[en] A stumbling block to the adoption of silvoarable agroforestry systems is the lack of quantitative knowledge on the performance of different crops when competing for resources with trees. In North-Western Europe, light is likely to be the principal limiting resource for understorey crops, and most agronomic studies show a systematic reduction of final yield as shade increases. However the intensity of the crop response depends on both the environmental conditions and the shade characteristics. This study addressed the issue by monitoring winter wheat (Triticum aestivum L.) growth, productivity and quality under artificial shade provided by military camouflage shade-netting, and using the Hi-sAFe model to relate the artificial shade conditions to those applying in agroforestry systems.
The field experiment was carried out over two consecutive years (2013–14 and 2014–15) on the experimental farm of Gembloux Agro-Bio Tech, Belgium. The shade structures recreated two shade conditions: periodic shade (PS) and continuous shade (CS), with the former using overlapping military camouflage netting to provide discontinuous light through the day, and the latter using conventional shade cloth. The experiment simulated shading from a canopy of late-flushing hybrid walnut leaves above winter wheat. Shading was imposed 16 (2013–14) and 10 (2014–15) days before flowering and retained until harvest. The crop experienced full light conditions until the maximum leaf area index stage (LAImax) had been reached. In both years, LAI followed the same dynamics between the different treatments, but in 2013–2014 an attack of the take-all disease (Gaeumannomyces graminis var. tritici) reduced yields overall and prevented significant treatment effects. In season 2014–15 the decrease in global radiation reaching the crop during a period of 66 days (CS: – 61% and PS: – 43%) significantly affected final yield (CS: – 45% and PS: – 25%), mainly through a reduction of the average grain weight and the number of grain per m2. Grain protein content increased by up to 45% under the CS treatment in 2015. Nevertheless, at the plot scale, protein yield (t/ha) did not compensate for the final grain yield decrease.
The Hi-sAFe model was used to simulate an agroforestry plot with two lines of walnut trees running either north-south or east-west. The levels of artificial shade levels applied in this experiment were compared to those predicted beneath trees growing with similar climatic conditions in Belgium. The levels used in the CS treatment are only likely to occur real agroforestry conditions on 10% of the cropped area until the trees are 30 years old and only with east-west tree row orientation.
Abbate, P.E., Andrade, F.H., Culot, J.P., Bindraban, P.S., Grain yield in wheat: effects of radiation during spike growth period. Field Crops Res. 54 (1997), 245–257.
Athanasiou, K., Dyson, B.C., Webster, R.E., Johnson, G.N., Dynamic acclimation of photosynthesis increases plant fitness in changing environments. Plant Physiol. 152 (2010), 366–373, 10.1104/pp.109.149351.
Bah B.B., Engels P., Colinet G., Bock L., Bracke C., Veron P., 2005. Légende de la Carte Numérique des Sols de Wallonie (Belgique). Sur base de la légende originale de la Carte des sols de la Belgique de l'IRSIA à 1/20.000.
Barro, R.S., Varella, A.C., Lemaire, G., Medeiros, R.B., de Saibro, J.C., de Nabinger, C., Bangel, F.V., Carassai, I.J., Forage yield and nitrogen nutrition dynamics of warm-season native forage genotypes under two shading levels and in full sunlight. Rev. Bras. Zootec. 41 (2012), 1589–1597.
Batish, D., Ecological Basis of Agroforestry. 2008, CRC Press, Boca Raton, FL.
Bouttier, L., Paquette, A., Messier, C., Rivest, D., Olivier, A., Cogliastro, A., Vertical root separation and light interception in a temperate tree-based intercropping system of Eastern Canada. Agrofor. Syst., 2014, 10.1007/s10457-014-9721-6.
Cannell, M.G.R., van Noordwijk, M., Ong, C.K., The central agroforestry hypothesis: the trees must acquire resources that the crop would not otherwise acquire. Agrofor. Syst. 34 (1996), 27–31.
Chirko, C.P., Gold, M.A., Nguyen, P.V., Jiang, J.P., Influence of direction and distance from trees on wheat yield and photosynthetic photon flux density in a Paulownia and wheat intercropping system. For. Ecol. Manag. 83 (1996), 171–180.
Demotes-Mainard, S., Jeuffroy, M.-H., Effects of nitrogen and radiation on dry matter and nitrogen accumulation in the spike of winter wheat. Field Crops Res. 87 (2004), 221–233, 10.1016/j.fcr.2003.11.014.
Dufour, L., Metay, A., Talbot, G., Dupraz, C., Assessing light competition for cereal production in temperate agroforestry systems using experimentation and crop modelling. J. Agron. Crop Sci. 199 (2013), 217–227, 10.1111/jac.12008.
