It could be that microorganisms that use glucose also absorb nitrogen, NH4? I think the opposite is the case: Decomposition of organic matter, such as compost, can be limited by nitrogen deficiency. Does the effect of glucose persist in a bacteria-free system?

I suggest that the microbes have rapidly consumed oxygen using the highly available carbohydrate and that the system is sufficiently reduced to produce NH3

It could be that introducing glucose to the soil increased the microbial population in your soil which also increased the level of soil urease. As we all know, urease catalyzes the formation of ammonia from urea.

Yes, introducing glucose to the soil increased the microbial population and more urease is produced and catalyzed to form NH3.

Sebastian Kuśmierz , I doubt that the urease and depletion of O2 explain the described effect. You need to explain 1) the massive formation of NH4 and ii) the parallel process of alkalization. My hypothesis is as follows. Glucose is used by microorganisms as a main C source. Additional C source is the N-containing organic compounds from manure. Microbial growth stoichiometry requires the C:N ratio to be about 10:1, most probably in your system there was an excess of organic N (proteins, amino acids, ...), therefore microorganisms took the C-part and excreted excessive N as NH4. It caused a rise of pH. The second source of NH4 is decaying microbial biomass accumulated from the growth on glucose. Usually, glucose is consumed in 3-5 days, then cells start to starve and lyse releasing intracellular cations, e.g., K, Ca, Mg, and plenty of additional NH4. Quite possible that cell lysis is accelerated by amaeba and other small animals present in your compost. Thus, a combination of three powerful factors led to the formation of NH4 and parallel alkalization resulted in NH3 emission: NH4 + OH- --> NH3 + H2O