Abstract: Spring maize(Zea mays) field experiment of soil water stress and sowing date were conducted in the maize zone of Jilin province in spring of 2010 and 2011, which set 4 soil moisture levels and 3 sowing dates. The soil moisture, irrigation water amount, and rainfall were observed in the period from sowing to 7-leaf, and the leaf age, plant height and biomass dry weight of maize plant were observed after 7-leaf. The impact of soil water change on the state of maize seeding growth was analyzed by using of regression method. The results showed that the soil water stress inhibited the growing of maize leaves and plant, retarded the amassment of seeding biomass. The relationship between relative leaf age of maize seedling, relative plant height and relative biomass and soil moisture in the period from sowing to 7-leaf were significant quadratic function. Every 1 percentage point decline in soil moisture, the maize seedling leaf age, plant height and dry weight decreased 5.5, 5.6 and 11.0 percentage point respectively. Soil moisture in 21.5%-24.0% (or available soil water in 70-85mm) in the period was suitable for maize seedlings growth. If the soil moisture decreased to 18.0%, the maize relative leaf age, relative plant height and relative dry weight dropped to 80%, 85% and 70% from appropriate conditions of 100% respectively. When the soil moisture was below 16.0%, the leaf age, plant height and dry weight decreased to 68%, 70% and 50% respectively. The results had guidance function on evaluation of maize seeding growth, spring drought impact and irrigation.

Key words: Spring maize, Field experiment, Growth of seedlings, Soil moisture, Relative leaf age, Relative plant height, Relative dry weight