Nasar Jamal, Wang Gui Yang, Zhou Feng Jue, Gitari Harun, Zhou Xun Bo, Tabl Karim M, Hasan Mohamed E, Ali Habib, Waqas Muhammad Mohsin, Ali Izhar, Jahan Mohammad Shah
Guangxi Key Laboratory of Agro-environment and Agro-products Safety, Guangxi Colleges and Universities Key Laboratory of Crop Cultivation and Tillage, Agricultural College of Guangxi University, Nanning, China.
Department of Agricultural Science and Technology, School of Agriculture and Enterprise Development, Kenyatta University, Nairobi, Kenya.
Front Plant Sci. 2022 Oct 4;13:1014640. doi: 10.3389/fpls.2022.1014640. eCollection 2022.
Maize-soybean intercropping is practiced worldwide because of some of the anticipated advantages such as high crop yield and better utilization of resources (i.e., water, light, nutrients and land). However, the shade of the maize crop has a detrimental effect on the growth and yield of soybean under the maize-soybean intercropping system. Hence, this experiment was conducted to improve the shade tolerance of such soybean crops with optimal nitrogen (N) fertilization combined with foliar application of iron (Fe) and molybdenum (Mo). The treatments comprised five (5) maize-soybean intercropping practices: without fertilizer application (), with N fertilizer application (), with N fertilizer combined with foliar application of Fe (), with N fertilizer coupled with foliar application of Mo () and with N fertilizer combined with foliar application of Fe and Mo (). The findings of this study showed that maize-soybean intercropping under treatment had significantly ( 0.05) increased growth indices such as leaf area (cm), plant height (cm), stem diameter (mm), stem strength (g pot), and internode length (cm) and yield indices (i.e., No of pods plant, grain yield (g plant), 100-grain weight (g), and biomass dry matter (g plant)) of the soybean crop. Moreover, intercropping under treatment enhanced the chlorophyll SPAD values by 26% and photosynthetic activities such as Pn by 30%, gs by 28%, and Tr by 28% of the soybean crops, but reduced its CO by 11%. Furthermore, maize-soybean intercropping under treatment showed improved efficiency of leaf chlorophyll florescence parameters of soybean crops such as Fv/Fm (26%), qp (17%), ϕPSII (20%), and ETR (17%), but reduced NPQ (12%). In addition, the rubisco activity and soluble protein content of the soybean crop increased by 18% in maize-soybean intercropping under treatment. Thus, this suggested that intercropping under optimal N fertilization combined with foliar application of Fe and Mo can improve the shade tolerance of soybean crops by regulating their chlorophyll content, photosynthetic activities, and the associated enzymes, thereby enhancing their yield and yield traits.
由于预期的一些优势，如作物高产和资源（即水、光、养分和土地）的更好利用，玉米-大豆间作在全球范围内都有应用。然而，在玉米-大豆间作系统中，玉米作物的遮荫对大豆的生长和产量有不利影响。因此，本试验旨在通过优化氮肥施用，并结合叶面喷施铁（Fe）和钼（Mo）来提高此类大豆作物的耐荫性。试验处理包括五种玉米-大豆间作方式：不施肥（）、施氮肥（）、施氮肥并叶面喷施铁（）、施氮肥并叶面喷施钼（）以及施氮肥并叶面喷施铁和钼（）。本研究结果表明，处理下的玉米-大豆间作显著（0.05）提高了大豆作物的生长指标，如叶面积（平方厘米）、株高（厘米）、茎粗（毫米）、茎强度（克/盆）和节间长度（厘米）以及产量指标（即每株豆荚数、籽粒产量（克/株）、百粒重（克）和生物量干物质（克/株））。此外，处理下的间作使大豆作物的叶绿素SPAD值提高了26%，光合活性如净光合速率（Pn）提高了30%，气孔导度（gs）提高了28%，蒸腾速率（Tr）提高了28%，但胞间二氧化碳浓度（Ci）降低了11%。此外，处理下的玉米-大豆间作显示大豆作物叶片叶绿素荧光参数的效率有所提高，如最大光化学效率（Fv/Fm）提高了26%，光化学猝灭系数（qp）提高了17%，实际光化学量子产量（ϕPSII）提高了20%，电子传递速率（ETR）提高了17%，但非光化学猝灭系数（NPQ）降低了12%。此外，处理下的玉米-大豆间作中大豆作物的核酮糖-1,5-二磷酸羧化酶（rubisco）活性和可溶性蛋白含量增加了18%。因此，这表明在优化氮肥施用并结合叶面喷施铁和钼的情况下进行间作，可以通过调节大豆作物的叶绿素含量、光合活性及相关酶来提高其耐荫性，从而提高其产量和产量性状。
