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Acta Agronomica Sinica ›› 2023, Vol. 49 ›› Issue (11): 3090-3099.doi: 10.3724/SP.J.1006.2023.34029

• TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY • Previous Articles     Next Articles

Effects of sowing date and density on stem, leaf growth, and yield formation in strip intercropping soybean

GAO Chao(), CHEN Ping, DU Qing, FU Zhi-Dan, LUO Kai, LIN Ping, LI Yi-Ling, LIU Shan-Shan, YONG Tai-Wen(), YANG Wen-Yu   

  1. College of Agronomy, Sichuan Agricultural University / Key Laboratory of Crop Ecophysiology and Farming System in Southwest, Ministry of Agriculture and Rural Affairs / Sichuan Engineering Research Center for Crop Strip Intercropping System, Chengdu 611130, Sichuan, China
  • Received:2023-02-17 Accepted:2023-05-24 Online:2023-11-12 Published:2023-06-02
  • Supported by:
    China Agriculture Research System of MOF and MARA(Soybean, CARS-04-PS20);Sichuan Science and Technology Plan(21NZZH0063)

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Abstract:

Based on the problems of weak light environment, variety and density selection in soybean-maize strip intercropping after rapeseed harvest in Southwest China, two varieties with different of maturity periods, Nanxiadou 25 (ND25, intermediate-late maturing, multi-branched) and Qihuang 34 (QH34, early maturing, less branched) were selected to explore the effects of sowing date (2021, S1: May 17, S2: May 27, S3: June 6; 2022, S1: May 10, S2: May 25, S3: June 9) and density (D1: 81,000 plants hm-2, D2: 101,000 plants hm-2, D3: 140,000 plants hm-2, D4: 171,000 plants hm-2) on the stem and leaf growth and yield formation of soybeans in strip intercropping. The results showed that at the same density, as the sowing date was delayed, the leaf area index of the two varieties decreased gradually at the beginning seed stage and the light transmittance inside the canopy increased gradually, the distribution ratio to pods of ND25 increased gradually and the lodging rate gradually decreased, while the distribution ratio to pods of QH34 to pods gradually decreased and the lodging rate gradually increased. At the same sowing date, with the increase of density, the leaf area index of the two varieties at the beginning seed stage gradually increased, the light transmittance gradually decreased, the dry matter distribution ratio of the pods gradually decreased, and the lodging rate gradually increased. Differences in light environment and dry matter distribution had different effects on the yield of different varieties. For ND25, S3 > S2 > S1 and D1 > D2 > D3 > D4, optimum yield was obtained with the yield of 1752.89 kg hm-2 at S3 and D1. For QH34, S1 > S2 > S3 and D3 > D2 > D1 > D4, optimum yield was obtained with the yield of 1538.64 kg hm-2 at S1 and D3. Therefore, intermediate-late maturing varieties should be appropriately sown later, while early maturing varieties should be appropriately sown earlier. Multi-branched varieties should be appropriately thinly planted, while less-branched varieties should be appropriately densely planted. The yield of soybeans can be increased through the synergy of sowing date and density for each variety.

Key words: soybean-maize strip intercropping, sowing date, density, photosynthetic characteristics, dry matter allocation, yield

Fig. 1

Field planting image of soybean-maize strip intercropping"

Fig. 2

Internal light transmittance of soybean canopy under different sowing dates and densities ND25: Nanxiadou 25; QH34: Qihuang 34. Sowing date (S) 2021, S1: May 17; S2: May 27; S3: June 6; 2022, S1: May 10; S2: May 25; S3: June 9. Density (D) D1: 8.1×104 plants hm-2; D2: 10.1×104 plants hm-2; D3; 14×104 plants hm-2; D4: 17.1×104 plants hm-2. V5: the fifth trifoliate; R5: beginning seed. Different lowercase letters indicate significant difference in the 0.05 probability level among the different densities of the same sowing date."

Fig. 3

SPAD of soybean leaves at different sowing dates and densities Abbreviations and treatments are the same as those given in Fig. 2. Different lowercase letters indicate significant difference in the 0.05 probability level among the different densities of the same sowing date."

Fig. 4

Leaf area index of soybean leaves at different sowing dates and densities Abbreviations and treatments are the same as those given in Fig. 2. LAI: leaf area index. Different lowercase letters indicate significant difference in the 0.05 probability level among the different densities of the same sowing date."

Fig. 5

Dry matter distribution of soybeans under different sowing dates and densities Abbreviations and treatments are the same as those given in Fig. 2. Different lowercase letters indicate significant difference in the 0.05 probability level for the same indicator at different densities of the same sowing date."

Fig. 6

Lodging rate of soybeans under different sowing dates and densities Abbreviations and treatments are the same as those given in Fig. 2. Different lowercase letters indicate significant difference in the 0.05 probability level among the different densities of the same sowing date."

