According to the explanation given by the Secretary, the eucalypt is a tough plant that can grow even on barren land, so there is actually no need to apply pesticides.
Examples (Wiktionary)
Mandarin
盛产芋头的甲仙，其贫瘠土壤下蕴藏多种化石，还有平埔文化保存在山间。
盛產芋頭的甲仙，其貧瘠土壤下藴藏多種化石，還有平埔文化保存在山間。
shèng chǎn yù tou de jiǎ xiān ， qí pín jí tǔ rǎng xià yùn cáng duō zhǒng huà shí ， hái yǒu píng pǔ wén huà bǎo cún zài shān jiān ．
In Jiasian, which grows a lot of taro, fossils lie buried in the poor quality soil, and some Pingpu Aboriginal culture still survives.