Nitrate Nitrogen Content Characteristics in Groundwater of Typical Planting Areas in Liao River Basin

The contents of nitrate nitrogen（NO-3-N） in underground water from typical planting areas in Liao river basin were analyzed, so as to provide theoretical basis for rational fertilization and effectively prevent the NO-3-N content from exceeding standard. The results showed that difference of the contents of NO-3-N in groundwater from different typical planting areas was significant. The highest content of NO-3-N in underground water was 37.4 mg/L from flower-growing region, then 22. 3 mg/L from maize-growing region, 21.9 mg/L from vegetable-growing region, and the lowest content of NO-3-N in underground water was 19.2 mg/L from rice-growing region. Except rice-growing region, the contents of NO-3-N in underground water of the samples in all planting areas were exceeding standard limit; potential health risk still existed in rice-growing region. Accordingly 12.5%-87.5%, 9.4%-75.5%, 17.9%-58.9% and 21.4%-96.0% of the samples were exceeding standard limit in maize growing region, rice-growing region, vegetable-growing region and flower-growing region. The contents of NO-3-N in under-groundwater before the rainy season was higher than that of NO-3-N in under-groundwater after the rainy season at the same depth of the well.

Spatio-Temporal Changes in the Rice Planting Area and Their Relationship to Climate Change in Northeast China: A Model-Based Analysis

Rice is one of the most important grain crops in Northeast China （NEC） and its cultivation is sensitive to climate change. This study aimed to explore the spatio-temporal changes in the NEC rice planting area over the period of 1980-2010 and to analyze their relationship to climate change. To do so, the CLUE-S （conversion of land use and its effects at small region extent） model was ifrst updated and used to simulate dynamic changes in the rice planting area in NEC to understand spatio-temporal change trends during three periods： 1980-1990, 1990-2000 and 2000-2010. The changing results in individual periods were then linked to climatic variables to investigate the climatic drivers of these changes. Results showed that the NEC rice planting area expanded quickly and increased by nearly 4.5 times during 1980-2010. The concentration of newly planted rice areas in NEC constantly moved northward and the changes were strongly dependent on latitude. This conifrmed that climate change, increases in temperature in particular, greatly inlfuenced the shift in the rice planting area. The shift in the north limit of the NEC rice planting area generally followed a 1＆#176;C isoline migration pattern, but with an obvious time-lag effect. These ifndings can help policy makers and crop producers take proper adaptation measures even when exposed to the global warming situation in NEC.

Impacts of the Minimum Purchase Price Policy for Grain on the Planting Area of Rice in Hubei Province Based on a Mixed Linear Model

Impacts of the minimum purchase price policy for grain on the planting area of rice in Hubei Province were analyzed based on a mixed linear model.After the indicator system containing the minimum purchase price policy and other factors influencing the planting area of rice was constructed,principal component analysis of the system was conducted,and then a mixed linear model where the planting area of rice was as the dependent variable was established.The results show that after the exclusion of the interference from other factors,the minimum purchase price policy for grain had a positive impact on the planting area of rice in Hubei Province.That is,the minimum purchase price policy significantly stimulated the growth of rice planting area in Hubei Province.

Risk Regionalization of Low-temperature Disasters for Flue-cured Tobacco Planting in Qujing Area Based on GIS

There is a prominent,complex and diverse three-dimensional climate and a variety of meteorological disasters in Qujing area. The risk zoning of low-temperature disasters for flue-cured tobacco planting in Qujing area was studied to provide reference for drawing on advantages and avoiding disadvantages in flue-cured tobacco planting,disaster reduction,and disaster relief services. According to the production practice of fluecured tobacco and local climate analysis,it was determined that flue-cured tobacco in Qujing area was very vulnerable to low temperature during the seedling stage（ from early February to middle April） and in the mature period（ from early July to early September）. Based on the quantitative analysis and evaluation of risk of disaster-causing factors,sensitivity of disaster-breeding environment,vulnerability of carriers,and disaster prevention and reduction capability,a risk assessment model of meteorological disasters was established to precisely evaluate and zone the risk of low-temperature disasters for flue-cured tobacco planting in allusion to the seedling and mature stage in Qujing area by using GIS technology. The risk of lowtemperature disasters for flue-cured tobacco planting during the two periods was divided into four grades,namely low,medium,high and very high risk.

