scholarly journals Calculation of Subgrade Moisture Index in Seasonally Frozen Regions considering Evapotranspiration at Subzero Temperatures and the Pavement Coverage Effect

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Dongxue Li ◽  
Zongyuan Sun ◽  
Jianming Ling ◽  
Cong Li
Keyword(s):  
Potential Evapotranspiration ◽  
Climatic Conditions ◽  
Correction Coefficient ◽  
Water Runoff ◽  
Moisture Index ◽  
Balance Principle ◽  
Food And Agriculture ◽  
Subzero Temperatures ◽  
Food And Agriculture Organization ◽  
Seasonally Frozen Regions

The moisture index of subgrade material directly below a paved highway is typically represented by that of an uncovered slope. However, existing studies have demonstrated the existence of a significant moisture content difference between an uncovered slope and covered subgrade owing to evapotranspiration. Moreover, under the influence of solar radiation, wind, and other factors, soil evapotranspiration persists even at subzero temperatures. This paper presents an improved method for subgrade moisture index calculation for regions that freeze seasonally. Instead of the conventional Thornthwaite method, the Food and Agriculture Organization Penman–Monteith (FAO-56 PM) method was employed to estimate the potential evapotranspiration (PE) of slope soil at subzero temperatures. Based on the moisture balance principle, the PE and water runoff and deficit were used as input parameters to calculate the moisture index of an uncovered slope. After the effect of pavement cover on subgrade humidity was defined through a correction coefficient determined via the matric suction dependence of soil water content, an optimized calculation formula was developed to estimate the moisture index of the subgrade material according to that of the corresponding slope. The results calculated on a typical seasonally frozen region in Northeast China demonstrated the applicability and accuracy of the proposed method for predicting the subgrade moisture. The potential evapotranspiration of an uncovered highway slope soil at subzero temperatures could reach 9.8%–15.7% of the total annual evapotranspiration. The moisture index range for seasonally frozen regions was −14.2–57.3. These findings will have important implications for effective improvements in the design and construction of subgrade in regions that freeze seasonally or face similar climatic conditions.

FRUIT AND BERRIES WORLD PRODUCTION AND INTERNATIONAL TRADE

2020 ◽  
Vol 10 (8) ◽  
pp. 1445-1464
Author(s):  
R.R. Mukhametzyanov ◽  
◽  
E.V. Britik ◽  
Keyword(s):  
International Trade ◽  
Large Scale ◽  
Import Substitution ◽  
World Market ◽  
Climatic Conditions ◽  
Global Rating ◽  
Production Volume ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
The World

Horticulture is an important branch of agriculture with particular importance in some countries of the world. The production of fruits, berries and nuts is an important part of forming a high-grade food supply for the population in many countries, including the developing ones. Basing on the statistical data from the Food and Agriculture Organization of the United Nations (UN), the authors examined the change in the production volume of these products in the world as a whole for 1961-2018, as well as for the period 1992-2018 in some countries - twenty largest producers in 2018; and a number of trends were identified. In particular, it was noted that in 2018 the global gross harvest of fruits and berries increased by 4.34 times compared to 1961, while that of nuts - by 7.04 times. A deeper analysis in the context of states, which are the main producers of fruits, berries and nuts, carried out for 1922-2018, indicates that there is a change in the positions of these countries in the corresponding world ranking. The quantitative and qualitative changes we observe inevitably have a significant impact both on the volume of the world market in terms of production, and, consequently, the supply of fruit and berry products, and on the parameters of international trade in fruits, berries and nuts. Due to the fact that the Russian Federation is not among the countries - largest producers of fruit and berry products (in 2018 it was the 31st in the global rating for fruits and berries, and the 52nd for nuts), it occupies a very significant position in the world on its imports, especially on some of them. In connection with the policy of import substitution, deployed in response to sanctions from a number of Western states, some positive changes are also observed in the Russian gardening industry. However, imports in the resources of fruits and berries still amounted to 53.6% in 2018. Naturally, many types of fruit and berry products are economically inexpedient to cultivate on an industrial scale in the natural and climatic conditions of our country, but it is necessary to carry out scientifically grounded and systematic work to increase the production of relatively traditional for Russia fruit and berry plants in the large-scale commodity sector.

