A new study suggests that, in the case of global catastrophe, urban agriculture alone could sustain only about one fifth of the population of a temperate, median-sized city, but the whole city could be fed by also farming land within a short distance of the urban area.
The city in question is in new zealand. While new york may be temperate (though it doesn’t show up in the maps I see - might be looking at maps on my phone) that doesn’t mean it is really comparible.