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81.
为探究区域种养业减排增效潜力,采用最新温室气体清单指南,对区域种养业生产系统温室气体排放与土壤固碳的途径和计算方法进行梳理,以黑龙江农垦种养业生产系统为研究对象,计算分析与评价该系统2009—2018年温室气体排放量与土壤固碳量。结果表明:1)在温室气体排放方面,黑龙江农垦种养业生产系统的温室气体排放量呈现“增长—下降后平稳”的趋势,2018年为2.48×1010 kg,秸秆焚烧碳排放、主要物资碳排放、稻田CH4排放为主要来源,约占排放总量的84.87%。2)在土壤固碳方面,玉米和大豆的秸秆、根系输入引起的土壤有机碳的累积变化量分别为2.15×109和1.53×108 kg,而奶牛、肉牛、蛋鸡、肉鸡和生猪有机肥输入引起的土壤有机碳的累计变化量分别为-1.43×108、-5.46×107、-2.67×106、2.26×106和-9.68×107 kg。3)近年来黑龙江农垦种养业生产系统温室气体净排放量有所增长、经济效益有所下降。基于研究结果,提出如下建议:1)加大农作物秸秆和畜禽粪便资源综合利用,建立第三方集中处理中心,减少秸秆焚烧和畜禽粪便未利用;2)确定适宜的有机物料输入种类与量,促进土壤碳固定;3)开展农机具使用效率研究。  相似文献   
82.
Through the long-term measurement and development of a method for partitioning the products of decomposing litter, the impact of chemical components of forest debris on soil organic carbon (SOC) accumulation was studied in a forest succession series in South China. We quantified how litter quality is strongly correlated with the partitioning of respiration, dissolved organic carbon (DOC) and fragments of decomposing litter. In the succession sequence of 60-year-old pine forest (PF), to 80-year-old mixed pine and evergreen broadleaved forest (MF) to more than 400-year-old monsoon evergreen broadleaved forest (MEBF), the litter C/N ratios and lignin contents were gradually decreasing, which in turn were correlated with increasing litter decomposition constants (k-values), gradually shortening residence times of standing litter pool. And, 53.5%, 65.6% and 76.2% of the gravimetric litter mass losses were going belowground through both DOC and fragmentation. Correspondingly, the SOC accumulation rates in the top 20 cm of mineral soils for the three forests from 1978 to 2008 were 26 ± 4, 33 ± 5 and 67 ± 5 g C m−2 yr−1, respectively. Results of the study support the idea that in order to increase carbon sequestration in soils and long-term functional ability of forest ecosystems to act as carbon sinks, “Kyoto Forests” should be designed and reconstructed with a high diversity of broadleaved species, especially containing nitrogen-fixing trees.  相似文献   
83.
For the requirement of building up the battery management system (BMS) of hybrid vehicles(HEVs), the real time measurement and estimation of charge (SOC) of the Ni MH batteries are investigated, because the popular SOC definition is unsuitable under the condition of variable current discharge. The origin of this kind unsuitability are analyzed ,and the characteristics and existing problems of different kinds of SOC measuring methods are compared. On the basis of mentioned above, some corrections are given to the popular SOC definition, and the new conception of SOC is proposed. The corrected definition of SOC is suitable for the real time SOC estimation under the variable current condition of the batteries used in HEVs. Based on the corrected SOC definition, the computational model of the new SOC is built and simulated. Satisfactory result has been obtained from comparisons of the simulating results, which shows that the theoretical model provides a basis for optimizing the adaptation of power system to the hybrid vehicles (HEVs).  相似文献   
84.
