Spatial Differentiation of Agricultural Potential and the Level of Development of Voivodeships in Poland in 2008–2018

: Polish agriculture is characterized by regional differentiation. These differences affect the production potential, generate income, or development which is an indispensable element of eco ‐ nomic efficiency. The aim of the article is to assess the spatial diversification of agriculture potential in relation to the development of voivodeships in Poland using a synthetic measure. Choice of variables in 2009–2018 was conditioned by the availability of data collected in the city system at the Central Statistical Office. Method of Technique for Order Preference by Similarity to an Ideal So ‐ lution was used to build synthetic measures. The synthetic measure of agricultural potential in voivodships in Poland was negatively correlated with the measure of the natural environment, the measure of infrastructure, the number of unemployed and the area of forest land. It was correlated with the area of arable land, number of tractors, cattle population, pigs and the production of milk, basic crops, sugar beet. The measure of the voivodeship development is negatively correlated with the synthetic measure of agricultural potential, area of arable land, arable land and number of people employed in agriculture. Conclusions drawn may allow local governments to define po ‐ tential directions of optimization of socio ‐ economic development of rural communes. Conceptualization, P.D., P.P., M.B.; methodology, P.D., P.P.; software, P.D., P.P., M.B.; P.D., P.P., M.B.;


Introduction
Polish agriculture is characterized by regional differentiation. They are shaped by demographic, natural, economic, as well as historical and many other conditions. The low level of development, concentration of agricultural land in small and medium-sized farms or high employment in the agricultural sector hinder the process of multifunctional and sustainable development of rural areas. It is important that the concentration processes in agriculture become more intense, which would allow more rational use of the existing labor force [1]. Differences in the spatial level of agricultural development affect the production potential, efficiency and ability to generate income. The integration of the state policy with the rural development policy is necessary to compensate for the existing disproportions [2].
Agriculture is an important sector of the Polish economy. It is the source of the most important product of mankind. It also affects the socio-economic situation of rural inhabitants and the condition of the natural environment. Agriculture is a pillar of the

Materials and Methods
The level of socio-economic development, agricultural potential, demographic processes, potentials of the natural environment and infrastructure are mutually dependent phenomena. The indicated voivodship potentials constitute a difficult-to-measure category. It is difficult to express them with a single universal measure that would reflect all their important features while allowing for assessments of the surveyed regions [25]. They create a multidimensional space of functioning. Since they are interdependent when acting for the benefit of a given community, they should be considered jointly [26,27]. Due to the multidimensional nature of the phenomenon of development, an ag-gregate measure was built, which was used to measure individual conditions for the expansion of rural areas and the synthetic level of development. It was assumed in the study that the level of development is the result of individual components [28].
A set of variables (creating a potential set of indicators) was initially proposed for research on the potential of agriculture and the socio-economic development of voivodships. In the case of voivodships, the choice of variables was largely determined by the availability of statistical data collected in the BDL CSO (for the years 2008-2018). The difficulties related to the implementation of the research are related to changes in legal provisions regarding the income system, the scope of tasks performed by territorial units, budget reporting and reporting by statistical offices. Significant problems in spatio-temporal research (indicators are calculated for 10-year variables) include: changes in the administrative division (e.g., transformation of a commune from rural into urbanrural), changes in the socio-economic situation, random events. Therefore, in this article, the authors focused on selected variables described in Table 1. Foundations, associations and social organizations per 1000 inhabitants, Emission of dust pollutants per 1 km 2 , Sewage treated annually together treated per 1 km 2 , Waste collected during the year in total 1 km 2 of the area, Users of installations in% of the total population/sewage system, population per 1 the library facility (including library points recognized in accordance with the seat of the parent unit) was removed from further research due to the value of the coefficient of variation or correlations based on the merode of inverse correlation. Source: study based on Local Data Bank of the Central Statistical Office data.
The research was carried out in several successive stages. In the beginning, a set of simple variables describing the studied phenomenon was selected. The selected set of variables is presented in the form of an observation matrix in the form: where-denotes the values of the j-th feature for the i-th object, i-object number (i = 1, 2, ..., n), j-variable number (j = 1, 2, ..., m) [29][30][31][32].