Table 1

Yield composition of soybeans under different sowing dates and densities"

年份
Year		 品种
Variety		 播期
Sowing		 有效株数NEP (plant m-2) 单株粒数 GNP 百粒重 GW (g) 产量 Yield (kg hm-2)
D1 D2 D3 D4 D1 D2 D3 D4 D1 D2 D3 D4 D1 D2 D3 D4
2021 ND25 S1 6.99 c 8.21 b 8.59 ab 8.85 a 64.63 a 48.90 b 41.33 c 38.70 c 24.52 b 25.28 ab 25.56 a 25.92 a 1107.67 a 1014.10 ab 906.74 bc 887.55 c
S2 7.31 d 8.43 c 9.10 b 10.35 a 75.60 a 58.43 b 48.15 c 41.30 d 24.90 a 25.31 a 25.45 a 25.82 a 1375.87 a 1246.59 b 1115.39 c 1103.14 c
S3 7.72 d 9.07 c 10.48 b 11.25 a 88.47 a 66.53 b 49.90 c 43.93 d 25.28 a 25.40 a 25.59 a 26.23 a 1727.28 a 1533.45 b 1339.71 c 1296.28 c
QH34 S1 7.69 c 9.10 b 11.47 a 12.08 a 62.17 a 57.87 b 52.42 c 35.20 d 23.60 b 24.11 b 24.37 b 25.88 a 1127.71 c 1268.98 b 1465.43 a 1100.25 c
S2 7.50 d 8.65 c 10.71 b 11.35 a 53.00 a 49.67 a 41.70 b 27.67 c 22.78 b 23.22 b 23.49 ab 24.53 a 904.09 b 994.67 ab 1047.10 a 770.26 c
S3 7.28 c 8.37 b 10.16 a 10.71 a 38.36 a 37.58 a 33.27 b 22.77 c 20.62 b 21.54 b 22.97 a 23.64 a 575.86 c 677.40 b 775.76 a 575.99 c
2022 ND25 S1 7.05 d 8.56 c 9.20 b 10.00 a 68.77 a 55.67 b 46.23 c 42.25 c 25.32 a 25.87 a 25.31 a 25.17 a 1229.29 a 1231.40 a 1079.87 b 1066.96 b
S2 7.40 d 8.94 c 9.81 b 11.06 a 84.58 a 66.50 b 50.85 c 42.25 d 25.04 a 25.39 a 25.24 a 25.94 a 1567.65 a 1509.12 a 1258.34 b 1211.40 b
S3 7.79 d 9.26 c 10.42 b 11.76 a 89.93 a 69.10 b 51.85 c 45.06 d 25.38 a 25.45 a 25.79 a 25.87 a 1778.49 a 1628.73 b 1392.63 c 1369.61 c
QH34 S1 7.63 c 9.46 b 12.02 a 12.53 a 68.65 a 60.86 b 55.63 b 37.97 c 23.16 b 23.25 b 24.16 b 25.47 a 1212.16 c 1335.79 b 1611.85 a 1212.30 c
S2 7.34 d 9.17 c 11.03 b 11.63 a 55.12 a 49.59 a 43.19 b 30.25 c 22.70 b 23.07 b 23.54 ab 24.48 a 918.30 b 1047.43 a 1121.88 a 861.43 b
S3 7.08 c 8.94 b 10.48 a 10.96 a 46.88 a 44.93 a 38.75 b 22.70 c 21.33 c 22.52 b 23.22 ab 23.74 a 707.10 b 904.46 a 941.89 a 588.74 c
有效株数 单株粒数 百粒重 产量 有效株数 单株粒数 百粒重 产量
NEP (plant m-2) GNP GW (g) Yield (kg hm-2) NEP (plant m-2) GNP GW (g) Yield (kg hm-2)
F值
F-value		 ND25 年份Y 31.81** 38.26** 0.10 ns 53.63** 9.78** 26.47** 0.00 ns 43.17**
播期S 105.71** 127.12** 1.43 ns 181.24** 46.22** 229.72** 40.94** 493.83**
密度D 344.54** 644.65** 5.10** 60.05** 493.53** 241.61** 35.36** 85.48**
Y×S 2.60ns 2.89 ns 0.05 ns 3.49* 0.10 ns 2.53 ns 3.05 ns 2.17 ns
Y×D 4.14* 1.89 ns 1.30 ns 0.85 ns 2.64 ns 1.36 ns 0.06 ns 0.89 ns
S×D 7.45** 15.06** 0.47 ns 2.55* 3.19* 2.59* 1.41 ns 3.42**
Y×S×D 0.77 ns 0.91 ns 0.73 ns 0.32 ns 0.14 ns 0.95 ns 0.36 ns 1.50 ns
[1] Man W, Fu L, Song W, Wu C, Jiang B, Hou W, Ren G, Han T. Temporospatial characterization of nutritional and bioactive components of soybean cultivars in China. J Am Oil Chem Soc, 2016, 93: 1637-1654.
doi: 10.1007/s11746-016-2908-4
[2] 潘雪婷, 穆月英. 国际关系对中国大豆进口来源的影响. 世界农业, 2022, 44(7): 57-66.
Pan X T, Mu Y Y. The influence of international relations on China's soybean import sources. World Agric, 2022, 44(7): 57-66 (in Chinese).
[3] 王禹, 李干琼, 喻闻, 冯瑶, 钟鑫, 刘然, 许世卫. 中国大豆生产现状与前景展望. 湖北农业科学, 2020, 59(21): 201-207.
