Seasonal forecasting of green water components and crop yields of winter wheat in Serbia and Austria

A probabilistic crop forecast based on ensembles of crop model output (CMO) estimates offers a myriad of possible realizations and probabilistic forecasts of green water components (precipitation and evapotranspiration), crop yields and green water footprints (GWFs) on monthly or seasonal scales. The present paper presents part of the results of an ongoing study related to the application of ensemble forecasting concepts for agricultural production. The methodology used to produce the ensemble CMO using the ensemble seasonal weather forecasts as the crop model input meteorological data without the perturbation of initial soil or crop conditions is presented and tested for accuracy, as are its results. The selected case study is for winter wheat growth in Austria and Serbia during the 2006–2014 period modelled with the SIRIUS crop model. The historical seasonal forecasts for a 6-month period (1 March-31 August) were collected for the period 2006–2014 and were assimilated from the European Centre for Medium-range Weather Forecast and the Meteorological Archival and Retrieval System. The seasonal ensemble forecasting results obtained for winter wheat phenology dynamics, yield and GWF showed a narrow range of estimates. These results indicate that the use of seasonal weather forecasting in agriculture and its applications for probabilistic crop forecasting can optimize field operations (e.g., soil cultivation, plant protection, fertilizing, irrigation) and takes advantage of the predictions of crop development and yield a few weeks or months in advance

Agricultural Meteorology and Climatology

Agricultural Meteorology and Climatology is an introductory textbook for meteorology and climatology courses at faculties of agriculture and for agrometeorology and agroclimatology courses at faculties whose curricula include these subjects. Additionally, this book may be a useful source of information for practicing agronomists and all those interested in different aspects of weather and climate impacts on agriculture. In times when scientific knowledge and practical experience increase exponentially, it is not a simple matter to prepare a textbook. Therefore we decided not to constrain Agricultural Meteorology and Climatology by its binding pages. Only a part of it is a conventional textbook. The other part includes numerical examples (easy-to-edit worksheets) and recommended additional reading available on-line in digital form. To keep the reader's attention, the book is divided into three sections: Basics, Applications and Agrometeorological Measurements with Numerical Examples

UV radiation in Novi Sad (Serbia): UV Index monitoring and variability of high erythemal UV radiation doses

The UV monitoring in Novi Sad has been in operation by broadband Yankee UVB-1 biometer at the campus of the University of Novi Sad (45.33° N, 19.85° E, 84 m above sea level) since 2003. Data of UV index are taken every 30 s, averaged over 10 min intervals, and automatically saved in the database. The time series were reconstructed using an improved reconstruction technique that is based on parametric numerical model NEOPLANTA calculations of erythemal radiation and the empirical relationship between the erythemal doses and sunshine duration. In this study, we presented the maximum daily UV index values over the period 2003-2018 and the variability of reconstructed high erythemal UV doses (hUVery) over the period 1971-2018. Additionally, the influence of low total ozone column (TOC), low cloud cover conditions, and high surface albedo on hUVery was analyzed on a seasonal basis. Analyzing the measurements we concluded that maximum daily values are almost the same in the period of sixteen years, in the summer months maximum values are about 9. Based on the 90th percentile of each month we assessed a set of 1691 days with hUVery (10.65 %). The fraction of hUVery days in the last two decades was considerably larger (12.29%) than in the period before (6.97%) and during (8.68%) TOC depletion. We observed a statistically significant increase in the annual number of days with hUVery of +6.26 days/decade (p<0.01). The increase was statistically significant in all seasons, except winter, while it was the most pronounced in summer (+2.44 days/decade, p<0.01). However, the increase was not uniform over the entire observation period. Over the period of TOC depletion (1971-1980), the number of days with hUVery decreased, followed by a steep significant increase over the period of TOC depletion (1981-1996) of +16.75 days per decade (p<0.05). After 1996 hUVery increased slowly (+3.19 days/decade), but the trend was not statistically significant. Considering the influence of each UV affecting factor separately, the analysis showed that low cloud cover had slightly more influence on the occurrence of hUVery days than TOC in all seasons except winter. Of the total number of hUVery days, 89.47% were recorded when the cloud cover was low, while 80.65% of hUVery were recorded when the TOC was low. However, the most frequent reason for hUVery is the combination of these two factors (75% of all hUVery days). In the winter season-high surface albedo influenced the appearance of 18.26% of hUVery days. It is important to emphasize that we analyzed the reconstructed erythemal doses, not the measured data. Reconstructed data (implying the quality of the reconstruction) provide valuable resources for insight into UV variability in the past although cannot replace measurements. The results indicate even if the TOC recovers in the 21st century as expected, the appearance of days with high erythemal doses will still be significantly affected by future changes in the cloud cover