International Wheat Council

1961 ◽  
Vol 15 (2) ◽  
pp. 339-340
Keyword(s):  
World War Ii ◽  
The United States ◽  
Climatic Conditions ◽  
Annual Review ◽  
Producer Price ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Price Supports ◽  
The Press ◽  
The World

The International Wheat Council held its 31st session in London from November 7 to 19, 1960, for the purpose of reviewing the world wheat situation in accordance with article 21 of the 1959 International Wheat Agreement. The meeting was attended by representatives of 29 member countries and by observers from the UN Food and Agriculture Organization (FAO) and the European Economic Community. According to the press, the results of the second annual review, published on December 12, 1960, revealed that although climatic conditions had created unusually favorable preconditions for an expansion of the world wheat trade during 1960–61, the world surplus at the end of the season was expected to be larger than ever. The press reported that the cause of the wheat surplus problem was government intervention in production, pricing, and trading. Government measures introduced during and shortly after World War II to meet supply deficiencies in a war-disrupted world had been allowed to continue in effect, although the years since the war had seen growing surpluses. According to reports, there had been few changes in national policies affecting producer price supports in 1960; among 25 cases classified by the Council, supports had been reduced in only two instances, while in six instances they had been raised and in seventeen they had remained unchanged. In the four main wheat exporting countries—the United States, Canada, Argentina, and Australia—the end-of-season carry-overs as of July 31 were expected to reach an unprecedented total of 60.4 million metric tons, 37.3 million metric tons over the normal stock surplus. The ultimate solution of wheat surplus problems, concluded the press, depended on a growing adjustment of national wheat policies to international realities.

scholarly journals Prediction of Biome-Specific Potential Evapotranspiration in Mongolia under a Scarcity of Weather Data

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2470
Author(s):  
Khulan Batsukh ◽  
Vitaly A. Zlotnik ◽  
Andrew Suyker ◽  
Paolo Nasta
Keyword(s):  
Potential Evapotranspiration ◽  
Aridity Index ◽  
Crop Coefficient ◽  
Weather Data ◽  
Gobi Desert ◽  
Area Index ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Practical Guidelines ◽  
Specific Potential

We propose practical guidelines to predict biome-specific potential evapotranspiration (ETp) from the knowledge of grass-reference evapotranspiration (ET0) and a crop coefficient (Kc) in Mongolia. A paucity of land-based weather data hampers use of the Penman–Monteith equation (FAO-56 PM) based on the Food and Agriculture Organization (FAO) guidelines to predict daily ET0. We found that the application of the Hargreaves equation provides ET0 estimates very similar to those from the FAO-56 PM approach. The Kc value is tabulated only for crops in the FAO-56 guidelines but is unavailable for steppe grasslands. Therefore, we proposed a new crop coefficient, Kc adj defined by (a) net solar radiation in the Gobi Desert (Kc adjD) or (b) leaf area index in the steppe region (Kc adjS) in Mongolia. The mean annual ETp obtained using our approach was compared to that obtained by FAO-56 guidelines for forages (not steppe) based on tabulated Kc values in 41 locations in Mongolia. We found the differences are acceptable (RMSE of 0.40 mm d−1) in northern Mongolia under high vegetation cover but rather high (RMSE of 1.69 and 2.65 mm d−1) in central and southern Mongolia. The FAO aridity index (AI) is empirically related to the ETp/ET0 ratio. Approximately 80% and 54% reduction of ET0 was reported in the Gobi Desert and in the steppe locations, respectively. Our proposed Kc adj can be further improved by considering local weather data and plant phenological characteristics.

scholarly journals Evapotranspiration and crop coefficient for potato in organic farming

2013 ◽  
Vol 33 (1) ◽  
pp. 201-211 ◽  
Author(s):  
Daniel F. de Carvalho ◽  
Dione G. da Silva ◽  
Hermes S. da Rocha ◽  
Wilk S. de Almeida ◽  
Eraldo da S. Sousa
Keyword(s):  
Water Consumption ◽  
Solanum Tuberosum L ◽  
Meteorological Data ◽  
Crop Coefficient ◽  
Climatic Conditions ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Historical Series ◽  
The One ◽  
Crop Coefficients

The aim of this study was to quantify the water consumption and the crop coefficients (Kc) for the potato (Solanum tuberosum L.), in Seropédica, Rio de Janeiro (RJ), Brazil, under organic management, and to simulate the crop evapotranspiration (ETc) using the Kc obtained in the field and the ones recommended by the Food and Agriculture Organization (FAO). The water consumption was obtained through soil water balance, using TDR probes installed at 0.15m and 0.30m deep. At the different stages of development, the Kc was determined by the ratio of ETc and reference evapotranspiration, obtained by Penman-Monteith FAO 56. The crop coefficients obtained were 0.35, 0.45, 1.29 and 0.63. The accumulated ETc obtained in the field was 109.6 mm, while the ETc accumulated from FAO's Kc were 142.2 and 138mm, respectively, considering the classical values and the values adjusted to the local climatic conditions. The simulation of water consumption based on meteorological data of historical series from 1961 to 2007 provided higher value of ETc when compared with the one obtained in the field. From the meteorological data of historical series, it was observed that the use of Kc recommended by FAO may overestimate the amount of irrigation water by 9%, over the same growing season.