Wang Y, Li G Q, Yu W, Feng Y, Zhong X, Liu R, Xu S W. Current situation and prospect of soybean production in China. Hubei Agric Sci, 2020, 59(21): 201-207 (in Chinese with English abstract).
[4] 农业农村部: 编发大豆玉米带状复合种植指南. 农业机械, 2022, 65(2): 46.
Ministry of Agriculture and Rural Affairs: guide for braided soybean and corn strip compound planting. Farm Mach, 2022, 65(2): 46 (in Chinese).
[5] Umburanas R C, Yokoyama A H, Balena L, Dourado-Neto D, Teixeira W F, Zito R K, Reichardt K, Kawakami J. Soybean yield in different sowing dates and seeding rates in a subtropical environment. Int J Plant Prod, 2019, 13: 117-128.
doi: 10.1007/s42106-019-00040-0
[6] Xu C L, Li R D, Song W W, Wu T T, Sun S, Han T F, Wu C X. High density and uniform plant distribution improve soybean yield by regulating population uniformity and canopy light interception. Agronomy, 2021, 11: 1880.
doi: 10.3390/agronomy11091880
[7] 程彬, 刘卫国, 王莉, 许梅, 覃思思, 卢俊吉, 高阳, 李淑贤, Raza A, 张熠, Ahmad I, 敬树忠, 刘然金, 杨文钰. 种植密度对玉米-大豆带状间作下大豆光合、产量及茎秆抗倒的影响. 中国农业科学, 2021, 54: 4084-4096.
doi: 10.3864/j.issn.0578-1752.2021.19.005
Cheng B, Liu W G, Wang L, Xu M, Qin S S, Lu J J, Gao Y, Li S X, Raza A, Zhang Y, Ahmad I, Jing S Z, Liu R J, Yang W Y. Effects of planting density on photosynthesis, yield and stem toppling resistance of soybean under corn-soybean zonal intercropping. Sci Agric Sin, 2021, 54: 4084-4096 (in Chinese with English abstract).
[8] 赵建华, 孙建好, 李伟绮. 玉米播期对大豆/玉米间作产量及种间竞争力的影响. 中国生态农业学报, 2018, 26: 1634-1642.
Zhao J H, Sun J H, Li W Q. Effects of maize sowing date on yield and interspecific competitiveness of soybean/maize. Chin J Eco-Agric, 2018, 26: 1634-1642 (in Chinese with English abstract).
[9] 赵建华, 孙建好, 陈亮之, 李伟绮. 玉米行距对大豆/玉米间作作物生长及种间竞争力的影响. 大豆科学, 2019, 38: 229-235.
Zhao J H, Sun J H, Chen L Z, Li W Q. Effects of maize row spacing on growth and interspecific competitiveness of soybean/ maize intercropping. Soybean Sci, 2019, 38: 229-235 (in Chinese with English abstract).
[10] 徐婷. 播期和密度对套作大豆光合特性、干物质积累及产量的影响. 四川农业大学硕士学位论文,四川成都, 2014.
Xu T. Effects of Sowing Date and Density on Photosynthetic Characteristics, Dry Matter Accumulation and Yield of Intercropped Soybean. MS Thesis of Sichuan Agricultural University, Chengdu, Sichuan, China, 2014 (in Chinese with English abstract).
[11] 李国强, 汤亮, 张文宇, 曹卫星, 朱艳. 施氮量对不同株型小麦品种叶型垂直分布特征的影响. 作物学报, 2011, 37: 127-137.
doi: 10.3724/SP.J.1006.2011.00127
Li G Q, Tang L, Zhang W Y, Cao W X, Zhu Y. Effects of nitrogen application rate on vertical distribution characteristics of leaf patterns of wheat cultivars with different plant types. Acta Agron Sin, 2011, 37: 127-137 (in Chinese with English abstract).
doi: 10.3724/SP.J.1006.2011.00127
[12] 程伟燕, 李志刚, 李瑞平. 密度对大豆光合特性和产量的影响. 作物杂志, 2010, (4): 69-72.
Cheng W Y, Li Z G, Li R P. Effects of density on photosynthetic characteristics and yield of soybean. Crops, 2010, (4): 69-72 (in Chinese with English abstract).
