Wheat cultivars with small root length density in the topsoil increased post-anthesis water use and grain yield in the semi-arid region on the Loess Plateau

Abstract Large distribution of roots in topsoil layers allow more uptake soil water and nutrients during the vegetative growth, but it may be disadvantageous if deficit develops reproductive stage. The relationship between (0–0.4 m) use, dry matter nitrogen (N) accumulations, grain yield was examined winter wheat (Triticum aestivum L.) with contrasting root size topsoil. Two old landraces (CW134 JM47, larger length biomass topsoil) two modern cultivars (CH58 LH7, smaller system topsoil), were grown field seasons (2016–2017 2017–2018) under rainfed irrigation conditions semi-arid farmland on Loess Plateau. Root density (RLD) significantly higher than (P