scholarly journals Optimal Selection of Empirical Reference Evapotranspiration Method in 36 Different Agricultural Zones of China

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 31
Author(s):  
Yong Yang ◽  
Rensheng Chen ◽  
Chuntan Han ◽  
Zhangwen Liu ◽  
Xiqiang Wang
Keyword(s):  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Aridity Index ◽  
Empirical Method ◽  
Climatic Conditions ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Temperature Method ◽  
The Relationship ◽  
Selection Of

The Food and Agriculture Organization has proposed the current version of the Penman–Monteith method (FAO56-PM) as the standard for calculating reference evapotranspiration (ET0); however, high meteorological data requirements limit its application in many areas. There is thus an urgent need to identify the best alternative empirical method to accurately calculate ET0 in regions that lack sufficient meteorological data. In this study, three temperature-based methods and five radiation-based methods were evaluated using ET0 values generated using the FAO56-PM method in 36 agricultural zones in China based on meteorological data from 823 stations, measured between 2011 and 2020. The results showed that the optimal temperature-based method and radiation-based method differed for different agricultural zones, and no one temperature method or radiation method could be suitable for all agricultural zones. The eight empirical methods were regionally calibrated to improve the ET0 calculation accuracy in the different zones. The relationship between the optimal methods and climatic conditions showed that the most reliable empirical method could be selected according to the local annual mean temperature and aridity index. The results provide useful guidance for the selection of reliable empirical ET0 methods in agricultural zones outside China.

scholarly journals Evaluation of Potential Evapotranspiration Based on CMADS Reanalysis Dataset over China

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1126 ◽  
Author(s):  
Ye Tian ◽  
Kejun Zhang ◽  
Yue-Ping Xu ◽  
Xichao Gao ◽  
Jie Wang
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Potential Evapotranspiration ◽  
Swat Model ◽  
Western China ◽  
Reanalysis Dataset ◽  
The North ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Monteith Equation

Potential evapotranspiration (PET) is used in many hydrological models to estimate actual evapotranspiration. The calculation of PET by the Food and Agriculture Organization of the United Nations (FAO) Penman–Monteith method requires data for several meteorological variables that are often unavailable in remote areas. The China Meteorological Assimilation Driving Datasets for the SWAT model (CMADS) reanalysis datasets provide an alternative to the use of observed data. This study evaluates the use of CMADS reanalysis datasets in estimating PET across China by the Penman–Monteith equation. PET estimates from CMADS data (PET_cma) during the period 2008–2016 were compared with those from observed data (PET_obs) from 836 weather stations in China. Results show that despite PET_cma overestimating average annual PET and average seasonal in some areas (in comparison to PET_obs), PET_cma well matches PET_obs overall. Overestimation of average annual PET occurs mainly for western inland China. There are more meteorological stations in southeastern China for which PET_cma is a large overestimate, with percentage bias ranging from 15% to 25% for spring but a larger overestimate in the south and underestimate in the north for the winter. Wind speed and solar radiation are the climate variables that contribute most to the error in PET_cma. Wind speed causes PET to be underestimated with percentage bias in the range −15% to −5% for central and western China whereas solar radiation causes PET to be overestimated with percentage bias in the range 15% to 30%. The underestimation of PET due to wind speed is offset by the overestimation due to solar radiation, resulting in a lower overestimation overall.

scholarly journals CALIBRATION OF THE HARGREAVES-SAMANI EQUATION FOR SPECIFIC PERIODS OF THE YEAR IN THE MUNICIPALITY OF JAÍBA-MG, BRAZIL

2017 ◽  
Vol 25 (5) ◽  
pp. 445-453
Author(s):  
Anunciene Barbosa Duarte ◽  
Lucas Borges Ferreira ◽  
Edson Fagne Dos Santos
Keyword(s):  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Climatic Conditions ◽  
Crop Water ◽  
Climatic Effects ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Crop Water Demand ◽  
Limited Application ◽  
Monteith Equation

