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Effects of Nitrogen Application Levels on Ammonia Volatilization and Nitrogen Utilization during Rice Growing Season

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Rice science 2012年第2期19卷 125-134页

作者： LIN Zhong-cheng DAI Qi-gen YE Shi-chao WU Fu-guan JIA Yu-shu CHEN Jing-dou XU Lu-sheng ZHANG Hong-cheng Huo Zhong-yang Xu Ke WEt Hai-yan Key Laboratory of Crop Genetics and Physiology of Jiangsu Province / Innovation Center of Rice Cultivation Technology in Yangtze Valley Ministry of Agriculture Yangzhou University Yangzhou 225009 China agriculture Committee of Wujiang county Jiangsu Province Wujiang 215200 China agriculture bureau of guannan county Jiangsu Province Guannan 222500 China

We conducted field trials of rice grown in sandy soil and clay soil to determine the effects of nitrogen application levels on the concentration of NH4＋-N in surface water, loss of ammonia through volatilization from paddy fields, rice production, nitrogen-use efficiency, and nitrogen content in the soil profile. The concentration of NH4＋-N in surface water and the amount of ammonia lost through volatilization increased with increasing nitrogen application level, and peaked at 1-3 d after nitrogen application. Less ammonia was lost via volatilization from clay soil than from sandy soil. The amounts of ammonia lost via volatilization after nitrogen application differed depending on the stage when it was applied, from the highest loss to the lowest： N application to promote tillering 〉 the first N topdressing to promote panicle initiation （applied at the last 4-leaf stage）〉 basal fertilizer 〉 the second N topdressing to promote panicle initiation （applied at the last 2-leaf stage）. The total loss of ammonia via volatilization from clay soil was 10.49-87.06 kg/hm2, equivalent to 10.92%-21.76% of the nitrogen applied. The total loss of ammonia via volatilization from sandy soil was 11.32-102.43 kg/hm2, equivalent to 11.32%-25.61 % of the nitrogen applied. The amount of ammonia lost via volatilization and the concentration of NH4＋-N in surface water peaked simultaneously after nitrogen application; both showed maxima at the tillering stage with the ratio between them ranging from 23.76% to 33.65%. With the increase in nitrogen application level, rice production and nitrogen accumulation in plants increased, but nitrogen-use efficiency decreased. Rice production and nitrogen accumulation in plants were slightly higher in clay soil than in sandy soil. In the soil, the nitrogen content was the lowest at a depth of 40-50 cm. In any specific soil layer, the soil nitrogen content increased with increasing nitrogen application level, and the soil nitrogen content was higher in

关键词： ammonia volatilization nitrogen application level soil type nitrogen-use efficiency rice

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Closing the nitrogen use efficiency gap and reducing the environmental impact of wheat-maize cropping on smallholder farms in the Guanzhong Plain,Northwest China

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Journal of Integrative agriculture 2019年第1期18卷 169-178页

作者： Lü Feng-lian HOU Miao-miao ZHANG Hong-tao Asif Khan Muhammad Ayaz QIANGJIU Ciren HU Chang-lu YANG Xue-yun SUN Ben-hua ZHANG Shu-lan College of Natural Resources and Environment Northwest A&F University/Key Laboratory of Plant Nutrition and the Agro-environment in Northwest ChinaMinistry of Agriculture agriculture and Husbandry bureau of Cuona county Agriculture and Husbandry Bureau of Cuona County

A high crop yield with the minimum possible cost to the environment is generally ***,the complicated relationships among crop production,nitrogen(N) use efficiency and environmental impacts must be clearly *** conducted a series of on-farm N application rate experiments to establish the linkage between crop yield and N_2 O emissions in the Guanzhong Plain in Northwest *** also examined crop yield,partial factor productivity of applied N(PFPN) and reactive N(Nr) losses through a survey of 1 529 and 1 497 smallholder farms that grow wheat and maize,respectively,in the *** optimum N rates were 175 and 214 kg ha^(-1) for winter wheat and summer maize,respectively,thereby achieving the yields of 6 799 and 7 518 kg ha^(-1),correspondingly,with low N_2 O emissions based on on-farm N rate *** the smallholder farms,the average N application rates were 215 and 294 kg ha^(-1) season^(-1),thus producing 6 490 and 6 220 kg ha^(-1) of wheat and maize,*** corresponding PFPN values for the two crops were 36.8 and 21.2 kg N kg^(-1),and the total N_2 O emissions were 1.50 and 3.88 kg ha^(-1),*** N balance,large Nr losses and elevated N_2 O emissions could be explained by the overdoses of N application and low grain yields under the current farming *** crop yields,N application rates,PFPN and total N_2 O for wheat and maize were 18 and 24% higher,42 and 37% less,75 and 116% higher,and 42 and 47% less,correspondingly,in the high-yield and high-PFPN group than in the average smallholder *** conclusion,closing the PFPN gap between the current average and the value for the high-yield and high-PFPN group would increase crop production and reduce Nr losses or the total N_2 O emissions for the investigated cropping system in Northwest China.

