Straw-returning to field 基本例句 还田 Maize straw returning to the field can increase the soil total nitrogen and inorganic nitrogen content.秸秆还田增加了土壤全氮和无机氮含量。 He has been working in the field, top dressing crop-stalk made fertilizers to the crop.他这几天一直在地里为庄稼还田。