Reference evapotranspiration (ET0) explains the climatic effects on crop water demand. The Food and Agriculture Organization (FAO) recommends the Penman Monteith equation as a standard method for estimating ET0. However, because this equation requires a large amount of meteorological data, it has limited application. An alternative is the Hargreaves-Samani (HS) equation, which only requires air temperature data, and can be calibrated to specifc locations and periods. The present study aimed to calibrate the empirical parameters (coeffcients and exponent) of the HS equation for specifc periods of the year, as well as evaluate the behavior and calibration of this equation throughout the year in the municipality of Jaíba-MG, Brazil. The daily meteorological data from 1996 to 2011 were gathered from a weather station located in the municipality of Jaíba-MG. A general calibration was performed per semester, per season, per month, and during periods with similar climatic conditions. The calibration of the HS equation, in all of the forms studied, promoted better ET0estimations. The calibrations for specifc periods of the year only promoted slight increases in performance in relation to the general calibration, therefore they, in general, presented equal performance to each other.

Food waste and dynamic complex systems: The case of Peru and a solution model proposal Part 1: Peruvian Anchoveta (Engraulis ringens)

2020 ◽  
Author(s):  
Carlos A Almenara
Keyword(s):  
United Nations ◽  
Complex Systems ◽  
Revenue Management ◽  
Food Waste ◽  
Intelligent Systems ◽  
Solution Model ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Engraulis Ringens ◽  
The United Nations

[THE MANUSCRIPT IS A DRAFT] According to the Food and Agriculture Organization of the United Nations (FAO, 2020), food waste and losses comprises nearly 1.3 billion tonnes every year, which equates to around US$ 990 billion worldwide. Ironically, over 820 million people do not have enough food to eat (FAO, 2020). This gap production-consumption puts in evidence the need to reformulate certain practices such as the controversial monocropping (i.e., growing a single crop on the same land on a yearly basis), as well as to improve others such as revenue management through intelligent systems. In this first part of a series of articles, the focus is on the Peruvian anchoveta fish (Engraulis ringens).

To the Empire and Beyond

2018 ◽  
Author(s):  
Gregory A. Barton
Keyword(s):  
Second World War ◽  
World War ◽  
Chemical Fertilizers ◽  
Basic Principles ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Organic Farmers ◽  
Southern Rhodesia ◽  
The Government ◽  
Second World

This chapter traces the expansion of industrial agricultural methods after the Second World War. Western governments and the Food and Agriculture Organization pushed for increased use of chemical fertilizers to aid development and resist Soviet encroachment. Meanwhile small groups of organic farmers and gardeners adopted Howard’s methods in the Anglo-sphere and elsewhere in the world. European movements paralleled these efforts and absorbed the basic principles of the Indore Method. British parliament debated the merits of organic farming, but Howard failed to persuade the government to adopt his policies. Southern Rhodesia, however, did implement his ideas in law. Desiccation theory aided his attempts in South Africa and elsewhere, and Louise Howard, after Albert’s death, kept alive a wide network of activists with her publications.

scholarly journals Characteristics of Phomopsis juglandina (Sacc.) Hohn. Associated with Dieback of Walnut in the Climatic Conditions of Southern Romania

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 46
Author(s):  
Cristina Mihaescu ◽  
Daniel Dunea ◽  
Adrian Gheorghe Bășa ◽  
Loredana Neagu Frasin
Keyword(s):  
Growth Temperature ◽  
Potential Evapotranspiration ◽  
Optimal Growth ◽  
Climatic Conditions ◽  
Cultural Characteristics ◽  
Optimal Growth Temperature ◽  
Conidial State ◽  
Optimal Ph

Phomopsis juglandina (Sacc.) Höhn., which is the conidial state of Diaporthe juglandina (Fuckel) Nitschke, and the main pathogen causing the dieback of branches and twigs of walnut was recently detected in many orchards from Romania. The symptomatological, morphological, ultrastructural, and cultural characteristics, as well as the pathogenicity of an isolate of this lignicolous fungus, were described and illustrated. The optimum periods for infection, under the conditions prevailing in Southern Romania, mainly occur in the spring (April) and autumn months (late September-beginning of October). Strong inverse correlations (p < 0.001) were found between potential evapotranspiration and lesion lengths on walnut branches in 2019. The pathogen forms two types of phialospores: alpha and beta; the role of beta phialospores is not well known in pathogenesis. In Vitro, the optimal growth temperature of mycelial hyphae was in the range of 22–26 °C, and the optimal pH is 4.4–7. This pathogen should be monitored continuously due to its potential for damaging infestations of intensive plantations.

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