117 research outputs found

    Nitrogen fertilisation management in precision agriculture: a preliminary application example on maize

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    The adoption of precision agriculture techniques for N management has the potential for improving agronomic, economic and environmental efficiency in the use of such input. The present work was aimed at testing a simplified N balance method for the prescription of N fertilisation in uniform management zones defined from information on measured soil properties on grain maize in central Italy. The results of this preliminary experience show that the application of the N balance prescription map did not bring to significant differences, from a uniform N fertilisation, in terms of grain yield, economic return above N cost and nitrate content in the soil profile at the end of the growing season. However, the adoption of the prescribed N fertilisation strategy for the whole field would have caused a limited saving in the amount of fertiliser employed, quantified at about 10 kg N ha–1

    Soil properties zoning of agricultural fields based on a climate-driven spatial clustering of remote sensing time series data

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    The identification of zones within an agricultural field that respond differently to environmental factors and agronomic management is a key requirement for the adoption of more precise and sustainable agricultural practices. Several approaches based on spatial clustering methods applied to different data sources, e.g. yield maps, proximal sensors and soil surveys, have been proposed in the last decades. The current availability of a huge amount of free remote sensing data allows to apply these approaches to agricultural areas where ground or proximal data are not available. However, in order to provide useful agronomic management information, it is essential that the zoning obtained by clustering is linked to the underlying spatial variability of soil properties. In this work we explore the hypothesis that the response of crop vigor to temporal climate variability, assessed by remote sensing data time series, selected to correspond to specific growth phases and seasonal climate patterns, provides indications on the variability of soil properties within agricultural fields, for both herbaceous and tree crops. NDVI time-series for 38 years (1984–2021) were obtained for fourteen non-irrigated herbaceous and tree crop fields in Central Italy, from multispectral satellites data (Landsat 5/7/8, Sentinel 2). The Standardized Precipitation-Evapotranspiration Index (SPEI) was used to classify time series into three climatic classes (dry/ normal/wet) for five different periods of the growth season, covering the main phenological phases. K-means clustering was used to identify patterns of crop growth from climatically classified image sets, as well as for all the bulked images for comparison (bulk clustering). Clustering results were compared with soil maps obtained from spatialized ground data, for soil texture (clay, silt and sand), soil organic matter and available soil water (ASW). The agreement between the different clustering results and soil maps was assessed by the Adjusted Rand Index. Agreement with soil maps varied depending on the field, the phenological phase considered and the soil property considered. Climate driven clustering from long, late growth season periods best matched soil properties, both for herbaceous and tree crops, despite being based on a limited number of images. The clustering from images spanning a longer growth period for dry years systematically outpaced the bulk clustering for silt, sand and ASW, while the clustering for normal climatic conditions was the best for organic matter. The performance of the matching between clustering and soil maps increased with soil variability significantly more (P < 0.05) than in the bulk clustering (mean slopes respectively 0.468 ± 0.167; 0.113 ± 0.270). The integration of the SPEI climatic index into the clustering procedure systematically improved the identification of zones with homogeneous soil properties, highlighting that a greater attention should be posed to the climate-crop-field interactions when using remotely sensed image

    Produzione, qualitĂ  e analisi della filiera produttiva del lino da fibra in Italia

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    Fibre flax (Linum usitatissimum L.) is disappeared from the ltalian crop systems, while the textile industry has reached a leading position. The reintroduction of the crop is than potentially promising but the crop techniques and the production processes have to be set up. In 12 environments: crop development and growth, cultivar response, straw, fibre and seed yields, and fibre quality were analysed in the 1992-98 period. The data pointed out crop cycles of 176 and 110 d for the autumn and the spring sowing time respectively, corresponding to 1125 and 990°C d cumulated growing degree. Straw yield at pulling was on average of 6.3 t ha-1, with relevant differences among years and environrnents. Early maturity cultivar yielded more in the less favourable sites. N fertilization was occasionally relevant, and a generally distributions of 60 kg N ha-1 was the more effective. In the Mediterranean environments, with the autumn, sowing flax was more productive and the yield steady. The long fibre ratio was often low (10-13%) and the quality uneven because of the insufficient cleanliness due to retting difficulties. Occasionally, the value of the fibre was affected by the insufficient stem length. In the less dense crop, the seed yield was on average 0.9 t ha-1. Such productions were similar to those assessed for the more dense crop. In conclusion: because of the complexity of the interactions among the crop growth, the yield, the retting process and the fibre quality flax reintroduction is doubtful. In the production processes retting seems to be the crucial phase. Il lino da fibra (Linum usitatissimum L.) è da tempo assente negli ordinamenti colturali italiani, mentre è assai importante l'industria di filatura. La reintroduzione della coltura appare quindi potenzialmente promettente, ma richiede la messa a punto dell'agrotecnica e della filiera produttiva. Nel periodo 1992-1998 in 12 ambienti sono stati esaminati: lo sviluppo e la crescita della coltura, l'adattamento di cultivar, la produzione di paglia, fibra e seme, la resa alla stigliatura, la qualità della fibra. I dati raccolti evidenziano cicli colturali in media di 176 e 110 d rispettivamente per le semine autunnali (ambienti del centro-sud) e vemino-primaverili; corrispondenti a somme termiche di 1125 e 990°C d. La produzione di paglia alla estirpatura è stata in media di 6.3 t ha-1 con valori assai variabili tra annate e ambienti. Le varietà a ciclo corto sono apparse migliori nelle condizioni difficili. L'effetto della concimazione azotata è apparsa talvolta rilevante e comunque con dosi ottimali prossime a 60 kg ha-1 di N. Negli ambienti del centro-sud le semine autunnali si sono dimostrate spesso le più interessanti e sicure. La resa in fibra lunga è stata bassa (10-13%) e la qualità variabile per la scarsa pulizia dovuta alle difficoltà di macerazione. La modesta lunghezza tecnica dello stelo sovente riduce il valore del prodotto. In coltura rada, la produzione di seme è variata da 0.5 a 1.5 t ha-1; tali valori non si sono discostati in modo apprezzabile da quelli ottenuti in coltura fitta. In conclusione, la diffusione del lino appare problematica per le complesse interazioni tra la produzione, il processo di macerazione e la qualità della fibra. Soprattutto la macerazione appare il passaggio chiave

    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

    Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both

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    Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81 years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16-2.61) and patients with dementia (HR 1.75, 95% CI 1.06-2.90) had a higher risk of death at one year. The Kaplan-Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population
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