关键词： N fertiliser grain yield PFPN N balance reactive nitrogen losses N2O emission

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Effect of Farming Practices on the Variability of Phosphorus Status in Intensively Managed Soils

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Pedosphere 2015年第3期25卷 438-449页

作者： SUN Wei-Xia HUANG Biao QU Ming-Kai TIAN Kang YAO Li-Peng FU Ming-Ming YIN Li-Ping Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of Sciences Soil and Fertilizer Technology Extension Center Bureau of Agriculture of Rugao County

Phosphorus(P) in agricultural soils is an important factor for soil quality and environmental protection. Understanding of P and its fractions in soils on a regional scale is imperative for effective management or utilization of P and the improvement of P availability in soils. To study spatial variability and changes of soil P and its fractions as affected by farming practices, soil samples were taken in Rugao county, Jiangsu Province of China, an intensive agricultural area in the Yangtze River Delta region, in years of 1982(n = 1 514), 1997(n = 1 651), and 2002(n = 342). High spatial variabilities of Olsen P and total P(TP) were observed throughout the study area. Loamy Stagnic Anthrosols and clay or loamy Aquic Cambosols had significantly higher concentrations of Olsen P and TP than sandy Ustic Cambosols and Aquic Cambosols. Olsen P and TP were increased from 1982 to 2002. The accumulations of Olsen P and TP in the cultivated soils were likely related to the increased application of P fertilizer, organic input,and soil incorporation of crop residues as well as conversion of soil use. Accumulated soil P was dominantly in labile and semi-labile P fractions. These P fractions may be utilized by future crop production by adjusting management practices, but they also pose a serious threat to nearby water bodies. Future strategies should include decreasing P fertilization in soils and supporting sustainable management. The information from this study can be used to monitor changes in soil fertility and environmental risks so that the use of fertilizers can become more rational.

关键词： agriculture management Olsen phosphorus phosphorus availability phosphorus fractionation total phosphorus

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Protection efficiency assessment and quality of coastal shelterbelt for Dongshan Island at the coastal section scale

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Journal of Forestry Research 2017年第3期28卷 577-584页

作者： Liyun Wu Dongjin He Zhirong Ji Weibin You Yong Tan Xiaoyan Zhen Jianwen Yang Forestry College Fujian Agriculture and Forestry UniversityFuzhou 350002People's Republic of China Dongshan county Technology bureau Dongshan 363400People's Republic of China

The coastal shelter forest in China is under threat of destruction and degradation because of the impact of human activities. Protection efficiency assessment of the coastal shelterbelt is an important component of shelterforest remediation planning and sustainable management. In this study, a protection efficiency index （PEI） model was established using the projection pursuit method to assess the protective quality of the coastal shelter forest at the coastal section scale of Dongshan Island, China. Three criteria were used, including forest stand structure, forest belt structure, and windbreak effect; each criterion further comprised multiple factors. Based on survey data of 31 plots in the coastal shelter forest of Dongshan Island, we calculated PEI values using a projection of a pursuit model. The result showed 64.5 % of the PEIs fell at or below the middle level, which can indicate the status of the coastal shelterbelt is unsatisfactory. To further explore whether the different bays and land use types create significant differences in PEIs and evaluation indices, we used an ANOVA to test the influence of various bays and forms of land use on coastal shelterbelts. The results showed that PEI and most of the indices differed significantly by bay; mean tree height, mean DBH, mean crown width, stand density, vegetation coverage, and wind velocity reduction differed significantly by land use. Therefore, relevant measures for different locations, bays and surrounding land use can be proposed to improve the existing conditions of the coastal shelterbelt. The results of this study provide a theoretical and technical framework for future changes and sustainable management of coastal shelterbelt on Dongshan Island.

