Abstract: In order to explore the technology for soil water storage and yield improvement of dryland wheat by mulching, an experiment was carried out in Wenxi County, Shanxi Province from 2011 to 2012. The effects of mulching methods and time on water storage and yield formation of dryland wheat were studied through whole mulching, half mulching and no mulching at 30 and 60 days after wheat harvest. The results showed that the soil water storage from sowing stage to booting stage significantly increased by mulching. Especially, the soil water storage of 140-200 cm layer at sowing stage, 160-300 cm layer at wintering stage and turning green stage, 80-160 cm layer at elongation stage, 0-120 cm and 200-300 cm layers at booting stage increased obviously. The overall effect of whole mulching at 30 days after wheat harvest was best. The tiller number increased from wintering stage to booting stage, and dry matter significantly increased at mature stage. The ear number was significantly improved, with an increase of 3%-14%. Furthermore, the yield of wheat dramatically increased by 171-815 kg·hm^-2. The percentage of earbearing, economic coefficient, yield and its component factors with whole mulching were higher than those with half mulching, with a better effect for whole mulching at 30 days after wheat harvest. The results also showed that the soil water storage at sowing stage was closely related to ear number, grain number per spike and yield, especially for the deep water storage. Until the booting stage, the water storage of 200-300 cm layer was still closely associated with dry matter, ear number and yield. To sum up, early mulching during fallow period is beneficial to storing the rainfall, especially improving the water storage in deeper layers up to the depth of 300 cm; early mulching is also beneficial to building a reasonable community and enhancing the yield through improving the ear number, with a better effect for the whole mulching.

Key words: mulching, soil infiltration characteristics, Phyllostachys heterocycla, root length density, soil fauna