Would anyone be able to point me in the right direction for some primary and secondary sources on the specialization of agriculture after the black death? Thank you!
A good introduction and lots of references to sources can be found in vol 1 of the Cambridge economic history of Europe (and vol 4 for the 16th-17th centuries), BH Slicher van Bath's Agrarian history of western Europe AD 500-1850 and Wilhelm Abel's earlier Agricultural Fluctuations in Europe.
Specialisation had of course long been practiced subject to climate, terrain, soil and market access & demand, but Genicot confirms local shifts to livestock, barley, legumes, roots, vines, flax, hops, oil and dyestuffs. Part of the trend pre-dated the Plague, as in the rise of English wool output and the spread of vetch cultivation, while some crops (buckwheat, rice) only arrived later.