Chen Guopeng, Ren Yongfu, Mohi Ud Din Atta, Gul Hina, Chen Hanlin, Liang Bing, Pu Tian, Sun Xin, Yong Taiwen, Liu Weiguo, Liu Jiang, Du Junbo, Yang Feng, Wu Yushan, Wang Xiaochun, Yang Wenyu
College of Agronomy, Sichuan Agricultural University, Chengdu, China.
Sichuan Engineering Research Center for Crop Strip Intercropping System, Key Laboratory of Crop Ecophysiology and Farming System in Southwest China (Ministry of Agriculture), Chengdu, China.
Front Plant Sci. 2022 Nov 15;13:1031024. doi: 10.3389/fpls.2022.1031024. eCollection 2022.
Intercropping is a high-yield, resource-efficient planting method. There is a large gap between actual yield and potential yield at farmer's field. Their actual yield of intercropped maize remains unclear under low solar radiation-area, whether this yield can be improved, and if so, what are the underlying mechanism for increasing yield? In the present study, we collected the field management and yield data of intercropping maize by conducting a survey comprising 300 farmer households in 2016-2017. Subsequently, based on surveyed data, we designed an experiment including a high density planting (Dense cultivation and high N fertilization with plough tillage; DC) and normal farmer practice (Common cultivation; CC) to analyze the yield, canopy structure, light interception, photosynthetic parameters, and photosynthetic productivity. Most farmers preferred rotary tillage with a low planting density and N fertilization. Survey data showed that farmer yield ranged between 4-6 Mg ha, with highest yield recorded at 10-12 Mg ha, suggesting a possibility for yield improvement by improved cropping practices. Results from high density experiment showed that the two-years average yield for DC was 28.8% higher than the CC. Compared to CC, the lower angle between stem and leaf (LA) and higher leaf area index (LAI) in DC resulted in higher light interception in middle canopy and increased the photosynthetic productivity under DC. Moreover, in upper and lower canopies, the average activity of phosphoenolpyruvate (PEP) carboxylase was 70% higher in DC than CC. Briefly, increase in LAI and high Pn improved both light interception and photosynthetic productivity, thereby mediating an increase in the maize yield. Overall, these results indicated that farmer's yields on average can be increased by 2.1 Mg ha by increasing planting density and N fertilization, under plough tillage.
间作是一种高产、资源高效的种植方法。在农民田间，实际产量与潜在产量之间存在很大差距。在低太阳辐射地区，间作玉米的实际产量仍不明确，这种产量是否可以提高，如果可以，增产的潜在机制是什么？在本研究中，我们通过对2016 - 2017年300户农户进行调查，收集了间作玉米的田间管理和产量数据。随后，基于调查数据，我们设计了一个实验，包括高密度种植（深耕密植并高施氮肥；DC）和常规农民做法（常规种植；CC），以分析产量、冠层结构、光截获、光合参数和光合生产力。大多数农民更喜欢采用低密度种植和施氮肥的旋耕方式。调查数据显示，农民的产量在4 - 6 Mg/ha之间，最高产量记录为10 - 12 Mg/ha，这表明通过改进种植方式有可能提高产量。高密度实验结果表明，DC的两年平均产量比CC高28.8%。与CC相比，DC中茎与叶（LA）之间的夹角较小且叶面积指数（LAI）较高，导致中层冠层的光截获量更高，并提高了DC下的光合生产力。此外，在上层和下层冠层中，DC中磷酸烯醇式丙酮酸（PEP）羧化酶的平均活性比CC高70%。简而言之，LAI的增加和高光合速率（Pn）改善了光截获和光合生产力，从而促进了玉米产量的增加。总体而言，这些结果表明，在深耕条件下，通过增加种植密度和氮肥施用量，农民的平均产量可以提高2.1 Mg/ha。
