Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： Irrigation zones located in the lower reaches of Yellow River is a vital food security base in China. Currently, this area is facing the problem of rapid decline of groundwater level due to serious water shortage and insufficient water resources allocation. Therefore, there are many unknown and uncertain impacts on the future agriculture and ecological environment, and it is the current hotspot of agroecosystem research. However, under the dynamic scenarios, for innovatively carrying out the studies on large groundwater table from surface, and conducting the critical process researches such as sectional structure of farmland soil, crop root growth dynamics, interaction between surface water and groundwater, groundwater-soil-plant-atmosphere continuum response, dynamic variation and influence mechanism of water-salt-nutrient of agroecosystem, it is urgently needed to build a comprehensive experiment simulation infrastructure. Funded by the “Key Scientific and Technological Infrastructure Construction Project for the Field Station Network of Chinese Academy of Sciences (CAS)”, Yucheng Comprehensive Experiment Station of Chinese Academy of Sciences (Shandong Yucheng Agro-ecosystem National Observation and Research Station) completed the platform construction of Groundwater#2;Agroecosystem Experimental Simulator (Yucheng GAS), an infrastructure with three floors (10 m underground) constituted by 16 bottom sealed sample plots with controllable groundwater levels after five-year strenuous efforts (from 2016 to 2020). Yucheng GAS integrates nine subsystems including the large scale bottom sealed sample plots system, underground water level automatic controlling; soil temperature, water content, and salinity monitoring; soil water sampling; root growth monitoring; groundwater quantity and quality monitoring; critical zone observation of agroecosystem; water-carbon-nitrogen nexus in agroecosystem; and multispectral crop condition monitoring by unmanned aerial vehicle (UAV). Yucheng GAS, a comprehensive monitoring methodology with multiple methods of stereo-position monitoring, multi-factors chromatograph, and multi-scales three-dimensional observation, is expected to support the basic experimental research and international frontier explore in water-carbon-nitrogen cycles in agroecosystem, food security, ecological security, and environmental security under the scenario of dynamically changed groundwater in future.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： One of the burning questions of food security in current China is how to produce sufficient forage products and animal feeds. The limited arable land has to be devoted to cereal production, and exploring more terrestrial land is a prerequisite for the sustainable forage production and the development of grass-based livestock husbandry. Bohai rim is consist of coastal line of the North China Plain, which has a significant amount of medium-low yielding fields and unutilized saline-alkali land as well as intensive livestock production. In this study, a new concept of “Coastal Grass Belt”, proposed by LI Zhensheng, an academician of Chinese Academy of Sciences (CAS), was introduced, which addresses how to develop grass/forage farming system according to the severity of salinity. This concept can not only improve soil quality but also provide sufficient forage for livestock. Meanwhile, the concept is also aligned with China’s national strategies of storing grain in land and in agricultural technology to ensure the self-sufficiency of important agricultural products and the integration of the security of land and marine ecosystems. This paper provides a detailed description of the “Coastal Grass Belt” concept, elaborates its goals, key scientific issues and innovative modes, and analyzes the ecological environmental and economic-industrial benefits. Finally, the much-needed innovation platforms, agro-industry modes and policies for the development of “Coastal Grass Belt” are discussed.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： The Yellow River Delta is the world’s youngest delta and new land, also the youngest ecosystem. Its ecological environment is fragile, and the interaction among the river, the sea, and the land forms a unique geographical environment. The salinization of land and the wide distribution of saline land are two of the main features of the region, and agriculture is one of the leading industries in the region. Agricultural development is related to the efficient use and rational distribution of water resources in this area, related to the protection of the estuary wetland and the ecological environment of the whole region, and related to the efficient development and safety of land resources. It is also about the overall development of land and sea, as well as about the revitalization of the countryside. Therefore, the high quality development of saline agriculture is the important part of sustainable development of the region, while the development of high-quality agriculture in saline land is an important challenge. Based on the major strategic needs of the country, the current situation, and major problems of the development of the Yellow River Delta, this study puts forward a new model of efficient agricultural development in the saline-alkali areas of the Yellow River Delta, as well as some suggestions for the future ecological protection and high-quality development of the region. This study is also of great significance for the efficient development of saline land in China.
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-11-07 Cooperative journals: 《中国生态农业学报》
Abstract：秸秆的质量, 特别是C/N 是影响秸秆分解速率和养分释放的重要因素。在秸秆还田条件下, 如何科学合理地施用氮肥是秸秆利用和优化施肥研究的关键问题。本研究以秸秆还田施入碳氮的C/N 为切入点, 于2012—2013 年通过田间试验(设秸秆不还田不施肥、秸秆还田不施氮、秸秆还田施用无机氮肥调节C/N 为10∶1、16∶1 和25∶1 以及秸秆还田施用有机氮肥调节C/N 为25∶1 处理), 研究秸秆还田不同氮输入对小麦-玉米轮作田土壤无机氮、土壤微生物量氮、酶活性以及作物产量的影响。结果表明: 1)在C/N 为25∶1 下, 施用有机氮肥和无机氮肥对土壤无机氮含量无显著影响; 在施用无机氮肥的情况下, C/N 越低土壤无机氮含量越高。2)秸秆还田施氮提高了土壤微生物量氮含量, 但是各秸秆还田施氮处理之间差异不显著; 秸秆还田不同施氮处理对脲酶活性无显著影响; 秸秆还田施氮提高了FDA 水解酶活性, 并随C/N 降低呈升高趋势, 施用无机氮肥的效果强于施用有机氮肥的。3)秸秆还田施用无机氮肥显著提高了小麦和玉米地上部生物量, 施用无机氮肥调节C/N 为10∶1 和16∶1 相比于C/N 为25∶1 提高了小麦和玉米的苗期和成熟期地上部生物量; 施用有机氮肥调节C/N 为25∶1 相比秸秆还田不施氮对地上部生物量无显著影响。秸秆还田施用无机氮肥提高了作物产量, 施用无机氮肥调节C/N 为16∶1 产量最高, 而施用有机氮肥调节C/N 为25∶1 有降低作物产量的趋势。综合以上结果来看, 施用无机氮肥调节C/N 为16∶1 较为合理。
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