Cassava is growing in importance in Nigeria as a food and industrial crop. Current yields are low due to poor soil fertility and because farmers do not use improved germplasm, clean planting material, or improved crop management in Nigeria. To provide feasible agronomic recommendations targeting increased root yield, the effects of tillage intensity, fertilizer application, plant density and weed control were tested in 230 farmers’ fields in southwestern Nigeria over two years. In 2016, tillage treatments were zero, single and double passage with a disc plough, followed by ridging (soil shaping) versus leaving the soil flat. Fertilizer application at 75:20:90 kg ha⁻¹ NPK was tested against a control and two plant densities (10,000 versus 12,500 ha⁻¹) were compared. In 2017, plant density at 10,000 ha⁻¹ and double plough were excluded, while pre- and post-emergence herbicide application versus farmer’s choice of weed control (i.e. manual weeding using hand hoe) was introduced. Cassava was harvested at 12 months after planting, and yields were recorded as fresh root mass. In 2016, double plough (15.9 Mg ha⁻¹) had a minor advantage over single plough (14.3 Mg ha⁻¹), while zero plough produced 12.9 Mg ha⁻¹ (P < 0.001). Ridging increased yield significantly (P < 0.01) by 2.3 Mg ha⁻¹ after single and zero plough, but not after double plough. Across tillage treatments, planting at 12,500 plants ha⁻¹ and fertilizer application increased yields by 1.5 and 4.2 Mg ha⁻¹, respectively. In 2017, ridging resulted in a yield increase of 1.7 Mg ha⁻¹ after single plough and 5.6 Mg ha⁻¹ after zero plough. Fertilizer application increased root yield by 2.9 Mg ha^-1 across tillage treatments. The use of herbicides negatively affected cassava yields in zero plough fields, compared with manual weeding. After ploughing, yield in herbicide based and manual weed control were not different. Cassava root yield response to tillage intensity strongly varied across fields, with low-yielding fields commonly responding less frequently to tillage. We conclude that unresponsive fields require measures other than increased tillage intensity to increase cassava root yields and that cost-intensive tillage operations must be targeted to responsive fields together with fertilizer application and improved weed control.

在尼日利亚，木薯作为粮食和工业作物的重要性正日益提高。由于土壤肥力差，并且尼日利亚农民没有使用改良的种质，清洁的种植材料或改善的作物管理，目前的单产较低。为了提供针对增加根系产量的可行农艺建议，在两年多的时间里，在尼日利亚西南部的230个农民田间试验了耕作强度，肥料施用，植物密度和杂草控制的影响。在2016年，耕种处理为零，单次和两次通过圆盘犁耕，然后进行翻耕（土壤整形）而不是使土壤平坦。针对对照和两种植物密度（10,000与12,500 ha ^-1的肥料），以75:20:90 kg ha ^-1 NPK的施肥量进行了测试。）进行比较。在2017年，不包括10,000 ha ^-1的植物密度和双犁，同时介绍了出苗前和出苗后施用除草剂与农民选择的除草方法（即使用hand头人工除草）。木薯在播种后12个月收获，收获量记录为鲜根质量。2016年，双犁（15.9 Mg ha ^-1）较单犁（14.3 Mg ha ^-1）有较小的优势，而零犁产生12.9 Mg ha ^-1（P <0.001）。单次耕作和零次耕作后，套垄显着提高了2.3 Mg ha ^-1的产量（P <0.01），而两次耕作后则没有。整个耕作处理中，种植面积为12,500公顷公顷^-1施肥和施肥分别使产量增加1.5 Mg ha ^-1和4.2 Mg ha ^-1。在2017年，皱纹状变形造成1.7镁公顷的产量增加^-1单犁和5.6镁公顷之后^-1之后零犁。施肥可将根产量提高2.9 Mg ha ^-1耕作处理。与人工除草相比，除草剂的使用在零耕田不利地影响了木薯的产量。耕作后，基于除草剂和人工除草的产量没有差异。木薯根产量对耕作强度的响应在各个田间差异很大，低产田通常对耕作的响应频率较低。我们得出的结论是，无响应的田地除了增加耕作强度以外还需要采取其他措施来增加木薯根的产量，而且必须将成本高昂的耕作操作针对于响应性田地以及肥料施用和改善的杂草控制。