Gansu Academy of Agricultural Sciences, Lanzhou, China.
National Research Center of Intercropping, The Islamia University of Bahawalpur, Bahawalpur, Pakistan.
Sci Rep. 2023 Oct 7;13(1):16916. doi: 10.1038/s41598-023-43288-3.
Cereal/legume intercropping is becoming a popular production strategy for higher crop yields and net profits with reduced inputs and environmental impact. However, the effects of different spatial arrangements on the growth, grain yield, nitrogen uptake, and land-use advantage of wheat/soybean relay intercropping are still unclear, particularly under arid irrigated conditions. Therefore, in a three-year field study from 2018 to 2021, soybean was relay intercropped with wheat in different crop configurations (0.9 m, narrow strips; 1.8 m, medium strips; and 2.7 m, wide strips), and the results of intercropping systems were compared with their sole systems. Results revealed that intercrops with wide strips outperformed the narrow and medium strips, when the objective was to obtain higher total leaf area, dry matter, nitrogen uptake, and grain yield on a given land area due to reduced interspecific competition between intercrops. Specifically, at maturity, wide strips increased the dry matter accumulation (37% and 58%) and its distribution in roots (37% and 55%), straw (40% and 61%), and grains (30% and 46%) of wheat and soybean, respectively, compared to narrow strips. This enhanced dry matter in wide strips improved the soybean's competitive ability (by 17%) but reduced the wheat's competitive ability (by 12%) compared with narrow strips. Noticeably, all intercropping systems accumulated a significantly higher amount of nitrogen than sole systems, revealing that wheat/soybean relay intercropping requires fewer anthropogenic inputs (nitrogen) and exerts less pressure on the ecosystem than sole systems. Overall, in wide strips, intercropped wheat and soybean achieved 62% and 71% of sole wheat and soybean yield, respectively, which increased the greater total system yield (by 19%), total land equivalent ratio (by 24%), and net profit (by 34%) of wide strips compared to narrow strips. Our study, therefore, implies that the growth parameters, grain yields, nutrient accumulation, and land-use advantage of intercrop species could be improved with the proper spatial arrangement in cereal/legume intercropping systems.
间作是一种提高作物产量和净收益的生产策略，同时减少投入和对环境的影响。然而，不同的空间配置对小麦/大豆套作的生长、产量、氮吸收和土地利用优势的影响仍不清楚，特别是在干旱灌溉条件下。因此，在 2018 年至 2021 年的三年田间试验中，在不同的作物配置（0.9m，窄带；1.8m，中带；2.7m，宽带）下，对大豆进行了小麦套作，将套作系统的结果与单作系统进行了比较。结果表明，由于套作间的种间竞争减少，与窄带和中带相比，宽带套作获得了更高的总叶面积、干物质、氮吸收和产量。具体而言，在成熟时，宽带套作分别增加了小麦和大豆的干物质积累（37%和 58%）及其在根（37%和 55%）、茎（40%和 61%）和籽粒（30%和 46%）中的分配。与窄带相比，宽带套作中增加的干物质提高了大豆的竞争力（提高 17%），但降低了小麦的竞争力（降低 12%）。值得注意的是，所有套作系统比单作系统积累了更多的氮，这表明小麦/大豆套作比单作系统需要更少的人为投入（氮），对生态系统的压力也更小。总体而言，在宽带套作中，套作小麦和大豆分别达到了单作小麦和大豆产量的 62%和 71%，提高了总系统产量（提高 19%）、总土地当量比（提高 24%）和净收益（提高 34%）。因此，我们的研究表明，通过在间作系统中进行适当的空间配置，可以改善间作物种的生长参数、产量、养分积累和土地利用优势。
