when we collected urine in the past in a systematic way for a little while, we “fermented” it for a month to convert some of the urea into ammonia - which is much more beneficial to plants (though it is also volatile and some can be lost). There is a good reason for doing that, but I do not recall it - possibly something to do with “alkalinity”. But urea would also ferment or otherwise be metabolized well enough in situ. If there is too much in one place, it can affect salinity though and might be detrimental. What amount - not sure.