The nitrogen in São Paulo’s herd manure

Português · English

Plate No. 081, the first of four in the collection Manure that feeds the soil, in the manner of the Eurostat and OECD gross nutrient balance and the European Environment Agency’s livestock density maps. Phosphorus is on plate 082; the comparison with harvests on 083; biogas digestate on 084.

What the files contain

Layer (GPKG)	Geometry	Content
municipios	polygon	645 municipalities. 2024 PPM herds (bovinos without milked cows, vacas_ordenhadas, bubalinos, equinos, suinos without sows, matrizes, galinhas, frangos = all chickens minus hens, ovinos, caprinos, codornas); area_agro_ha (MapBiomas) and area_lavoura_ha (PAM); n_dejetos_t and each herd’s part (n_bovinos_t, n_leite_t, n_aves_t, n_suinos_t, n_outros_t); n_kg_ha_agro; the fields of plates 082 to 084; sem_info_ppm
regioes_intermediarias, limite_estadual	polygon	reference

The GPKG is shared by all four plates, with each one’s QGIS styles (n_kg_ha_agro, p2o5_kg_ha_agro, cob_n_pct, cob_p2o5_pct, cob_k2o_pct, dig_cob_p2o5_pct). The CSV has the municipal table without geometry; the coefficients CSV lists every number used, with its source.

Method

1. Herds. Head counts on 31/12/2024 from the PPM (table 3939) by municipality; milked cows from table 94, retrieved through the SIDRA API on 18/10/2026. Milked cows are taken out of all cattle, sows out of all pigs and hens out of all chickens (the rest are broilers). Where IBGE does not publish milked cows (42 municipalities), the whole herd counts as beef cattle.
2. Nitrogen per head. Excretion rate (kg of N per 1,000 kg of live weight per day, table 10.19) times typical mass (table 10A.5), IPCC 2019 Latin American means, times 365. Per head per year: milked cow 72.3 kg; beef animal 34.3; buffalo 47.1; horse 40.0; sow 18.3; pig 13.6; hen 0.60; broiler 0.40; sheep 3.6; goat 3.0. The coefficients are in the CSV.
3. Per hectare. Sum over the herds divided by the 2024 MapBiomas farmland (pasture, temporary and perennial crops, sugarcane, citrus and mixed use), the same as plate 045. Six classes, closed on the right: up to 10, 10 to 25, 25 to 50, 50 to 100, 100 to 170 and over 170 kg of N per hectare.
4. The European cap. The Nitrates Directive (91/676/EEC) limits manure applied in vulnerable zones to 170 kg of N per hectare per year. Here it is only a yardstick: the cap applies to spread manure, not to what is excreted on pasture, and Brazil has no equivalent rule.

Limitations

• These are estimates. Nitrogen comes from mean per-head coefficients, not from farm measurements; diet, breed, weight and productivity change excretion. The numbers show the order of magnitude and where the load concentrates.
• Excreted nitrogen is not what reaches the soil: part is lost as ammonia and nitrous oxide in the shed, the manure store and the field. An account of available nitrogen would need loss factors for each management system.
• Beef cattle leave their manure on the pasture, spread out; their load per hectare does not compare with that of a poultry farm, which concentrates its manure in one place.
• 28 municipalities in Greater São Paulo and on the coast have no PPM data and are hatched as no data, never as zero.
• The PPM counts animals on a single day (31/12); broiler farms raise several flocks a year, and the per-head coefficient already assumes an animal present all year.