Initial modelled outputs at field scale
Gosme, M., Blitz-Frayret, C., Burgess, P.J., Crous-Duran, J., Dupraz, C., Dux, D., Garcia de Jalon, S., Graves, A.R., Herzog, F., Lecomte, I., Moreno, G., Oliveira, T., Palma, J.H.N., Paulo, J.A., Sereke, F., Tomé, M. (2016). Initial modelled outputs at field scale. Deliverable 6.16 (6.1): Initial modelled outputs at field scale to support best management practices for resource efficiency of agroforestry systems. AGFORWARD project. 23 August 2016. 29 pp.
Download the reportD6.16 Initial modelled outputs.pdf (1.3 MiB)
The above report comprises the abstracts from two papers published in peer-reviewed journals (Palma et al. 2014 and Sereke et al. 2015), an abstract from a paper about to be submitted, and copies of four papers presented at the Third European Agroforestry Conference (Crous Duran et al. 2016; Dupraz et al. 2016; Palma et al. 2016, and Garcia de Jalon et al. 2016).
One of the questions raised by the stakeholder groups was the most appropriate spatial arrangement of silvoarable systems. This is addressed in the paper by Dupraz et al. (2016). Using the Hi-sAFe model, the team at INRA indicate that for winter and summer cereal crops, north-south tree lines should be preferred at high latitudes (>50°) and east-west tree lines should be preferred at low latitudes (<40°) to maximize the crop irradiance during the grain filling phases. At high latitudes, given the low late summer irradiance of crops with east-west tree lines, summer crops should not be associated with east-west tree lines. For temperate latitudes (40° to 50°), the tree line orientation is reported to have no significant impact on crop irradiation at key phenological stages such as flowering or grain filling.
Although the work was not directly supported by AGFORWARD, Sereke et al. (2015) and other researchers from the AGFORWARD project used the Yield-SAFE model to estimate the land equivalent ratios of agroforestry systems in Switzerland (timber-arable vs fruit-arable vs timber-grassland vs and fruit-grassland) with different tree species (cherry vs walnut) and with either 40 or 70 trees ha−1. Mixing trees and crops was commonly (in 12 out of the 14 options) predicted to be more productive than growing them in separate forestry and arable systems i.e. a land equivalent ratio higher than 1 (predicted land equivalent ratios ranged from 0.95 to 1.30).
A useful feature of modelling studies is that they allow quick assessment of the potential for new systems in regions where they are not currently being implemented. For example, agroforestry with eucalyptus is not practised in Portugal, but the stakeholders from a cork-producing region in Portugal asked researchers to evaluate its potential in their region (Palma et al. 2016). Using Yield-SAFE, land equivalent ratios of simulated eucalyptus-ryegrass agroforestry systems were found to range between 1 (irrigated system with 52 trees per hectare) and 1.2 (for rainfed-systems with 203 trees per hectare). The results also suggested that similar stand biomasses can be achieved with less trees (=> lower establishment cost) in agroforestry than in forest monoculture.
The Yield-SAFE model also gave good results in predicting the acorn production of dehesa/montado systems (Crous-Duran et al. 2016), which will be useful to test the capacity of agroforestry to address the strong seasonality of forage resources for pigs. Yield-SAFE was used to compare carbon storage achieved through different scenarios of land use (agroforestry vs forestry) allocation to different types of soils (low vs high water holding capacity (Palma et al. 2014). The modelled results indicate that on land with a high water holding capacity, it is possible to maintain food production (through the crop/animal component of agroforestry) and achieve higher rates of carbon sequestration in the agroforestry trees than in the trees of a forest on poorer land. Furthermore, the simulations show that an implementation of 10% of agroforestry in areas with high soil water holding capacity results in approximately the same carbon storage as 50% implementation in poorer agricultural land. This type of analysis, comparing different scenarios of adoption in different soil and climate conditions is particularly interesting for land use planners who allocate different land uses to different soils, and policy makers who determine the type of financial incentives given to support carbon sequestration.
Carbon emissions from field operations (fuel and machinery and agrochemicals manufacture) have been evaluated in Farm-SAFE (Garcia de Jalon et al. 2016) using a life cycle assessment model to compare the emissions of the different land uses (arable, forestry and agroforestry). Farm-SAFE has also started to be used to convert the provision of some environmental externalities into monetary terms, hence allowing a financial and economic assessment of costs and benefits of alternative land uses.
- Crous Duran, J., Moreno, G., Oliveira, T.S., Paulo, J.A., Palma, J.H.N. (2016). Modelling holm oak acorn production in South-Western Iberia. In: 3rd European Agroforestry Conference Book of Abstracts, pp. 344-346 (Eds. Gosme, M. et al.). Montpellier, France, 23-25 May 2016.
- Dupraz, C., Lecomte, I., Molto, Q., Blitz-Frayret, C., Gosme, M. (2016). Agroforestry at all latitudes? Unexpected results about best designs to allow more light to the crops at various latitudes. In: 3rd European Agroforestry Conference Book of Abstracts, pp. 359-362 (Eds. Gosme, M. et al.). Montpellier, France, 23-25 May 2016
- Garcia de Jalon, S., Graves, A., Kaske, K.J., Palma, J., Crous-Duran, J., Burgess, P.J. (2016). Assessing the environmental externalities of arable, forestry, and silvoarable systems: new developments in Farm-SAFE. In: 3rd European Agroforestry Conference Book of Abstracts, pp. 363-366 (Eds. Gosme, M. et al.). Montpellier, France, 23-25 May 2016.
- Palma, J.H.N., Paulo, J.A., Tomé, M. (2014). Carbon sequestration of modern Quercus suber L. silvoarable agroforestry systems in Portugal: a YieldSAFE-based estimation. Agroforestry Systems 88: 791–801. doi: 10.1007/s10457-014-9725-2.
- Palma, J.H.N., Oliveira, T.S., Crous-Duran, J., Paulo, J.A. (2016). Using Yield-SAFE model to assess hypothetical eucalyptus silvopastoral systems in Portugal. In: 3rd European Agroforestry Conference Book of Abstracts, pp. 348-351 (Eds. Gosme, M. et al.). Montpellier, France, 23-25 May 2016.
- Sereke, F., Graves, A.R., Dux, D., Palma, J.H.N., Herzog, F. (2015). Innovative agroecosystem goods and services: key profitability drivers in Swiss agroforestry. Agronomy for Sustainable Development 35: 759–770. doi: 10.1007/s13593-014-0261-2.