scholarly journals Evolution of Agricultural Production in Portugal during 1850–2018: A Geographical and Historical Perspective

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 776
Author(s):  
Cláudia M. Viana ◽  
Dulce Freire ◽  
Patrícia Abrantes ◽  
Jorge Rocha
Keyword(s):  
Time Series ◽  
Food Security ◽  
Agricultural Production ◽  
Security Evaluation ◽  
Global Food Security ◽  
Historical Perspectives ◽  
Production Values ◽  
Current Production ◽  
Changes Over Time ◽  
Over Time

Agricultural statistical data enable the detection and interpretation of the development of agriculture and the food supply situation over time, which is essential for food security evaluation in any country. Based on the historical agricultural statistics, this study produces a long spatial time-series with annual production values of three cereals relevant to global food security—wheat, maize, and rice, aiming to provide geographical and historical perspectives. Therefore, we reconstructed past and current production patterns and trends at the district level over 169 years, which supported a space–time cross-reading of the general characteristics of the regional agricultural production value distributions and relative densities in Portugal. Particularly, the production trends of wheat, maize, and rice showed three different situations: growth (maize), stability (rice), and decline (wheat). For decades, maize and wheat production alternated, depending on agricultural years and political aspects, such as the Wheat Campaign (1929–1938). The changes over time presented a pattern that, in the case of these three cereals, enabled a clear division of the country into major regions according to cereal production. Overall, maize and rice, both grown on irrigated croplands, presented a similar pattern in some regions of Portugal, mainly the central region. In this study, a preliminary analysis was presented and related to successive public policies; however, notably, there are more lessons to be learned from this long spatial time-series.

scholarly journals The Current State of the Agricultural Sector in the Context of Food Security in Ukraine

2020 ◽  
Vol 22 (1) ◽  
pp. 112-118
Author(s):  
Karina Utenkova ◽  
Keyword(s):  
Sustainable Development ◽  
Food Security ◽  
Agricultural Production ◽  
Agricultural Sector ◽  
Food Products ◽  
Economic Security ◽  
Animal Origin ◽  
Global Food Security ◽  
Security Index ◽  
Global Food

Introduction. The article is devoted to the problems of agricultural development as a basis for ensuring food security in Ukraine. Food security is one of the important components of economic security, which creates a basis for further progress and development of the state. Achieving food security is one of the Global Goals for Sustainable Development by 2030, set by the UN to member countries at the Summit on Sustainable Development. The purpose of the article is to reveal the problems and prospects for the development of the agricultural sector in the context of ensuring food security in Ukraine. Results. It has been determined that the contribution of agricultural production to the GDP in Ukraine is quite significant. According to the results of 2018, 89% of agricultural enterprises have received a profit. The consumption of main types of food products by the population of Ukraine is less than the scientifically substantiated norms, namely: the actual consumption of meat is 64% of the norm; milk and dairy products – 52%; eggs – 94.8%; fish – 59%; fruits, berries and grapes – 53%. At the same time, there is a steady increase in the share of agricultural products in the structure of exports (in 2019 – 44.2%). According to the Global Food Security Index, Ukraine does not have the best positions and yields not only to all European countries, but also to those countries to which it exports food. Conclusions. Ukraine occupies the 76th out of 112 positions in the 2019 Global Food Security Index. Problems that pose potential threats to food security are acute, particularly, the lack of balance in the diet of Ukrainians. Due to the products of animal origin, the caloric value of the diet is provided only by 28% at the optimal level of 55%. The share of the population’s expenditures on food products is unacceptably high: more than half of the total aggregate expenditures, which is higher than the similar indicators of the EU countries by 3-5 times. The increase in agricultural production should take place in compliance with environmental norms and international food quality standards.

A Note on Rainfall Variability and Trends in Nigeria: Implications for Agricultural Production*

2021 ◽  
pp. 232102222110514
Author(s):  
Kolawole Ogundari ◽  
Adebola Abimbola Ademuwagun ◽  
Ogechukwu Appah
Keyword(s):  
Food Security ◽  
Coefficient Of Variation ◽  
Agricultural Production ◽  
Hypothesis Test ◽  
Rainfall Variability ◽  
Climatic Variability ◽  
Least Square ◽  
Annual Rainfall ◽  
Average Annual Rainfall ◽  
Over Time

The climatic change crisis has led to a renewed interest in understanding the dynamic of climatic variability over time. This is because rainfall variability in response to climate change poses a severe threat to global food security and agricultural production in general. As a result of this, the study investigates the convergence of rainfall variability in Nigeria. We use historical climate data on annual rainfall collected from meteorological stations across 12 states and covering 1992–2013. This gives rise to a balanced panel data of 12 states and 20 periods, which yields 240 observations. The study used a sigma convergence hypothesis test estimated using ordinary least square, fixed-effect and feasible generalized least square models. The coefficient of variation is taken as a measure of rainfall variability in the study. The results showed a negative (declining) linear correlation between rainfall’s coefficient of variation and data year. This means that rainfall variability decreased over time. This indicates evidence of convergence of rainfall, which means states with lower average annual rainfall are catching up on states with higher average annual rainfall over time. And, from the agricultural production standpoint, this result shows that the potential threat of rainfall variability to food security is not severe. In addition, it indicates a decrease in risk and uncertainty in food crop production associated with rainfall variability. JEL Classifications: O13, O55, Q10, Q54