关键词： ANOVA analysis Dongshan Island Coastal shelterbelt Protection efficiency assessment Projection pursuit

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The Type of Low-yielding Fields,Using Direction and Land Fertility Building Measures in Suiping county

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Asian Agricultural Research 2014年第11期6卷 81-82,86页

作者： Jiuyi HU Suiping county bureau of agriculture

Using the evaluation indicator system for arable land fertility in Suiping county,this paper analyzes some factors influencing agricultural production,such as physical and chemical properties of soil,site conditions,soil management,and soil nutrients concerning various types of low-yielding fields in the county. In accordance with the dominant soil constraint factors and main direction of improvement,the lowyielding fields in the county are divided into four types: irrigation improvement type,waterlogging drainage type,barren soil fertilization and barrier layer type. Finally this paper offers specific guidance on the construction of arable land.

关键词： Type of low-yielding fields Using direction Land f

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Analysis of Climatic Characteristics and Vulnerability of Fog in Changzhou

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Meteorological and Environmental Research 2013年第12期4卷 43-46页

作者： Yingying Zhong Yiming Wu Zhengcui Lei Xiaofeng Yang Xichun Dong Changzhou Meteorological bureau guannan Meteorological bureau

[Objective]The study aimed to analyze climatic characteristics and vulnerability of fog in Changzhou. [Method]Based on the data of fog from 2006 to 2012 observed at Longhutang observation station and disaster condition in Changzhou in recent years,fog distribution and vulnerability of Changzhou were analyzed. [Result]Most fog happened from November to February in 2006 and 2007,while less fog happened in 2010,and fog seldom occurred in summer. Average monthly fog days were from 0. 3 to 4. 0,and the maximum appeared in November. The average visibility was 382 m. Generally,the fog with long duration appeared in autumn and winter. The average duration of fog in 2010 was the shortest among these years,about 3 h,while the longest duration of fog was in 2008,up to 7 h. Fog mainly caused damage to traffic systems,human health and economy. Population density,GDP per capita,civil aviation landing flights and highway mileage density were selected to evaluate fog disaster vulnerability,and the results showed that Changzhou was the most vulnerable,followed by Jintan,then Liyang. [Conclusion]The research could provide scientific references for the reduction of losses caused by fog.

关键词： Vulnerability Visibility Duration Disaster bearing body China

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Low Root Zone Temperature Limits Nutrient Effects on Cucumber Seedling Growth and Induces Adversity Physiological Response

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Journal of Integrative agriculture 2013年第8期12卷 1450-1460页

作者： YAN Qiu-yan DUAN Zeng-qiang MAO Jing-dong LI Xun DONG Fei State Key Laboratory of Soil and Sustainable agriculture Institute of Soil ScienceChinese Academy of Sciences Department of Chemistry and Biochemistry Old Dominion University Agricultural bureau of Xiangfen county Shanxi Province

Effects of root-zone temperatures （RZT）（12℃-RZT and 20℃-RZT） and different N, P, and K nutrient regimes on the growth, reactive oxygen species （ROS）, and antioxidant enzyme in cucumber seedlings were investigated in hydroponics. Strong interactions were observed between RZT and nutrient on the dry weight （P=0.001）, root length （P=0.001） and leaf area （P=0.05）. Plant dry weights were suppressed at low RZT of 12℃, while higher biomass and growth of cucumber seedlings were produced at elevated RZT of 20℃ under each nutrient treatment. Growth indexes （plant height, internode length, root length, and leaf area） at 12℃-RZT had less difference among nutrient treatments, but greater response was obtained for different nutrients at high RZT. RZT had larger effects （P=0.001） on cucumber seedling growth than nutrients. In addition, N was more effective nutrients to plant growth than P and K under low root temperature to plant growth. Higher hydrogen peroxide （H202）, malondialdehyde （MDA）, soluble sugar （SS） contents in leaves were observed at 12℃-RZT in all nutrient treatments than those at 20℃-RZT, indicating the chilling adversity damaged to plant growth. In general, antioxidant enzyme had larger response under low root-zone temperature. Superoxide dismutase （SOD） activities were higher in both leaves and roots while peroxidase （POD） and catalase （CAT） showed large different action in leaves and roots at both the two root-zone temperature.

