Bai Wen-Lian, Zhang Meng-Yao, Liu Zhen-Yang, Zheng Yi, Tang Li, Xiao Jing-Xiu
College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China.
Guizhou Academy of Forestry, Guiyang 550005, China.
Ying Yong Sheng Tai Xue Bao. 2021 Apr;32(4):1317-1326. doi: 10.13287/j.1001-9332.202104.027.
The intercropping of legume and cereal crops could affect crop roots growth. The relationship among intercropping, root morphology and phosphorus (P) acquisition under different P levels is still unclear. With field experiments and a rhizo-box experiment, we examined the changes of yield, biomass, P acquisition and root morphology of wheat and faba bean under different planting patterns (monocropped wheat, MW; monocropped faba bean, MF; and wheat and faba bean intercropping, W//F) and different P levels. In the rhizo-box experiment, both root weight and root-shoot ratio were increased by 21.2% and 61.5%, respectively, but shoot weight was decreased by 14.6% when wheat intercropped with faba bean. Root P content and P uptake of intercropping wheat (IW) increased by 23.8% and 12.1% when compared to MW. Both shoot and root weight, root-shoot ratio, total root length, and root volume of intercropping faba bean (IF) increased by 16.5%, 47.3%, 24.0%, 3.5%, and 8.4% as compared to MF, respectively, which resulted in higher shoot and root P content and P acquisition of IF. In the field experiment, P uptake by IW decreased by 8.7% at tillering stage, but P acquisition increased by 40.6%, 19.7%, 7.8% and 12.4% at join-ting, heading, filling, and maturity stages as compared to MW. By contrast, P acquisition of IF decreased by 9.8%, 9.0% and 5.2% at flowering, podding, and maturity stages as compared to MF. Partial least squares (PLS) regression analysis showed that root surface area and total volume of wheat and root surface area of faba bean had the greatest contribution to crop P acquisition. Intercropping induced higher root volume and root surface area which resulted in higher P acquisition under low P stress. In conclusion, interspecific interaction amplified the root-soil interface zone and increased P uptake at seedling stage under low P stress, which could contribute to the intercropping advantages at later stage.
豆科作物与谷类作物间作可能会影响作物根系生长。不同磷水平下间作、根系形态与磷吸收之间的关系仍不明确。通过田间试验和根箱试验，我们研究了在不同种植模式（单作小麦、MW；单作蚕豆、MF；小麦与蚕豆间作、W//F）和不同磷水平下小麦和蚕豆的产量、生物量、磷吸收及根系形态的变化。在根箱试验中，小麦与蚕豆间作时，根重和根冠比分别增加了21.2%和61.5%，但地上部重量下降了14.6%。间作小麦（IW）的根磷含量和磷吸收量与单作小麦相比分别增加了23.8%和12.1%。间作蚕豆（IF）的地上部和根重、根冠比、总根长和根体积与单作蚕豆相比分别增加了16.5%、47.3%、24.0%、3.5%和8.4%，这使得IF的地上部和根磷含量及磷吸收量更高。在田间试验中，IW在分蘖期的磷吸收量下降了8.7%，但与单作小麦相比，在拔节期、抽穗期、灌浆期和成熟期的磷吸收量分别增加了40.6%、19.7%、7.8%和12.4%。相比之下，IF在开花期、结荚期和成熟期的磷吸收量与单作蚕豆相比分别下降了9.8%、9.0%和5.2%。偏最小二乘（PLS）回归分析表明，小麦的根表面积和总体积以及蚕豆的根表面积对作物磷吸收的贡献最大。间作诱导了更大的根体积和根表面积，从而在低磷胁迫下提高了磷吸收。总之，种间相互作用扩大了根-土界面区，并在低磷胁迫下增加了苗期的磷吸收，这有助于后期的间作优势。
