Abstract: The distribution position of cotton root system in the tilth is closely related with cotton yield. Research material indicates that ground film mulching serves to make lateral roots move upward so that their primordia occur only 2-3 cm from the ground surface, i, e, moving upward twice as much as cotton directly seeded in the open field. With shallow application of organic fertilizer at 0-10cm, the root dry weight accounts for 84.5-87.5% of the total dry weight, i.e.9.8-12.8% heavier than the 74.7% when it is deeply applied. Results of research conducted during 1983-1988 indicate that in the pot experiment, cotton yield, with organic fertilizer shallowly placed, increased 11.7-23.8%; in the field experiment, yield increased 13.6-17.4%; while in large area demonstration, yield increased 18.87%.

Key words: Cotton, Organic fertilizer, Farmland mulching, Yield structure