van Heerwaarden Joost, Baijukya Frederick, Kyei-Boahen Stephen, Adjei-Nsiah Samuel, Ebanyat Peter, Kamai Nkeki, Wolde-Meskel Endalkachew, Kanampiu Fred, Vanlauwe Bernard, Giller Ken
Plant Production Systems, Wageningen University, P.O .Box 430,6700. AK, Wageningen, The Netherlands.
International Institute of Tropical Agriculture (IITA), Dar es Salaam, Tanzania.
Agric Ecosyst Environ. 2018 Jul 1;261:211-218. doi: 10.1016/j.agee.2017.08.016.
Improving bacterial nitrogen fixation in grain legumes is central to sustainable intensification of agriculture in sub-Saharan Africa. In the case of soyabean, two main approaches have been pursued: first, promiscuous varieties were developed to form effective symbiosis with locally abundant nitrogen fixing bacteria. Second, inoculation with elite bacterial strains is being promoted. Analyses of the success of these approaches in tropical smallholder systems are scarce. It is unclear how current promiscuous and non-promiscuous soyabean varieties perform in inoculated and uninoculated fields, and the extent of variation in inoculation response across regions and environmental conditions remains to be determined. We present an analysis of on-farm yields and inoculation responses across ten countries in Sub Saharan Africa, including both promiscuous and non-promiscuous varieties. By combining data from a core set of replicated on-farm trials with that from a large number of farmer-managed try-outs, we study the potential for inoculation to increase yields in both variety types and evaluate the magnitude and variability of response. Average yields were estimated to be 1343 and 1227 kg/ha with and without inoculation respectively. Inoculation response varied widely between trials and locations, with no clear spatial patterns at larger scales and without evidence that this variation could be explained by yield constraints or environmental conditions. On average, specific varieties had similar uninoculated yields, while responding more strongly to inoculation. Side-by side comparisons revealed that stronger responses were observed at sites where promiscuous varieties had superior uninoculated yields, suggesting the availability of compatible, effective bacteria as a yield limiting factor and as a determinant of the magnitude of inoculation response.
提高豆科粮食作物的细菌固氮能力是撒哈拉以南非洲农业可持续集约化的核心。就大豆而言，主要采取了两种方法：第一，培育杂交品种，使其与当地丰富的固氮细菌形成有效的共生关系。第二，推广接种优良菌株。对这些方法在热带小农户系统中的成功分析很少。目前尚不清楚现有的杂交和非杂交大豆品种在接种和未接种的田块中的表现如何，不同地区和环境条件下接种反应的变化程度仍有待确定。我们对撒哈拉以南非洲十个国家的农场产量和接种反应进行了分析，包括杂交和非杂交品种。通过将一组核心的重复农场试验数据与大量农民管理的试验数据相结合，我们研究了接种对两种品种类型增产的潜力，并评估了反应的幅度和变异性。接种和未接种情况下的平均产量估计分别为1343公斤/公顷和1227公斤/公顷。试验和地点之间的接种反应差异很大，在较大尺度上没有明显的空间模式，也没有证据表明这种差异可以用产量限制或环境条件来解释。平均而言，特定品种的未接种产量相似，但对接种的反应更强。并排比较显示，在杂交品种未接种产量较高的地点观察到更强的反应，这表明存在兼容、有效的细菌是产量限制因素和接种反应幅度的决定因素。
