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Estimation of key surface parameters in semi-arid region and their impacts on improvement of surface fluxes simulation

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Science China Earth Sciences 2016年第2期59卷 307-319页

作者： LIU Ye GUO WeiDong SONG YaoMing Institute for Climate and Global Change Research School of Atmospheric Sciences Nanjing University College of Atmospheric Science Nanjing University of Information Science and Technology

Uncertainties in some key parameters in land surface models severely restrict the improvement of model capacity for successful simulation of surface-atmosphere interaction. These key parameters are related to soil moisture and heat transfer and phy- sical processes in the vegetation canopy as well as other important aerodynamic processes. In the present study, measurements of surface-atmosphere interaction at two observation stations that are located in the typical semi-arid region of China, Tongyu Station in Jilin Province and Yuzhong Station in Gansu Province, are combined with the planetary boundary layer theory to estimate the value of two key aerodynamic parameters, i.e., surface roughness length zorn and excess resistance κB-1. Multiple parameterization schemes have been used in the study to obtain values for surface roughness length and excess resistance κB-1 at the two stations. Results indicate that Zorn has distinct seasonal and inter-annual variability. For the type of surface with low-height vegetation, there is a large difference between the default value of Zorn in the land surface model and that obtained from this study, κB-1 demonstrates a significant diurnal variation and seasonal variability. Using the modified scheme for the estimation of Zom and κB-1 in the land surface model, it is found that simulations of sensible heat flux over the semi-arid region have been greatly improved. These results suggest that it is necessary to further evaluate the default values of various parameters used in land surface models based on field measurements. The approach to combine field measurements with atmospheric boundary layer theory to retrieve realistic values for key parameters in land surface models presents a great potential in the improvement of modeling studies of surface-atmosphere interaction.

关键词： semi-arid region Turbulent transfer Surface roughness length Excess resistance Field experiments

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Numerical Study of Impacts of Soil Moisture on the Diurnal and Seasonal Cycles of Sensible/Latent Heat Fluxes over semi-arid region

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Advances in Atmospheric Sciences 2009年第2期26卷 319-326页

作者：宋耀明郭维栋张耀存 Department of Atmospheric Sciences Nanjing University Key Laboratory of regional Climate-Environment for Temperate East Asia (RCE-TEA) Institute of Atmospheric PhysicsChinese Academy of Sciences

The semi-arid regions, as climatic and ecosystem transitional zones, are the most vulnerable to global environmental change. Earlier researches indicate that the semi-arid regions are characterized by strong landatmosphere coupling in which soil moisture is the crucial variable in land surface processes. In this paper, we investigate the sensitivity of the sensible/latent heat fluxes to soil moisture during the growing season based on the enhanced observations at Tongyu in the Jilin province of China, a reference site of international Coordinated Energy and Water Cycle Observations Project （CEOP） in the semi-arid regions, by using a sophisticated land surface model （NCAR_CLM3.0）. Comparisons between the observed and simulated sensible/latent heat fluxes indicate that the soil moisture has obvious effects on the sensible/latent heat fluxes in terms of diurnal cycle and seasonal evolution. Better representation of the soil moisture could improve the model performance to a large degree. Therefore, for the purpose of simulating the land-atmosphere interaction and predicting the climate and water resource changes in semi-arid regions, it is necessary to enhance the description of the soil moisture distribution both in the way of observation and its treatment in land surface models.

关键词： semi-arid region soil moisture latent/sensible heat flux diurnal cycle seasonal evolution

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Institutional performance and participatory paradigms: Comparing two groups of watersheds in semi-arid region of India

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International Soil and Water Conservation Research 2020年第2期8卷 164-172页

作者： Biswajit Mondal Nagarajan Loganandhan Sekhargowda L.Patil Anurag Raizada Suresh Kumar Gopal L.Bagdi ICAR-National Rice Research Institute(NRRI) CuttackIndia Krishi Vigyan Kendra HirehalliICAR-Indian Institute of Horticultural ResearchBangaloreIndia ICAR-Indian Institute of Soil&Water Conservation BellaryIndia National Research Centre on Integrated Farming Pipra KothiEast ChamparanIndia ICAR-Central Sheep and Wool Research Institute AvikanagarIndia

Watershed development programmes carried out in different agroclimatic conditions in India resulted in beneficial impact in terms of productivity enhancement and natural resources conservation, but less attention paid to institutional and participatory aspects. This paper explored the performance of various institutions regarding execution of watershed development programmes in semi-arid region of India. Recorded observations from documents maintained at watershed level and information collected through primary survey as well as focus group discussion with different types of stakeholders were used for analysis. The results indicated lacunae in participatory aspects during programme implementation process like monitoring activities, management of common property resources and equity. Gap in linkages and differential level of performance of various watershed level functionaries indicates the necessity for corrections in the structures and linkages pattern for sustainability of the infrastructure and institutions. The study also showed unequal priorities by the implementing agencies towards in-stitutions, land and water resources development, production enhancement activities and fodder re-sources development as well as rationalities of technical, economic, financial, political and social aspects among the watersheds.

