13 research outputs found

    A high-resolution, integrated system for rice yield forecasting at district level

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    To meet the growing demands from public and private stakeholders for early yield estimates, a high-resolution (2 km × 2 km) rice yield forecasting system based on the integration of the WARM model and remote sensing (RS) technologies was developed. RS was used to identify rice-cropped area and to derive spatially distributed sowing dates, and for the dynamic assimilation of RS-derived leaf area index (LAI) data within the crop model. The system—tested for the main European rice production districts in Italy, Greece, and Spain—performed satisfactorily; >66% of the inter-annual yield variability was explained in six out of eight combinations of ecotype × district, with a maximum of 89% of the variability explained for the ‘Tropical Japonica’ cultivars in the Vercelli district (Italy). In seven out of eight cases, the assimilation of RS-derived LAI improved the forecasting capability, with minor differences due to the assimilation technology used (updating or recalibration). In particular, RS data reduced uncertainty by capturing factors that were not properly reproduced by the simulation model (given the uncertainty due to large-area simulations). The system, which is an extension of the one used for rice within the EC-JRC-MARS forecasting system, was used pre-operationally in 2015 and 2016 to provide early yield estimates to private companies and institutional stakeholders within the EU-FP7 ERMES project

    Downstream Services for Rice Crop Monitoring in Europe: From Regional to Local Scale

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    The ERMES agromonitoring system for rice cultivations integrates EO data at different resolutions, crop models, and user-provided in situ data in a unified system, which drives two operational downstream services for rice monitoring. The first is aimed at providing information concerning the behavior of the current season at regional/rice district scale, while the second is dedicated to provide farmers with field-scale data useful to support more efficient and environmentally friendly crop practices. In this contribution, we describe the main characteristics of the system, in terms of overall architecture, technological solutions adopted, characteristics of the developed products, and functionalities provided to end users. Peculiarities of the system reside in its ability to cope with the needs of different stakeholders within a common platform, and in a tight integration between EO data processing and information retrieval, crop modeling, in situ data collection, and information dissemination. The ERMES system has been operationally tested in three European rice-producing countries (Italy, Spain, and Greece) during growing seasons 2015 and 2016, providing a great amount of near-real-time information concerning rice crops. Highlights of significant results are provided, with particular focus on real-world applications of ERMES products and services. Although developed with focus on European rice cultivations, solutions implemented in the ERMES system can be, and are already being, adapted to other crops and/or areas of the world, thus making it a valuable testing bed for the development of advanced, integrated agricultural monitoring systems

    Development of generic crop models for simulation of multi-species plant communities in mown grasslands

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    Plant diversity supports the high aptitude of grassland covers to provide fodder production for animal feedingand contribute to the storage of carbon, while also granting pollination and aesthetics of landscapes. This abilitydepends on the management intensity of the grassland system, physical constraints and climatic characteristics.Most of current grassland models simulating the impact of weather conditions, soil fertility and the intensity ofuse of grassland systems (by grazing and/or mowing) on fodder production and carbon-nitrogenfluxes inheriteco-physiological and biophysical details from crop models without considering explicitly temporal changes intaxonomic and functional composition. The dynamic grassland model CoSMo (COmmunity Simulation MOdel)includes a set of rules to simulate explicitly seasonal changes in species composition of managed grasslandsunder various soil, climate and management drivers, and it is consistent with the degree of complexity of themost generic crop simulators. The incorporation of CoSMo functionalities into the standalone crop simulatorsCropSyst and WOFOST is proposed as a way to: (i) reduce the uncertainty in estimations of harvested above-ground biomass (AGB) and (ii) simulate dynamically the relative abundance of species (for respectively thewhole community and individual species). Considering three mixtures of grassland species (with increasingcomplexity from Mix 1 to Mix 3) in a mown hay meadow in central Italy (Massa Marittima, 43° 03′N, 10° 53′E,380 m a.s.l.), we show that CoSMo overall improved the model ability to reproduce observed AGB in Mix 1 and 2(e.g. with CropSyst in Mix 2 relative root mean square error [RRMSE] lowered from 35.01 to 25.27%) while themodel performance for Mix 3 appeared as not unambiguously linked to considering plant diversity. An assess-ment of the relative abundance estimates for the whole community indicates 30% <RRMSE< 40% with bothCoSMo-coupled CropSyst and WOFOST in Mix 1 and Mix 2, while it increases up to∼60% in Mix 3. Theconsequences of explicitly accounting for plant diversity for simulated grassland outputs depend on the con-ditions evaluated, which require further studies. However, our results suggest that grassland modelling omittingplant diversity dynamics are likely over- or underestimating harvested biomass of the plant community, thusbiasing projections of future fodder production and estimates of animal feed supplies. This work proves for thefirst time that CoSMo can support the simulation of grassland systems beyond its theoretical framework

