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This study aims to explore the effects of microplastic input and straw addition on soil nitrogen leaching in farmland. Fluvo-aquic soil and yellow-brown soil were taken as the research objects. Eight treatments were set for each soil, including control (CK), low microplastics (PE1), medium microplastics (PE2), high microplastics (PE3), straw (S), straw + low microplastics (S+PE1), straw + medium microplastics (S+PE2), and straw + high microplastics (S+PE3). A systematic investigation was made to clarify the effects of microplastic input on soil nitrogen leaching with/without the straw. The results showed that there was no significant difference in the TN leaching loss among PE1, PE2 and PE3 treatments in the fluvo-aquic soil with microplastics only, compared with the CK. In yellow-brown soil, PE1 treatment significantly increased the TN leaching loss. There was no significant difference in the TN leaching loss between PE2 and PE3 treatments. The addition of straw in the fluvo-aquic soil significantly reduced the leaching amount of NO3- -N, NH4+ -N and TN, which decreased by 31.15%, 13.45% and 15.26%, respectively, compared with the CK. The addition of straw in the yellow-brown soil significantly increased the leaching amount of TN, which increased by 22.56%. Compared with no straw treatment, the cumulative leaching loss of NO3- -N, NH4+ -N and TN under different concentrations of microplastic input in fluvo-aquic soil showed a decreasing trend, whereas, the low amount of microplastic input in the yellow-brown soil reduced the TN leaching loss, and the high amount of microplastic input increased the TN leaching loss. Partial least squares path model (PLS-PM) analysis showed that the addition of straw in the fluvo-aquic soil mainly affected nitrogen leaching via the pH of the leaching solution and NO3--N leaching loss, and the amount of added microplastics had no significant effect on nitrogen leaching. In the yellow-brown soil, the nitrogen leaching was affected by the leaching loss of NO3- -N and NH4+-N in the leaching solution. The microplastics mainly affected the nitrogen leaching for the leaching loss of NH4+ -N in the leaching solution. The research results can provide a sound basis for the control of the risk of microplastic pollution in farmland soil and the reduction of soil nitrogen leaching. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

China is a vast agricultural country which produces a large amount of crop straw. If the crop straw was used irrationally, the airborne pollutant concentration would increase, and the soil moisture and organic matter content would reduce. It does harm to ecological environment. Beijing-Tianjin-Hebei region is the political, economic and cultural center of China and plays an essential role in the development of social economy of China. There are severe environment problems occurring in this region such as smog happening frequently. Burning of crop straw is concerned to be one of the main reasons for the smog in this region. The research of crop straw resource was carried out in the Beijing-Tianjin-Hebei region aimed to promote the comprehensive utilization of crop straw. The production and utilization of crop straw resources and their application potential were evaluated and analyzed. Furthermore, the emission characteristics of gaseous pollutants generated from open burning of major crop straw in the region were quantitatively estimated that. The results showed that the theoretical amount of crop straw in the Beijing-Tianjin-Hebei region was 5.4×107 t in 2012, and the main crop species were corn and wheat straw. Crop straw resources could be used as high quality fertilizer with high contents of nitrogen (N), phosphorus (P) and potassium (K), and the amounts were 3.7×104, 7.4×104 and 1.0×106 t for N, P and K respectively. Straw returned to field was the major utilization method for crop residue in the Beijing-Tianjin-Hebei region. However, the returned amounts were accounting for 67.7%, 27.3% and 61.2% of the total crop residue amounts in Beijing, Tianjin and Hebei respectively. Interestingly, the returned amount of wheat residue in Beijing was accounting for 94.5%, which was higher than Hebei (78.5%) and Tianjin (47.1%). The amount of wasted and burned straw accounted for 1.7%, 0.5% and 1.4% respectively in Beijing, Tianjin and Hebei. The nutrient resource such as N, P and K of crop straw returned to soil in the Beijing-Tianjin-Hebei region was 2.4×104, 1.9×104 and 6.1×105 t, respectively. However, there was still a large amount of crop straw abandoned or open burned. Wheat and maize residue were the major crop residue open burned in the region, which accounted for 93.0% of the total straw amount open burned. In Hebei, 14.9% and 31.8% of total straw resource were abandoned and open burned respectively, while 8.2% and 5.9% in Tianjin, and 0.6% and 0.8% in Beijing. According to the statistical data, 8.7×104 t CO, 9.6×105 t CO2, 2.5×102 t NO2, 5.5×102 t NO and 8.1×102 t NOx from open burning of wheat and maize straw were emitted to atmosphere in Hebei Province, which were as three times as that in Tianjin City. Due to