关键词： Participation paradigm index Participatory watershed development index Rationality analysis semi-arid region Stakeholder analysis Watershed development programme

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Effects of plastic sheet on water saving and yield under furrow irrigation method in semi-arid region

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International Journal of Agricultural and Biological Engineering 2018年第1期11卷 172-177页

作者： Muhammad Sohail Memon Kausar Ali Altaf Ali Siyal Jun Guo Shamim Ara Memon Shakeel Ahmed Soomro Noreena Memon Changying Ji College of Engineering Nanjing Agricultural UniversityNanjing 210031China Faculty of Agricultural Engineering Sindh Agriculture University Tandojam 70060Pakistan U.S.-Pakistan Center for Advanced Studies in Water(USPCAS-W) Mehran University of Engineering and TechnologyJamshoroSindh 76062Pakistan Yancheng Vocational Institute of Industry Technology Yancheng 224005China

The increasing demand of water in the country highlights the need to introduce low-input and water saving technologies for agricultural sustainability and crop production,mainly in semi-arid region.A study was conducted to minimize deep percolation losses from the furrow bottom under two different irrigation treatments viz.(1)furrow bottom with plastic sheet(T1)and(2)furrow bottom without plastic Sheet(T0).The physical and chemical analyses of soil profile were taken at a depth of 0-80 cm before and after crop *** dry density of soil slightly increased(0.01 g/cm^(3))under both treatments,while soil pH decreased under *** average yield was 8332 kg/hm^(2) and 7575 kg/hm^(2),with 21.56 m^(3) and 31.09 m^(3) total volume of irrigation water applied under T1and T0,*** saving percentages of water under treatments were 52.22% and 31.00% under T1 and T0 respectively as compared to the saving of water under traditional irrigation ***,better performance,in terms of crop production and water saving,was obtained with use of plastic sheet integrated with bottom of ***,it is suggested that the furrow irrigation method with plastic sheet may be used to preventing moisture and minimize deep percolation losses from furrow bottom.

关键词： furrow irrigation semi-arid region water saving yield plastic sheet deep percolation okra crop soil pH

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Impact of rainfed and irrigated agriculture systems on soil carbon stock under different climate scenarios in the semi-arid region of Brazil

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Journal of arid Land 2022年第4期14卷 359-373页

作者： André L CARVALHO Renato A ARAúJO-NETO Guilherme B LYRA Carlos E P CERRI Stoécio M F MAIA Center for Agrarian Sciences Federal University of AlagoasRio Largo 57072-900Brazil Luiz de Queiroz College of Agriculture The University of Sao PauloPiracicaba 13418-900Brazil Federal Institute of Alagoas Marechal Deodoro 57160-000Brazil

Understanding the dynamics of soil organic carbon(SOC) is of fundamental importance in land use and management, whether in the current researches or in future scenarios of agriculture systems considering climate change. In order to evaluate SOC stock of the three districts(Delmiro Gouveia, Pariconha, and Inhapi districts) in the semi-arid region of Brazil in rainfed and irrigated agriculture systems under different climate scenarios using the Century model, we obtained RCP4.5 and RCP8.5 climate scenarios derived from the Eta regional Climate Model(Eta-Had GEM2-ES and Eta-MIROC5) from the National Institute for Space Research, and then input the data of bulk density, p H, soil texture, maximum temperature, minimum temperature, and rainfall into the soil and climate files of the Century model. The results of this study showed that the Eta-Had GEM2-ES model was effective in estimating air temperature in the future period. In rainfed agriculture system, SOC stock under the baseline scenario was lower than that under RCP4.5 and RCP8.5 climate scenarios, while in irrigated agriculture system, SOC stock in the almost all climate scenarios(RCP4.5 and RCP8.5) and models(Eta-Had GEM2-ES and Eta-MIROC5) will increase by 2100. The results of this study will help producers in the semi-arid region of Brazil adopt specific agriculture systems aimed at mitigating greenhouse gas emissions.

关键词： soil carbon stock agriculture systems climate scenarios Century model semi-arid region

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Discussion on an Eco-Agriculture Model in the semi-arid region of China

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Ecological Economy 2005年第2期1卷 28-31页

作者： ZhangPeidong InstituteofEnvironmentalandEcologicalEconomicsofLanzhouCommercialCollege Lanzhou730020P.R.China

The semi-arid region of China covers an area of 2.2 x106km2. Water shortage in this region is the core but not the only one factor for the sustainable development of agriculture. Effective application of the energy and all kinds of resources and overall maintenance of the balance of ecological environment must be emphasized for sustainable development of the agriculture in the region. The extensive development of rural yard-economy is the only way to realize the intensive agricultural development there. A model is developed on the basis of our studies in recent years.