    Estimating Crop Nutritional Status Using Smart Apps to Support Nitrogen Fertilization. A Case Study on Paddy Rice

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    Accurate nitrogen (N) management is crucial for the economic and environmental sustainability of cropping systems. Different methods have been developed to increase the efficiency of N fertilizations. However, their costs and/or low usability have often prevented their adoption in operational contexts. We developed a diagnostic system to support topdressing N fertilization based on the use of smart apps to derive a N nutritional index (NNI; actual/critical plant N content). The system was tested on paddy rice via dedicated field experiments, where the smart apps PocketLAI and PocketN were used to estimate, respectively, critical (from leaf area index) and actual plant N content. Results highlighted the system&#8217;s capability to correctly detect the conditions of N stress (NNI &lt; 1) and N surplus (NNI &gt; 1), thereby effectively supporting topdressing fertilizations. A resource-efficient methodology to derive PocketN calibration curves for different varieties&#8212;needed to extend the system to new contexts&#8212;was also developed and successfully evaluated on 43 widely grown European varieties. The widespread availability of smartphones and the possibility to integrate NNI and remote sensing technologies to derive variable rate fertilization maps generate new opportunities for supporting N management under real farming conditions

    Improving cereal yield forecasts in Europe – The impact of weather extremes

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    The impact of extreme events (such as prolonged droughts, heat waves, cold shocks and frost) is poorly represented by most of the existing yield forecasting systems. Two new model-based approaches that account for the impact of extreme weather events on crop production are presented as a way to improve yield forecasts, both based on the Crop Growth Monitoring System (CGMS) of the European Commission. A first approach includes simple relations – consistent with the degree of complexity of the most generic crop simulators – to explicitly model the impact of these events on leaf development and yield formation. A second approach is a hybrid system which adds selected agro-climatic indicators (accounting for drought and cold/heat stress) to the previous one. The new proposed methods, together with the CGMS-standard approach and a system exclusively based on selected agro-climatic indicators, were evaluated in a comparative fashion for their forecasting reliability. The four systems were assessed for the main micro- and macro-thermal cereal crops grown in highly productive European countries. The workflow included the statistical post-processing of model outputs aggregated at national level with historical series (1995–2013) of official yields, followed by a cross-validation for forecasting events triggered at flowering, maturity and at an intermediate stage. With the system based on agro-climatic indicators, satisfactory performances were limited to microthermal crops grown in Mediterranean environments (i.e. crop production systems mainly driven by rainfall distribution). Compared to CGMS-standard system, the newly proposed approaches increased the forecasting reliability in 94% of the combinations crop × country × forecasting moment. In particular, the explicit simulation of the impact of extreme events explained a large part of the inter-annual variability (up to +44% for spring barley in Poland), while the addition of agro-climatic indicators to the workflow mostly added accuracy to an already satisfactory forecasting system.Part of the methodology of this study has been funded under the European Community's Seventh Framework Programme (FP7/2007-2013), grant agreement no. 613817 (MODEXTREME, Modelling vegetation response to extreme events, http://modextreme.org).Peer reviewe

    Estimating Leaf Area Index (LAI) in Vineyards Using the PocketLAI Smart-App

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    Estimating leaf area index (LAI) of Vitis vinifera using indirect methods involves some critical issues, related to its discontinuous and non-homogeneous canopy. This study evaluates the smart app PocketLAI and hemispherical photography in vineyards against destructive LAI measurements. Data were collected during six surveys in an experimental site characterized by a high level of heterogeneity among plants, allowing us to explore a wide range of LAI values. During the last survey, the possibility to combine remote sensing data and in-situ PocketLAI estimates (smart scouting) was evaluated. Results showed a good agreement between PocketLAI data and direct measurements, especially for LAI ranging from 0.13 to 1.41 (R\ub2 = 0.94, RRMSE = 17.27%), whereas the accuracy decreased when an outlying value (vineyard LAI = 2.84) was included (R\ub2 = 0.77, RRMSE = 43.00%), due to the saturation effect in case of very dense canopies arising from lack of green pruning. The hemispherical photography showed very high values of R\ub2, even in presence of the outlying value (R\ub2 = 0.94), although it showed a marked and quite constant overestimation error (RRMSE = 99.46%), suggesting the need to introduce a correction factor specific for vineyards. During the smart scouting, PocketLAI showed its reliability to monitor the spatial-temporal variability of vine vigor in cordon-trained systems, and showed a potential for a wide range of applications, also in combination with remote sensing
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