The keys of catchment cultivation techniques were broad film and "V"-size. Several years of field experiment and demonstration showed that the method could increase soil water and raise water utilization; it could prompt the growth and up-growth of the crops and its ripeness in advance; it could raise the per unit yield of about 20%.Of the reason were

(1)that V-size cater more water;(2)that broad film add temperature and unit plant temperature area;(3)the method cut down soil harness. But the problem was that broad film and total covering airtight

crop roots breath with difficulty.