Casella Alejandra, Orden Luciano, Pezzola Néstor A, Bellaccomo Carolina, Winschel Cristina I, Caballero Gabriel R, Delegido Jesús, Gracia Luis Manuel Navas, Verrelst Jochem
Permanent Observatory of Agro-Ecosystems, Climate and Water Institute-National Agricultural Research Centre (ICyA-CNIA), National Institute of Agricultural Technology (INTA), Nicolás Repetto s/n, Hurlingham 1686, Buenos Aires, Argentina.
Estación Experimental Agropecuaria INTA Ascasubi (EEA INTA Ascasubi), Ruta 3 Km 794, Hilario Ascasubi 8142, Buenos Aires, Argentina.
Agronomy (Basel). 2022 Aug 11;12(8):1884. doi: 10.3390/agronomy12081884.
The production of onions bulbs ( L.) requires a high amount of nitrogen. According to the demand of sustainable agriculture, the information-development and communication technologies allow for improving the efficiency of nitrogen fertilization. In the south of the province of Buenos Aires, Argentina, between 8000 and 10,000 hectares per year are cultivated in the districts of Villarino and Patagones. This work aimed to analyze the relationship of biophysical variables: leaf area index (LAI), canopy chlorophyll content (CCC), and canopy cover factor (fCOVER), with the nitrogen fertilization of an intermediate cycle onion crop and its effects on yield. A field trial study with different doses of granulated urea and granulated urea was carried out, where biophysical characteristics were evaluated in the field and in Sentinel-2 satellite observations. Field data correlated well with satellite data, with an R of 0.91, 0.96, and 0.85 for LAI, fCOVER, and CCC, respectively. The application of nitrogen in all its doses produced significantly higher yields than the control. The LAI and CCC variables had a positive correlation with yield in the months of November and December. A significant difference was observed between U250 (62 Mg ha) and the other treatments. The U500 dose led to a yield increase of 27% compared to U250, while the difference between U750 and U500 was 6%.
洋葱（L.）鳞茎的生产需要大量氮肥。根据可持续农业的需求，信息开发与通信技术有助于提高氮肥施用效率。在阿根廷布宜诺斯艾利斯省南部，比利亚里诺和帕塔贡内斯地区每年种植面积在8000至10000公顷之间。这项工作旨在分析生物物理变量：叶面积指数（LAI）、冠层叶绿素含量（CCC）和冠层覆盖因子（fCOVER）与中周期洋葱作物氮肥施用的关系及其对产量的影响。进行了一项不同剂量颗粒尿素和颗粒尿素的田间试验研究，在田间和哨兵2号卫星观测中评估生物物理特征。田间数据与卫星数据相关性良好，LAI、fCOVER和CCC的R值分别为0.91、0.96和0.85。所有剂量的氮肥施用均产生了显著高于对照的产量。在11月和12月，LAI和CCC变量与产量呈正相关。观察到U250（62 Mg/ha）与其他处理之间存在显著差异。与U250相比，U500剂量导致产量增加27%，而U750和U500之间的差异为6%。
