This study focused on assessing supply-demand balance of nitrogen in compost/vegetable productions at vacant lots in subdivisions as well as in barangays, in Quezon City in Metro Manila. We obtained data on the recommended rate of fertilizer application per each vegetable from the precedent studies. The analysis of composition of sample compost was conducted and a total nitrogen amount of locally produced compost was estimated. GIS was used for understanding spatial characteristics of nitrogen balance. We found that almost half of the subdivisions were faced to oversupply though several subdivisions were deemed to be in quite short supply. Cooperation among subdivisions in each barangay had a potential of better nitrogen balance; however, the current centralized composting facilities might not be good support for continued compost recycle system because of their distribution patterns. We proposed that the current barangay-based policies on organic waste management and urban agriculture should be more flexible and more attentions to coordinating system between subdivisions across barangay boundaries. This scheme can contribute to further organic material recycling within living spaces, thereby promoting sustainable living spaces in the suburban residential area.