调查采集长江荆江段湿地围垦农田土壤的表土样品,实验室分析总有机碳(SOC)、热水溶性有机碳(HWEC)、颗粒态有机碳(POC)、易氧化有机碳(LOC)及有机碳键合组分含量特征,比较分析不同土地利用方式下湿地起源土壤有机碳组分的变化。结果表明,棉田土壤总有机碳含量为(8.86±0.73)g/kg,桔园的为(9.07±0.01)g/kg,湿地的为(10.30±0.37)g/kg,稻田的为(15.57±1.92)g/kg。即棉田和桔园的总有机碳含量接近于湿地的,而稻田的较大幅度高于前面旱地和湿地的。同时,稻田的热水溶性有机碳含量显著高于棉田的(p<0.05);颗粒态有机碳含量显著高于桔园的(p<0.05);易氧化有机碳含量变化与总有机碳一致。但是,从不同组分比率来说,湿地、稻田、棉田间HWEC/SOC、POC/SOC和LOC/SOC均无显著差异(p>0.05),而桔园HWEC/SOC显著高于其他利用方式的(p<0.05),棉田POC/SOC显著高于桔园的(p<0.05),桔园LOC/SOC显著高于湿地的(p<0.05)。供试土壤中铁铝键合态有机碳含量均显著高于相应钙键合态有机碳(p<0.05),且后者在不同土地利用方式下变化微弱。从研究结果来看,同是湿地起源的土壤,化学键合组分的差异明显大于物理分离组分的差异,特别是稻田铁铝键合态有机碳和残渣态有机碳含量及其比例显著高于棉田、桔园和湿地的(p<0.05),这进一步说明稻田土壤存在的氧化铁化学结合稳定机制促进了氧化铁活性较高的稻田土壤有机碳稳定积累。  相似文献   
85.
基于酶传感对农药浓度进行检测,设计了以丝网印刷酶电极作为敏感元件、由SOC单片机和微电流测量电路组成的检测装置。通过与CHI660B型电化学工作站测量对比实验可知:该装置对微电流测量的精度达0.01uA,最大误差小于0.19uA,检出时间小于3min;装置尺寸小,适合于现场农药浓度的快速检测。  相似文献   
86.
Soils are the third biggest sink of carbon on the earth. Hence, suitable land uses for a climatic condition are expected to sequester optimum atmospheric carbon in soils. But, information on how climatic conditions and land uses influence carbon accumulation in the soils on the Himalayan Mountains is not known. This study reports the impact of four climatic conditions (sub-tropical, altitude: 500–1200 m; temperate 1200–2000 m; lower alpine 2000–3000 m; upper alpine, 3000–3500 m) and four land uses (forest, grassland, horticulture, agriculture) on the concentrations and stocks of soil organic carbon (SOC) in upper (0–30 cm) and deeper (30–100 cm) soil depths on the western Himalayan Mountains of India. The study also explored the drivers which influenced the SOC stock build up on the mountains. Rainfall and soil moisture showed quadratic relations, whereas temperature declined linearly with the altitude. SOC stock as well as concentration was the highest (101.8 Mg ha− 1 in 0–30 cm, 227.97 Mg ha− 1 in 0–100 cm) in temperate and the lowest in sub-tropical climate (37 Mg ha− 1 in 0–30 cm, 107.04 Mg ha− 1 in 0–100 cm). Pattern of SOC stock build up across the altitude was: temperate > lower alpine > upper alpine > sub-tropical. SOC stocks in all land uses across the climatic conditions, except agriculture in lower alpine, was higher (0.7 to 41.6%) in the deeper than upper soil depth. SOC stocks in both the depths showed quadratic relations with soil temperature and soil moisture. Other factors like fine soil particles, land-use factor and altitude influenced positively whereas slope and pH, negatively to the SOC stocks. In all climatic conditions, other than temperate, SOC stocks were greater in natural ecosystems like forests and pastures (112.5 to 247.5 Mg ha− 1) than agriculture (63 to 120.4 Mg ha− 1). In temperate climate, SOC stock in agriculture (253.6 Mg ha− 1) on well formed terraces was a little higher than forest (231.3 Mg ha− 1) on natural slope. These observations, suggest that land uses on temperate climate may be treated as potential sinks for sequestration of the atmospheric carbon. However, agriculture in subtropical climate need to be pursued with due SOC protection measures like the temperate climate for greater sequestration of the atmospheric carbon.  相似文献   
87.