The importance of ground-based and satellite observations for monitoring and estimation of UV radiation in Novi Sad (Serbia)

Solar ultraviolet (UV) radiation is a significant health hazard in the warm part of the year. In order to assess the level of hazard and the effects of UV radiation on the living world, long-term measured or estimated data are needed. In Novi Sad, the measurement of UV radiation has been performed since 2003, while ozone measurements have been made since 2007. However, those data sets are too short for assessing long-term biological effects. Therefore, several techniques for reconstruction of UV radiation doses have been developed. Reconstruction techniques are based on using available ground-based measurements of the meteorological data and satellite measurements of the total ozone column. It is shown that techniques that use ozone data show better performance than those that use only ground-based meteorological measurements. However, the difference between the performances of the methods is smaller when it comes to the monthly values, indicating that the techniques which use only ground-based meteorological measurements are roughly as good as the ozone-based techniques for assessing long-term changes in the surface UV radiation. The statistically significant increasing long term-trend of annual mean erythemal UV doses (ERY) and the decreasing trend in the total ozone column in Novi Sad since 1981 have been noticed. An increase in ERY has been noticed in all the seasons except in autumn and it is the highest in winter. The analysis showed that the increase in the ERY in the period 1981–1996 was mainly caused by the total ozone column, while the increase after 1996 is largely caused by cloudines

The importance of ground-based and satellite observations for monitoring and estimation of UV radiation in Novi Sad (Serbia)

Solar ultraviolet (UV) radiation is a significant health hazard in the warm part of the year. In order to assess the level of hazard and the effects of UV radiation on the living world, long-term measured or estimated data are needed. In Novi Sad measurement of UV radiation has been performing since 2003, while ozone measurements are made since 2007. However, those data sets are too short for assessing long-term biological effects. Therefore, several techniques for reconstruction of UV radiation doses are developed. Reconstruction techniques were based on using available ground-based measurements of the meteorological data and satellite measurements of total ozone column. It is shown that techniques that use ozone data show better performance than those that use only ground-based meteorological measurements. However, the difference between the performances of the methods is smaller when it comes to the monthly values, indicating that the techniques which use only ground-based meteorological measurements are roughly as good as the ozone-based techniques for assessing long-term changes in the surface UV radiation. The statistical significant increasing long term-trend of annual mean erythemal UV doses (ERY) and the decreasing trend in total ozone column in Novi Sad since 1981 have been noticed. An increase in ERY was noticed in all seasons except in autumn and it was the highest in winter. The analysis showed that the increase in the ERY in the period 1981-1996 is mainly caused by the total ozone column, while the increase after 1996 is largely caused by cloudiness.This conference was held from 10 to 13 May in Petnica Science Centre, City of Valjevo

Exchange of greenhouse gases between biosphere and atmosphere

<p>The concentrations and fluxes of greenhouse gases (GHG) in the land-atmosphere system are controlled by complex interactions between emissions, turbulent transfer, dry deposition and chemical transformations. The forest canopy can significantly affect turbulent fluxes between the atmosphere, the canopy crown and the understory where most of the sinks or sources of mass and energy are located. Exchange processes depend on canopy homogeneity and isotropy, as well as morphological, aerodynamic and thermal characteristics. Therefore, it is anticipated that the forest canopy structure will play a significant role in the exchange of GHG species.</p