Bayesian Inference of Trend and Difference-Stationarity

1994 ◽  
Vol 10 (3-4) ◽  
pp. 596-608 ◽  
Author(s):  
Robert E. McCulloch ◽  
Ruey S. Tsay
Keyword(s):  
Time Series ◽  
Bayesian Inference ◽  
Model Selection ◽  
Odds Ratio ◽  
Model Discrimination ◽  
Posterior Probabilities ◽  
Competing Models ◽  
Computational Difficulty ◽  
Changes Over Time ◽  
Over Time

This paper proposes a general Bayesian framework for distinguishing between trend- and difference-stationarity. Usually, in model selection, we assume that all of the data were generated by one of the models under consideration. In studying time series, however, we may be concerned that the process is changing over time, so that the preferred model changes over time as well. To handle this possibility, we compute the posterior probabilities of the competing models for each observation. This way we can see if different segments of the series behave differently with respect to the competing models. The proposed method is a generalization of the usual odds ratio for model discrimination in Bayesian inference. In application, we employ the Gibbs sampler to overcome the computational difficulty. The procedure is illustrated by a real example.

International trade as a factor in ensuring food security in the modern world

2020 ◽  
pp. 5-16
Author(s):  
Natalia Anatolevna Baryshnikova ◽  
Olga Mikhailovna Kiriliuk
Keyword(s):  
International Trade ◽  
Food Security ◽  
Economic Integration ◽  
Agricultural Production ◽  
Global Market ◽  
Modern World ◽  
Global Food Security ◽  
Underdeveloped Countries ◽  
High Level

Today one of the most pressing global problems is the problem of hunger and malnutrition, the solution of which is directly related to ensuring food security. In the context of increasing economic integration, international trade is the most important tool for ensuring food security. Food trade is one of the most steadily developing segments of the global market. Today, the leading exporters are also the largest importers of food, wisely combining the benefits of international economic integration and the principle of developing domestic agricultural production. The role of international trade in ensuring food security was assessed by comparing the global food security index and the value of net food exports, which made it possible to develop a typology of countries. The first two groups include countries that provide their citizens with a high level of food security through domestic efficient agricultural production or through imports. The third and fourth groups include agricultural underdeveloped countries, where the problem of hunger and malnutrition can potentially be solved through international trade and increased efforts of the international community.

scholarly journals Food security and comparative analysis of situation in Serbia and neighbouring countries

2020 ◽  
Vol 67 (4) ◽  
pp. 1191-1204
Author(s):  
Dragica Božić ◽  
Marija Nikolić
Keyword(s):  
Food Security ◽  
Sustainable Development Goals ◽  
Public Expenditure ◽  
Global Food Security ◽  
Development Goals ◽  
Per Capita ◽  
Security Index ◽  
Key Indicators ◽  
Global Food ◽  
Over Time

The concept of food security has expanded significantly over time, and due to its importance, it is on the list of priorities of the UN Sustainable Development Goals. The aim of this paper is to analyze the state of individual dimensions and key indicators of food security in Serbia and selected neighboring countries using the Global Food Security Index (GFSI). The index was created in 2012 by the Economist Intelligence Unit and it is calculated every year to measure the risk of food insecurity in individual countries. The latest data indicate that Serbia has the worst rank among the neighboring countries. The analysis showed that two GFSI indicators for Serbia (gross domestic product per capita and public expenditure on agriculture) are the worst evaluated and represent the main limitations of improving food security in Serbia.

scholarly journals Investigating changes over time of annual rainfall in Zimbabwe

2010 ◽  
Vol 14 (12) ◽  
pp. 2671-2679 ◽  
Author(s):  
D. Mazvimavi
Keyword(s):  
Time Series ◽  
Regression Analysis ◽  
Quantile Regression ◽  
Rainy Season ◽  
Annual Rainfall ◽  
Rainfall Time Series ◽  
Average Rainfall ◽  
Quantile Regression Analysis ◽  
Changes Over Time ◽  
Over Time

Abstract. There is increasing concern in southern Africa about the possible decline of rainfall as a result of global warming. Some studies concluded that average rainfall in Zimbabwe had declined by 10% or 100 mm during the last 100 years. This paper investigates the validity of the assumption that rainfall is declining in Zimbabwe. Time series of annual rainfall, and total rainfall for (a) the early part of the rainy season, October-November-December (OND), and (b) the mid to end of the rainy season, January-February-March (JFM) are analysed for the presence of trends using the Mann-Kendall test, and for the decline or increase during years with either high or low rainfall using quantile regression analysis. The Pettitt test has also been utilized to examine the possible existence of change or break-points in the rainfall time series. The analysis has been done for 40 rainfall stations with records starting during the 1892–1940 period and ending in 2000, and representative of all the rainfall regions. The Mann-Kendal test did not identify a significant trend at all the 40 stations, and therefore there is no proof that the average rainfall at each of these stations has changed. Quantile regression analysis revealed a decline in annual rainfall less than the tenth percentile at only one station, and increasing of rainfall greater than the ninetieth percentile at another station. All the other stations had no changes over time in both the low and high rainfall at the annual interval. Climate change effects are therefore not yet statistically significant within time series of total seasonal and annual rainfall in Zimbabwe. The general perception about declining rainfall is likely due to the presence of multidecadal variability characterized by bunching of years with above (e.g. 1951–1958, 1973–1980) and below (e.g. 1959–1972, 1982–1994 ) average rainfall.

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