In the next stage, the nature of each of the selected variables was examined, distinguishing stimulants (S) and destimulants (D), taking into account the substantive importance of the feature and its correlation connections. Most of the variables are of an obvious nature (it results from the substantive experience of the researcher and the analysis of the literature). In doubtful cases, the procedure of Grabiński (1985) can be used, which uses the fact that stimulants should be positively correlated with each other, similarly to destimulants, and negatively with destimulants [33].
Variables characterized by a greater discriminant ability (limit value of the coefficient of variation equal to 0.10) and a low correlation with others (a diagonal element in the inverse correlation matrix significantly exceeding 10) were removed from the structure of the synthetic measure [34,35].
All variables selected for the analysis are characterized by sufficient discriminant ability and are slightly correlated with the others. The analyzed indicators can be related to the three dimensions of cohesion, which is the European Union's objective of public authorities' actions in the implementation of regional policy, with economic, social and territorial cohesion. Table 2 lists the basic descriptive parameters of the variables belonging to the final set, which are the basis for the construction of the synthetic measure. All the variables selected for the analysis are characterized by sufficient discriminant ability (spatial variability exceeds the assumed threshold Vj > 10%, low correlation). The value of the coefficient of variation for the variables used in the construction of the synthetic measure ranged from −1. 63   The set of diagnostic variables, on which the credibility of the results and the accuracy of decisions made on their basis depends, should be defined in such a way as to fully characterize the phenomenon under study.
Successively, the destimulant was replaced with a stimulant according to the formula [36]: The selected variables were subjected to the zeroed unitarisation procedure using the formula: where: S-stimulant, xij-denotes the value of the j-th feature for the i-th object, max {xij}-the maximum value of the j-th variable, min {xij}-the minimum value of the j-th variable. The value is in the range [0; 1]. The value of 1 means that the variable obtained the maximum value among all the examined objects in the whole examined period of time. A value equal to 0 means that the object took the minimum value [37,38]. The research was carried out dynamically, determining the values of min {xij} and max {xij} for the entire period, i.e., 2009 2018. As a result of the transformations, a matrix of unitized values of variables was obtained: where: denotes the unitary value of the j feature for the i object.
One of the solutions for conducting research on multifaceted phenomena with the use of aggregated values of diagnostic features is the use of synthetic measures. These measures allow for a numerical description of complex phenomena that cannot be directly measured. This enables a multidimensional view of the level of this phenomenon in individual examined objects, conducting comparative analyzes of objects (in spatial and time terms) and their linear ordering and classification [39].
The Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method was used to build a synthetic measure of the agricultural potential of voivodships in Poland and its spatial differentiation. A significant advantage of the TOPSIS method is its computational simplicity, indication of the distance from the pattern and the anti-pattern within the studied area, a large number of alternative criteria in the process of assessing the phenomenon and the global ordering of objects, legibility of the obtained results [40][41][42][43].
Within the adopted method of determining the synthetic measure, the distance of the unit from the standard (=1) and the anti-template (=0) was determined separately for each commune [44,45]. The Euclidean distances of individual objects were calculated according to the formulas: where n-means the number of variables forming the pattern or anti-pattern, zij -means the unitized value of the j feature for the tested unit, / -means the pattern or anti-pattern object [46,47]. The values of the synthetic variable are estimated using aggregate functions. The synthetic measure according to the TOPSIS method for individual objects was determined on the basis of the formula: , gdzie 0 q 1, i 1, 2, . . . , n; where: ∈ [0; 1]-value of synthetic maira; -means the distance of the object from the anti-pattern (from 0), means the distance of the object from the pattern (from 1).
A higher value of the measure indicates a better situation of an individual in the analyzed area [47,48]. The synthetic measure of development potential was determined as the average value of the synthetic measure of the studied areas, i.e., economic, demographic, natural environment, infrastructure. We can calculate it from the formula: ∑ -arithmetic mean as the value of a synthetic measure of development, -synthetic value of the potential category (according to the determined method, defined potential), n-number of tested potentials (categories).
The analyzed research area (voivodeships) was divided into typological groups according to a synthetic measure. The first, second and third quartiles were adopted as threshold values. The size of the synthetic measure in the first group means the better unit, and in the next-weaker units. The correlation coefficient (Pearson), the scatter plot with the fit line and linear regression analysis were also presented [49,50].