Sustainable Intensification and Large-scale Operation of Cultivated Land Use at the Farmers’ Scale:A Case Study of Shandong Province,China

Sustainable intensification of cultivated land use(SICLU) and large-scale operations(LSO) are widely acknowledged strategies for enhancing agricultural performance.However,the existing literature has faced challenges in precisely defining SICLU and constructing comprehensive indicators,which has hindered the exploration of factors influencing LSO within the SICLU framework.To address this gap,we integrated self-efficacy theory into the design of an index framework for evaluating SICLU.We subsequently employed econometric models to analyze the significant factors that impact LSO.Our findings reveal that SICLU can be divided into four key dimensions:intensive management,efficient output,resource conservation,and ecological environment optimization.Furthermore,it is crucial to incorporate belief-based cognitive factors into the index system,as farmers’ understanding of fertilizer and pesticide application significantly influences their willingness to engage in LSO.Moreover,we identify grain market turnover as the most influential factor in promoting LSO,with single-factor contribution rates reaching 70.9% for cultivated land transfer willingness and 62.5% for the total planting areas.Interestingly,unlike irrigation and agricultural machinery inputs,increased labor inputs correspond to larger planting areas for farmers.This trend may be attributed to reduced labor availability because of rural labor migration,whereas the reduction in irrigation and agricultural input is contingent on innovations in production practices and the transfer of cultivated land management rights.Importantly,SICLU dynamically influences LSO,with each index related to SICLU having an optimal range that fosters LSO.These insights offer valuable guidance for policymakers,emphasizing farmers as their central focus,with the adjustment of input and output factors as a means to achieve LSO as the ultimate goal.In conclusion,we propose research avenues for further enriching the SICLU framework to ensure that it aligns with the specific characteristics of regional agricultural development.

Quantity of plant leaf area on three major public squares in Kunming City, China

Regressive formulae to calculate the quantity of plant leaf area for 13 species of ornamental plants were set up based on investigation data of 30 species on 3 major public squares (Dongfeng square, Shengli square and Guandu square) in Kun-ming City, China, which were applied to calculate quantities of plant leaf area of these 13 species. The quantities of plant leaf area for the other 17 ornamental plant species on these squares were directly measured, and the total quantity of plant leaf area of each studied square was obtained individually. The results showed that the quantity of plant leaf area on Shengli square with ornamental plants structure composed of arbor tree species, shrub tree species and turf grass was highest among the three squares. It is believed that the design model of multi-storied vertical structure and proper tending of plant community could not only increase the quantity of plant leaf area, but also play an important role in generating ecological and landscaping benefits. Some corresponding suggestions were put forward on the basis of comprehensive analyses on the plant leaf area quantity of the three representative squares in Kunming urban area.

Use of Linear Spectral Mixture Model to Estimate Rice Planted Area Based on MODIS Data

MODIS （Moderate Resolution Imaging Spectroradiometer） is a key instrument aboard the Terra （EOS AM） and Aqua （EOS PM） satellites. Linear spectral mixture models are applied to MOIDS data for the sub-pixel classification of land covers. Shaoxing county of Zhejiang Province in China was chosen to be the study site and early rice was selected as the study crop. The derived proportions of land covers from MODIS pixel using linear spectral mixture models were compared with unsupervised classification derived from TM data acquired on the same day, which implies that MODIS data could be used as satellite data source for rice cultivation area estimation, possibly rice growth monitoring and yield forecasting on the regional scale.

Design and Construction of the Power Plant Multi-flue Chimneys in East China Area

This paper mainly introduces the designand construction of the multi-flue chimneysof Beilungang Power Plant, ShidongkouSecond Power Plant and Waigaoqiao PowerPlant which have been used in East Chinaarea. This paper contains the generalsituation of construction, material selection,lifting scheme of steel inner flue, designfeatures and construction method. It could bereferential to concerned design andconstruction companies.

Sugarcane Requirement of Water and Effect of Fertigation on Sugarcane

The sugarcane is a main sugar crop in China. The seasonal drying is one of the problems that influence the improvement of output and quality of sugarcane in China. The experimental results for the water requirement and fertigation of the sugarcane showed, that the distribution of the rainfall in spring, autumn and winter, all could not suit the requirements for sugarcane growth. Detailedly, it can suit that sugarcane requirement of 74.4%, 68.6% and 35.7% respectively at seedling emerging stage, tillering stage and mature stage according to sugarcane growth. The drought has already limited the yield of sugarcane. Application of fertigation can enhance the fertilizer use efficiency, and it is also a water saving technique in sugarcane production.

An Analysis on Utilization of Wheat Varieties in Henan Province

The new wheat varieties with more than 6.67x104 hm2 of planting area in Henan Province during 2007-2017 were analyzed. The results showed that in the past eleven years, there were total 43 varieties from 23 breeding units of which the annual planting areas were more than 6.67x104 hm2. Among them, the annual planting areas of 13 varieties from 7 breeding units exceeded 3.33x10 hm2. The total cultivation area of 43 wheat varieties accounted for about 80% of the total wheat cultivation area in Henan in that year. Most of the varieties come from provincial universities and research institutes and municipal agricultural academies, Zhengmai 9023 was the spring wheat variety that had the largest annual and accu- mulated cultivation area, and Aikang 58 was the semi-winter wheat cultivar with the largest annual and accumulated planting area. Semi-winter varieties were the domi- nator. Among the wheat varieties planted in large area in Henan Province, medium- gluten and state-approved varieties are dominant; and provincial and municipal academies are the breeders of the major wheat cultivars in Henan.

