A root-zone soil regime of wheat: physiological and growth responses to furrow irrigation in raised bed planting in northern China
Different irrigation methods in wheat (Triticum aestivum L.) result in different water and nutrient use efficiencies and, ultimately, plant growth. A field experiment was conducted during the 2006–2007 and 2007–2008 crop cycles to investigate the effects of furrow irrigated raised bed planting and the effects of flood irrigated conventional planting on growth and productivity in winter wheat. In Zadoks Stages 5–31, wheat that was grown in raised bed planting suffered from a lower soil temperature by producing fewer tillers per plant with much slower growth and development than wheat grown in conventional planting. Subsequent flood irrigation in conventional planting improved soil moisture status while increasing soil bulk density and caused a deep percolation of irrigation water and soil nutrients. In contrast, furrow irrigation in a raised bed planting system improved root-zone soil moisture and nutrient regimes, decreased soil bulk density by 8.5 to 10.4%, increased soil respiration by 3.2 to 10.4%, root vitality by 4.8 to 8.9%, and root dry weight by 2.8 to 3.7%. Consequently, compared with the conventional planting, the furrow-irrigated wheat in raised bed planting developed greater leaf photosynthetic capacity, Photosystem II (PSII) potential (Fv/Fm), and actual (PSII) quantum yields of photochemical processes, leaf area index (LAI), and dry matter accumulation (DMA). Ultimately, wheat on raised beds produced a grain yield of 698.7 g m–2, 7.6% higher than that in conventional planting. Based on these data, we can conclude that furrow-irrigated raised bed planting optimizes the root-zone soil regime, promotes plant growth and development, and increases wheat productivity.