Spatial autocorrelation is a situation in which the occurrence of one phenomenon in one spatial unit causes the increase or decrease of the probability of the occurrence of this phenomenon in neighboring units [51,52]. Spatial autocorrelation is defined as the influence of a phenomenon occurring in a spatial unit on the probability of its finding in neighboring spatial formations. It is therefore a measure of the homogeneity of spatial structures that can be classified as positive (positive), negative (negative) or zero (no autocorrelation).
Positive spatial autocorrelation occurs when we observe the spatial accumulation of high or low values of the observed variables. It means the spatial formation of clusters of high or low values of variables. Negative autocorrelation means neighboring high values with low values in the space, and low values with high values, the graphic image of which is a checkerboard pattern [53]. Lack of spatial autocorrelation means spatial randomness, i.e., high and low values of the observed variables are distributed independently [7]. By analyzing the autocorrelation result, it is possible to determine clusters of objects similar to each other. Knowing and understanding the structures of space enables better anticipation of changes and facilitates taking actions in development policy [54].
The global and local I Moran spatial correlation coefficient can be used to investigate spatial relationships [55][56][57]. They will indicate, pointing to statistically significant clusters of similar values in neighboring locations. The I Moran statistic takes a value from the interval (−1.1), where the value "0" means no spatial autocorrelation, negative values are negative autocorrelation (<−1.0; units with different values occur next to each other in space, differentiation of the examined objects), positive values signal a positive spatial correlation (0.1>; units with similar values occur next to each other, forming clusters) [58,59].
Moran I Global Statistics is an analysis that made it possible to check whether the adjacent plots form clusters with similar values of the synthetic measure. According to Kopczewska (2011) [60], the presence of spatial autocorrelation means that geographically close objects are more similar to each other in terms of the analyzed variable than distant ones and have the ability to form clusters. On this basis, it can be concluded that plots with a similar synthetic index can combine and form spatial clusters. Global autocorrelation results from the existence of correlation within the entire studied spatial unit. Global statistics I Moran allows to determine the general similarity of spatial units in terms of the studied phenomenon. According to Upton and Fingleton (1985) [61,62], the Moran global coefficient was determined on the basis of the following formula: where: n-number of spatial objects (number of points or polygons), xi, xj-these are the values of the variable for the compared objects, -is the average value of the variable for all objects, wij-elements of the spatial weight matrix (weights matrix standardized with rows to one), So= ∑ ∑ , Local measures, on the other hand, show spatial relationships of a given variable with neighboring units in a specific location. Local statistics of spatial autocorrelation indicate statistically significant clusters of similar values in neighboring locations. They enable the assessment of stationarity assumptions, identification of non-stationarity areas, identification of outliers, clusters of large and small values and homogeneous sub-areas. Moreover, local statistics allow for the identification of the maximum distance of perceivable interdependencies in space.
The local version of the Moran statistics is the most popular analysis known as LISA (Local Indicators of Spatial Association). It determines the similarity of a spatial unit to its neighbors and examines the statistical significance of this relationship. The local form of the I Moran coefficient for observations i is given by the formula: where: n-number of spatial objects (number of points or polygons), xi, xj-these are the values of the variable for the compared objects, -is the average value of the variable for all objects, wij-elements of the spatial weight matrix (weights matrix standardized with rows to one), High values of the coefficient indicate the presence of clusters of similar values, low-the occurrence of the so-called hot spots, and values close to the expected value E (Ii) for a random distribution of the studied variable in space. Local Moran statistics take negative values when a given area is surrounded by regions with significantly different values of the studied variable (negative autocorrelation). The positive values of the statistics should be interpreted as follows: the region is surrounded by similar regions (positive autocorrelation). Thanks to this, it is possible to determine clusters with low or high values of the studied variable [63,64].
To illustrate the spatial dependence of the distribution of agricultural potential in voivodships and their development, the I Moran statistics were calculated, using the Queen matrix standardized by rows to one (using the PQStat program for this purpose).