An Investigation Report on Production Conditions of Sugarcane in Guangxi in 2016

To predict and assess production conditions of sugarcane in Guangxi in 2016,by using methods of field survey and data collection,the seedling situation,breed structure,planting area,planting period,plant diseases and insect pests of sugarcane in six major sugarcane producing cities of Guangxi were surveyed. The results show that the overall situation of sugarcane seedlings in Guangxi in 2016 became slightly worse than that in 2015,but there were enough good sugarcane seedlings in 2016. The dead heart rate of sugarcane decreased in most sugarcane regions from 2015 to 2016,that is,the comprehensive control of borers gave initial results; the smut infection rate of sugarcane rose from 2015 to 2016 and tended to increase. The situation of decrease in the planting area of sugarcane in three consecutive years was controlled,and the planting area of sugarcane increased slightly from 2015 to 2016. Due to the construction of ' double high' bases,the breed variety of sugarcane in Guangxi was improved further in 2016. It is necessary to strengthen field management and conduct chemical weeding,prevention and control of borers and aphids in the later period in time.

Rare and endangered plant species of the Chinese Altai Mountains

Altai (also named Altay in China) Mountain Country (Mountain System) is a unique natural region,located on the border between different floristic regimes of the Boreal and ancient Mediterranean sub-kingdoms,where distribution of plant species is actually limited. It is known to have sufficient endemic floral biodiversity in the Northern Asia. Many plants of Altai Mountain System need effective care and proper conservation measures for their survival and longer-term protection. Important Plant Area identified as the IUCN (the International Union for Conservation of Nature),specified criteria attract global attention for protection of floral biodiversity across the world. The records of 71 plant species from the Chinese Altai Mountains attributed to the criterion A and the dark conifer forests of Chinese Altai Mountains satisfied the criterion C,which may help qualify to fulfill the national obligation of the Convention on Biological Diversity.

Feasibility of Wind Power Generation for the Reduction of Power Costs in Residential Buildings

The installation of wind power generators on buildings located in areas with regular winds may be a suitable investment in a renewable power source. Brazil has a high eolic potential, where the annual mean wind speed may reach over eight meters per second. This case study is aimed to assess the economic feasibility of the installation of small wind power plants in urban areas. This work evaluates a project for the installation of a vertical axis wind turbine in three buildings （15-, 22-, and 26-story） including the following stages： （1） installation of a real-time power meter in the 15-store unit; （2） demand analysis of the 26-store building＇s power consumption; （3） winds survey along the coast of the State of Ceara; （4） analysis of the wind turbines available in the market; （5） simulation aimed to choose the system. Vertical wind power generators offer better conditions of use in urban areas. The turnover time was established to be between four and six years in the three studied units. The installation of a wind power generator on buildings in regions with an adequate eolic regimen reaches a financial return of the investment before the end of the equipment＇s lifespan.

Synchronous Construction and Operation of Coal Mine and Power Plant in Mining Area

In accordance with the experience withSynchronous construction of coal mine andpower plant in Yongxia mining area, thispaper discusses the existing issues regardingmine mouth power plant including capital,power grid connection, electricity price for gridconnection, installed capacity generation setselection as well as self- protection of coalindustry. It is regarded that under marketeconomy as long as the benefits of the threesectors of coal, electricity and the local arecomprehensively considered, a suitable waycan be arrived for conl industry to operate electricity business.

Linking species performance to community structure as affected by UV-B radiation:an attenuation experiment

Aims UV-B radiation is known to affect plant physiology and growth rate in ways that can influence community species composition and structure.Nevertheless,comparatively little is known about how UV-B radiation induced changes in the performance of individual species cascades to affect overall community properties.Because foliage leaves are primarily responsible for photosynthesis and carbon gain and are the major organ that senses and responds to UV-B radiation,we hypothesized that,under reduced UV-B radia-tion,species with larger leaf areas per plant would manifest higher growth rates and hence tend to improve their community status compared to species with smaller leaf areas per plant in herba-ceous plant communities.Methods We tested this hypothesis by examining plant traits(leaf area per plant and plant height),plant growth rate(aboveground biomass per plant and plant biomass per area)and community status(spe-cies within-community relative biomass)for 19 common species in a two-year field experiment in an alpine meadow on Tibetan Plateau.Important findings Aboveground biomass per plant,as well as per area,progressively increased in a 39%reduced(relative to ambient)UV-B treatment dur-ing the experimental period.At the second year,11 out of 19 species significantly or marginally significantly increased their plant height,leaf area per plant and aboveground biomass per plant.No species was negatively affected by reducing UV-B.As hypothesized,the increase in aboveground biomass per plant increased with increasing leaf area per plant,as indicated by cross-species regression analysis.Moreover,the change in species within-community status increased with increasing leaf area per plant.Our study demonstrates that UV-B radiation has differential effects on plant growth rate across species and hence significantly affects species composition and plant commu-nity structure.We suggest that UV-B radiation is an ecological factor structuring plant communities particularly in alpine and polar areas.