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Connecting the drops: A methodological challenge for the deployment of ICTs in mediterranean irrigation systems
Get PDFThe vulnerability of irrigated systems in areas coping with water scarcity has boosted the demand for information and communication technologies (ICTs), e.g. tools and services derived from field sensors or satellite data. ICTs are promising tools to track and quantify water flows and transfers, yet their increased accessibility and production benefits does not often lead to their increased deployment beyond the group involved in the initial design and testing process. To support technological innovation scaling, an interdisciplinary approach and an original methodology are developed and implemented. The objective is to explore the dynamics of ICTs initiatives in irrigation systems and facilitate horizontal outreach. Technological emergence and diffusion is captured through in-depth analyses of information and collaboration processes operated by the technologies. Investigation into global and local datasets to map irrigation technical layouts at a regional scale shows a gap between representations of irrigation phenomenon, but used in combination these information sources can help characterize diffusion potential. Feedbacks from empirical works in a set of multistakeholder innovation platforms show that collaborative mechanisms during technological experimentations can be diverse but remain crucial to empower irrigation communities. This methodological investigation fuels the debate on digital agriculture, and shows that there are alternative avenues for irrigation sustainable development through technology. Finally, pathways for information and knowledge circulation across actors, scales, and contexts are identified, highlighting researchers' role to collect, document, and share datasets and stories. Still, learning opportunities should not obscure the operational challenges towards a translocal network of ICTs initiatives for irrigation systems
Effect of bin width on variogram model accuracy: A case study of teak tree volume specific to Solomon clone in Tawau, Sabah, Malaysia
Get PDFThe volume of teak trees (Tectona grandis Linn. f.) was analyzed using data from a teak plantation managed by the research and development team at Sabah Softwood Berhad in Brumas Camp, Tawau, Sabah, Malaysia. To fit the exponential model to the experimental variogram, various bin widths were used to obtain different variogram models. These models were plotted for comparison, and the root mean square error (RMSE) was calculated. Additionally, cross-validation was performed to assess the predictive accuracy of each model for the unseen data. The analysis indicated that a bin width of 0.003—that was approximately 333 m apart—was ideal for fitting the exponential model. This width demonstrated the lowest RMSE and ideal graphical observations. This study confirms that selecting the optimal bin width significantly affects the accuracy of model predictions, regardless of the sample size
Love thy neighbour? Tropical tree growth and its response to climate anomalies is mediated by neighbourhood hierarchy and dissimilarity in carbon- and water-related traits
Get PDFTaxonomic diversity effects on forest productivity and response to climate extremes range from positive to negative, suggesting a key role for complex interactions among neighbouring trees. To elucidate how neutral interactions, hierarchical competition and resource partitioning between neighbours' shape tree growth and climate response in a highly diverse Amazonian forest, we combined 30 years of tree censuses with measurements of water- and carbon-related traits. We modelled individual tree growth response to climate and neighbourhood to disentangle the relative effect of neighbourhood densities, trait hierarchies and dissimilarities. While neighbourhood densities consistently decreased growth, trait dissimilarity increased it, and both had the potential to influence climate response. Greater water conservatism provided a competitive advantage to focal trees in normal years, but water–spender neighbours reduced this effect in dry years. By underlining the importance of density and trait-mediated neighbourhood interactions, our study offers a way towards improving predictions of forest dynamics
Performance evaluation of Sentinel-2 imagery, agronomic and climatic data for sugarcane yield estimation
No full textGiven the importance of the sugarcane sector, machine learning techniques are being used as an important tool to improve yield estimation. This study aims to select the most relevant predictors from Sentinel-2 imagery, agronomic, and climatic data, using the Random Forest algorithm (RF), to estimate sugarcane yield before the harvest in a mill in the west of S˜ao Paulo state. We used radiometric bands (Red-edge1 to Red-edge3 , Red, NIR, SWIR1 , and SWIR2 ) and vegetation indices from Sentinel-2 multispectral reflectance data (NDVIRE1 to NDVIRE3, EVI, CIRE1 to CIRE3, NDVI, NDWI1 , NDWI2 , SIWSI, NDMI, SAVI); agronomic data (soil type, number of harvests, variety, slope); climatic and agroclimatic data (temperature, precipitation, radiation, and crop water balance). We built four datasets to create yield estimation models for the mill: (i) the first dataset included all variables; (ii) in the second dataset, the strongly correlated variables from the dataset (i) were removed; (iii) the third dataset included the variables identified by feature selection within the 2nd dataset using RF algorithm's impurity index (best model results); (iv) the fourth dataset, consisting of the 20 highest ranked variables from dataset 1 selected by SHapley Additive exPlanations (SHAP). The models showed R2 values ranging from 0.58 to 0.70 with dataset 3, and the d-Willmott index ranged from 0.83 to 0.89. The most relevant variables for estimating sugarcane yield were the number of harvests, climatic data and vegetation indices that used Red-edge, near-infrared narrow, red and SWIR bands
La politique agricole de l'Inde. Des succès aux impasses de la révolution verte