Regression analysis is the study of the relationship between the variables of interest to us, aimed at the construction of the model. It allows us to indicate the relationship between the dependent variable (Y) and independent variables (X). Linear regression analysis aims to calculate regression coefficients such that the model predicts the value of the dependent variable as well as possible, so that the estimation error is as small as possible. We describe a linear regression model by the following formula: For the multiple regression model, we use the following formula for the regression line: where: b-is the regression coefficient calculated for individual predictors in the model, x-independent (explanatory) variable, y-dependent variable (explained) by the model, a-is an intercept.
The regression analysis permits checking whether the built model allows for significant predictions of the value of the explained variable. In the process of building a regression model, autocorrelation of variables should be excluded. Next, determine the percentage of the variance explained by reading the (preferably corrected) R 2 statistic. Its values range from 0 to 1. The closer to 1, the better the regression function fits the empirical data [65][66][67][68][69].

Results
In order to make a comparative analysis of voivodships in terms of the achieved level of socio-economic development and agricultural potential, the TOPSIS method of building a synthetic measure and spatial analysis (global and local statistics of I Moran) were used. The results of ordering the voivodships from the best to the worst for the selected years of the 2008-2018 period are presented in Table 3, while Table 4 provides descriptive characteristics of the synthetic measure of development and agricultural potential for the extreme years of the research period, i.e., for 2008 and 2018. Table 3 shows the division of voivodships into four groups with a similar level of development or agricultural potential. The groups were determined based on the value of quartiles (1, 2, 3). There is a spatial differentiation in the level of development and potential of agriculture in voivodships of eastern Poland. The synthetic qi of the agricultural potential ranged from 0.14 (Lubuskie, the weakest unit) to 0.  The Figure 1 shows the classification of voivodships in Poland according to the synthetic measure of development and agricultural potential (dark color of the best unit, the lighter color of the weaker units). The classification of communes was carried out on the basis of quartiles, which were threshold values for subsequent groups. In terms of development, the best units in 2008 were Śląskie, Pomorskie, Mazowieckie, and Lubuskie. In 2018, Mazowieckie, Pomorskie, and Śląskie were the strongest, while the weakest ones were Lubelskie and Świętokrzyskie, respectively. The best regions were characterized by high development potential, thanks to which further development was possible. The weaker economic situation of the regions does not allow for such a quick catching up and may be one of the reasons for the lower level of economic development in these regions in the coming years, due to the lower development opportunities.
The agricultural potential in voivodships in Poland was influenced by the fact that a given area belonged to one of the three former partitions: the Prussian partition (the most dynamically developing, fairly good situation; modern agricultural production, the existence of an absorbent market), the Austrian partition (slower development, farms more and more fragmented), the Russian partition (the weakest development, farms fragmented, poorly equipped with technical devices).
In the case of the measure of agricultural potential, the Wielkopolskie, Oposkie, Kujawsko-Pomorskie provinces turned out to be the best in 2018 (and 2008), the weakest Lubuskie, Warminsko-Mazurskie (2008) and Zachodniopomorskie, Lubuskie (2018) (Figure 1). Apart from natural factors, agricultural activity is influenced by the relief, soil quality and climate, as well as by non-natural factors. These factors include, among others basic soil cultivation, soil fertilization-fertilization, melioration, chemical plant protection, crop care. The socio-economic factors of agricultural development are also of great importance, including: the size of farms, specialization of agricultural production, marketability of agricultural production, mechanization of work, employment in agriculture and the agricultural policy of the authorities.  Having a large area of agricultural land and appropriate equipment with agricultural machinery and equipment, high yields and crops are obtained at lower unit costs of cultivating the land. There are still too many small semi-subsistence farms in Poland. The production in them is usually small and expensive (poorly specialized and mechanized). It is also more difficult to sell small crops from small farms at favorable prices for the farmer. The solution is good quality, attracting the customer with quality, distinguishing himself on the market, direct sales, short supply chains, i.e., getting the producer closer to the end-user (omitting intermediaries), customer trust in the producer, local markets, direct sales, good quality and taste, own processing, etc. It is thanks to small farms that employment in agriculture reaches over a dozen percent. The greatest fragmentation of farms occurs in South-Eastern Poland, where small farms account for over 70% of all farms. There is also the lowest level of agricultural production marketability (Świętokrzyskie, Małopolska, Podkarpacie). The highest marketability is recorded in the west of Poland, especially in areas with good soils (Kujawsko-Pomorskie, Zachodniopomorskie, Pomorskie, Wielkopolskie). In the indicated provinces, the largest number of large farms specializing in a specific type of agricultural production, e.g., in the cultivation of cereals or other mono-season plants (sugar beet, rape), or in the breeding of pigs or poultry.
