Since late October, the domestic ammonium sulfate market has continued to rise, ushering in a round of "warm winter" market. As of December 22, the domestic mainstream transaction price has exceeded 560 yuan (ton price, the same below), and the northeastern region has even reached about 640 yuan, a continuous increase of more than 12%. It has basically repaired the fall adjustment that began in August and stood firm. Above the annual average price.