Dupraz, C., Burgess, P., Gavaland, A., Graves, A., Herzog, F., Incoll, L.D., Jackson, N., Kessman, K., Lawson, G., Lecomte, I., Liagre, F., Mantzanas, K., Mayus, M., Moreno, G., Palma, J., Papanastasis, V., Paris, P., Pilbeam, D., Reisner, Y., Werf Van der, W., SAFE Final Report (Technical Report No. Silvoarable Agroforestry for Europe (SAFE) European Research Contract QLK5-CT-2001-00560)., 2005, INRA-UMR Systems Editions, Montpellier.
Dupraz, C., Tree-crop Interaction Models: State of the Art Report (Technical Report No. Deliverable D.1.1 of the SAFE European Research Contract QLK5-CT-2001-00560)., 2002, INRA, Montpellier.
Ehret, M., Graß, R., Wachendorf, M., The effect of shade and shade material on white clover/perennial ryegrass mixtures for temperate agroforestry systems. Agrofor. Syst. 89 (2015), 557–570, 10.1007/s10457-015-9791-0.
Eichhorn, M.P., Paris, P., Herzog, F., Incoll, L.D., Liagre, F., Mantzanas, K., Mayus, M., Moreno, G., Papanastasis, V.P., Pilbeam, D.J., Pisanelli, A., Dupraz, C., Silvoarable systems in Europe–past, present and future prospects. Agrofor. Syst. 67 (2006), 29–50, 10.1007/s10457-005-1111-7.
Estrada-Campuzano, G., Miralles, D.J., Slafer, G.A., Yield determination in triticale as affected by radiation in different development phases. Eur. J. Agron. 28 (2008), 597–605, 10.1016/j.eja.2008.01.003.
FAO, World Reference Base for Soil Resources 2014 International Soil Classification System for Naming Soils and Creating Legends for Soil Maps. 2014, FAO, Rome.
Fischer, R.A., Stockman, Y.M., Kernel number per spike in wheat (Triticum aestivum L.): responses to preanthesis shading. Funct. Plant Biol. 7 (1980), 169–180.
Friday, J.B., Fownes, J.H., Competition for light between hedgerows and maize in an alley cropping system in Hawaii, USA. Agrofor. Syst. 55 (2002), 125–137.
Gillespie, A.R., Jose, S., Mengel, D.B., Hoover, W.L., Pope, P.E., Seifert, J.R., Biehle, D.J., Stall, T., Benjamin, T.J., Defining competition vectors in a temperate alley cropping system in the midwestern USA: 1. Production Physiology. Agrofor. Syst. 48 (2000), 25–40.
Herzog, H., Source and sink during the reproductive period of wheat. Development and its Regulation with Special Reference to Cytokinins, 1986, Paul Parey Scientific Pub.
Toward agroforestry design: an ecological approach. Jose, S., Gordon, A.M., (eds.) Advances in Agroforestry, 2008, Springer, Dordrecht.
Kwak, Y.-S., Weller, D.M., Take-all of wheat and natural disease suppression: a review. Plant Pathol. J. 29 (2013), 125–135, 10.5423/PPJ.SI.07.2012.0112.
Leroy, C., Sabatier, S., Wahyuni, N.S., Barczi, J.-F., Dauzat, J., Laurans, M., Auclair, D., Virtual trees and light capture: a method for optimizing agroforestry stand design. Agrofor. Syst. 77 (2009), 37–47, 10.1007/s10457-009-9232-z.
Li, F., Meng, P., Fu, D., Wang, B., Light distribution, photosynthetic rate and yield in a Paulownia-wheat intercropping system in China. Agrofor. Syst. 74 (2008), 163–172, 10.1007/s10457-008-9122-9.
Li, H., Jiang, D., Wollenweber, B., Dai, T., Cao, W., Effects of shading on morphology, physiology and grain yield of winter wheat. Eur. J. Agron. 33 (2010), 267–275, 10.1016/j.eja.2010.07.002.
Liu, N., Light distribution in tree intercropping area and its agricultural value. Agrofor. Syst. China, 1991, 14–21.
Luedeling, E., Smethurst, P.J., Baudron, F., Bayala, J., Huth, N.I., van Noordwijk, M., Ong, C.K., Mulia, R., Lusiana, B., Muthuri, C., Sinclair, F.L., Field-scale modeling of tree-crop interactions: challenges and development needs. Agric. Syst. 142 (2016), 51–69, 10.1016/j.agsy.2015.11.005.
