Xin phép hỏi các anh/chị. Đoạn văn dưới đây là trong bản tin fertecon của ngành phân bón về thị trường Ammonia ở Mỹ. Các cụm từ gạch chân dưới đây có phải ám chỉ là họ dùng NH3 trực tiếp cho đất không? Corn preplant có phải là phương pháp xử lý đất trước khi trồng ngô không? Nếu có anh/chị nào hiểu về vấn đề này, rất mong có thể giải đáp giúp em. Vì e tra google các trang tiếng không thấy có ứng dụng của NH3 với trồng trọt "In the domestic market for direct application of ammonia wholesalers in north-central Illinois report that spring ammonia run to corn preplant is around 50% complete. Ammonia moved in heavy volume to corn preplant in centre and east of South Dakota, state-wide in Nebraska and also in west and central Iowa. Demand for ammonia was moderate going to corn plowdown in east Colorado and west Kansas. Light volume ammonia was still moving to corn preplant in central and east Kansas and west Missouri. Light volume ammonia is getting knifed in under grass in central and south-west Oklahoma. Volume was light for ammonia going to corn sidedress in north-central, central and the coastal bend of Texas. Application is running well west of the Mississippi and western Illinois but is slow to get started in the eastern markets. Values are reportedly still holding $550-560/ston fob in the eastern cornbelt. The weather conditions in the northern cornbelt (North Dakota, Minnesota, Wisconsin and Michigan) are still somewhat wintery and wholesalers expect activity to pick-up next week. Spotty rains continue to limit fertilizer application in the eastern cornbelt (north and central Indiana and north and central Ohio). It is heard that Agrium’s ammonia plant at Borger, Texas could go down for a two months planned turnaround/upgrade works soon although this could not be fully confirmed at the time of publication. The plant’s capacity is around 490,000 t/y ammonia and if indeed it will go ahead, it is estimated that two months of downturn is will remove up to 70,000 t of ammonia from the market at the time it’s going into the peak demand season"