关键词： Cucumis sativus L. growth indexes antioxidant enzyme reactive oxygen

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The Relationship between Forestland Soil Fertility and Gathering Firewood in the Zhuxi Watershed in the Red Soil Hilly Region of China

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Journal of Mountain Science 2013年第1期10卷 75-83页

作者： CHEN Zhi-qiang CHEN Zhi-biao CHEN Hai-bin YUE Hui College of Geographical Sciences Fujian Normal University Soil and Water Conservation bureau of Changting county

Declining soil fertility has become an increasingly urgent problem and gathering firewood is one of the important contributing *** to the excessive exploitation of natural resources especially for firewood,the red soil hilly region has become one of the most vulnerable eco-environment regions in *** pressure of gathering firewood on forestland soil fertility in forestland has been generally estimated by geographical information system and questionnaire method in this paper in the Zhuxi watershed of Changting county,Fujian Province,China,a typical representative in the red soil hilly region of *** results of this study show that：i） Forestland soil fertility is negatively affected by gathering firewood,which is more intensive in the integrated buffer zone than out of *** forestland soil fertility grade,OM,total N,available N,total P,available P,total K,available K,pH and ＆lt;2μm clay content are lower and bulk density is higher in the integrated buffer zone than those ***） The forestland soil fertility grade,OM,total N,available N,total P,available P,total K,available K,pH and ＆lt;2μm clay content tend to be lower and bulk density tends to be higher in the village buffer zones than those out in Datian,Chenguang and Youfang ***） The population density,economic development and terrain might be the key driving forces contributing to the relationship between gathering firewood and forestland soil *** population density leads to more massive firewood collection and imposes more pressure on forestland soil *** the use of firewood stove may reduce firewood consumption and thus release the pressure of gathering firewood on forestland soil *** affects the accessibility to gathering firewood thus affects forestland soil *** driving forces influencing the relationship between gathering firewood and forestland soil fertility should also be taken into account in the further study.

关键词： Gathering firewood Soil fertility Questionnaire method GIS Zhuxi watershed

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Catalytic Hydrogenation of Nitrobenzene to Aniline by Ag/γ-Fe_2O_3

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Chinese Journal of Structural Chemistry 2016年第6期35卷 872-878页

作者：赵玲玲王海峰祁刚 Department of Chemistry and Chemical Engineering Yancheng Institute of Technology Binhai county Safety Supervison bureau

The Ag/γ-Fe_2O_3 nanocomposite was synthesized by solvothermal reduction method via using ferric nitrate and silver nitrate as raw materials, and ethylene glycol as the reducing agent. The composite was characterized by X-ray powder diffraction, scanning electron microscope, transmission electron microscope, and energy dispersive X-ray. The prepared Ag/γ-Fe_2O_3 was used for the catalytic hydrogenation of nitrobenzene to aniline by hydrazine hydrate. The factors such as the silver content in the catalyst, reaction time, reaction temperature and the regeneration of catalyst were investigated. The results showed that the yield of aniline reached 100% by utilizing the 1%wt（nitrobenzene） Ag/γ-Fe_2O_3 for the catalytic hydrogenation of nitrobenzene for 3 h to obtain aniline at 78 ℃, hydrazine hydrate as the hydrogen source, while the silver content in the catalyst was 3%mol.

关键词： Ag/γ-Fe2O3 hydrazine hydrate nitrobenzene aniline catalytic hydrogenation

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Temperature Field of PC Box Girder Bridge Based on GPRS Temperature Collection System

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Wuhan University Journal of Natural Sciences 2015年第3期20卷 269-276页

作者： YANG Zeying LIU Jing QU Jianbo ZHOU Xiangshan LI Lixin School of Civil Engineering Shandong University Highway bureau of Shandong Province Transportation bureau of Jiaxiang county Highway bureau of Yantai City

In order to study the temperature distribution and the corresponding temperature effects on pre-stressed concrete（PC） curved box girder bridge in Shandong Province, this paper builds and adopts an automatic remote real-time temperature collection system to collect temperature data on site, and further uses the software ANSYS for analysis. Based on the comparisons between the measured data and the simulation results, the following conclusions can be drawn： 1 Our temperature monitoring system is reliable; 2 The corresponding measured data of the web plate and flange plate exposed to the sun, vary more severely than that at other positions, so these plates need higher standard design and construction requirements; 3 In the cold wave where still is sunshine, the box girder temperature effect behaves as sine-like curve.

关键词： bridge engineering concrete curved box girder bridge temperature distribution and temperature effect measured data and finite element analysis

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