Senghor Yolande, Balde Alpha B, Manga Anicet G B, Affholder François, Letourmy Philippe, Bassene César, Kanfany Ghislain, Ndiaye Malick, Couedel Antoine, Leroux Louise, Falconnier Gatien N
Département Productions Végétales et Agronomie, UFR des Sciences Agronomiques, de l'Aquaculture et des Technologies Alimentaires (S2ATA), Université Gaston Berger, B.P. 234, Saint Louis, Senegal.
CIRAD, UPR AIDA, F-34398, Montpellier, France.
Heliyon. 2023 Jul 1;9(7):e17680. doi: 10.1016/j.heliyon.2023.e17680. eCollection 2023 Jul.
Cereal-legume intercropping has been traditionally practiced across West Africa by farmers and provides resilience of agriculture to climate variability. Intensification of these extensive intercropping systems in order to meet future food demand is critical. This study aims at evaluating the agronomic performance of the intensification of millet-cowpea intercropping with low cowpea density, and its variation with climate variability, using an on-station experiment in Bambey, Senegal. Two trials (irrigated vs rainfed) were set up to compare millet sole- and inter-cropping with a grain and a fodder variety of cowpea, in 2018 and 2019. Two levels of fertilization were tested: 0 kg(N) ha and 69 kg(N) ha. The two cropping years were contrasting and water stress around flowering and/or during grain filling (indicated by the Fraction of Transpirable Soil Water) was higher in 2019 than in 2018 in the rainfed experiment. In both experiment and for all treatments, land equivalent ratio (LER) in the intercropping was 1.6 and 1.4 for grain and biomass respectively. Millet aboveground biomass was significantly higher in intercropping than in sole cropping in the irrigated experiment but not in the rainfed experiment. In the rainfed experiment, the interaction between cropping system and year was significant, so that millet aboveground biomass was greater in intercropping than in sole cropping in 2018 (year of lower water stress) but not in 2019 (year of higher water stress). The effect of fertilization on millet aboveground biomass did not significantly interact with cropping system (sole vs intercrop). For grain yield, fertilization interacted significantly with the cropping system in the irrigated trial: the benefits of intercropping on millet grain yield were greater with 69 kg(N) ha than with 0 kg(N) ha. This significant interaction could not be observed in the rainfed trial, potentially due to water stress. These results show that the level of water stress (related here to the year and to the rainfed or irrigated experiment) and that of fertilization modulate the performance of millet-cowpea intercropping in the semi-arid context of Senegal. Overall, fertilization had a stronger effect on millet grain yield than intercropping. The two strategies (intercropping and mineral fertilization) can be complementary to achieve sustainable intensification of cropping system in semi-arid areas of West Africa.
在西非，农民们传统上一直采用谷物 - 豆类间作的方式，这种方式能使农业对气候变化具有适应能力。为了满足未来的粮食需求，强化这些粗放的间作系统至关重要。本研究旨在通过在塞内加尔班贝进行的田间试验，评估低密度豇豆强化粟 - 豇豆间作的农艺性能及其随气候变化的差异。2018年和2019年设置了两个试验（灌溉与雨养），以比较粟的单作和间作，以及豇豆的籽粒型和饲料型品种。测试了两个施肥水平：0千克（氮）/公顷和69千克（氮）/公顷。这两个种植年份情况不同，在雨养试验中，2019年开花期和/或灌浆期的水分胁迫（用可蒸发土壤水分分数表示）高于2018年。在两个试验以及所有处理中，间作的土地当量比（LER），籽粒型为1.6，生物量型为1.4。在灌溉试验中，间作的粟地上生物量显著高于单作，但在雨养试验中并非如此。在雨养试验中，种植系统与年份之间的交互作用显著，因此在2018年（水分胁迫较低的年份）间作的粟地上生物量大于单作，但在2019年（水分胁迫较高的年份）并非如此。施肥对粟地上生物量的影响与种植系统（单作与间作）没有显著的交互作用。对于籽粒产量，在灌溉试验中施肥与种植系统有显著的交互作用：与0千克（氮）/公顷相比，69千克（氮）/公顷时间作对粟籽粒产量的益处更大。在雨养试验中未观察到这种显著的交互作用，可能是由于水分胁迫。这些结果表明，水分胁迫水平（这里与年份以及雨养或灌溉试验有关）和施肥水平会调节塞内加尔半干旱地区粟 - 豇豆间作的性能。总体而言，施肥对粟籽粒产量的影响比对间作的影响更强。这两种策略（间作和矿物施肥）可以相互补充，以实现西非半干旱地区种植系统的可持续强化。
