Is it permissible to combine separate plantings within one year to reach the minimum threshold (Nisab) for Zakat?

Primary text

The yield of a single year is combined, irrespective of whether the time of sowing and harvesting coincided or differed. If there are summer (Sayfi) and spring (Rabee'i) crops, the summer crop is joined with the spring crop to complete the Nisab. Furthermore, if corn (Dhurah) and millet (Dukhn) are harvested, and then their stubble grows back, one yield is added to the other to complete the Nisab. This is permissible because all constitute the planting of a single year, and thus one part is joined to the other, similar to cases where sowing and harvesting are closely timed.