Advanced Materials Research Vols. 726-731

Abstract: Five-year field experiments were conducted using late-maturing and sparse-planting variety Danyu 39, medium-late-maturing and close-planting variety Zhengdan 958 as experimental materials to evaluate the relationship between physiological indexes and environmental changes. The results were shown that physiological indexes responded differently to environmental changes from year to year. Sunshine hours and light intensity were the main factors affecting physiological indexes, and then temperature. Photosynthetic rate affected the most, followed by chlorophyll content and light transmittance. Environmental changes led to the accumulation changes of photosynthetic products between years, thereby affecting the yield formation. The contributions of physiological index of the yield were different. Contribution rate of chlorophyll content to the yield in Danyu 39 was great, secondly for photosynthetic rate. Photosynthetic rate was dominant factor in affecting the yield of Zhengdan 958.

Abstract: Ear differentiation of different shade-resistance maize were studied under the shade stress using paired near isogenic, easy barren-stalk and not easy barren-stalk hybrids and inbred lines as test materials. The test verified the phenomenon of genetic defective barren stalk of maize preliminarily, revealed the relationship between barren stalk under the shade stress and ear differentiation and light intensity range inducing maize genetic defective barren stalk. Low light stress would make different varieties cause barren stalk and differences among varieties were obvious; easy barren stalk near-isogenic Shennong 98A was the most sensitive to low light stress and the stress intensity should be below 38% shade. Shade resistance of non-barren stalk near-isogenic Shennong 98B was close to normal inbred line Chang 7-2 and its intensity range of light stress were between 38%~60% shade; there were significant differences between hybrids of easy barren stalk D90, D80 and non-easy barren stalk Zheng Dan 958 under the 75% shade; shade stress could make young female ear short, grains per panicle reduce, the number of abortive grain increase and rates of barren stalk increase, which would aggravate with the increase of shade intensity and the reactions of easy barren stalk varieties were much more obvious, even caused 100% barren stalk led by female ear agenesis.

Abstract: Urban greening helps cooling and humidifying the air; shading provided by buildings also affects outdoor thermal environment. Therefore, they both influence the thermal perceptions of people in outdoor spaces. The sky view factor (SVF) is a commonly used parameter in the research on urban climate, indicates the relationship between the visible area of the sky and the area covered by urban structures. The current paper first gives a brief introduction of the SVF and fisheye imagery. It then describes a method conducted to estimate SVF for urban environment analysis by using fisheye lenses and applying the ENVI platform as well. Finally, micro-climate characteristics over three typical urban underlying surfaces, including sunlit asphalt roads, shaded roads by building and by chinars were analyzed based on on-site observations. For a high-density city such as Nanjing, the present study reveals that the higher building shaded, chinar canopy density, and the lower sky transmittance, humidification and cooling of the air is more significant under the same climate condition and the same road. For benefiting urban environmental planning and assessment in high-density cities, more cases simulation with different combinations of factors are needed, which can provide a set of better greening guides and the optimal shading level.

Abstract: The process of urbanization has significant and various impacts on the environment of the earth, either positive or negative. In this paper, multi-disciplined methods such as GIS and bird survey were used to monitor the landscape change and ecosystem transformation by urbanization. The case study in Xiaguanyin Town of Northwest China demonstrated that urbanization can probably have positive environmental influences on a relatively arid place.

Abstract: In recent years, the decrease of total arable land area and the area per capita of available arable land resource are serious problems in China. These problems will become more serious with the development of economy. In this paper, based on the statistical data of cultivated land in Hefei city from 1998 to 2009, their driving forces of the cultivated land change were analyzed by means of principal component analysis. The results showed the changing trends. The total and per capita of cultivated land were declining, but the speed of change was not the same. The sharp decrease was occurred in the period of 2002-2005. Nine affecting factors having influenced on cultivated land change which were analyzed by principal component analysis. The results show that population growth, economic development and efficiency of agricultural production were main driving forces affecting cultivated land change in Hefei city.

