African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6900

Full Length Research Paper

Non-hydraulic root-sourced signaling and grain yield stability under shade of maize during progressive soil drying in soybean

Jing Zhang1,2, Weiguo Liu1, Xinfu Chen1, Wenyu Yang1* and Donald L. Smith2
  1Department of Crop Cultivation and Tillage, College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China. 2Department of Plant Science, Agricultural and Environmental Sciences, McGill University, Ste-Anne de Bellevue, QC H9X 39V, Canada.
Email: [email protected]

  •  Accepted: 20 October 2011
  •  Published: 19 November 2011

Abstract

 

Production practice shows shaded soybean in wheat-maize-soybean; relay strip intercropping system has better tolerance to drought as compared with sole cropping soybean. Our researches are to understand the reasons through non-hydraulic root signals (nHRS), yield and the relationships among them. Pot experiments were conducted with two soybean cultivars, under shade of maize (LI) and normal irradiance (HI). nHRS were traced during manipulative progressive soil drying period at branching stage under good soil conditions (HW), water stress treatment (LW), in 2010. Well-watered (WW), light drought (LD), moderate drought (MD) and severe drought (SD) were applied in 2009. In response to soil drying, nHRS appeared earlier in Gongxuan No.1 (GX) than Gongqiudou 05-8 (GQ) under two irradiance treatments, but it disappeared earlier for GX than GQ under normal irradiance. GX exhibited a wider average soil water content threshold range (TR) of nHRS under low irradiance. Drought stress significantly decreased the shoot dry mass, root mass and grain yield (P<0.05), excluding LD and nHRS treatments. Water use efficiency was significantly higher (P<0.05) in GX than GQ under drought conditions in both irradiances. In a conclusion, soybean cultivar GX has wider TR in low irradiance condition, light drought had no significant effect on yield, nHRS maybe beneficial to maintain soybean yield under drought condition.

 

Key words: Soybean, drought, shade, non-hydraulic root-sourced signal, water use efficiency, yield stability.