由于土壤结构稳定性的丧失和土壤有机碳 (SOC) 的迅速消耗,作物生产力日益受到限制,因此通过在低肥力土壤上进行集约化农业实践来实现粮食安全具有挑战性。因此,从传统的单作向豆类谷物间作的转变,尤其是采用综合施肥,可能会以最少的生态足迹增加作物产量。我们在裂区设计中进行了为期 2 年的田间试验,其中豇豆-玉米单作和间作在不同的有机-无机施肥方案下进行,包括不施肥(对照)、仅有机投入(堆肥)、仅化学投入(NPK) , 和多营养丰富的堆肥 (NPKEC)。我们观察到,当施以 NPKEC 肥料时,与相应的单一栽培相比,间作玉米的生物量产量显着提高。然而,在所有施肥方案下,单一栽培和间作地块之间的豇豆生物量产量差异是可比的。相比之下,与单作相比,间作制度下玉米和豇豆的产量优势显着增强,NPKEC在所有施肥制度中表现出最显着的效果。在比较施肥制度对 SOC 的相对贡献时,NPKEC 肥料提供了最高的 SOC 固存(0.30 Mg C/ha yr 与单作相比,间作制度下玉米和豇豆的产量优势显着增强,NPKEC在所有施肥制度中表现出最显着的效果。在比较施肥制度对 SOC 的相对贡献时,NPKEC 肥料提供了最高的 SOC 固存(0.30 Mg C/ha yr 与单作相比,间作制度下玉米和豇豆的产量优势显着增强,NPKEC在所有施肥制度中表现出最显着的效果。在比较施肥制度对 SOC 的相对贡献时,NPKEC 肥料提供了最高的 SOC 固存(0.30 Mg C/ha yr-1 )。同时,种植制度对固碳的影响表明,间作提供了最高的固碳(0.17 Mg C/ha yr -1) 与两种作物的单一栽培相比。尽管与未施肥的对照地块相比,堆肥应用显着增加了矿物相关 (MAOC) 和颗粒相关有机碳 (PAOC) 浓度,但 NPKEC 施肥与间作系统是最有效的组合,导致两个土壤碳库随着时间的推移而增加最大。基于冗余分析 (RDA),MAOC 和 PAOC 与 C 封存的正相关表明这两种有机部分作为进行 SOC 储存的主要 C 储层的重要性。重要的是,尽管单独堆肥与间作相关的碳固存较低,但它与更好的土壤结构相关,这可以通过其与宏观和微观聚集体、水稳定聚集体 (WSA) 和平均重量直径的正相关关系得到证实。 MDA)。全面的,
"点击查看英文标题和摘要"
Role of fertilization regime on soil carbon sequestration and crop yield in a maize-cowpea intercropping system on low fertility soils
Achieving food security through intensive agricultural practices on low fertility soils is challenging as crop productivity is increasingly curtailed by the loss of soil structural stability and rapid depletion of soil organic carbon (SOC). As such, the conversion from traditional mono-cropping to legume-cereal intercropping, especially with integrated fertilization, may increase crop yields with the least ecological footprint. We set up a 2-year field experiment in a split-plot design with cowpea-maize monoculture and intercropping under different organic–inorganic fertilization regimes, including no fertilization (control), organic input only (compost), chemical input only (NPK), and multi-nutrient enriched compost (NPKEC). We observed that intercropped maize had a significantly higher biomass yield compared to the corresponding monoculture when fertilized with NPKEC fertilizer. However, cowpea biomass yield differences between monoculture and intercropped plots were comparable under all fertilization regimes. In contrast, the grain yield advantage of both maize and cowpea was significantly enhanced under the intercropping system compared to monoculture, with NPKEC showing the most significant effect among all fertilization regimes. When comparing the relative contribution of the fertilization regime to SOC, the NPKEC fertilizer provided the highest SOC-sequestration (0.30 Mg C/ha yr−1). At the same time, the effect of the cropping system on C-sequestration showed that intercropping provided the highest C-sequestration (0.17 Mg C/ha yr−1) compared to monocultures of both crops. Although compost application significantly increased mineral associated (MAOC) and particulate associated organic carbon (PAOC) concentrations compared to unfertilized control plots, NPKEC fertilization with intercropping system was the most effective combination causing the greatest increase of both soil C pools over time. Based on redundancy analysis (RDA), the positive association of MAOC and PAOC with C-sequestration suggests the importance of both organic fractions as primary C reservoirs conducting SOC storage. Importantly, although compost alone in association with intercropping had a lower C-sequestration, it was associated to a better soil structure as confirmed by its positive relationship with macro-and micro-aggregation, water stable aggregates (WSA), and mean weight diameter (MDA). Overall, our results indicate the importance of restoring soil structure in degraded soils through appropriate land management solutions, such as stoichiometrically balanced fertilization practices (NPKEC) and crop diversification (intercropping), in order to achieve significant gains in SOC storage and, ultimately, improve crop productivity.