Abstract: Used Erigeron breviscapus Rhizosphere soil aqueous extract and mix soil (E. breviscapu Rhizosphere soil and vegetable field ) to cultivate three crops (Pisum sativum Linn, Chinese cabbage, Brassica campestris L), got investigated physiological and biochemical indicators of the above three crop seeds. The results show that seed germination rates, root length and fresh weight decreas with the aqueous extract concentration and rhizosphere soil proportion increase after Pisum sativum Linn was used. All of these physiological indicators of Brassica campestris clearly are not stable. Meatime, E. breviscapu Rhizosphere soil aqueous extract and mixed soil promote Chinese cabbage growth. Allelopathic sensitivity indexes of Chinese cabbage are positive value. So, Chinese cabbage can be as appropriate rotation crop with E.breviscapus. E.breviscapus cropland can also use to plant Chinese cabbage to achieve cultivated resource utilization.

Abstract: Exploring the distribution of soil pH and nutrients are significant to the sustainable development of tropical agricultural growth. Taking Longjiang Farm in Hainan province as the research plot, and exploring the distribution characteristics of soil nutrients in study area by applying the GIS spatial analysis tools. The results indicated that the soil is acidic and the contents of soil nutrients are varied significantly in research area. The spatial distributions of available Ca, available Mg, available Cu and available Zn were mainly determined by the distributions of soil parent materials. The contents of soil organic matters and total N are escalated gradually from north to south in study area. The spatial analysis tools can be applied to explore the distribution of soil nutrients in areas, which is significant to the regional agricultural planning.

Abstract: The re-establishment of natural species-rich health lands on abandoned farmland is one of the main measures in soil erosion control in the Loess Plateau of China. This study was conducted to understand how enzyme activities changed with nutritional properties and microbial biomass in different vegetation types in the loessial gully region of the Loess Plateau. Soil samples were collected in different vegetations which had planted for almost 30 years. For the collected soils, nutritional, microbial and enzymatic properties were determined. The result showed that soil nutritional properties and microbial biomass were enhanced in black locust-amorpha, compared with black locust, but weakened in Chinese pine-amorpha compared with Chinese pine. Besides, soil urease, α-amylase, alkaline phosphatase, catalase, saccharase and cellulase activities in creased with restoration, but decreased polyphenol oxidase. Moreover, urease activity was obviously high in korshinsk peashrub and black locust for the nitrogen fixation of them, and α-amylase was high in Chinese pine for low pH value. However, there still was a certain gap to Chinese arborvitae which was considered to be the climax community in the region. In general, the distance of vegetations to Chinese arborvitae was grassland > black locust > Chinese pine> korshinsk peashrub > Chinese pine-amorpha > black locust-amorpha.

Abstract: Based on the meteorological data for the period of 1951-2009 in Fuxin,the article estimates the photosynthesis, photo-temperature and climate potential productivity of dryland farming in Fuxin of Liaoning province, and analyzes the potential productivity interannual change in crop growth period (April-September). The result shows that the long-time average value of the photosynthesis, photo-temperature and climate potential productivity are 31.89×10⁴kg/hm², 26.80×10⁴kg/hm² and 18.29×10⁴kg/hm² in Fuxin. The interannual change trend of potential productivity is that the photosynthesis, photo-temperature and climate potential productivity are overall reduced, the photosynthesis and photo-temperature potential productivity are not obvious, and the climate potential productivity is obvious. The monthly climate potential productivity contour maps show that the climate potential productivity change dramatically, and the low evalue areas of crop growth period have the continue expansion trend after 2009.

Abstract: In contrast to Chinas rapid urbanization, the development of urban & rural planning technologies remained relatively lagged behind; their guiding framework, urban & rural planning and design theories are also increasingly rendered invalid in addressing the ever-growing types of urban problems. Concepts such as eco-city have attracted wide attention in recent years due to their potential in solving urban problems. However, many of them remain at a theoretical stage and most ecological development index derived from these researches cannot be directly used in guiding urban & rural planning. This paper try to study the basic principles of ecological planning and the rules of the planning analysis models in an effort to establish an ecologically-oriented planning method.