Geography and Environmental Engineering Department, Baoji University of Arts and Sciences, Baoji, 721013, China.
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, 712100, Shaanxi, China.
Sci Rep. 2021 Aug 3;11(1):15760. doi: 10.1038/s41598-021-95242-w.
The relative contribution of above- and below-ground competition to crop yield under intercropping systems is critical to understanding the mechanisms of improved yield. Changes in the content of above- and below-ground biomass, leaf photosynthetic rate (Pn), leaf area index (LAI), chlorophyll meter reading (SPAD), diffuse non interceptance (DIFN), soil water storage (SWS), crop nitrogen (N), and phosphorus (P) uptake were examined in a 2-year trial of different maize-soybean intercropping systems on the Loess Plateau, China. Compared with the sole cropping system, shoot biomass of maize was increased by 54% in M2S2 and 62% in M2S4 strip intercropping treatment. The crop N and P uptake of maize increased significantly, by 54% and 50% in M2S2 and by 63% and 52% in M2S4 compared with their respective sole crop. LAI values of maize in intercropping systems were 14% and 15% for M2S2 and M2S4 less than that in the sole crop. The DIFN of intercropped maize was increased by 41% and 48% for M2S2 and M2S4 compared to monocrop. There were no significant differences in Pn and SWS in both crops between the two cropping systems. The contribution rate of DIFN in M2S2 and crop P uptake in M2S4 on the biological yield in intercropping system was the highest among all factors. We conclude that the sowing proportion affects above- and below-ground competition in maize-soybean intercropping systems.
在间作系统中，地上和地下竞争对作物产量的相对贡献对于理解产量提高的机制至关重要。本研究在中国黄土高原进行了为期两年的不同玉米-大豆间作系统试验，调查了地上和地下生物量、叶片光合速率（Pn）、叶面积指数（LAI）、叶绿素计读数（SPAD）、漫射非截取（DIFN）、土壤水储量（SWS）、作物氮（N）和磷（P）吸收的变化。与单作系统相比，M2S2 和 M2S4 条带间作处理下玉米地上生物量分别增加了 54%和 62%。与各自的单作相比，玉米的作物 N 和 P 吸收量显著增加，M2S2 增加了 54%和 50%，M2S4 增加了 63%和 52%。间作系统中玉米的 LAI 值比单作低 14%和 15%，M2S2 和 M2S4。与单作相比，间作玉米的 DIFN 增加了 41%和 48%。两种作物在两种种植系统之间，Pn 和 SWS 没有显著差异。在间作系统中，DIFN 的贡献率和 M2S4 中作物 P 吸收量对生物产量的贡献最高。我们得出的结论是，播种比例会影响玉米-大豆间作系统中地上和地下的竞争。
