The influence of three levels of water supply (unlimited (WW); water stress during flowering (RO); rainfed (P)) on radiation properties and yield of two soybean varieties (Sinara, Sin; Sigalia, Sig) were evaluated. Sin is considered to be tolerant to water stress. The effect of leaf area index, year, variety, and meteorological variables on evapotranspiration (ET) was analysed by hierarchical regression. This study attempted to identify how water supply affects the crop–light relationship between photosynthetically active radiation (PAR) transmission and radiation use efficiency (RUE), which were involved in qualitative and quantitative traits related to soybean production (biomass and yield attributes: seed yield, 1000-grain weight, oil and protein content). Unstandardized coefficients of air temperature (T_a) showed that a 1 °C increase in daily mean T_a induced a higher ET, on average 0.16 mm day⁻¹. Soil moisture strongly affected sowing time. When averaged across three seasons at flowering, 97.7, 95.1 and 97.3% of incoming PAR were intercepted by the canopies of plants in WW, RO and P, respectively. The average extinction coefficient (k) and RUE pooled across both varieties were 0.42 and 1.32 g MJ PAR⁻¹ for WW, and 0.46 and 0.98 g MJ PAR⁻¹ for RO, respectively, compared with 0.44 and 1.15 g MJ PAR⁻¹ for P. As expected, water treatment significantly affected all yield traits: RO decreased yield whereas WW increased yield compared to P. Practically, both varieties are suitable for cultivation under water stress during flowering but Sin showed greater yield under unlimited watering and rainfed conditions.

评估了三个供水水平（无限（WW）；开花期水分胁迫（RO）；雨育（P））对两个大豆品种（Sinara，Sin； Sigalia，Sig）的辐射特性和产量的影响。罪被认为可以忍受水分胁迫。通过分层回归分析了叶面积指数，年，品种和气象变量对蒸散量（ET）的影响。这项研究试图确定供水如何影响光合有效辐射（PAR）传输和辐射利用效率（RUE）之间的作物与光的关系，这些关系涉及与大豆生产相关的定性和定量特征（生物量和产量属性：种子产量） ，1000粒重，油脂和蛋白质含量）。空气温度的非标准化系数（T _a）表明每日平均T _a升高1°C会导致更高的ET，平均ET第^-1天^-1。土壤水分严重影响播种时间。在三个季节的开花平均值上，分别有97.7％，95.1％和97.3％的传入PAR被WW，RO和P的植物冠层截获。的平均消光系数（ķ跨两个品种汇集）和RUE分别为0.42和1.32克MJ PAR ^-1为WW，和0.46和0.98克MJ PAR ^-1为RO，分别与0.44和1.15克MJ PAR相比^-1 如预期的那样，水处理显着影响了所有产量性状：与P相比，RO降低了产量，而WW增加了产量。实际上，两个品种都适合在开花期间在水分胁迫下种植，而Sin在无限的浇水和雨水条件下表现出更高的产量。