Slash-and-burn agriculture, or tavy, is the predominant farming system in eastern Madagascar and the major cause, in combination with increasing population and scarcity of fertile land, of deforestation and upland degradation. Current land use trends suggest increasing rainforest loss and between five to ten times faster upland degradation then previously believed. Despite degradation and declining yields, farmers’ remain committed to tavy. Incredibly, no technical alternatives or functional extension services are locally available. 

The objectives of this research were to study upland use strategies and degradation dynamics and develop fire-less alternatives to intensify and improve agricultural production. A multidisciplinary approach was used, combining qualitative inquiry, indigenous knowledge study, biophysical soil and fallow characterization, and agricultural experimentation.

Upland degradation was described through fallow species succession in relation to post-deforestation cycles. Indigenous fallow categories were identified that integrate species composition, vegetation aspect, and agricultural productivity; provide management guidelines and identify the ‘point of no return’ after which soils are lost to agriculture. Quantification of biomass and nutrient stocks along a degradation gradient showed that tree fallows (Trema orientalis) obtained highest nutrient stocks after 5 years. For short fallows, the shrubs Rubus moluccanus and Psiadia altissima were most productive. Very low nutrient accumulation occurred with Imperata cylindrica. As expected, soil nutrient stocks decreased with increasing degradation.

Tavy was compared with three techniques: mulching alone (M0) and with the addition of 40 and 80 kg/ha applications of phosphorus using locally available guano-phosphate (M40, M80 respectively), on a rotation of upland rice, beans, ginger, and Crotalaria grahamiana fallow on the four above-mentioned fallows. Traditional or tavy practices yielded 1.2 t of rice, 0.2 t of beans and 4.3 t of ginger per ha. Although tavy showed slightly higher productivity for the first rice crop, M80 outperformed tavy with respect to beans, ginger, and Crotalaria by 324%, 195%, and 366%. M40 was less productive than M80 but was significantly better than M0 and tavy. M0’s yields were better than tavy only for ginger. Crotalaria’s nutrient stocks at one year were 6 to 20 times greater than those of natural fallow. M80 can be recommended, with guano applied once during an intensified rotation followed by a leguminous fallow. The additional investment in M40 or M80 was 185 or 370$/ha/rotation, however, after only one rotation, the M40 and M80 treatments produced $700 and $1350 in additional returns relative to tavy. If the current government policy is to protect remaining forest, farmers will need to intensify agriculture and eliminate fire from the landscape. The fire-less approach presented is one possible pathway.