Malézieux, E., Crozat, Y., Dupraz, C., Laurans, M., Makowski, D., Ozier-Lafontaine, H., Rapidel, B., Tourdonnet, S., Valantin-Morison, M., Mixing plant species in cropping systems: concepts, tools and models. A review. Agron. Sustain. Dev. 29 (2009), 43–62, 10.1051/agro:2007057.
Mu, H., Jiang, D., Wollenweber, B., Dai, T., Jing, Q., Cao, W., Long-term low radiation decreases leaf photosynthesis, photochemical efficiency and grain yield in winter wheat. J. Agron. Crop Sci. 196 (2010), 38–47, 10.1111/j.1439-037X.2009.00394.x.
Murchie, E.H., Niyogi, K.K., Manipulation of photoprotection to improve plant photosynthesis. Plant Physiol. 155 (2011), 86–92, 10.1104/pp.110.168831.
Pearcy, R.W., Krall, J.P., Sassenrath-Cole, G.F., Photosynthesis in fluctuating light environments. Photosynthesis and the Environment, 1996, Springer, 321–346.
Peri, P.L., McNeil, D.L., Moot, D.J., Varella, A.C., Lucas, R.J., Net photosynthetic rate of cocksfoot leaves under continuous and fluctuating shade conditions in the field. Grass Forage Sci. 57 (2002), 157–170.
Plaut, Z., Butow, B., Blumenthal, C., Wrigley, C., Transport of dry matter into developing wheat kernels and its contribution to grain yield under post-anthesis water deficit and elevated temperature. Field Crops Res. 86 (2004), 185–198, 10.1016/j.fcr.2003.08.005.
Retkute, R., Smith-Unna, S.E., Smith, R.W., Burgess, A.J., Jensen, O.E., Johnson, G.N., Preston, S.P., Murchie, E.H., Exploiting heterogeneous environments: does photosynthetic acclimation optimize carbon gain in fluctuating light?. J. Exp Bot. 66 (2015), 2437–2447, 10.1093/jxb/erv055.
Reynolds, P.E., Simpson, J.A., Thevathasan, N.V., Gordon, A.M., Effects of tree competition on corn and soybean photosynthesis, growth, and yield in a temperate tree-based agroforestry intercropping system in southern Ontario, Canada. Ecol. Eng. 29 (2007), 362–371, 10.1016/j.ecoleng.2006.09.024.
Rivest, D., Cogliastro, A., Vanasse, A., Olivier, A., Production of soybean associated with different hybrid poplar clones in a tree-based intercropping system in southwestern Québec, Canada. Agric. Ecosyst. Environ. 131 (2009), 51–60, 10.1016/j.agee.2008.08.011.
Schnyder, H., The role of carbohydrate storage and redistribution in the source-sink relations of wheat and barley during grain filling – a review. New Physiol. 123 (1993), 1469–8137.
Smith, J., Pearce, B.D., Wolfe, M.S., Reconciling productivity with protection of the environment: is temperate agroforestry the answer?. Renew. Agric. Food Syst. 28 (2013), 80–92, 10.1017/S1742170511000585.
Talbot, G., Dupraz, C., Simple models for light competition within agroforestry discontinuous tree stands: are leaf clumpiness and light interception by woody parts relevant factors?. Agrofor. Syst. 84 (2012), 101–116, 10.1007/s10457-011-9418-z.
Tsonkova, P., Böhm, C., Quinkenstein, A., Freese, D., Ecological benefits provided by alley cropping systems for production of woody biomass in the temperate region: a review. Agrofor. Syst. 85 (2012), 133–152, 10.1007/s10457-012-9494-8.
Varella, A.C., Moot, D.J., Pollock, K.M., Peri, P.L., Lucas, R.J., Do light and alfalfa responses to cloth and slatted shade represent those measured under an agroforestry system?. Agrofor. Syst. 81 (2010), 157–173, 10.1007/s10457-010-9319-6.
Waeyaert, N., 2014. Chiffres clés de l'agriculture. L'agriculture en Belgique en chiffres. (Service Public Fédéral Economie). Direction générale Statistiques – Statistics Belgium.
Zhang, L., van der Werf, W., Bastiaans, L., Zhang, S., Li, B., Spiertz, J.H., Light interception and utilization in relay intercrops of wheat and cotton. Field Crops Res. 107 (2008), 29–42.
Agroforestry Systems in China. Zhu, Z., Cai, M., Wang, S., Jiang, Y., (eds.), 1991, Chinese Academy of Forestry and Intern. Canada Development Research Center.