Carbon stored by the aboveground and underground components of land use systems on the northern highland hillsides of Oaxaca State, Mexico ranged from 54 to 306 Mg ha-1. The amount of stored C was related more to soil depth and climate conditions than to vegetation systems.

Most C was stored in underground pools, with approximately 50% of the total C content stored in the top 50 cm of soils. The C content in all pools of annual agricultural systems pH %rel 300. ■■ -.


CEC %rel

SB %rel

Pols %rel

SB %rel

Figure 24.2 Radar-type graphical index used to establish deviation from "ideal" values (100%). CEC = cation exchange capacity; LC = milpa under conservation tillage; LT = milpa under traditional tillage; MFVCAFE = MIAF system with coffee plants as living wall; bosque = forest; OM = organic matter; Pols = extractable soil phosphorus by sodium bicarbonate solution; PBS = percentage base saturation; SB = sum of exchangeable bases.

(milpa) was similar to that found in the secondary-growth forest systems.

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