Rural communes of eastern Poland are characterized by significant disproportions in terms of the financial situation and demographic potential. Communes distinguished by a higher level of the financial situation have a higher demographic potential index.  Table 4).
The communes of the first (the best) group in relation to the communes of the fourth (weakest) group were characterized by a higher value of the agricultural potential, a weaker situation in terms of demography, development, environment and infrastructure. In the case of variables describing the potential of agriculture, in the case of most of the variables, they were higher in group I than in group IV both in 2008 and 2018. A similar situation took place with regard to most of the development potential variables. Units with a better agricultural potential are not characterized by a better level of development. Regions located peripheral to the central center are characterized by, e.g., the effect of capital leaching (siphoning capital from the periphery to the central center). According to Rosner's research [70], there is a close relationship between the processes related to population (population, age and occupational structure, birth rate, migration balance, population density) and the level of socio-economic development. The age structure of the population shapes the situation on the labor market, and this indirectly influences the infrastructural potential and local finances. The decrease in the number of the unemployed in all groups, the increase in the number of the employed and the number of entities and natural persons conducting business activity should be assessed positively.
Statistical characteristics of the synthetic measure of the financial situation of rural communes in eastern Poland in 2008 compared to 2018 show the stability of the analyzed phenomenon. The standard deviation was 0.08-0.08 in terms of agricultural potential and 0.06-0.07 in terms of development (Table 5). It indicates a slight differentiation of units in the examined aspect. An increase in the standard deviation value indicates that the values of the variable are more scattered around the mean. The classical coefficient of variation (0.26-0.25 for agricultural potential, i.e., a decrease in diversity; 0.15-0.16 for development, i.e., a slight increase in diversity) shows slight disproportions. The coefficient of variation is used to test the degree of variation in the value of a variable. An increase in the value of the coefficient means an increase in the diversity of variables and indicates the heterogeneity of the studied population. The range (0.26-0.29 for the agricultural potential; 0.20-0.23 for development) indicates how large is the spread between the smallest and the largest value of the variable in the studied area, it indicates a slight increase in the diversity of the phenomenon in the studied area. The value of agriculture, as one of the three main branches of the Polish economy, is determined by: the possibility of feeding the country's population and exporting it outside Poland, the level of employment, agricultural products have a high position in foreign trade; ability to generate part of GDP. Pearson's correlation coefficient between the value of the synthetic measure in 2008 was −0.335, and in 2018 −0.561 (an increase in the value of the development potential will mean that the potential of agriculture is likely to do the opposite and will decrease (and vice versa), Figure 2). The region's economic efficiency is created, among others, by professional activity of inhabitants, local labor market, entrepreneurship, infrastructure, and the condition of the natural environment. Its proper level influences the growth of the living standard, in-creasing production and causes favorable social situation [71,72]. Migration causes important changes in the level of population, spatial distribution and in various population structures [73]. The number of economic entities shows the level of entrepreneurship in the region. The more entities, the greater, positive pro-development impulses that entrepreneurship exerts on the economy.
