Spain’s agricultural employment declined at an average annual rate of 4 percent, slightly above the rate for Italy and France. The implication is that if Bulgaria is to follow the development path of these latter countries, then it should be reducing its farm labor force at an even faster rate. The success of such a policy, however, rests on a development in the industrial and service sectors that is sufficient to absorb the surplus labor pool. It is not clear that Bulgarian agriculture was over-manned in 1989. On the one hand, Rock argues that most people in Bulgaria knew that almost enterprises had excess labor, and the European Union pointed out that Bulgarian agriculture was labor intensive with low-average productivity compared with other sectors. On the other hand, Karp calculated that the agricultural share of employment was in keeping with the shares of other countries with similar income levels. Therefore there would not be a significant exodus from agriculture, for a given level of output, unless incomes rose. These findings from other transition economies confirm the conclusions made here that the outflow from agriculture is what might have been expected and could be lower than needed for an efficient agriculture. Improved awareness of rural population is also critical to developing economic and social strategies. The significance of the village survey results is that official data may under-estimate the number of persons in rural villages that might be available for work,procona valencia buckets or that might make potential claims on benefits from rural development schemes.

If incomes in agriculture are to rise, this could happen through a recovery in the level of output, by more capital investment or by transfers through agricultural policy. The first of these is unlikely to happen while government policies suppress prices to farmers as they have been for grain for the last three years. The second is also unlikely while agriculture is unprofitable and discouraging to investors. There are few signs that Bulgarian policy makers have the will or resources to make income transfers to farmers. So far, the transfers are in the opposite direction. It seems clear that rural and urban employment and unemployment issues cannot be considered separately; nor can the issues of employment and income. Effective policy responses will involve investment in infrastructure that will make the labor market efficient. These changes include a nationwide data bank and information system, improvements in housing that will facilitate labor mobility, and targeted educational and training program. The first of these changes can be done at relatively low cost. It would provide job seekers and employers with a way of finding one another. The other changes are more expensive and may include acomprehensive system of income supplements for the poor . Macroeconomic stabilization would help in stimulating economic development and job growth. However, it is not a necessary condition for microeconomic structural reforms . Such reforms can be started now.

Currently, Bulgaria has an under-employed labor force that represents a waste of human resources that could otherwise contribute to the country’s economic and social development. If this situation persists, agriculture will remain a low wage sector with relatively low productivity. This is not consistent with a long-run strategy for agricultural development.Plastic products are advantageous because of their low cost, malleability, and durability. Global plastic production has increased from 1.7 million tons in 1950 to 368 million tons in 2019 . However, only 9 % of the plastic was recycled, 12 % was burned, and the remaining 79 % was released into the environment . Because of their refractory to biodegradation, plastics can remain in the environment for even centuries, where they are constantly broken and form small plastic particles under physical, chemical, or biological actions. Thompson et al. introduced the term microplastic in the study of plastic debris in the ocean. Microplastic is now universally acknowledged as plastic particles smaller than 5 mm . Since then, microplastic pollution has become an emerging environmental concern and the occurrence of microplastics in marine water , fresh-water , deep–sea sediments , soil , atmosphere and even polar glaciers has been studied. In comparison with the ocean ecosystem, it has been estimated that the amounts of microplastics released into terrestrial ecosystems are 4–23 times greater than those into the ocean . Farmlands may represent the core sinks of microplastics as they can enter agricultural soil through a wide range of routings, including plastic mulch, organic fertilizer application, artificial irrigation, and atmospheric deposition. Globally, approximately 20 million hectares of farmland are covered with plastic mulch , and the main component of the plastic film is polyethylene . After the functional period of mulching, the toughness of plastic film reduces, making it hard to recover. The remaining plastic film will be fragmented under multiple environmental conditions , and ultimately form microplastics in farmland soil . Irrigation water, including surface water, groundwater, and purified sewage, is also an essential source of microplastics in agricultural lands.

