Earthworms are known to play an important role in improving soil, decomposing agricultural litter, and enhancing soil fertility and crop yield. The acute toxicity of 17 herbicides to Eisenia fetida was determined by a contact filter paper toxicity bioassay and an artificial soil toxicity bioassay. Results of 48 h by the contact filter paper toxicity bioassay, metamifop was high toxicity to E. fetida with LC₅₀ (median lethal concentration) value of 7.6 μg∙cm^-2; pretilachlor, haloxyfop-R-methyl, and bentazone were moderate toxicity to E. fetida with LC₅₀ values of 10.7, 12.7, and 61.3 μg∙cm^-2, respectively; quinclorac, MCPA-Na, topramezone, glufosinate ammonium, nicosulfuron, and bispyribac-sodium were low toxicity to E. fetida with LC₅₀ values of 143.0, 198.2, 211.1, 466.9, 433.7, and 649.2 μg∙cm^-2, respectively; pyrazosulfuron-ethyl, penoxsulam, pyribenzoxim, cyhalofop-butyl, fluoroglycofen, pendimethalin, and mesotrione were slight toxicity to E. fetida with LC₅₀ values greater than 1000 μg∙cm^-2. Results of 14 d by the artificial soil toxicity bioassay, haloxyfop-R-methyl showed the highest toxicity to E. fetida with LC₅₀ value of 148.9 mg∙kg^-1; followed by pretilachlor, MCPA-Na, pendimethalin, and metamifop, the LC₅₀ values were 211.5, 335.0, 342.4, and 345.7 mg∙kg^-1, respectively; the other tested herbicides were low toxicity to E. fetida with LC₅₀ values greater than 500 mg∙kg^-1. According to the guidelines of environmental safety evaluation for chemical pesticides, the 17 herbicides determined by an artificial soil toxicity bioassay were low toxicity to E. fetida. The results of this study can provide new data information for assessing the ecological risk of herbicides to earthworm, and also provide technical guidance for the safe use of herbicides in agricultural production.

Farmland is fundamental to grain production. Recently, as the grain output increased year by year, resources and environment faced with multiple challenges. The farmland is high-intensity used, seriously overdrawn, deteriorated, and polluted, which severely restrict the agricultural sustainable development in China. It is a specific way to realize the implementation of a food crop production strategy based on farmland management and the application of technology by carrying out farmland rotation and fallow system to expand overall farmland production capacity, which has a strategic significance on promoting the development of green agriculture and guaranteeing national food security. This paper analyses the advancements and practices on farmland rotation and fallow system in and abroad, and put forward the research priorities and objectives on exploring pilot program of farmland rotation and fallow system. Including investigating farmland resources and regionalization suitable for rotation and fallow in key areas, discussing technological approaches to implement farmland rotation and fallow system in key areas, and establishing systems and mechanisms for exploring pilot program of farmland rotation and fallow system. All is to provide consultation for realizing agricultural transition in the 13th Five-Year Plan and assuring grain production capacity and national food security.