The  Table 6). The regression analysis of the agricultural potential and development variables indicates that the presented regression model allows us to explain 0.734062 of model variability, i.e., that it is explained by the variability of independent variables. It can be concluded that the model is fit enough. The model shows an important role for population km 2 , the number of unemployed and working people per 1000 inhabitants, entities entered in the register per 1000 inhabitants, share of financial income in total income, forest land area and housing resources per 1000 inhabitants. In shaping the agricultural potential of voivodships in Poland. These are the variables that build the endogenous economic base of the region, which has an impact on the development process. The endogenous potential of the region is built, among others, by professional activity, local labor market, entrepreneurship, infrastructure, and the condition of the natural environment. Its appropriate level affects, among others raising the standard of living, increasing production, better social situation. The region's potential is the result of a combination of local conditions, it defines its possibilities and directions of development. Their impact on economic development is diversified; nevertheless, each of these factors contributes, and the occurrence of development processes is not possible without any of them. The substitution of components that are deficient in a certain territory by others that are in relative excess is limited. The fit of the model is measured with the corrected R 2 (0.722981). The adjusted coefficient of the determination reached 72%. Further increasing the multidimensionality of the model would result in a slight increase in value, and the model could include statistically insignificant variables. The model could include statistically insignificant variables. This error is eliminated by the corrected R 2 . It shows the actual fit of the model, independent of the number of added variables that have no significant influence on the model. The F statistic is F (7, 168) 66.24644 and is statistically significant (p) ( Table 7). The values captured by the global statistics of Moran's I mean the occurrence of a diversified level of the studied phenomenon in distant units in relation to the neighboring ones. On the basis of the obtained values, it can be noticed that in the period in question there is a slight negative autocorrelation and a decrease in its value (in relation to 2018 to 2008; Table 8) for the measure synthetyczny rozowju. There is also a slight autocorrelation in the development area, but the significance levels of these measures are quite high, which suggests insignificant statistical values, therefore no spatial autocorrelation (p > 0.05; values are distributed randomly). This means that any observed level of agricultural potential can emerge in any location with equal probability. It can be stated that the agricultural potential in terms of voivodeships does not, therefore, show spatial autocorrelation. The decreasing value of the considered statistics means a decreasing spatial dependence. This means there is a tendency to concentrate similar values (i.e., high and low) in the area of the studied variable in a given region. In the next step of the analysis, local Moran statistics were determined for each voivodship. The obtained values of these statistics are presented in Table 9. Significant and high positive and negative values of local statistics of Moran I were obtained in Zachodniopomorskie, Opolskie, Łódzkie, Podlaskie, Wielkopolskie, Warmińsko-Mazurskie, Śląskie (in 2008) and Opolskie, Zachodniopomorskie, Łódzkie, Śląskie, Lubuskie, Warmińsko-Mazurskie (2018) in aspect of the sythetic potential of agriculture. In the case of the development measure, the following answers were: Voivodeships with positive values of local statistics can be treated as outliers. These voivodships are surrounded by units with significantly similar levels of potential within the studied area. A high p-value suggests insignificant values of the Moran statistic, therefore no autoco-spatial relation. At the same time, the decreasing tendency of the value of the considered statistics in the period under consideration means a weakening spatial relationship.  Spatial interactions between the development potential and the division of voivodeships in Poland are shown in Figure 3. The local statistics of I Moran were determined for each trait. The manner of spatial connections between communes was determined using the neighborhood matrix.

Discussion
Better-developing voivodships were found in western and central Poland (Mazowieckie, Wielkopolskie). Due to geographic and natural conditions and the influence of socio-economic factors, individual regions of the country are characterized by a different economic situation. The processes take place within regions and translate directly into the living conditions, as well as the well-being of the inhabitants [74]. Agriculture is a branch of the economy dependent on many factors. The multidimensionality of both the development aspect and the agricultural potential should be emphasized. The discussed potentials determine numerous variables included in Table 1, which also determine the strength of the region. The multidimensionality and multifaceted nature of the connec-tions taking place in the local (regional) economy requires building a network of relations simultaneously at all levels of operation, i.e., micro, meso and macro. Additionally, the multidimensionality is noticeable in the context of the functioning of regions in the economic, social, cultural and environmental spheres.
Its development is influenced by natural, social and economic conditions (including human capital, agrarian structure, the level of mechanization and technical infrastructure). These variables are interdependent and occur at the same time. They should therefore be considered together. The potential of agriculture in Poland is a complex and spatially diversified phenomenon. It results from differences in: natural conditions, type of agricultural production, agrarian fragmentation or the level of economic development of voivodships [75].