[13] 吕丽华, 陶洪斌, 夏来坤, 张雅杰, 赵明, 赵久然, 王璞. 不同种植密度下的夏玉米冠层结构及光合特性. 作物学报, 2008, 34: 447-455.
doi: 10.3724/SP.J.1006.2008.00447
Lyu L H, Tao H B, Xia L K, Zhang Y J, Zhao M, Zhao J R, Wang P. Canopy structure and photosynthetic characteristics of summer maize under different planting densities. Acta Agron Sin, 2008, 34: 447-455 (in Chinese with English abstract).
doi: 10.3724/SP.J.1006.2008.00447
[14] Cheng B, Raza A, Wang L, Xu M, Lu J J, Gao Y, Qin S S, Zhang Y, Ahmad I, Zhou T, Wen B X, Yang W Y, Liu W G. Effects of multiple planting densities on lignin metabolism and lodging resistance of the strip intercropped soybean stem. Agronomy, 2020, 10: 1177.
doi: 10.3390/agronomy10081177
[15] 范虹, 殷文, 柴强. 间作优势的光合生理机制及其冠层微环境特征. 中国生态农业学报, 2022, 30: 1750-1761.
Fan H, Yin W, Chai Q. Photosynthetic physiological mechanism and canopy microenvironment characteristics of intercropping dominance. Chin J Eco-Agric, 2022, 30: 1750-1761 (in Chinese with English abstract).
[16] 翟云龙, 章建新, 薛丽华, 李宁. 密度对超高产春大豆农艺性状的影响. 中国农学通报, 2005, 22(2): 109-111.
Zhai Y L, Zhang J X, Xue L H, Li N. Effect of density on agronomic characters of super high yield spring soybean. Chin Agric Sci Bull, 2005, 22(2): 109-111 (in Chinese with English abstract).
[17] 高永刚, 高明, 杨晓强, 刘丹, 张志国, 孙守军. 播期对大豆开花期和鼓粒期叶片光合特性及产量的影响. 大豆科学, 2020, 39: 227-234.
Gao Y G, Gao M, Yang X Q, Liu D, Zhang Z G, Sun S J. Effects of sowing date on photosynthetic characteristics and yield of soybean leaves at flowering and filling stage. Soybean Sci, 2020, 39: 227-234 (in Chinese with English abstract).
[18] 白磊.施氮量与密度对高油大豆光合生产及产质量的影响. 东北农业大学硕士学位论文, 黑龙江哈尔滨, 2019.
Bai L. Effects of Nitrogen Application Rate and Density on Photosynthetic Production and Yield Quality of High Oil Soybean. MS Thesis of Northeast Agricultural University, Harbin, Heilongjiang, China, 2019 (in Chinese with English abstract).
[19] 田艺心, 高祺, 王春雨, 曹鹏鹏, 朱冠雄, 高凤菊. 高蛋白大豆新品种菏豆38播期与密度优化. 黑龙江农业科学, 2022, 45(7): 8-13.
Tian Y X, Gao Q, Wang C Y, Cao P P, Zhu G X, Gao F J. Sowing date and density optimization of a new soybean variety with high protein, Hedou 38. Heilongjiang Agric Sci, 2022, 45(7): 8-13 (in Chinese with English abstract).
[20] 徐海风, 杨加银, 熊正海. 播期、 密度对夏大豆新品种淮豆12产量的影响. 大豆科技, 2016, 24(4): 8-11.
Xu H F, Yang J Y, Xiong Z H. Effects of sowing date and density on yield of a new summer soybean variety Huaidou 12. Soybean Sci Technol, 2016, 24(4): 8-11 (in Chinese with English abstract).
[21] 李思同, 张桂花, 谷传彦, 黄兴蛟, 海亚耕. 播期•密度对夏大豆产量和脂肪含量的影响. 安徽农业科学, 2007, 35: 9185-9186.
Li S T, Zhang G H, Gu C Y, Huang X J, Hai Y G. Effects of sowing date and density on yield and fat content of summer soybean. J Anhui Agric Sci, 2007, 35: 9185-9186 (in Chinese with English abstract).
[22] 吴俊彦. 播期对黑河主栽大豆生育进程和产量及品质的影响. 中国农业科学院硕士学位论文,北京, 2013.
Wu J Y. Effects of Sowing Date on Growth Process, Yield and Quality of Main Soybean in Heihe. MS Thesis of Chinese Academy of Agricultural Sciences, Beijing, China, 2013 (in Chinese with English abstract).
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