传统生土技术改良策略及应用--基于乡村振兴中建筑实践的思考

生土建筑在我国乡村建设中历史悠久,但由于耐久性不高等缺点,在当代逐渐被边缘化。依托浙江安吉泥土学校、宁夏中卫民宿、四川大邑艺术中心等实践案例,从配比改进、质感提升、性能优化及成本控制等方面对传统生土技术改良策略进行了探索。结果表明,在乡村建设中应用生土改良技术,不仅能够满足办公、民宿及教室等多种建筑类型的功能需求,还具有地域特色浓厚、空间舒适度较高、节能环保等特点,对乡村振兴传承地域特色、改善生态环境具有重要意义。

改良生土技术下的浙江省乡村建筑物化阶段减碳策略

针对当前浙江省乡村建筑物化阶段碳排放长时间处于较高水平的问题,在调整材料配比、做法的基础上,改良传统生土技术.首先,在建筑材料生产阶段,使用改良夯土、改良三合土、竹片泥墙、轻质填充土、生土抹面等代替工业材料;然后,在材料运输阶段,通过就地取材代替车辆运输;最后,将节省的造价用于抵消碳汇.为验证技术的有效性,依托泥土学校进行实践,研究结果表明:用改良生土技术建造乡村建筑能够在浙江省发挥显著的减碳作用,在浙江省乡村建筑物化阶段运用改良生土技术具有巨大减碳潜力.

西北地区生土窑洞的改造技术与再生策略研究

本文在研究中通过对陇东地区镇原县塔李村的实地调查和相关数据分析,总结出了当下生土窑洞所面临的一些突出问题,基于窑洞的主要结构形式对窑洞破坏类型进行了归纳分析,按照窑洞结构构造组成从窑洞生土技术层面总结了改造技术要点;同时,结合乡村振兴战略要求,提出了生土窑洞的再生策略。

Soil microbial properties and nutrients in pure and mixed Chinese fir plantations

An investigation on soil organic carbon, total N and P, NO3-N, available P, microbial biomass C, N and P, basal respiration and metabolic quotients （qCO2） was conducted to compare differences in soil microbial properties and nutrients between 15-year-old pure Chinese fir （Cunninghamia lanceolata） and two mixed Chinese fir plantations （mixed plantations with Alnus crernastogyne, mixed plantations with Kalopanax septemlobus） at Huitong Experimental Station of Forest Ecology （26°45′N latitude and 109°30′E longitude）, Chinese Academy of Sciences in May, 2005. Results showed that the concentrations of soil organic carbon, total N, NO3^--N, total P and available P in mixed plantations were higher than that in pure plantation. Soil microbial biomass N in two mixed plantations was averagely higher 69% and 61% than that in pure plantation at the 0-10 cm and 10-20 cm soil depth, respectively. Soil microbial biomass C, P and basal respiration in mixed plantations were higher 11%, 14% and 4% at the 0-10 cm soil depth and 6%, 3% and 3% at the 10-20 cm soil depth compared with pure plantation. However, soil microbial C： N ratio and qCO2 were averagely lower 34% and 4% in mixed plantations than pure plantation. Additionally, there was a closer relation between soil microbial biomass and soil nutrients than between basal respiration, microbial C： N ratio and qCO2 and soil nutrients. In conclusion, introduction of broad-leaved tree species into pure coniferous plantation improved soil microbial properties and soil fertility, and can be helpful to restore degraded forest soil.

Application of Biotechnology in Environmental Remediation of Mining Area

Based on the characteristics of the ecological environmental remediation of mining area, the application of biotechnology was proposed to do the remediation of the polluted environment in the mining area, mainly including the treatment of gangue dump and tailing heap, improvement of reclamation soil as well as the re- mediation of contaminated soil. Finally, the application and deveiopment trend of biotechnology in environmental remediation and soil remediation of mining area were pointed out.

Studies on nutrient uptake of rice and characteristics of soil microorganisms in a long-term fertilization experiments for irrigated rice

The ecosystem characteristics of soil microorganism and the nutrient uptake of irrigated rice were investigated in a split-block experiment with different fertilization treatments, including control (no fertilizer application), PK, NK, NP, NPK fertilization, in the main block, and conventional rice and hybrid rice comparison, in the sub block. Average data of five treatments in five years indicated that the indigenous N supply (INS) capacity ranged from 32.72 to 93.21 kg/ha; that indigenous P supply (IPS)capacity ranged from 7.42 to 32.25 kg/ha; and that indigenous K supply (IKS) capacity ranged from 16.24 to 140.51 kg/ha, which showed that soil available nutrient pool depletion might occur very fast and that P, K deficiency has become a constraint to increasing yields of consecutive crops grown without fertilizer application. It was found that soil nutrient deficiency and unbalanced fertilization to rice crop had negative effect on the diversity of the microbial community and total microbial biomass in the soil.The long-term fertilizer experiment (LTFE) also showed that balanced application of N, P and K promoted microbial biomass growth and improvement of community composition. Unbalanced fertilization reduced microbial N and increased C/N ratio of the microbial biomass. Compared with inbred rice, hybrid rice behavior is characterized by physiological advantage in nutrient uptake and lower internal K use efficiency.