One-dimensional analysis of its level may not be sufficient. It should be strengthened by a multidimensional (synthetic) approach. Examples of the use of linear ordering methods in agricultural economics were presented by the potential of agriculture by Anna Majchrzak and Feliks Wysocki [12], Feliks Wysocki and Agnieszka Kozera [13], Walenty Poczta and Natalia Bartkowiak [10], Luiza Osowska and Dorota Janiszewska [14]. Individual authors used different sets of features characterizing the potential of agriculture. Difficulties in the description and measurement of phenomena occurring in agriculture result from the complexity of the production process in agriculture. This is due to from regional differentiation of production conditions, demographic and social processes. The selection of the features was made after reading the professional literature and the necessary statistical calculations. Many economists studying the potential of agriculture have focused on assessing the level of potential compared to other countries. Less attention was paid to regional analysis (e.g., by voivodship) [76,77]. The authors, through the prism of the multitude of synthetic mairy, present the diversification of the potential of agriculture in voivodships in Poland (Figure 1). The topic of the potential of agriculture is present not only in Poland but all over the world. This is evidenced by numerous scientific studies. Gudrun Loose points out that the natural conditions influenced by climate, water, soil and vegetation strongly affect the basic agricultural potential in Central and Eastern Europe [78].
Clawson M., Landsberg H.H., Alexander L.T. analyze the agricultural potential of the Middle East, including countries such as Egypt, Israel, Jordan, Lebanon, Syria, Iraq and Saudi Arabia. They indicate that the development potential should be considered in such areas as natural resources, land and water management, inputs, labor, farms, crops, livestock, production, marketing and trade [79]. X Deng, J Huang, S Rozelle, E Uchida pointed out that the potential development and productivity of agriculture has an impact on China's food security [80]. Research conducted in the USA by AJ Planting, RN Lubowski, and RN Stavins indicates the relationship between irreversible and uncertain land development and the value of agricultural land [81]. An issue that relates to this issue is the market position of farms in market networks. It can be considered in two perspectives-as the position of some farms against others, and as the market power of farms against other economic entities, e.g., producers of means of production or trading companies [82,83].
Contemporary agriculture is going through a period of intense changes. They are related to the search for management methods that guarantee the achievement of economic, social and environmental goals. The level of development (including agricultural development) is characterized by large spatial differentiation, both in terms of the potential and the degree of its use. The decline in the number of agricultural workers results from the progressing technological, economic, structural and organizational changes as well as migration processes.
The conducted analyzes of the synthetic measure of the potential of agriculture show that Polish agriculture is characterized by a large spatial differentiation. Its level was influenced by the measure of the natural environment, the measure of infrastructure, the number of unemployed (especially in rural areas) and working people, or the share of income from transfers from the state budget in total income, and the area of forest land. The indicated ones also shaped the development process, it was also shaped by the variables of the agricultural potential ( Table 6). The indicated elements constitute the local economic base of the region. Skillful use of the potential of agriculture together with structural changes may decide the development (competitiveness) of the region. Significant and growing spatial disproportions in the level of socio-economic development may shape the processes taking place in agriculture.
R. Grabowski and S. Self emphasized the special importance of technological changes in agriculture. They indicated that changes in agricultural technology had a positive impact on the region's growth [84]. The same dependence in the field of technology development is also indicated in the latest study by Vesna Vesna MrdaljHamid El Bilali [85]. Other authors indicate that specialization is a way to better use the potential of agriculture. Its increase may lead to increased profitability and may also increase the risk of farming and environmental hazards [86]. The analysis of numerous studies has shown that the potential of agriculture is correlated with climate change as a result of an increase in the concentration of greenhouse gases. This is indicated, inter alia, by C Rosenzweig and FN Tubiello, who believe that it is necessary to implement an environmental protection strategy with simultaneous socio-economic pressure [87]. Martin L. Parry, Timothy R. Carter, Nicolaas T. Konijn, also link the influence of climate to various aspects of agriculture, referring in their research to Iceland [88]. It should be emphasized that this is a global problem, but nevertheless, solutions should be adapted to regions, due to appropriate natural, social and economic factors.

Conclusions
Agriculture is one of the three main sectors of the economy. It produces food. The basic natural factors influencing the development of agriculture are soil quality, climate and topography. Non-natural factors of agriculture development include the level of agrotechnics, farm size, commodity and specialization of agricultural production, employment in agriculture, agricultural policy of the authorities. There are still too many small semi-subsistence farms in Poland-they dominate the east of the country.