关键词： semi-arid region yard-economy water-harvested agriculture development model.

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Plastic-film-side seeding,as an alternative to traditional film mulching,improves yield stability and income in maize production in semi-arid regions

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Journal of Integrative Agriculture 2023年第4期22卷 1021-1034页

作者： ZHANG Bing-chao HU Han GUO Zheng-yu GONG Shuai SHEN Si LIAO Shu-hua WANG Xin ZHOU Shun-li ZHANG Zhong-dong College of Agronomy and Biotechnology China Agricultural UniversityBeijing 100193P.R.China Institute of Maize Shanxi Agricultural UniversityXinzhou 034000P.R.China

Planting under plastic-film mulches is widely used in spring maize production in arid-cold regions for water conservation and warming the *** ameliorate the associated issues such as plastic-film residues and additional labor during the“seedling release”in spring maize production,we have developed a plastic-film-side seeding(PSS)technology with the supporting *** the semi-arid regions of Northwest China,a 7-year trial demonstrated that PSS increased plant number per hectare by 6547 and maize yield by 1686 kg ha–1compared with the traditional method of seeding under plastic-film mulch(PM).Two-year experiments were conducted in two semi-arid regions to further understand the effects of PSS on three important aspects of production:(i)the moisture and temperature of soil,(ii)maize development,yield output,and water use efficiency(WUE),and(iii)the revenue and plastic-film residuals in comparison with that of flat planting(CK)and *** monitoring of the soil status demonstrated that,compared with CK,the PSS treatment significantly increased the temperature and moisture of the 0–20 cm soil in the seeding row at the early stage of maize development,and it also promoted grain yield(at 884–1089 kg ha^(–1))and WUE,achieving a similar effect as the PM ***,the labor inputs of PSS were equal to CK,whereas the PM cost an additional 960 CNY ha–1in labor for releasing the seedlings from below the ***,the PSS system increased profits by 5.83%(547 CNY ha^(–1)yr^(–1))and 8.16%(748 CNY ha^(–1)yr^(–1))compared with CK and PM,***,PSS achieved a residual film recovery rate of nearly 100%and eliminated 96 to 130 kg ha^(–1)of residual plastic-film in PM in 3–5 years of maize ***,these results show that PSS is an eco-friendly technique for improving yield stability and incomes for the sustainable production of maize in semi-arid regions.

关键词： maize soil water content soil temperature yield plastic-film plastic-film-side seeding semi-arid region

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Small-Scale Spatial Variability of Soil Nutrients and Vegetation Properties in semi-arid Northern China

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Pedosphere 2006年第6期16卷 778-787页

作者： CHEN Fu-Sheng ZENG De-Hui HE Xing-Yuan Daqinggou Ecological Station Institute of Applied Ecology Chinese Academy of Sciences Shengyang 110016 （China） Life College Nanchang University Nanchang 330047 （China）

A field experiment was conducted at Kezuohouqi County, Inner Mongolia Autonomous region of China, which was located on the southeastern edge of the Horqin Sandy Land, to study the spatial variability of soil nutrients for a smallscale, nutrient-poor, sandy site in a semi-arid region of northern China; to investigate whether or not there were 'islands of fertility' at the experimental site; and to determine the key nutrient elements that sustained ecosystem stability. Results obtained from geostatistical analysis indicated that the spatial distribution pattern of soil total nitrogen (STN) was far different from those of soil organic matter (SOM), total phosphorus (STP), and total potassium (STK). Compared to SOM, STP, and STK, STN had a lower structural heterogeneity ratio and a longer range, while other elements were all similar. In addition, STN had an isotropic spatial structure, whereas the others had an anisotropic spatial structure. The spatial structure patterns of herbage species, cover,and height also differed, indicating that spatial variability was subjected to different ecological factors. Differences in the spatial variability patterns among soil nutrients and vegetation properties showed that soil nutrients for a small-scale were not the primary limiting factors that influenced herbage spatial distribution patterns. Incorporating spatial distribution patterns of tree species, namely, Pinus sylvestris var. mongolica Litv. and shrub Lespedeza bicolor Turcz. in a research plot and using fractal dimension,SOM, STP, and STK were shown to contribute to the 'islands of fertility' phenomenon, however STN was not, possibly meaning that nitrogen was a key limiting element. Therefore, during restoration of similar ecosystems more attention should be given to soil nitrogen.

