The relationship between 'Ushr (tithe on produce) and Kharaj (land tax) in determining Zakat liability.
Chapter on Zakat on Crops and Fruits
Al-Mughni
Book of Zakat
Primary text
Abu Hanifa's ruling regarding honey is based on the principle that 'Ushr and Kharaj do not coexist (meaning if land is subject to Kharaj, 'Ushr is not taken).