The subject of the research was to compare the potential of agriculture in voivodships in Poland. A synthetic measure was chosen as the research method, which allows for their ranking. On the basis of the synthetic variable, voivodeships were divided into typological groups. A division into quartile groups was proposed, assuming one, two, three quartiles as threshold values. The analyzes were carried out for the years 2008 and 2018. This slowly assessed the changes in the potential of agriculture in the analyzed period. The values of single simple (diagnostic) variables in individual groups can be characterized by a fairly large dispersion. The total measure (synthetic variable) shows the actual position of the voivodship. The goodness of the variables for the study may affect the position of the individual in the examined aspect. The position of the unit may also result from the construction of the synthetic measure. The obtained results should be treated with caution, as the use of a different measure or the selection of a different area of the test may have a significant impact on the test result. The synthetic measure of the agricultural potential ranged from 0.14 (Lubuskie) to 0. The level of the synthetic measure of agricultural potential in voivodships in Poland was negatively correlated with the measure of the natural environment, the measure of infrastructure, the number of unemployed and the area of forest land. In the aspect of variables describing agriculture, the measure of agricultural potential was correlated with the area of arable land, number of tractors, cattle population, pigs, and the production of milk, basic crops, sugar beet, and grain maize. The development was influenced by the level of migration, the number of employees (as well as economic entities and natural persons running a business, own income in total income, people using treatment, the measure of demographic potential and the labor market, the measure of economy and infrastructure.
In the case of the leading voivodships, in terms of the agricultural potential, we are dealing with a high level of their operational efficiency and their large area. Agriculture is fragmented in four voivodeships of south-eastern Poland. The decline in the number of agricultural employees resulted from the migration of workers, interest in expanding non-agricultural types of economic activity, and enabled better use of the remaining labor force and improvement of the agrarian structure of farms.
Expanding the aspect of non-agricultural activities, as part of multifunctional rural development, while maintaining the principles of the sustainable development concept, which means obtaining complementarity of individual functions of rural areas, while meeting the criteria of economic, social and environmental order. Developing a diverse offer of non-agricultural activities services, both on farms and in the environment, will generate higher farm incomes and create additional jobs in their surroundings. This will contribute to the development of both farms themselves and the economic strengthening of rural areas. The non-agricultural professional activity of the agricultural population will significantly and in the long term raise the standard of living of farming families by generating additional sources of income. The multi-functional development of rural areas is primarily aimed at counteracting economic and social marginalization and depopulation of rural areas.
Strengthening and development of infrastructure in rural areas should be the result of activities undertaken by local authorities as part of the implementation of multi-annual strategic plans developed at the local level. In the institutional aspect, one should also take into account not only the number and structure of public institutions, but also non-governmental organizations and the efficiency of their activities, and thus the development of civic activity, which will consequently constitute the basis for the development of the rural social economy.
Local authorities should first of all take care to improve the economic potential, which may increase the attractiveness of the areas and attract new entrepreneurs, create new jobs (including in non-agricultural sectors) and improve the quality of life of rural residents, thanks to activities aimed at accelerating multifunctional development of areas rural. It may also allow for a partial departure of the labor force from the agricultural sector and will positively reduce the so-called hidden unemployment in agriculture. Moreover, the possibility of finding a job outside agriculture may result in the liquidation of some small and ineffective farms and their takeover by larger, dynamically developing farms, thus positively influencing the change in the agrarian structure. In many regions of Poland you can still observe the so-called "land hunger", that is, owners of larger farms want to expand them, but find it difficult to find people willing to sell their land. Many small farms have a social function (place of residence and food production for self-supply). The acceleration of the transformation of the economic and social structure should also contribute to the improvement of the income structure, strengthening of financial independence, and improvement of the economic base in rural areas.
The presented methods make it possible to identify areas with a higher or lower level of agricultural and development potential, and then to program their support, e.g., from public funds under the regional policy. It can be used as a useful tool for local authorities in assessing the accuracy of past decisions, as well as the effectiveness of the regional management instruments used in the past. The low availability of statistical data on the agricultural potential makes it difficult to analyze the operation or programming, conduct and evaluation of the local government development policy. The lack of properly selected indicators increases the risk of their selective selection and the possibility of making wrong decisions in the future.