Effects of different irrigation methods on micro-environments and root distribution in winter wheat ifelds

摘要

The irrigation method used in winter wheat ifelds affects micro-environment factors, such as relative humidity (RH) within canopy, soil temperature, topsoil bulk density, soil matric potential, and soil nutrients, and these changes may affect plant root growth. An experiment was carried out to explore the effects of irrigation method on micro-environments and root distribution in a winter wheat ifeld in the 2007–2008 and 2008–2009 growing seasons. The results showed that border irrigation (BI), sprinkler irrigation (SI), and surface drip irrigation (SDI) had no signiifcant effects on soil temperature. Topsoil bulk density, RH within the canopy, soil available N distribution, and soil matric potential were signiifcantly affected by the three treatments. The change in soil matric potential was the key reason for the altered root proifle distribution patterns. Additional y, more ifne roots were produced in the BI treatment when soil water content was low and topsoil bulk density was high. Root growth was most stimulated in the top soil layers and inhibited in the deep layers in the SDI treatment, fol owed by SI and BI, which was due to the different water application frequencies. As a result, the root proifle distribution differed, depending on the irrigation method used. The root distribution pattern changes could be described by the power level variation in the exponential function. A good knowledge of root distribution patterns is important when attempting to model water and nutrient movements and when studying soil-plant interactions.