No full textLa révolution verte mis en place en Inde durant les années 1960 s'est distinguée par une politique agricole très offensive, assortis de soutiens publics notamment pour l'irrigation et le stockage public. Ce chapitre traite de l'évolution et surtout des répercussions de cette révolution sur les agriculteurs, leur santé et leur endettement, sur la productivité par actif agricole et sur les écosystèmes. L'Inde connaît une crise agraire, écologique et nutritionnelle
Étude des méthodes de capture et distribution des moustiques Aedes vecteurs de la dengue et du chikungunya à Saint-Joseph
Get PDFLa Réunion subit des épidémies de dengue et de chikungunya dont le vecteur majeur est Aedes albopictus. Le projet OpTIS vise à mesurer l'impact de la Technique de l'Insecte Stérile (TIS) renforcée sur les densités des moustiques Aedes et la transmission de ces deux arboviroses à Saint-Joseph. Ce stage a pour but de déterminer le type de pièges qui sera utilisé pour évaluer l'efficacité de l'intervention et explorer la distribution des deux espèces d'Aedes présentes dans le site d'étude. Pour cela, deux types de pièges ont été testé dans deux conditions différentes (BG-CO2-leurre, BG-CO2, OS-eau, OS-foin) suivant la méthode des carrés latins. Les moustiques piégés ont été identifiés et sexés. Aussi, des larves ont été prélevées et identifiées pour compléter l'analyse de la distribution des deux espèces d'Aedes. Les pièges BG-CO2 appâtés ou non de BG-leurre ont eu la même efficacité pour les deux espèces d'Aedes. Les pièges ovi-stickys (OS), quelle que soit la configuration, ne sont quant à eux pas adaptés à La Réunion, probablement dû à l'abondance des gîtes naturels rentrant en compétition avec ces pièges. Les résultats montrent que dans le site d'étude, Aedes aegypti se retrouve non seulement près des ravines mais également dans les habitations. Aussi, l'abondance de ces deux espèces varie en fonction des conditions météorologiques. Pour conclure, le suivi entomologique destiné à évaluer l'efficacité de l'intervention OpTIS sera effectué à l'aide de pièges BG-CO2 non appâtés de BG-leurre afin de réduire les coûts et la logistique
How to assess the dynamic capabilities needed to orchestrate a service ecosystem? A new methodology and framework
No full textTo accelerate sustainability transitions in the agricultural sector, supporting innovations appears to be crucial and coordinating this support is necessary while posing several challenges and requiring specific capabilities. It is thus important to assess if the coordinating organisation has the necessary capabilities to endorse this role. Yet, assessing capabilities constitutes a theoretical and methodological challenge. A key difficulty lies in the divergence between capability models proposed in academic literature and those applied by practitioners. This article integrates both perspectives to develop a comprehensive conceptual model, following a four-step methodology: (i) a literature review, (ii) a workshop with field experts, (iii) application to a case study for refinement, and (iv) comparison with capability models from other sectors to identify generic capabilities. The resulting model offers a valuable tool for evaluating the capabilities required by hub organisations in service ecosystems supporting agricultural innovation. Additionally, the methodology provides guidance for researchers and practitioners aiming to design capability models for other types of organisations
A comparison of optimization techniques for large-scale allocation of soybean crops
Get PDFThe optimal allocation of crops to different parcels of land is a problem of paramount practical importance, not only to improve food and feed production, but also to address the challenges posed by climate change. However, this optimization problem is inherently complex due to the large number of agricultural sites available which generates a vast search space that renders traditional optimization techniques impractical. Moreover, as maximizing average production may generate solutions characterized by high year-by-year instability and lead to large and unrealistic cultivated areas, it is necessary to optimize crop allocation considering several objectives at the same time. In order to tackle this complex optimization problem, we propose a multi-objective approach, simultaneously maximizing the average production, minimizing the year-on-year production variance, and minimizing the total cultivated surface. The approach relies on an established multi-objective evolutionary algorithm, and employs a machine learning model able to predict crop production from weather and irrigation conditions, trained on historical data, making it possible to tackle allocation problems of large size. The proposed approach is compared to a quadratic programming algorithm tailored to the target problem. A case study focusing on the allocation of soybean crops in the European continent for the years 2000-2023 shows that the proposed methodology is able to identify informative trade-offs between the three conflicting objectives considered, and identify realistic and meaningful crop allocations for supporting stakeholders' decisions
Micrografting technique of Hevea brasiliensis in vitro plantlets
Get PDFTo prepare Hevea brasiliensis plantations, selected planting material is propagated by grafting using illegitimate seedlings as rootstocks, whose paternal genotype is unknown. Recent advances in rubber tree in vitro cloning propagation open the possibility of using these techniques to supply new planting material. Micrografting is a promising technique to speed up the preparation of plant material for rootstock–scion interaction studies. This article describes the implementation of an efficient micrografting technique from Hevea in vitro plants from clone PB 260. The procedure combines several conditions to preserve the root system and the grafted scion and to prevent any breakage of rootstock buds. This technique paves the way for clonal propagation and holds potential for further development on other rubber clones for further studies on the interaction between rootstock and scion