Fragile Lands of Latin America Strategies for ... - PART - USAID

Indigenous Soil Management in Amazonia
Table 5
Production in Kilograms and Proteins per Hectare of Kayap6, Colonist and
Livestock Systems over Time
Production System Five Years Ten Years
Kayap6
Production of all crops
(kg/haIa 61,750 84,050
Protein (kg/ha)b 1,248 1,704
Colonist
Production of all cropsC 21,800 -
Protein 602 -
Livestock
Production (kg/ha) 350 700
proteinbd 1 05 210
(63) (1 26)
a Estimates based on in-field measurement, area/harvest weights, household
harvests, and informant estimates. The crops here include sweet potato, yam,
manioc, plantains and bananas, maize, beans, squash, and peanuts. Many
other minor crops such as Colocassia and other tubers, papayas,
watermelons, peppers, mangoes, and pineapples are not in the calculation.
Protein estimates derived from Dufour (1 988), USDA (1 981).
Based on average yields of rice, maize, and manioc in colonist agriculture in
Amazonia.
Assumes that viftually the entire animal, including the hide, is consumed and is
roughly 30% protein. If the animal is dressed out it weighs about 60% of its
liveweight. This protein yield is indicated in parentheses.
The Kayap6 system is largely based on root crops, especially sweet
potatoes which are very productive in the tropics. The sheer volume
of production assures carbohydrate adequacy and with minor supple-
ments, protein sufficiency. While these crops are often reviled for their
low protein contents (Gross, 1975), nutritional studies by Huang (1983)
on adult Yami tribesmen show that diets were nutritionally adequate
when subjects eat 2.5 kilos of sweet potatoes a day. Several studies in
New Guinea show that protein content varies significantly between
cultivars (Hayward and Nakikus 1981), and that intestinal flora of some
groups of New Guinean sweet potato eaters may have been able to fix
nitrogen (cited in Huang and Lee 1979).
Soil Efects
The next issue is what impact the high productivity of the Kayap6
system has on soil properties compared with colonist and livestock
systems. Soil samples were taken on sites with similar soil character-
istics, in this case dystrophic paleudults. Adjacent forest sites were used