Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： This study aimed to investigate the apparent soil nitrogen balance and tuber yield of Cyperus esculentus in sandy farmland under different levels of nitrogen application and provide a theoretical basis for increasing the yield of Cyperus esculentus in sandy farmland. Four nitrogen fertilizer treatments, 0 kg·hm−2(N0),75 kg·hm−2 (N1), 150 kg·hm−2 (N2), and 225 kg·hm−2 (N3), were applied to Cyperus esculentus in 2021 at the experimental site in Dengkou County, Bayannur City, Inner Mongolia, and Toketo County, Inner Mongolia Academy of Agricultural Sciences, Hohhot, China. The effects of the four different N application levels on agronomic traits, tuber yield, and clear soil nutrient balance of Cyperus esculentus were analyzed. The number of tillers, plant height, and single leaf area of C. esculentus increased alongside increasing N application, but excessive N application caused above-ground growth of C. esculentus, resulting in lower yield. At the application rate of 150 kg·hm−2(N2), Cyperus esculentus exhibited superior agronomic traits, including maximum root lengthand root volume, the highest whole plant dry weight and tuber yield, and a fresh tuber yield of 9298.87 kg·hm−2.The apparent nitrogen surplus rates in the two locations were negative at the levels of 0 kg·hm−2(N0) and 75 kg·hm− 2 (N1) and positive at the levels of 150 kg · hm− 2 (N2) and 225 kg · hm− 2 (N3). This pattern indicates that nitrogen reached a balanced state at the N2 level in both locations, signifying an optimal nitrogen application rate of 150 kg·hm− 2. RDA analysis showed that tiller number, maximum root length,root volume, and nitrogen uptake were the main factors driving the formation of dry matter and tuber yield in C. esculentus. Therefore, in northern sandy soil conditions, the application of N at 150 kg·hm− 2 can promote theabsorption of nutrients by Cyperus esculentus and maintain the apparent nutrient balance of soil, which isconducive to the growth, development, and yield formation of Cyperus esculentus.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： China is short of oil and natural gas resources and relatively rich in coal reserves. For a long time to come, coal will be still at the dominant position in the energy consumption structure in China. Clean and efficient utilization of coal is the main content of energy production and consumption revolution. It not only is an important way of clean and efficient utilization of coal, but also has a great significance to national energy security, sustainable economic and social development. The article analyzes the research status of coal clean and efficient conversion related technologies worldwide, as well as the layout of China’s efficient coal conversion, the research direction, and the development trend, in order to technologically support the improvement of clean and efficient conversion level of coal and the acceleration of energy consumption revolution in China.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： Black soil region in Northeast is one of important commercial food production bases in China, and is irreplaceable for the national food security. However, the sustainable development of agriculture in Northeast has been severely constrained by soil degradation caused by long-term intensive and unbalanced use of arable land without protection of it. To solve this problem, original Heilongjiang Institute of Agricultural Modernization, Chinese Academy of Sciences (CAS) established Hailun Agro-ecosystem Experimental Station (Hailun Station), CAS in the central black soil region in Northeast in 1978. Since then, a series of long-term experiments have been set up based on the structure and function of the region. The evolution of soil fertility has been divided into three periods in light of the long-term monitoring and research for key elements in agro-ecosystem. The thresholds of soil organic matter on regional scale were proposed, and the evolution of soil fertility under different management patterns of soil nutrients was expounded, which verified that appropriate arrangement of field crops could regulate and control the impact of pests on crops. 10 high-yield soybean varieties were bred with pedigree method and were applied in Heilongjiang Province. Through the research and development of critical technologies for constructing fertile cultivated soil layer, the protection and utilization patterns of black soil were established, which were demonstrated and extended in more than 10 major grain-producing counties in Heilongjiang Province. Long-term research provides scientific and technological support for the protection of black soil and regional agricultural development through the combination of basic research, critical techniques development and large-scale demonstration.
Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究1～21日龄和1～42日龄罗斯308肉仔鸡对饲粮25羟基维生素D3（25-OH-D3）的适宜需要量。选取500只1日龄罗斯308肉仔鸡公雏，随机分成10个组，每组5个重复，每个重复10只鸡。10组肉仔鸡分别饲喂25-OH-D3水平为50、100、200、400、600、800、1 600、2 400、3 200和4 000 IU/kg的饲粮。试验期42 d。结果表明：1)饲粮25-OH-D3水平由50 IU/kg提高到600 IU/kg时，1～21日龄和1～42日龄肉仔鸡的体重、平均日增重和平均日采食量显著提高（P0.05）。2）饲粮25-OH-D3水平由50 IU/kg提高到600 IU/kg时，21日龄和42日龄肉仔鸡的骨骼（股骨、胫骨和跖骨）强度、重量、长度、灰分重量以及灰分、钙和磷含量显著提高（P0.05）。3）饲粮25-OH-D3水平由50 IU/kg提高到600 IU/kg时，21日龄和42日龄肉仔鸡的血浆钙含量显著提高（P0.05）。饲粮25-OH-D3水平对肉仔鸡的血浆无机磷含量无显著影响（P>0.05）。4）饲粮25-OH-D3水平由50 IU/kg提高到800 IU/kg时，11～14日龄和31～34日龄肉仔鸡的钙和总磷沉积率显著提高（P0.05）。综合本试验结果，以生长性能指标和骨骼参数为评价指标，采用折线回归模型分析得出，1～21日龄肉仔鸡饲粮25-OH-D3的需要量为476 IU/kg，1～42日龄肉仔鸡饲粮25-OH-D3的需要量为448 IU/kg。
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