Abstract: 【Objective】 Rainfall during wheat growth period in dry land of China is less and uneven distribution, how to keep water conservation in fallow period to fulfill wheat production development in growing period is a hot spot of current research. This paper aimed at providing a theoretical basis for improving grain quality and yield based on improving soil moisture level, with the effective utilization of precipitation in fallow period. 【Method】 The experiment was carried out for 3 consecutive years (2009-2012) in Wenxi, Shanxi to study the effect of deep tillage and deep scarification in fallow period on soil water storage at the depth of 0-300 cm and grain protein formation.【Result】The results showed that soil water storage before sowing at the depth of 0-300 cm was improved in fallow period, and it was improved by 63-91 mm in dry year, by 41-70 mm in normal year and by 54-74 mm in humid year. The grain yield was significantly increased by tillage in fallow period, and it was improved by 981-1 330 kg•hm-2 in dry year, by 883-1 089 kg•hm-2 in normal year and by 1 256-1 457 kg•hm-2 in humid year. Deep tillage had better effects in dry and normal year, while deep scarification had better effects in humid year. Tillage in fallow period significantly improved the activity of glutamine synthetase (GS) and glutamate synthase (GOGAT) of post-anthesis 5-15 d in flag leaf in normal and humid year, and the activity of GS and GOGAT in grains under different rainfall years. It also improved grain albumin, gliadin, glutenin, protein content in normal and humid years, glu/gli in dry and humid year, and grain protein yield under different rainfall years. Grain protein yield in dry year and grain albumin, gliadin, protein content and yield in normal year under deep tillage in fallow period were significantly higher than the deep scarification in fallow period. Grain protein and its components content, protein yield and glu/gli in humid year under deep scarification significantly higher than deep tillage in fallow period. Under the condition of tillage in fallow period in different rainfall years, soil water in anthesis influenced the activity of GS and GOGAT in flag leaf, especially the activity of GS in flag leaf, and the activity of GS in flag leaf had a correlation with grain protein and its components content, glu/gli and protein yield, soil water in anthesis had a correlation with grain globulin, gliadin, protein content and yield, especially glu/gli had a better correlation with deep soil water in anthesis. 【Conclusion】 The above results suggested that tillage in fallow period was beneficial to conserve rainfall in fallow period, and improve the soil water storage before sowing, especially the deep soil water in dry year. It benefited the improvement of soil water storage in anthesis, especially in dry year, which had better effects on soil moisture conservation. Fallow tillage could improve grain yield. Soil water at anthesis influenced the activity of GS and GOGAT in flag leaf, especially the activity of GS in flag leaves, consequently improved grain protein content, and glu/gli had a close connection with deep soil water at anthesis, so it improved grain protein quality. In a word, tillage in fallow period was beneficial to improve soil moisture reserve level, thus improving yield and optimizing quality, and deep tillage in fallow period was better in dry and normal year, while in humid year, deep scarification in fallow period was better.

Key words: dryland wheat , precipitation years , tillage in fallow period , soil water storage , key enzyme activity for protein synthesis , correlation