美国伊利诺州唐拉公司从门冬氨酸大量制取聚门冬氨酸，生成时以液体形式出现，将其与液体或颗粒肥料同时施用。它们带有负电，能聚集土壤中带正电的营养成分铵、钾、钙、铁和镁离子，带负电的磷酸根等也同时被吸引至根区，使植物能更好利用原来可能要丢失的低于正常水平5～10倍 Polylactic acid is produced in large quantities from aspartic acid in the United States, Illinois, and is produced in the form of a liquid when applied simultaneously with liquid or granular fertilizers. They are negatively charged and can accumulate positively charged nutrients such as ammonium, potassium, calcium, iron and magnesium in the soil, negatively charged phosphates and the like, which are also attracted to the root zone, allowing plants to make better use of what might otherwise be lost Less than the normal level of 5 to 10 times