Another film "Let Us Extensively Plant Trees of Good Species" (Part 7) features a new species of poplar, Tumangang No.1, which is of high economic value. The species, which grows some 20 meters in five years, 30cm in diameter, can yield 500 cubic meters of timber per hectare.

From it, with little lignin substances, high-quality paper is manufactured without use of caustic soda.

Its leaf with 13.5 to 13.7 percent of protein content can be used as feed of goat, rabbit and cattle. Treated with microorganisms, it also serves as pig feed, reducing the consumption of grain by 40 to 50 percent.