farmers' high cognitive level and policy of government, a very small amount of straw was open burned in Beijing, and only 1.2×103 t CO, 1.3×104 t CO2, 4.3 t NO2, 8.5 t NO and 12.8 t NOx were emitted to atmosphere due to open burning of straw. The total amounts of pollutants emitted from wheat and maize straw open burning were 1.0×106 and 4.8×105 t, respectively. According to regional straw resource endowment and utilization potential, county (township) should be the unit to develop the “5 kinds of material” technology strategy based on the local conditions. What's more, system supporting policy measures should be formulated and taken based on straw returning mechanism, use mechanism out of the field, organization and management mechanism, and technology research and development mechanism. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The developed countries have already marched a long way and accumulated rich experience in utilizing crop straw, which is fairly ahead of China particularly in the fields of the administrative policies and regulations. The total yield of crop straw in China ranks the first place in the world in recent years. Yet the policies and regulations of crop straw management in China are insufficient, and it is of great importance to learn the specific practice and advanced management measures from foreign countries. Based on a large amount of literature research and analysis, in the paper we reviewed the policies and regulations of crop straw utilization in foreign countries and summarized the successful experiences. The results show that crop straw in developed countries gives priority to recycle as fertilizer to the field, which plays an important role in forming reasonable fertilization structure. And major developed countries have established mature and efficient system of straw collection, storage and transportation, which is the key issue to develop crop straw utilization industry. In order to make full use of crop straw and reduce open burning, many developed countries have carried out some pertinent policies and regulations. Policies of straw utilization in foreign countries mainly focus on target strategy, government investment and financial support, tax incentives and concessional loans, as well as incentive mechanism. The main 2 types of laws and regulations on crop straw utilization in foreign countries are agriculture-type regulation and energy-type regulation. The former type mainly involves the regulations on tillage conservation and soil fertilization by crop straw returning. The latter one involves the regulations on renewable energy and biomass energy. The crop straw in China has the characteristics of large quantity, scattered distribution, and so on. Policies and regulations of crop straw utilization and management should be made according to the reality in China. Based on the advanced experiences in foreign countries, the recommended policies and regulations on how to improve straw utilization in China are proposed as follows: 1) Clarify targets and dominant modes of crop straw utilization; the goals of straw utilization will be broken into achievable goals, projects and actions in different years and areas, and straw returning is recommended to establish the fertilization system in China which also includes stable manure and chemical fertilizer; 2) Bring government’s function into full play to improve investment supporting in order to provide various financial supports, and the main measures are as follows: supports on technology equipment development and industrialization demonstration project, financial subsidy of green products, purchase allowance on agricultural machinery, and subsidies of mechanization of straw returning based on working area; 3) Make and implement tax, and credit and loan preference polices on straw processing and utilization of enterprises, as well as straw collection and transportation companies, carry out investment tax compensation and deduction of value added tax (VAT) policy on straw utilization projects, and formulate and implement different carbon tax policies, such as laying high carbon tax on fossil energy but free carbon tax on biomass energy; 4) Establish policy incentive mechanism by improving the incentives for investing, such as building fund-raising system including central and local government and management body, and implementing rural electricity price on straw collection, storage and processing, and reduction and exemption policy on road and bridge toll; 5) Formulate and promulgate laws and regulations of straw utilization and set up relatively mature law system; amend laws about crop straw utilization, for example, add regulations of raising animal with crop straw to Animal Husbandry Law, and add relevant regulations of conservation tillage to Soil and Water Conservation Law, and establish regulations on crop straw collection-storage system and “5F” (fertilizer, fuel, fodder, fiber, feed stock) utilization. Requirement and relevant standards of straw comprehensive utilization and safe handling should be clarified in regulation of new countryside and beautiful countryside construction. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)