Transforming Citrus Cultivation in Bolivia with Dynamic Agroforestry Systems

In the year 1989 Oranges (var. late Valencia) were planted in 6x6m quadrants on a plot of 1.25 ha as a single crop in monoculture. Legumes (Glycine wighitii) were seeded to establish a ground cover. The conversion of this plantation into a Dynamic Agroforestry System (DAF) started in 1996.

Diverse Agroforestry: Bananas, Oranges & Native Trees for a Resilient Ecosystem

• Bananas (Cavendish type in combination with local tall growing shade tolerant types) were planted every 3m in between the row of the oranges.
• Additionally seeds of Inga spp in combination with other secondary tree species, as well as primary forest species and palm trees were sown or occasionally planted every 0.5 m in the row of the oranges.
• The trees planted to occupy the high stratum were selected to be species that lose their leaves in the dry season (i.e. Ceiba (Ceiba pentandra), Cedrillo (Spondias mombin), Ochóo (Hura crepitans), Tarara (Centrolobium ochroxylum), Mahagoni (Swetenia macrophilla) and others.
• In the year 2000 also coffee, cocoa, pepper and other native fruit species were planted in between.
• Different research about fruit fly infestation (Anastrepha ssp. y Ceratitis captitata), soil fertility and productivity in comparison on monoculture were realized (Soto, V. 2002).

The plantation described above includes now more than 60 species of timber and fruit trees in different canopy layers (strata) below and above the citrus trees. 650 trees and palms are present per hectare and soil fertility has increased in line with the development of the supporting flora within the plantation. During droughts it was particularly evident that compared to normal plantations in the region, this system did not show signs of stress and maintained productivity (yield).

Generally the yield harvested in the agroforestry systems was relatively constant and above the average yield of the region. The time invested in pruning and management resulted in and continues to enhance soil fertility, which cannot be said about monocultures. Within 2-3 years the system produced sufficient organic matter to maintain a permanent ground cover of material originating from pruning and fallen foliage, sustaining a high flow of carbon. Therefore no input of fertilizer was needed. However, it is important that the pruning of the shade trees is done in time to induce flowering of the citrus (aprox. three month before the development of flowers in the oranges). There are no significant problems anymore with pests and diseases in the agroforestry system.