Le semis très précoce : une stratégie agronomique pour améliorer les performances du soja en France ?

Abstract

Oilseeds & fats Crops and Lipids OCLAbstract -Very early sowing: an agronomic strategy to improve soybean performance in France ? This study was carried out on very early sowing of soybean in order to improve potential yield and/or reduce water requirements. Three varieties belonging to different maturity groups were selected to identify varietal traits of interest in very early sowing. A set of multi-location irrigated trials consisting in two sowing dates was performed from 2010 to 2014. Yield and water requirements were determined; crop development and growth was monitored on cv. Santana. The combined effects of low temperatures and photoperiod in very early sowing resulted in limited aboveground biomass production during vegetative period and increased grain filling duration. Maximal values for yield were observed in very early sowing modality, although yield was slightly lower in very early sowing compared to conventional one (3.7 t/ha vs. 3.9 t/ha).

Combining Simple Phenotyping and Photothermal Algorithm for the Prediction of Soybean Phenology: Application to a Range of Common Cultivars Grown in Europe

“…D1 and D5 represent new management practices. D1 begins to be tested in areas in order to escape water deficit around flowering and seed filling time (Maury et al, 2015). D5 is typical of double cropping systems, where soybean is planted after an early harvested crop (winter barley, pea) (Quinsac et al, 2014).…”

“…In the context of climate change, southern areas in Europe are expected to experience more frequent and severe drought and heat waves while northern areas may benefit from higher temperatures in late season (IPCC, 2014). Three cropping strategies could be proposed to grow soybean under these conditions: (i) early sowing to use less irrigation water in summer as escaping strategy (Maury et al, 2015); (ii) northward cultivation of the crop to extend its cropping area toward regions becoming more suitable with increasing temperatures (Olesen et al, 2011); or (iii) double cropping after cereals under late sowing to fully use the thermal time window (Seifert and Lobell, 2015). These new crop management systems using either early or late sowing and new cultivation areas will expose the crop to a wider range of thermal and photoperiodic conditions under higher latitudes (from 43°to 52°N).…”

“…The change in sowing dates, mostly tested on late maturity groups from III to VII (Bowers, 1995;Hu and Wiatrak, 2012;Salmeron et al, 2014), can place the early maturing soybean cultivars of interest in this study under suboptimal temperature conditions. Indeed, early planting increases the likelihood of exposing soybean to temperatures lower than T0 during early developmental stages (Meyer and Badaruddin, 2001;Maury et al, 2015), whereas late sowings for double cropping will lead to exposure to suboptimal temperatures for development at the end of the cycle and a risk of frost before harvest (Mahieu and Brinkman, 1990;Shapiro et al, 1992). The accumulation of thermal time for development can be calculated in different ways: (i) a linear equation, where daily thermal time is calculated by subtracting T0 from daily average temperature and then accumulated over the period of interest; (ii) a bilinear equation, which takes into account both T0 and Topt to obtain an upper bound temperature above which thermal time is not accumulated (Brisson et al, 2003); another bilinear triangular equation adds Tmax to impact the temperature accumulation between Topt and Tmax (Jones et al, 2003;Keating et al, 2003), and finally (iii) a nonlinear equation that uses the three cardinal temperatures and more closely represents temperature effect on biological functioning (Wang and Engel, 1998).…”

Facteurs antitryspiques de la graine de soja : évaluation de la variabilité génotypique dans une collection de référence ; effet du semis précoce et de la réduction de l’irrigation

“…En raison des différences pluviométriques entre les deux années (Maury et al 2015), l'effet de l'irrigation n'est significatif qu'en 2013 avec une valeur moyenne d'AAT supérieure pour les plantes cultivées en sec (41,6 TIU.mg −1 en sec vs. 40,3 TIU.mg −1 en irrigué). Cet écart reste de faible amplitude (l'AAT de la culture non irriguée n'est augmentée que de 3 % par rapport à l'irrigation selon la méthode IRRIsoja).…”

Combining Experimental and Modeling Approaches to Understand Genotype x Sowing Date x Environment Interaction Effects on Emergence Rates and Grain Yield of Soybean

“…This is especially true for southern European regions including South-West of France which is one of the two key French soybean production regions ( Terres Inovia, 2019 ). Summer drought in these regions has been reported as the main limiting factor that affect the flowering and seed filling phase, critical for soybean yield ( Maury et al, 2015 ). In contrast, an early sowing, as compared with conventional sowing dates, may provide higher crop yield in two ways across these regions ( Schoving, 2020 ; Schoving et al, 2020 ): (i) by allowing soybean to produce more pods and seeds due to early flowering, at a less advanced vegetative stage and (ii) by allowing the crop to escape water deficit around flowering and seed filling phase.…”