| The winter wheat dual-mulching experiments were carried out with plastic film mulching on ridges and
other different mulching materials in furrows in Weibei dryland from September 2007 to June 2009. The results showed that: The treatment of plastic film and straw dual-mulching can increase wheat yield significantly, the highest rate of increase is 39.62% (P<0.05) compared with the CK (no covering on ridges or in furrows), and the two-year average yield of wheat in the treatment of dual-mulching with plastic film and black liquid film increased by 32.16%, and the treatment of only plastic film mulching on ridges increased by 29.99 %. The treatment of dual-mulching with plastic film and straw has obvious effect of preserving soil moisture within 0~40 cm soil depth, which can effectively improve soil moisture content. The soil moisture content of 0~40 cm soil depth increased by 15.81% in heading stage. The treat-ment of dual-mulching with plastic film and black liquid flm has a good water-retention effect in the early growth period of wheat, which increased the water content by 11.01 % within 0~40 cm soil depth at jointing stage of winter wheat. The water use efficiency in the treatments of dual一mulching with plastic film and straw , and dual- mulching with plastic film and black liquid film were increased by 31.11% (P<0.05) and 26.20% (P<0.05) respectively compared with the CK. |