Journal of Integrative Agriculture ›› 2024, Vol. 23 ›› Issue (1): 122-140.DOI: 10.1016/j.jia.2023.05.006

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水氮减量密植玉米的产量和氮素吸收

  

  • 收稿日期:2023-03-14 接受日期:2023-04-10 出版日期:2024-01-20 发布日期:2024-01-06

Grain yield and N uptake of maize in response to increased plant density under reduced water and nitrogen supply conditions

Jingui Wei1, 2, Qiang Chai1, 2#, Wen Yin1, 2#, Hong Fan1, Yao Guo3, Falong Hu1, 2, Zhilong Fan1, 2, Qiming Wang1, 2   

  1. 1 State Key Laboratory of Aridland Crop Science, Lanzhou 730070, China

    2 College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China

    3 College of Life Sciences, Northwest Normal University, Lanzhou 730070, China

  • Received:2023-03-14 Accepted:2023-04-10 Online:2024-01-20 Published:2024-01-06
  • About author:#Correspondence Qiang Chai, Tel: +86-931-7631145, E-mail: chaiq@gsau.edu.cn; Wen Yin, E-mail: yinwen@gsau.edu.cn
  • Supported by:

    We are very grateful for financial support of the National Natural Science Foundation of China (U21A20218 and 32101857), the ‘Double First-Class’ Key Scientific Research Project of Education Department in Gansu Province, China (GSSYLXM-02), the Fuxi Young Talents Fund of Gansu Agricultural University, China (Gaufx-03Y10), and the “Innovation Star” Program of Graduate Students in 2023 of Gansu Province, China (2023CXZX-681).

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摘要：

现代农业发展要求减少水和化学氮肥的投入。增加种植密度能够保持较高的产量，但也会消耗更多的限制性资源。然而，在干旱灌区，增加玉米种植密度能否补偿水氮供应减少对籽粒产量和氮素吸收的负面影响尚不清楚。本研究是2016年开始的一项长期定位试验。2020 - 2021年在中国西北干旱灌区，采用裂裂区玉米田间试验设计，有2个灌溉水平：当地传统灌水减量20%(W1, 3240 m3 ha-1)和当地传统灌水(W2, 4050 m3 ha-1)，当地传统施氮减量25% (N1, 270 kg ha-1)和当地传统施氮(360 kg ha-1) 2个施氮水平，3种种植密度：当地传统密度(D1, 75000株ha-1)、种植密度增加30%(D2, 97500株ha-1)、种植密度增加60%(D3, 120000株ha-1)。结果表明，在水氮减量条件下，玉米籽粒产量和地上部氮素积累量降低，但增密30%可补偿水分和施氮减量引起的玉米籽粒产量和地上部氮素积累量的降低。灌水减量施氮量不变时，增密30%提高籽粒产量13.9%，提高地上部氮素积累量15.3%。在水氮减量条件下，增加玉米密度30%可提高氮素吸收效率和氮肥偏生产力，并补偿氮素收获指数和氮代谢相关酶活性。与W2N2D1相比，W1N1D2的氮素吸收效率和氮肥偏生产力分别提高28.6%和17.6%。W1N2D2较W2N2D1氮吸收效率提高8.4%，氮肥偏生产力提高13.9%。与W2N2D1相比，W1N2D2提高R2期脲酶活性5.4%和V6期硝酸还原酶活性19.6%，净收益和产投比分别提高22.1%和16.7%。与W2N2D1相比，W1N1D2和W1N2D2降低了R6期40 ~ 100 cm硝态氮和氨态氮含量。综上所述，增加密度30%可补偿水氮减量造成的籽粒产量和地上部氮素积累损失。同时，在干旱灌区灌水减量20%但施氮量不变时，玉米增密30%可提高籽粒产量和地上部氮素积累量。

Abstract:

The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.  Increasing the planting density can maintain higher yields, but also consumes more of these restrictive resources.  However, whether an increased maize density can compensate for the negative effects of reduced water and N supply on grain yield and N uptake in the arid irrigated areas remains unknown.  This study is part of a long-term positioning trial that started in 2016.  A split-split plot field experiment of maize was implemented in the arid irrigated area of northwestern China in 2020 to 2021.  The treatments included two irrigation levels: local conventional irrigation reduced by 20% (W1, 3,240 m3 ha–1) and local conventional irrigation (W2, 4,050 m3 ha–1); two N application rates: local conventional N reduced by 25% (N1, 270 kg ha–1) and local conventional N (360 kg ha–1); and three planting densities: local conventional density (D1, 75,000 plants ha–1), density increased by 30% (D2, 97,500 plants ha–1), and density increased by 60% (D3, 120,000 plants ha–1).  Our results showed that the grain yield and aboveground N accumulation of maize were lower under the reduced water and N inputs, but increasing the maize density by 30% can compensate for the reductions of grain yield and aboveground N accumulation caused by the reduced water and N supply.  When water was reduced while the N application rate remained unchanged, increasing the planting density by 30% enhanced grain yield by 13.9% and aboveground N accumulation by 15.3%.  Under reduced water and N inputs, increasing the maize density by 30% enhanced N uptake efficiency and N partial factor productivity, and it also compensated for the N harvest index and N metabolic related enzyme activities.  Compared with W2N2D1, the N uptake efficiency and N partial factor productivity increased by 28.6 and 17.6% under W1N1D2.  W1N2D2 had 8.4% higher N uptake efficiency and 13.9% higher N partial factor productivity than W2N2D1.  W1N2D2 improved urease activity and nitrate reductase activity by 5.4% at the R2 (blister) stage and 19.6% at the V6 (6th leaf) stage, and increased net income and the benefit:cost ratio by 22.1 and 16.7%, respectively.  W1N1D2 and W1N2D2 reduced the nitrate nitrogen and ammoniacal nitrogen contents at the R6 stage in the 40–100 cm soil layer, compared with W2N2D1.  In summary, increasing the planting density by 30% can compensate for the loss of grain yield and aboveground N accumulation under reduced water and N inputs.  Meanwhile, increasing the maize density by 30% improved grain yield and aboveground N accumulation when water was reduced by 20% while the N application rate remained constant in arid irrigation areas.


Key words: water and N reduction ,  plants density ,  maize, grain yield ,  N uptake ,  compensation effect