Abstract

Agricultural management practices, such as mulching and irrigation can change the characteristics of the soil surface and hence influence the hydrothermal properties of the soil. A two-year field experiment was conducted at the Changwu agro-ecosystem research station to evaluate the effects of mulch and irrigation practices on moisture and temperature in the upper layers of the soil and on crop growth and yield performance in spring maize (Zea mays L) fields. Four mulching and irrigation treatments were examined: supplementary irrigation (SI), film mulching (FM), straw mulching (SM; in 2008 only) and a rain-fed (RF) control. The soil water (0 - 15 cm depth range) and soil temperature (0 - 5 cm depth range) were studied during the crop growing season and the treatments' yield performances were compared. Over the whole season, the average topsoil water content was significantly higher (P < 0.05) under the SM (23.3% in 2008), SI (21.4% in 2007, 22.5% in 2008) and FM (20.0% in 2007, 21.6% in 2008) treatments than under RF (17.1% in 2007, 19.6% in 2008). The seasonal trends in atmospheric and soil temperatures were similar under all treatments. The seasonally-averaged soil temperature at 07:00 and 14:00 h was highest under the FM treatment and lowest under the SM treatment. Plant height and leaf and stem biomass were significantly higher (P < 0.05) under the SI treatment than under the RF and FM treatments from silking to physiological maturity. Both the FM and SI treatments significantly improved (P < 0.05) the crop grain yield (GY) and yield components.

Key words: Loess Plateau, soil water, soil temperature, spring maize.