Toward a Weather-Based Forecasting System for Fire Blight and Downy Mildew

The aim of this research is to present a weather-based forecasting system for apple fire blight (Erwinia amylovora) and downy mildew of grapevine (Plasmopara viticola) under Serbian agroecological conditions and test its efficacy. The weather-based forecasting system contains Numerical Weather Prediction (NWP) model outputs and a disease occurrence model. The weather forecast used is a product of the high-resolution forecast (HRES) atmospheric model by the European Centre for Medium-Range Weather Forecasts (ECMWF). For disease modelling, we selected a biometeorological system for messages on the occurrence of diseases in fruits and vines (BAHUS) because it contains both diseases with well-known and tested algorithms. Several comparisons were made: (1) forecasted variables for the fifth day are compared against measurements from the agrometeorological network at seven locations for three months (March, April, and May) in the period 2012&#8315;2018 to determine forecast efficacy; (2) BAHUS runs driven with observed and forecast meteorology were compared to test the impact of forecasted meteorological data; and (3) BAHUS runs were compared with field disease observations to estimate system efficacy in plant disease forecasts. The BAHUS runs with forecasted and observed meteorology were in good agreement. The results obtained encourage further development, with the goal of fully utilizing this weather-based forecasting system

Identifying Crop and Orchard Growing Stages Using Conventional Temperature and Humidity Reports

Vegetation is a climate modifier: It is a primary modifier, such as the Amazon rain forest, or secondary modifier, such as the agricultural fields of Pannonian lowlands in Central Europe. At periods of winter crop spring renewal and the start of the orchard growing season, enhanced evapotranspiration shifts energy balance partitions from sensible toward latent heat flux. This surface flux alteration converges into the boundary layer, and it can be detected in the daily variations of air temperature and humidity as well as daily temperature range records. The time series of micrometeorological measurements and phenological observations in dominant plant canopies conducted by Forecasting and Reporting Service for Plant Protection of the Republic of Serbia (PIS) are explored to select indices that best record the signatures of plant growth stages in temperature and humidity daily variations. From the timing of extreme values and inflection points of relative humidity (R1 and R2) and normalized daily temperature range (DTR/Td), we identified the following stages: (a) start of flowering (orchard)/spring start of the growing season (crop), (b) full bloom (orchard)/development (crop), (c) maximum LAI reached/yield formation (orchard and crop), and (d) start of dormancy (orchard)/leaf drying (crop). The average day of year (DOY) for dominant plants corresponds to the timing obtained from climatological time series recorded on a representative climate station

Agricultural Meteorology and Climatology

Agricultural Meteorology and Climatology is an introductory textbook for meteorology and climatology courses at faculties of agriculture and for agrometeorology and agroclimatology courses at faculties whose curricula include these subjects. Additionally, this book may be a useful source of information for practicing agronomists and all those interested in different aspects of weather and climate impacts on agriculture. In times when scientific knowledge and practical experience increase exponentially, it is not a simple matter to prepare a textbook. Therefore we decided not to constrain Agricultural Meteorology and Climatology by its binding pages. Only a part of it is a conventional textbook. The other part includes numerical examples (easy-to-edit worksheets) and recommended additional reading available on-line in digital form. To keep the reader\u27s attention, the book is divided into three sections: Basics, Applications and Agrometeorological Measurements with Numerical Examples

Agricultural Meteorology and Climatology

Agricultural Meteorology and Climatology is an introductory textbook for meteorology and climatology courses at faculties of agriculture and for agrometeorology and agroclimatology courses at faculties whose curricula include these subjects. Additionally, this book may be a useful source of information for practicing agronomists and all those interested in different aspects of weather and climate impacts on agriculture. In times when scientific knowledge and practical experience increase exponentially, it is not a simple matter to prepare a textbook. Therefore we decided not to constrain Agricultural Meteorology and Climatology by its binding pages. Only a part of it is a conventional textbook. The other part includes numerical examples (easy-to-edit worksheets) and recommended additional reading available on-line in digital form. To keep the reader's attention, the book is divided into three sections: Basics, Applications and Agrometeorological Measurements with Numerical Examples