addict
发表于 2025-4-2 21:29:23
http://reply.papertrans.cn/71/7039/703870/703870_71.png
即席
发表于 2025-4-3 00:27:27
s to fertilizer are invariably considerable and average yields per ha of cereals (the main component of man’s food) in the major countries are nearly proportional to the amounts of N + P.O. + K.O applied as fertilizer. Often responses to nitrogen fertilizer are restricted by shortage of some other n