Questions and Answers

Integrated crop-livestock systems are, at least in principle, adaptable to any property size, provided that edaphoclimatic (climate, soil, etc.) conditions are not restrictive. For example, one can recall that the intercropping of maize and grasses (Jaraguá and Tanzania) in the 1950s and 60s was a common practice for the manual introduction of pasture in slash-and-burn agriculture, and thus feasible to be adopted in small properties. However, in properties with intensive use of agricultural machinery and inputs (correctives, fertilizers, herbicides, pesticides), the scale of production might be a decisive factor for the economic feasibility of the system. Therefore, efficient planning, competent management, and the involvement of a multidisciplinary team are required.

In sloping soils, the main restriction is mechanization, but it is possible to use animal-drawn implements, and tree rows must be distributed over contour terraces. Other than that, there is already knowledge and technologies that have been adapted to different edaphoclimatic conditions.

If the farmer has no experience with the system, the recommendation is to introduce it in smaller areas first to acquire knowledge about the necessary processes and practices to implement the system and, in addition, minimize production and financial risks.

In a crop-livestock system, it is possible to expect positive returns after two years. In agrosilvopastoral systems, depending on the forestry practices adopted (pruning and lopping), positive returns can be expected in four to eight years.

In integrated crop-livestock systems, the intercropping of annual crops with grass is common in order to establish the pasture and produce stubble for no-till farming. In crop-livestock-forestry systems, annual crops (soybean, maize, sorghum, rice) are usually planted in the first two years between tree rows to minimize the negative cashflow and avoid animals damaging the forest component. As of the second year, depending on the tree species, it is possible to plant forages (livestock-forestry stage). Pasture can be introduced by intercropping grain crops and forages.

The appropriate choice of tree species to be introduced is extremely important for the system. Trees must be chosen according to their adaptation to local conditions; favorable canopy architecture; easiness of introduction; market demand for tree products; choice of species with fast growing rates; root type; control of erosion and rainwater surface flow; shade for animals; and compatibility with pasture and cattle, that is, no negative effects for animals such as toxicity, or negative influence for the other components (grain crops and pasture). Currently, the species with greatest potential for use in ICLF systems is eucalyptus due to its fast growth, offer of clones adapted to different regions, thin canopy, high economic yield, and production of multiple timber and non-timber products. Other species have been used such as: acacia (Acacia mangium), paricá (Schyzolobium amazonicum), African mahogany (Kaya ivorensis), Australian cedar (Toona ciliata), canafistula (Pelthophorum dubium), silky oak (Grevillea robusta), and pinus (Pinus spp). There is also research with Brazilian mahogany (Swietenia macrophila), teak (Tectona grandis), neem tree (Azadirachta indica), mulateiro (Calicophylum spruceanum), amarelão (Aspidosperma vargassi), kapok (Ceiba pentandra), taxi-branco (Sclerolobium paniculatum), balsam tree (Ochroma pyramidale), quickstick (Gliricidia sepium), among others.

Several arrangements are possible in ICLF systems according to the rural property's profile and objectives. The differences in the systems are also related to the regional characteristics of biomes and farms, such as: climate and soil conditions, infrastructure, farmer experience, and available technology. The adoption of ICLFS can be facilitated by an adequate distribution and spacing of trees in the area, resulting in soil and water conservation, more room for machinery, and observance of animal behavior. To this end, the simplest and most effective spatial arrangement is alley cropping, in which trees are planted in rows (single or multiple lines) with ample spacing between them. The tree rows should preferably run from east to west and be planted in terraces, avoiding soil erosion and water loss through surface flow.

If the purpose is to supply timber for sawmills, it is very important to prune trees to obtain the best quality of timber possible, free of knots. For eucalyptus, pruning can start when the plants exceed 8 cm in diameter at breast height (DBH). The pruning height must not exceed half the plant size, lest it harms the tree's development.

The eucalyptus tree uses water very efficiently and does not consume more water per unit of biomass than any other plant species. Water consumption in an eucalyptus forest is approximately 900 to 1200 mm a year.

No. The concept of ICLFS adopted by Embrapa includes systems with no trees (crop-livestock) and with trees (agroforestry, silvopastoral, and agrosilvopastoral systems).

More intensive systems, which use fertilization and/or association with leguminous plants (intercropped pastures), crops, and the forest component, are alternatives to improve land use efficiency, reducing GHG emissions. The use of fast-growth tree species contributes to quicker decomposition of deposited residue and to increases in soil organic matter (SOM), an important source of carbon storage, besides wood carbon stocks.

Integrated Crop-Livestock-Forestry systems is one of the technologies fostered by the Low-Carbon Agriculture Program (Agricultura de Baixo Carbono or ABC Program). The ABC Program was created in 2010 by the Brazilian federal government and offers benefits and credit for agricultural producers wishing to adopt sustainable agricultural practices. The interest rate of 5.5% a year is the lowest among all rural development loan programs for agribusiness, and the repayment period can extend to 15 years. Besides the ICLF systems, the ABC program also fosters initiatives related to no-till farming, biological nitrogen fixation, recovery of degraded areas, planting of forests, and animal waste treatment.