Agronomic, financial and demand analysis of the application of fertilizers in farming systems with respect to biowaste reuse in Manila [Philippines]

Metro Manila [Philippines] is projected to produce more than 390,000 tons per year of compost from biowaste. With an area of only about 262 ha devoted to urban agriculture in Metro Manila, the bulk of this compost will have to be marketed outside the metropolis. To provide some insights regarding how farmers view and use fertilizers and eventually come up with the potential demand for compost, a survey of 200 farmers from Bulacan, Cavite and Laguna [Philippines] (provinces peripheral to Metro Manila) and Benguet ( a northern Luzon province, where farmers are known to use organic fertilizers) was conducted. The survey shows that almost all of the farmers interviewed (96%) use inorganic fertilizers (alone or in combination with organic fertilizer and compost). Organic fertilizers are used by almost half (47%) of them and in stark contrast, only 21% report using compost. More than 50% of the growers of vegetables, corn and ornamentals, and all root crop farmers use organic fertilizers. On the other hand, the top three major users of compost are farmers cultivating nursery plants, vegetables, and ornamentals. Farmers with relatively small farm size prefer the use of compost and organic fertilizer. Compost is used more in farms adopting relay and succession type of cropping system. Farmers are not using compost because they lack knowledge about it. They also have difficulty procuring it. If shown the benefits, however, almost all of the non-users are willing to try it in their farm. Almost one-third of compost users prepares its own compost, another one-third buys it and just about the same proportion is dependent on the free compost given by the government. Most of the information obtained by farmers regarding compost and its use is sourced from their co-workers as well as extension workers. Compost users have a positive attitude towards the use of compost. Financial analysis of fertilizer and compost use for farmers growing rice, corn, coffee, lanzones, roses and chrysanthemums, either as a monocrop or in combination with other crops was also conducted. The exclusive use of inorganic fertilizer gave the lowest yield for all crops except for monocrop rice applied with inorganic and organic fertilizers, and for lanzones with organic fertilizer. Relative to the use of inorganic fertilizer alone, promotion of yield by organic fertilizer addition ranged from 7%- 207%, compost addition from 36%-89%, and the combination of both, from 4%-102%. Except in two cases (rice with vegetables, and monocrop coffee), net income was greater for crops applied with inorganic fertilizer combined with either organic fertilizer, compost or both, compared with that obtained from the use of inorganic fertilizer alone. Increase in income ranged from 50%-223% (with organic fertilizer), 24%-66% (with compost) and 32%-267% (with compost and inorganic fertilizer). These data clearly show the advantage of utilizing a combination of inorganic fertilizer with organic-based nutrient sources over the use of inorganic type alone. The potential demand for compost from provinces nearby Metro Manila is estimated at 67% of the total amount that can be produced annually in the metropolis. A huge market is predicted if the farming areas in Region 3 (Central Luzon) and 4 (CALABARZON) are included, estimated at more than 4x the capacity of compost being processed from biowaste in Metro Manila. The bright market prospect for compost, however, will not be realized unless there is an aggressive and massive information and education campaign regarding the use and benefits of compost, financial and otherwise.