The southeastern Tibetan Plateau, which profoundly affects East Asia by helping to maintain the stability of climate systems, biological diversity and clean water, is one of the regions most vulnerable to water erosion, wind erosion, tillage erosion, freeze–thaw erosion and overgrazing under global climate changes and intensive human activities. Spatial variations in soil erosion in terraced farmland (TL), sloping farmland (SL) and grassland (GL) were determined by the 137Cs tracing method and compared with spatial variations in soil organic carbon (SOC) and total nitrogen (total N). The 137Cs concentration in the GL was higher in the 0–0.03 m soil layer than in the other soil layers due to weak migration and diffusion under low precipitation and temperature conditions, while the 137Cs concentration in the soil layer of the SL was generally uniform in the 0–0.18 m soil layer due to tillage-induced mixing. Low 137Cs inventories appeared at the summit and toe slope positions in the SL due to soil loss by tillage erosion and water erosion, respectively, while the highest 137Cs inventories appeared at the middle slope positions due to soil accumulation under relatively flat landform conditions. In the GL, the 137Cs data showed that higher soil erosion rates appeared at the summit due to freeze–thaw erosion and steep slope gradients and at the toe slope position due to wind erosion, gully erosion, freeze–thaw erosion and overgrazing. The 137Cs inventory generally increased from upper to lower slope positions within each terrace (except the lowest terrace). The 137Cs data along the terrace toposequence showed abrupt changes in soil erosion rates between the lower part of the upper terrace and the upper part of the immediate terrace over a short distance and net deposition on the lower and toe terraces. Hence, tillage erosion played an important role in the soil loss at the summit slope positions of each terrace, while water erosion dominantly transported soil from the upper terrace to the lower terrace and resulted in net soil deposition on the flat lower terrace. The SOC inventories showed similar spatial patterns to the 137Cs inventories in the SL, TL and GL, and significant correlations were found between the SOC and 137Cs inventories in these slope landscapes. The total N inventories showed similar spatial patterns to the inventories of 137Cs and SOC, and significant correlations were also found between the total N and 137Cs inventories in the SL, TL and GL. Therefore, 137Cs can successfully be used for tracing soil, SOC and total N dynamics within slope landscapes in the southeastern Tibetan Plateau.  相似文献   
88.
针对海南文昌滨海台地3种森林类型(人促更新次生林、次生林、椰子林)林下枯落物现存量及土壤活性有机碳性状(有机碳、易氧化有机碳及轻组有机碳含量)进行了测定。结果如下:3种林型凋落物层现存量及总碳储量分别为:椰子林4.53、1.51 t/hm2;次生林1.76、0.65 t/hm2;人促更新次生林1.53、0.60 t/hm2;均为分解层(包括半分解层和全分解层)未分解层。1 m深土层深度内,3种林型土壤SOC、EOC及LFOC含量变化规律一致,均呈下降趋势,且不同林型不同土层间各组分含量差异显著(p0.05)。经相关性分析表明,土壤SOC、EOC及LFOC相互之间具有显著正相关。说明在土壤母质、土壤类型、气候条件基本一致条件下不同植被类型土壤碳库组分比例及变化规律相似,但土壤各组分含量大小各异,从土层分布情况来看,林下凋落物质量和人为因素是碳储量关键影响因子。  相似文献   
89.
The challenges of Vis‐NIR spectroscopy are permanent soil surface variations of moisture and roughness. Both disturbance factors reduce the prediction accuracy of soil organic carbon (SOC) significantly. For improved SOC prediction, both disturbance effects have to be determined from Vis‐NIR spectra, which is especially challenging for roughness. Thus, an approach for roughness quantification under varying moisture and its impact on SOC assessment using Support Vector Machines is presented here.  相似文献   
90.
土壤有机碳库的平衡状况与大气CO2含量密切相关。综述了土壤有机碳储量及影响土壤有机碳分解变化的因素,着重介绍土地利用方式、环境因子及添加有机物料等对土壤有机碳的影响,并提出今后农田土壤有机碳的研究方向。  相似文献   
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