Vetiver Hedges for Soil Conservation with Alternative Crops in Peru

Dr. Julio Alegre, Ing. Luis Arévalo, Ing. Abel Meza

Email:mailto:Julio Alegre <[email protected]>

Slash and burn agricultural and clearing of forest are traditional practices in the Peruvian jungle and the area of Aguaytía is no exception to this practice. Ash deposts which result from the burning contains nutrients that fertilize crops, but heavy rains on the sloping and hilly topography lead to problems associated with runoff and of nutrient and soil losses from erosion. This is the reality which agricultural projects encounter.

During 1999, the International Center for Research in Agroforestry (ICRAF) has been continuing its involvment in the project "Promotion of Agroforestry Systems for Economic Development and Conservation of Natural Resources in the Peruvian Amazon" with financing from US AID (via Winrock) under their Alternative Development Program. Emphasis is on the use of simple management practices and soil conservation with the goal of reducing erosion problems and its consequences and contribute to the sustainability of alternatives crops. Such sustainabale practices focus on agroforestry, use of adequate quantities of fertilizers (both organic and synthetic) and contour planting (utilizing the A-level) of crops and vegetative hedges with Vetiver (Vetiveria zizanioides).

Below is a brief summary of the reasons for Vetiver Grass Technology (VGT) promotion:

  1. Its growth habit (abundant and erect foliage and profound roots that can penetrate deep, hard pans in the soil) permits the plant to form a dense and permanent live hedge that retains soil "washed" by rainfall runoff, as well as increasing infiltration of water into the soil and improving soil moisture. It creates better conditions for crop growth while decreasing soil degradation.
  2. It has a wide range of adaptation to different climactic conditions (tropical, temperate, arid) and soils (sandy, loamy, clay).
  3. It is easy and fast to propogate by tillers (vegetatively), such that in only 6 months the plant can propogate 50 times its original number. Establishment and maintenance of hedges low-cost, compared to the benefit realized.
  4. It is not nutrient and water demanding; on the contrary, it increases soils nutrients and humidity indirectly. The deep roots feed in zones where crop roots do not reach; water and nutrients are "pumped" to the leaves, which when pruned, are then used to mulch the soil, conserving humidity and improving soil fertility.
  5. In different countries and within Peru, there is a growing interest regarding the use of VGT within public and private soil conservation and upland agricultural programs. Therefore, one cannot rule out that in the future it can be commercialized for this purpose.

All these qualities have increased the awareness amongst farmers this region highly susceptible to erosion where Aguaytía is located, where until today little or no conservation awareness existed. Previously ICRAF, in coordination with the projects financed by WINROCK-AID, had initiated use of VGT in areas growing or planning on raising alternative crops. Thus, villages located along the Federico Basadre Highway such as San Pedro de Chio (km. 139), Aguas Verdes (km. 143) y Huipoca (km. 148) already have propagation nurseries of Vetiver (containing about 600-900 each) that will supply their own parcels and those of their neighbors. Some have started to plant using the A-level between rows of "pijuayo" for palmito production. Along with this is intense training regarding the proper aspects of soil management in hillside farming.

It is worthwhile mentioning that due to vetiver's wide utility, it has been required that plantain producers in the neighboring zones of the Aguaytía River plant vetiver. Their practices have caused erosion problems along the river, destroying riverbanks during the rainy season. In these areas it is used to stabilize and prevent the silting up of drainages and ditches that are used to drain areas under plantain cultivation.