Massive abundance of microplastics accumulated in agricultural soils, potentially impacting the ecosystem functions. However, the microplastic concentrations used in the previous exposure studies were greatly manifold, making it difficult to compare the study results to obtain the ecological baseline. The potential reason could be the methodological challenges in quantification. A widely used method to quantify microplastics is visual inspection under stereoscope after flotation and further identification by Fourier Transform infrared spectroscopy  or Raman spectroscopy . No matter which method is used for the microplastic identifi- cation, the quantification relies typically on the visual inspection under a stereoscope, which may have a 33 % false detection rate for 50–100 μm microplastics and a 37 % false detection rate for <50 μm microplastics . Furthermore, the false detection rate increases with the microplastic size decreases . Therefore, a rapid and accurate method for the identification and quantification of microplastics in the soil is mandatory. Among all the identification methods, Raman spectroscopy has a better size resolution , but the background fluorescence of organic matter or pigments in polymers may strongly interfere with the required spectrum. Thus, this method may be an unfavorable choice of instrument for soil samples that contain rich organic matter. FTIR has a less precise size resolution , but its spectral quality is not influenced by fluorescence, which may be more suitable for identifying microplastics from soils. The main FTIR technologies include FTIR in attenuated total reflection mode , focal–plane–array FTIR , and laser direct infrared . ATR–FTIR requires the manual picking of suspected microplastic samples on the loading platform, which is more suitable for analyzing microplastics above 500 μm . Particles of 10–500 μm can be analyzed by FPA–FTIR or LDIR. FPA–FTIR collects all the information on the test window, which is time–consuming. Comparatively, LDIR first scans the entire window and automatically identifies and locates all the particles on it,procona buckets and then only collects the spectrum at the positions of the identified particles. Thus, only the valid data is collected and the detection speed is fast. Therefore, combining ATR-FTIR and LDIR may be a reliable method for microplastic identification and quantification in soil. In this study, the cotton field with long–term film mulching in Shihezi City of Xinjiang Uygur Autonomous Region was selected. This field was all film mulched, highly mechanized, and centrally managed, making it possible to collect soil samples with different mulching times while excluding other variables such as crop types. Techniques using laser Direct Infrared and total reflection Fourier– transform infrared methods were applied to detect microplastics ranging from 10–500 μm to 500 μm–5 mm, respectively. Furthermore, the distribution of abundance, particle size, polymer type, and shape of microplastics were investigated, and the possible source and migration ability of microplastics were critically discussed. This study will greatly enhance our understanding of the distribution and source of microplastics in farmland soil.The current study was conducted in Shihezi City, Xinjiang Uygur Autonomous Region, China . Shihezi is located in the middle of Northern Xinjiang and has a temperate continental climate characterized by rare precipitation and extreme dryness. The annual average temperature is 7–8 °C and the annual precipitation is 180–270 mm. The farmland in this area is a typically irrigated agricultural area.

The Eighth Agricultural Division of Xinjiang in Shihezi city introduced plastic film from Japan in 1980, carried out a demonstration in 1981, and started technical promotion in 1982. All cotton fields are covered with plastic film annually. According to China Rural Statistical Yearbook , the amount of plastic film used in Xinjiang in 2019 had reached 242,684 t. The mulching rate of plastic film in the cotton fields can be up to 89.5 %, and the recovered rate could be approximately 80 %. The fertilization was dominated by chemical fertilizers. Drip irrigation, with a total amount of 4000–5000 m3 per hectare per year, was applied to all cotton fields. The irrigation water had three local sources, Daquangou reservoir, Moguhu reservoir, and groundwater. Water in the Daquangou reservoir was the glacier melt water from Tianshan Mountains, while the water in the Moguhu reservoir was from the effluent of sewage treatment plants. During the irrigation processes, the water consumption from the two reservoirs was greater than that from groundwater. All the buried pipelines and related materials in the drip irrigation systems are made of polyvinyl chloride .Samples were collected from the cotton fields with continuous film mulching in August 2019. Three cotton fields with 5, 10, 20, and >30 years of film mulching were selected in the planting areas of No.142 Construction Corps , No.133 Construction Corps and Shihezi Academy of Agricultural Sciences individually. Cotton fields with different years of film mulching were at least 100 m apart. There were 2 main sources of microplastics in the sampling area, film mulching, and irrigation. Films were fixed with soils and crops and were hard to contaminate fields 100 m away. Irrigation systems were trickling irrigation, therefore, wouldn’t contaminate other fields. Moreover, there was little precipitation in the sampling area, therefore, contamination through surface runoff was unlikely to happen. At each field, three 5 m × 5 m quadrats were randomly placed. The soil cores were then collected from each quadrat and mixed thoroughly to make a composite sample per field. In total, 12 soil samples were collected. All samples were sealed in sterilized sampling bags for further laboratory analysis.For the extraction of 10–500 μm microplastics, five grams of air–dried soil were put in a glass beaker and dispersed thoroughly with 150 mL Fenton reagent for 3 h for the primary digestion. See Figs. S2 and S3 in the supplementary material for further information on digestion parameters. The beaker was then placed in an oven at 50 °C for 18–24 h until dry. Two hundred mL of saturated sodium chloride solution was added to the beaker, and the solution was agitated with a magnetic stirrer for 30 min to completely disperse soil samples. After 24 h of static settlement at room temperature, approximately 100 mL supernatants containing microplastics were collected in a beaker and then filtrated through 500 and 10 μm stainless steel filter mesh by vacuum suction filtration system. Samples containing10–500 μm MPs needed secondary digestion and flotation to meet the machine standard of LDIR. The 10 μm filter mesh attached with 10–500 μm microplastics was placed in a 250 mL glass beaker and immersed with hydrogen peroxide . After ultrasonication for 5 min, the filter mesh was rinsed with hydrogen peroxide to remove all the attached residues. After 24 h of the secondary digestion, the beaker was placed in an oven at 50 °C for approximately 12 h until dry. Saturated sodium chloride solution was added into the beaker containing residues and then transferred the samples to a 500 mL glass separating funnel. The beaker was rinsed with saturated sodium chloride solution 3 times. After 24 h of static settlement at room temperature, the lower liquid containing soil particles was completely purged. The upper transparent solution was filtered with a 10 μm stainless steel filter mesh. The filter mesh was placed in a beaker, and the chromatographic grade ethanol was added to immerse it. After ultrasonication for 5 min, the filter mesh was rinsed with ethanol and taken out. The ethanol solution containing microplastics was concentrated at 100 μL under nitrogen.