Australia produces some of the highest sweetpotato yields in the world but the health of the soil used to produce the crop is declining because it is repeatedly tilled to kill volunteer sweetpotatoes, incorporate cover crop residues and prepare beds for planting. Additional disturbance occurs when the swollen roots are harvested. An on-farm study showed that it is possible to replace this tillage-dominated farming system with an alternative that is not only productive, but is also likely to be sustainable in the long-term. When the soil was amended with organic matter, beds were formed 10 months prior to planting, two cover crops (forage sorghum followed by oats) were grown on the beds, residues from those crops were retained on the soil surface as mulch, and sweetpotato cuttings were planted into the mulched, undisturbed beds using strip tillage, the crop established well and yielded 93 t/ha. The only detrimental effect was that root-knot nematode (Meloidogyne incognita) caused severe damage. In contrast, a trial in the same field showed that when organic amendments were placed in a furrow in the centre of the bed so that the swollen roots were surrounded by the amendment as they developed, nematode control was much better. Sawdust and a mixture of sawdust and chicken litter were the most effective amendments, as they both reduced root-knot nematode populations and the severity of nematode damage, and increased marketable yield by 29%. The wide range of natural enemies found in soil collected from the amended furrow at harvest, and the results of a suppression assay in the laboratory suggested that the soils amended with sawdust and sawdust /chicken litter were biologically suppressive to root-knot nematode.

中文翻译：

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可持续甘薯耕作系统可改善土壤健康并减少根结线虫造成的损失

澳大利亚生产的甘薯产量是世界上最高的，但用于生产该作物的土壤的健康状况正在下降，因为它被反复耕种以杀死自愿甘薯，加入覆盖作物残留物并准备种植床。当收获肿胀的根时会发生额外的干扰。一项农场研究表明，有可能用一种不仅高产而且可能长期可持续的替代方法来取代这种以耕作为主的农业系统。当土壤用有机物质改良后，在种植前 10 个月形成床，在床上种植两种覆盖作物（高粱草料和燕麦），这些作物的残留物作为覆盖物保留在土壤表面，甘薯插条使用条带耕作将它们种植在覆盖的、不受干扰的床上，作物长势良好，产量为 93 吨/公顷。唯一的不利影响是根结线虫（Meloidogyne incognita）造成了严重的损害。相比之下，同一领域的一项试验表明，将有机改良剂放置在床中心的犁沟中，使肿胀的根部在生长时被改良剂包围，线虫控制效果要好得多。锯末以及锯末和鸡粪的混合物是最有效的改良剂，因为它们都减少了根结线虫的数量和线虫危害的严重程度，并将可销售的产量提高了 29%。在收获时从改良的犁沟收集的土壤中发现的各种天敌，