Why farmers rotate fields in maize-cassava-plantain bush fallow agriculture in the wet Peruvian Amazon

Abstract

The maize (Zea mays) -cassava (Manihot esculenta)-Musarelay-cropped sequence as practiced among 28 Yanesha families in the Palcazu Valley in Central Amazonian Peru was surveyed to determine why farmers rotate fields into bush fallow. Typically, this sequence is planted on alluvial Inceptisols after the clearing of 2–5 year tree and shrub growth. During the 18–30 months of cropping, fields showed a buildup of weeds and an increase in banana stem borer and nutrient deficiency symptoms. Farmers attributed the decline in Musayields from the first to third harvests to stem borer, weeds, or soil infertility but were not unanimous. Any or all of these factors facilitate the decision to abandon a field. A 3-year record of fields cleared by each farm family indicated that field rotation stems from two independent decisions: selection of a fallowed field to clear for maize and vegetables, important for family nutrition, which are planted right after field clearing, and discontinuation of weeding in old fields as labor is used primarily on new fields, a decision leading to bush fallow recovery. Work with these families during 4 years suggests that the distribution of land and labor is based on a sense of relative labor productivity, on diverse dietary needs and preferences, and on the maintenance of a balance between areas in cropping and under fallow.