As an example, when potash use is between 75kg/ha and 150kg/ha, an increase in nitrogen application from 150 to 225kg/ha increases the MPP of potash from 11.4 to 23.1.

• 例如，当钾肥用量为75~150公斤/公顷时，氮肥用量由150公斤/公顷增加到225公斤/公顷使得钾肥的边际产量由11.；4增至23