Jingchu University of Technology, Jingmen, 448000, Hubei, China.
Sci Rep. 2021 Mar 1;11(1):4913. doi: 10.1038/s41598-021-84208-7.
The objectives of this two-year field experiment were (1) to study the effect of irrigation frequency and irrigation amount on the root characteristics of drip-irrigated spring wheat (Triticum aestivum L.) and (2) to determine the relationship between these root characteristics and aboveground biomass and yield. A split-plot design was used with two wheat cultivars (Xinchun 6 and Xinchun 22). The irrigation treatments consisted of three irrigation intervals (D 13 d; D, 10 d; and D, 7 d) and three water amounts (W1, 3750 m/ha; W2, 6000 m/ha; and W3, 8250 m/ha). The results showed that root length density (RLD) and root weight density (RWD) were greater at 0-20 cm than at 20-40 cm at flowering. The RLD was greater in D1 and D2 than in D3 in the shallow soil layer and did not differ among the treatments with different irrigation frequencies in deep soil. The RLD at the 0-20 cm depth of W3 was 17.9% greater than that of W2 and 53.8% greater than that of W1, and the RLD trend was opposite at the 20-40 cm depth. The root-shoot ratio was significantly higher in D2 than in the other treatment, whereas the RLD, RWD, leaf Pn and LAI were significantly greater in D3. Leaf Pn and LAI both increased as the irrigation amount increased. Regression analysis showed a natural logarithmic relationship between RWD and aboveground biomass (R > 0.60, P < 0.05) and binomial relationships of the RWD at 0-20 cm depth (R = 0.43, P < 0.05) and the RLD at 20-40 cm depth (R = 0.34, P < 0.05) with grain yield. We found that with the optimum irrigation amount (W2), increasing drip irrigation frequency can increase wheat root length and root weight and aboveground biomass accumulation, thereby improving yield and water use efficiency.
（1）研究滴灌春小麦根系特性对灌溉频率和灌溉量的影响；（2）确定这些根系特性与地上生物量和产量之间的关系。采用裂区设计，设两个小麦品种（新春 6 号和新春 22 号）。灌溉处理包括三个灌溉间隔（D13d、D10d 和 D7d）和三个灌水量（W13750m/ha、W26000m/ha 和 W38250m/ha）。结果表明，开花期 0-20cm 土层的根长密度（RLD）和根重密度（RWD）大于 20-40cm 土层。浅层土壤中 D1 和 D2 的 RLD 大于 D3，而不同灌溉频率的深层土壤处理之间没有差异。W3 处理 0-20cm 土层的 RLD 比 W2 处理高 17.9%，比 W1 处理高 53.8%，而 20-40cm 土层的 RLD 则相反。D2 处理的根冠比显著高于其他处理，而 D3 处理的 RLD、RWD、叶片 Pn 和 LAI 则显著高于其他处理。叶片 Pn 和 LAI 均随灌水量的增加而增加。回归分析表明，RWD 与地上生物量呈自然对数关系（R>0.60，P<0.05），0-20cm 土层 RWD 和 20-40cm 土层 RLD 与籽粒产量呈二项式关系（R=0.43，P<0.05；R=0.34，P<0.05）。结果表明，在最优灌水量（W2）下，增加滴灌频率可以增加小麦根系长度和根重以及地上生物量的积累，从而提高产量和水分利用效率。
