Effects of cultivation patterns on winter wheat root growth parameters and grain yield

Abstract

Grain yields of winter wheat are greatly affected by different cultivation patterns through regulating root growth and development. In this study, we established four cultivation patterns, i.e. farmers’ traditional cultivation pattern (T1), optimized T1 cultivation pattern (T2), super high yield cultivation pattern (T3) and optimized T3 cultivation pattern (T4). The variations of wheat root growth parameters were analyzed in two growth years (2008–2009 and 2009–2010). The results indicated that there were significant differences in yield factors among four patterns. Temporal variations of total root dry weight (TRDW), total root length (TRL) and average root diameter (ARD) in four patterns exhibited a single peak curve. The maximum of TRDW and TRL in T1 appeared at the heading stage, whereas those in T2, T3 and T4 were postponed to anthesis. The peak appearance time (te) and the maximum growth rate (tm) of TRDW and TRL in T2, T3 and T4 were retarded. The maximum values (wmax), average growth rate (c¯) and maximum growth rage (cm) of TRDW, TRL and ARD in T2, T3 and T4 were significantly higher than those in T1. In comparison with T1, the mean values of RDWD and RLD in T2 in upper soil layers (0–20cm) reduced remarkably. Similarly, the mean values of RDWD and RLD in T4 were also markedly lower than those in T3. In the middle and lower soil layers (40–100cm), however, the mean values of RDWD and RLD in T2 were significantly higher than those in T1, and these parameters in T4 had also significant difference with T3. In the 20–100cm soil layers, the gray correlation coefficients among grain yield, RDWD, RLD and ARD in T2 were higher than T1. Above 60cm soil layers, these coefficients in T3 were higher than in T4. In deep soil layers (60–100cm), however, these coefficients in T3 were lower in T4. These results suggested that optimized cultivation patterns may enhance wheat grain yield by changing the root distribution among soil layers, prolonging the root growth duration, increasing root growth rate and enhancing the absorption ability to water and nutrition in deep soil layers.