Growth and development of soybean under changing light environments in relay intercropping system

PeerJ

article

Muhammad Ali Raza¹  Ling Yang Feng¹  Nasir Iqbal¹  Mukhtar Ahmed²  Yuan Kai Chen¹  Muhammad Hayder Bin Khalid¹  Atta Mohi Ud Din⁴  Ahsin Khan⁴  Waqas Ijaz⁵  Anwaar Hussain⁶  Muhammad Atif Jamil⁶  Muhammd Naeem¹  Sadam Hussain Bhutto¹  Muhammad Ansar²  Feng Yang¹  Wenyu Yang¹ 

[1] College of Agronomy, Sichuan Agricultural University;Department of Agronomy, University of Arid Agriculture Rawalpindi;Department of Northern Agricultural Sciences, Swedish University of Agricultural Sciences;College of Life Sciences, Sichuan Agricultural University;Chinese Academy of Agricultural Sciences, Institute of Environment and Sustainable Development in Agriculture;Northeast Forestry University, School of Forestry

关键词: Light intensity;    Relay intercropping;    Soybean;    Light quality;    Shade;   

DOI  :  10.7717/peerj.7262

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Background Maize-soybean relay-intercropping (MSR) is a famous system of crop production in developing countries. However, maize shading under this system directly affects the light quality and intensity of soybean canopy. This is a challenging scenario in which to implement the MSR system, in terms of varieties selection, planting pattern, and crop management since the duration of crop resource utilization clearly differs. Methods Therefore, this experiment aimed to elucidate the effect of leaf excising treatments from maize top to fully clarify the needs and balance of light quality and intensity of intercrop-soybean under MSR in field conditions. The effects of different leaf excising treatments (T0, no removal of leaves; T2, removal of two topmost leaves; T4, removal of four topmost leaves; T6, removal of six topmost leaves from maize plants were applied at first-trifoliate stage (V1) of soybean) on photosynthetically active radiation transmittance (PART), red to far-red ratio (R:FR), morphological and photosynthetic characteristics and total biomass production at second-trifoliate stage (V2), fifth-trifoliate stage (V5), and flowering-stage (R1) of soybean were investigated through field experiments for 2-years under MSR. Results As compared to T0, treatment T6 increased the PART and R:FR ratio at soybean canopy by 77% and 37% (V2), 70% and 34% (V5), and 41% and 36% (R1), respectively. This improved light environment in T6 considerably enhanced the leaf area index, SPAD values and photosynthetic rate of soybean plants by 66%, 25% and 49% at R1, respectively than T0. Similarly, relative to control, T6 also increased the stem diameter (by 29%) but decreased the plant height (by 23%) which in turn significantly increased stem breaking strength (by 87%) by reducing the lodging rate (by 59%) of soybean plants. Overall, under T6, relay-cropped soybean produced 78% of sole soybean seed-yield, and relay-cropped maize produced 81% of sole maize seed-yield. Our findings implied that by maintaining the optimum level of PART (from 60% to 80%) and R:FR ratio (0.9 to 1.1), we can improve morphological and photosynthetic characteristics of soybean plants in MSR. Therefore, more attention should be paid to the light environment when considering the sustainability of MSR via appropriate planting pattern selection.

【 授权许可】

CC BY