关键词： Pinus sylvestris war. mongolica Litv. semi-arid region soil nutrients spatial variability species richness

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Effect of Rotational Tillage on Soil Aggregates, Organic Carbon and Nitrogen in the Loess Plateau Area of China

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Pedosphere 2013年第4期23卷 542-548页

作者： HOU Xian-Qing LI Rong JIA Zhi-Kuan HAN Qing-Fang Chinese Institute of Water-Saving Agriculture Northwest A&F University Key Laboratory of Crop Physi-Ecology and Tillage Science in Northwestern Loess Plateau Ministry of Agriculture Northwest A&F University School of Agriculture Ningxia University

In rain-fed semi-arid agroecosystems, continuous conventional tillage can cause serious problems in soil quality and crop production, whereas rotational tillage （no-tillage and subsoiling） could decrease soil bulk density, and increase soil aggregates and organic carbon in the 0-40 cm soil layer. A 3-year field study was conducted to determine the effect of tillage practices on soil organic carbon （SOC）, total nitrogen （TN）, water-stable aggregate size distribution and aggregate C and N sequestration from 0 to 40 cm soil in semi-arid areas of southern Ningxia. Three tillage treatments were tested： no-tillage in year 1, subsoiling in year 2, and no-tillage in year 3 （NT-ST-NT）; subsoiling in year 1, no-tillage in year 2, and subsoiling in year 3 （ST-NT-ST）; and conventional tillage over years 1-3 （CT）. Mean values of soil bulk density in 0-40 cm under NT-ST-NT and ST-NT-ST were significantly decreased by 3.3% and 6.5%, respectively, compared with CT, while soil total porosity was greatly improved. Rotational tillage increased SOC, TN, and water-stable aggregates in the 0-40 cm soil, with the greatest effect under ST-NT-ST. In 0-20 and 2（}-40 cm soils, the tillage effect was confined to the 2-0.25 mm size fraction of soil aggregates, and rotational tillage treatments obtained significantly higher SOC and TN contents than conventional tillage. No significant differences were detected in SOC and TN contents in the 〉 2 mm and 〈 0.25 mm aggregates among all treatments. In conclusion, rotational tillage practices could significantly increase SOC and TN levels, due to a fundamental change in soil structure, and maintain agroecosystem sustainability in the Loess Plateau area of China.

关键词： semi-arid region SOC sorage soil bulk density tillage practice water-stable aggregates

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Interactive effects of deficit irrigation and vermicompost on yield,quality,and irrigation water use efficiency of greenhouse cucumber

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Journal of arid Land 2022年第11期14卷 1274-1292页

作者： Halimeh PIRI Amir NASERIN Ammar A ALBALASMEH Department of Water Engineering Faculty of College of Water and SoilUniversity of ZabolZabol ***Iran Department of Water Engineering Agricultural Sciences and Natural Resources University of KhuzestanMollasani ***Iran Department of Natural Resources and the Environment Faculty of AgricultureJordan University of Science and TechnologyIrbid 22110Jordan

Water scarcity is the most significant barrier to agricultural development in arid and semi-arid *** irrigation is an effective solution for managing agricultural water in these *** use of additives such as vermicompost(VC)to improve soil characteristics and increase yield is a popular *** this,there is still a lack of understanding of the interaction between irrigation water and VC on various *** study aimed to investigate the interaction effect of irrigation water and VC on greenhouse cucumber yield,yield components,quality,and irrigation water use efficiency(IWUE).The trials were done in a split-plot design in three replicates in a semi-arid region of southeastern Iran in 2018 and *** levels of VC in the experiments,i.e.,10(V_(1)),15(V_(2)),and 20 t/hm^(2)(V_(3)),and three levels of irrigation water,i.e.,50%(I_(1)),75%(I_(2)),and 100%(I_(3))of crop water requirement were *** results showed that the amount of irrigation water,VC,and their interaction significantly affected cucumber yield,yield components,quality,and IWUE in both *** the amount of irrigation water and VC application rates reduced the weight,diameter,length,and cucumber *** maximum yield(175 t/hm^(2))was recorded in full irrigation using 20 t/hm^(2)of VC,while the minimum yield(98 t/hm^(2))was found in I_(1)V_(1)*** maximum and minimum values of IWUE were recorded for I_(1)V_(3)and I_(3)V_(1)treatments as 36.07 and 19.93 kg/(m^(3)•hm^(2)),***,reducing irrigation amount decreased chlorophyll a and b,but increased vitamin ***,the maximum carbohydrate and protein contents were obtained in mild water-stressed conditions(I_(2)).Although adding VC positively influenced the value of quality traits,no significant difference was observed between V_(2)and V_(3)*** on the results,adding VC under full irrigation conditions leads to enhanced yield and ***,in the case of applying deficit ir

关键词： irrigation water use efficiency greenhouse size and weight of fruit soil amendment semi-arid region

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