The rise of medium-scale farmers across sub-Saharan Africa (SSA) is offering Conservation agriculture (CA) a new perspective. Such farmers not only cultivate increasingly large land areas but also provide machinery services, share knowledge, and can act as role models to smallholders. Although mechanization may incentivize CA adoption in SSA, little research has focused on the performance of mechanized CA using four-wheel tractors (4WTs). This study explores the short-term agronomic and economic differences between mechanized conventional tillage and mechanized CA. An on-farm experiment was set up in a randomized complete block design in Zambia to compare 1) disc harrowing (DH) plus residue burning, 2) ripping tillage (RT), and 3) direct seeding (DS) plus soil cover. The experiment focused on maize and soyabean and covered two years, of which the first was more “dry” and the second more “wet”. All treatments were replicated four times and crops were rotated in the subsequent season. All operations were performed using a 60 hp 4WT. For both maize and soyabeans, DS and RT treatments resulted in higher grain yields during the dry season than DH. However, in the wet season, DH and RT resulted in significantly higher yields than DS for maize, but not for soyabeans. RT and DS plots showed higher plant densities in maize and soyabeans at germination and maturity than DH plots. RT plots produced significantly higher maize vegetative biomass (5928 kg ha⁻¹) in the dry season while in the wet season DS recorded significantly higher biomass yields (7886 kg ha⁻¹). The cumulative time for all agronomic operations except harvesting for both maize and soyabean was significantly lower in DS while DH and RT treatments recorded no significant differences. Fuel-saving was significantly higher in DS and RT than in DH plots for the two crops. Maize gross margin was highest in DS plots (US$790 ha-1) in the dry season compared to US$746 ha-1 for DH and US$768ha-1 for RT. In the wet season, DH plots had the highest gross margins for maize (US$685 ha-1) as compared to US$576 ha-1 for DS and US$581 ha-1 for RT. Regarding soyabeans, DS treatments had the highest gross margins in both seasons, US$537 ha-1 and US$392 ha-1, respectively. The results of this short-term study demonstrate the potential of mechanized CA among small and medium-scale farmers in SSA.

撒哈拉以南非洲 (SSA) 中型农民的兴起为保护性农业 (CA) 提供了新的视角。这些农民不仅耕种越来越大的土地，还提供机械服务、分享知识，并可以成为小农的榜样。尽管机械化可能会激励在 SSA 中采用 CA，但很少有研究关注使用四轮拖拉机 (4WT) 的机械化 CA 的性能。本研究探讨了机械化常规耕作和机械化 CA 之间的短期农艺和经济差异。在赞比亚以随机完整区组设计进行农场试验，以比较 1) 圆盘耙 (DH) 加残茬焚烧，2) 翻耕 (RT)，和 3) 直播 (DS) 加土壤覆盖。该实验以玉米和大豆为重点，为期两年，其中第一个更“干”，第二个更“湿”。所有处理重复四次，并在随后的季节轮作作物。所有操作均使用 60 hp 4WT 进行。对于玉米和大豆，DS 和 RT 处理导致旱季谷物产量高于 DH。然而，在雨季，DH 和 RT 导致玉米的产量明显高于 DS，但大豆则不然。RT 和 DS 地块显示玉米和大豆在发芽和成熟时的植物密度高于 DH 地块。RT地块产生显着更高的玉米营养生物量（5928 kg ha DS 和 RT 处理导致旱季谷物产量高于 DH。然而，在雨季，DH 和 RT 导致玉米的产量明显高于 DS，但大豆则不然。RT 和 DS 地块显示玉米和大豆在发芽和成熟时的植物密度高于 DH 地块。RT地块产生显着更高的玉米营养生物量（5928 kg ha DS 和 RT 处理导致旱季谷物产量高于 DH。然而，在雨季，DH 和 RT 导致玉米的产量明显高于 DS，但大豆则不然。RT 和 DS 地块显示玉米和大豆在发芽和成熟时的植物密度高于 DH 地块。RT地块产生显着更高的玉米营养生物量（5928 kg ha^-1 ) 在旱季，而在雨季 DS 记录了显着更高的生物量产量（7886 kg ha ^-1）。除玉米和大豆收获外，所有农艺操作的累积时间在 DS 中显着降低，而 DH 和 RT 处理没有显着差异。对于两种作物，DS 和 RT 的燃料节省显着高于 DH 地块。旱季 DS 地块的玉米毛利率最高（790 ha-1 美元），而 DH 地块为 746 公顷 1 美元，RT 地块为 768ha-1 美元。在雨季，DH 地块的玉米毛利率最高（685 公顷-1 美元），相比之下，DS 地块的毛利率为 576 公顷，RT 地块为 581 公顷。在大豆方面，DS 处理在两个季节的毛利率最高，分别为 537 公顷和 392 公顷。这项短期研究的结果证明了机械化 CA 在 SSA 中小型农民中的潜力。