Analyse des données issues d'un réseau expérimental de systèmes de production cidricoles agroécologiques en vue de leur évaluation et de leur compréhension aspect trophique

BIBLIOGRAPHIE

Weinbaum SA, Klein I, Broadbent FE, Micke WC, Muraoka TT. Effects of time of nitrogen application and soil texture on the availability of isotopically labeled fertilizer nitrogen to reproductive and vegetative tissue of mature almond trees. Journal of the American Society for Horticultural Science. 1984;109(3):339-43.

Weinbaum SA, Merwin ML, Muraoka TT. Seasonal variation in nitrate uptake efficiency and distribution of absorbed nitrogen in non-bearing prune trees. Journal of the American Society for Horticultural Science. 1978;103:516-9.

Weinbaum SA, Neumann PM. Uptake and metabolism of 15N - labelled potassium nitrate by French prune (Prunus domestica L.) leaves and the effects of two surfactants. Journal of the American Society for Horticultural Science. 1977;102:601-4.

Weinbaum SA, Van Kessel C. Quantitative estimates of uptake and internal cycling of 14N-labeled fertilizer in mature walnut trees. Tree Physiology. 1998;18:795-801.

Wortmann CS. Calcium and Magnesium. Nutrient Management for Agronomic Crops in Nebraska [Internet]. 2014. Available from: http://www.ianrpubs.unl.edu/epublic/live/ec155/build/ec155.pdf

Wu J, Brookes PC, Jenkinson DS. Formation and destruction of microbial biomass during decomposition of glucose and ryegrass in soil. Soil Biology and Biochemistry. 1993;25:1435-41.

Zuoping Z, Sha Y, Fen L, Puhui J, Xiaoying W, Yan'an T. Effects of chemical fertilizer combined with organic manure on Fuji apple quality, yield and soil fertility in apple orchard on the Loess Plateau of China. International Journal of Agricultural and Biological Engineering. 2014 Apr 17;7(2):45-55.

SUMMARY

Sells of industrial and artisanal cider are currently growing. More and more cider orchards are being planted. Apple prices remain stable. At the same time, the socio-environmental background so as regulations urge the cider industry to reduce its environmental footprint. Therefore, the IFPC has carried out the Verger Cidricole de Demain program. This project aims at designing and assessing orchards with both high economic and environmental performances, before being offered to farmers. Nine experimental orchards have been planted at nine producers, located from the Upper-Normandy to Brittany. Each orchard plot is divided in two modalities: an innovative system compared with a control system, managed with the usual practices of the grower. This experiment does not aim at testing the individual effect of practices. It aims at evaluating the economic and environmental viability of the whole system in its context («system approach»). Orchards were established between 2010 and 2012. Economic, environmental and agronomic evaluations have been done. The agronomic evaluation, topic of this report, targets the understanding of yield and growth-determining factors, in order to identify the impact of the practices on the agronomic results. The main interest of this experimentation is to consider the interactions between factors, in order to consider systems such as complex entities. Thus, a group of hypothesis was formulated, based on technical and scientific references. After confronting the hypothesis with the data of our study, a few one were selected to be validated. First, a confidence rate and a validity area were attributed to each hypothesis. Depending on this validity area, different methods were used to test each hypothesis and improve its confidence level. For hypothesis with a validity area at the network scale, linear regression was performed to confirm the effect of some of the factors. Before modelling, correlations tests and principal component analysis were carried out to study the determining factors and reduce their number. For hypothesis only valid on a few plots, no generic method was found. Finally, it still remained a few hypothesis that could not been studied with the cases we have 1) either because the hypothesis concerns one plot; 2) or because the effect of the factors can be mixed with other factors. These hypothesis were studied thanks to a factorial experimentation. Links to the orchard management operations were seldom made. Among the hypothesis validated with a high rate of confidence, one showed a negative interaction between 2 type of weed control managements: the combination of a row covered with a woven plastic mulch and a not-mowing drive-alley disturbs the root development of the tree. Another hypothesis allowed showing the application of an organic fertilizer before orchard plantation can ensure sufficient nitrates for the trees, if temperature is high enough and if the competition between the row and the drive-alley is reduced. This study also allowed confirming relations between nutrients (Mg/K, Mg/Ca, K/N) and the importance of the management of the cation exchange capacity on the bioavailability of potassium and magnesium for the apple tree.