Optimization of Cr(VI) bioremediation in contaminated soil using indigenous bacteria

Bench-scale soil column experiments were carried out to evaluate the effectiveness of Cr（VI） bioremediation process in soils by using indigenous bacteria with the addition of bacteria nutrient media. Effects of particle size, spray intensity, initial Cr（VI） concentration, circulation mode and soil depth on Cr（VI） remediation were studied. Results show that soils after 6 d remediation with spray intensity controlled in the range of 29.6-59.2 mL/min could well fulfill the requirement of concrete aggregate and roadbed material usage, for the leaching toxicity concentration of the Cr（VI） in treated soils under the chosen condition is far less than 5 mg/L The leaching toxicity and fractions of both hexavalent chromium and trivalent chromium from remediated soils were determined and compared with that of untreated soil. The results show that water soluble Cr（VI） declines from 1520.54 mg/kg to 0.68 mg/kg, exchangeable Cr（VI） decreases from 34.83 mg/kg to 0.01 mg/kg and carbonates-bonded Cr（V1） falls from 13.55 mg/kg to 0.68 mg/kg. Meanwhile, a corresponding increase in carbonate-bonded Cr（III）, Fe and Mn oxides-bonded Cr（III） and organic matter-bonded Cr（III） are found. It reveals that indigenous bacteria can leach out water soluble Cr（VI）, exchangeable Cr（VI） and carbonates-bonded Cr（VI） from contaminated soil followed by converting into carbonate-bonded Cr（III）, Fe and Mn oxides-bonded Cr（IlI）, organic matter-bonded Cr（III） and residual Cr（III）.

Biochar for Soil Management： Effect on Soil Available N and Soil Water Storage

Soil management technologies for climate change adaptation and mitigation are needed to increase and sustain food production in smallholder agriculture while sequestering inert carbon in the soil. In a field studies at Crops Research Institute, Kwadaso-Kumasi Ghana, a control treatment, five inorganic fertilizer combinations （P30K60, N60P30K60, N120P30K60, NlsoP30K60 and N24oP3oK6o） and four biochar rates ＋ inorganic fertilizer （2 t/ha Biochar ＋ N60P30K60, 4 t/ha Biochar ＋ N60P30K60, 6 t/ha Biochar ＋ N6oP3oK6o and 8 t/ha Biochar ＋N6oP3oK6o） were assessed for their effect on soil moisture storage, soil available nitrogen and crop yield. The test crop was okra. Biochar amendments increased soil moisture storage by 14% relative to sole inorganic fertilizer applications. Biochar ＋ inorganic fertilizer relative to sole inorganic fertilizer increased soil available nitrate concentration by 85% at 0-15 cm soil depth but decreased soil ammonium-N by 71%. Compared to control, inorganic fertilizer （P3oK6o） resulted in more than 100% increase in okra fresh fruit yield. Addition of 60 kg N/ha to P3oK6o caused 23% decline in okra fresh fruit yield but showed 60% more okra fresh fruit yield than the control. Inorganic N rates of 120,180 kg N/ha and 240 kg N/ha combined with P3oK6o however caused a decline of 74% in okra fresh fruit yield. Biochar ＋ inorganic fertilizer increased okra fresh fruit yield by 100% compared to sole inorganic fertilizer. Biochar, an inert carbon, combined with inorganic fertilizer has tremendous potential to address food insecurity through soil moisture storage and soil N availability.

Establishing evaluation index system for desertification of Keerqin sandy land with remote sensing data

Keerqin sand land is located in the transitional terrain between the Northeast Plain and Inner Mongolia （42°41′-45°15′N, 118°35′-123°30′ E） in Northeast China and it is seriously affected by desertification. According to the configuration and ecotope of the earths surface, the coverage of vegetation, occupation ratio of bare sandy land and the soil texture were selected as evaluation indexes by using the field investigation data. The evaluation index system of Keerqin sandy desertification was established by using Remote Sensing data. and the occupation ratio of bare sandy land was obtained by mixed spectrum model. This index system is validated by the field investioation data and results indicate that it is suitable for the desertification evaluation of Keerqin.Foundation Item： This study is supported by a grant from the National Natural Science Foundation of China （No. 30371192）

Survey and Conservation of Indigenous Fruits of Western Ghats

Western Ghats region of India is one of the biodiversity hotspots of the world. The topography, wide rainfall variation and varied temperature conditions enable inhabitancy of several plant species. This plant wealth is being used in various forms by tribes and natives of the area for centuries. These gain further importance due to the fact that ripe fruits serve as a source of food and medicine to tribes throughout the year. These wild fruits are source of minerals and vitamins in the diet of the rural people. The potential productivity and floristic diversity of the area have attracted the experts. There are more than 50 wild edible fruit species are available in Western Ghats region. These belong to 25 families and 38 genera. Out of the 25 families, the important ones as a source of fruits are Apocynaceae, Anacardiaceae, Euphorbiaceae, Moraceae, Sapotaceae and Sapindaceae. The fruiting period of different species ranges between two and six months. The highest number of species mature from April to May. The availability of these fruits reduces after October. Some of these fruits, such as Mangifera indica, Artocarpus heterophyllus, Carissa carandas, Emblica officinalis and Syzygium cuminii, have been given emphasis in order to identify high yield and high fruit quality clones and standardization of production technologies. The collection, conservation and utilization on some of the fruits, such as Garcinia indica and Garcinia gummigutta have started at various research organizations. Some other fruits, namely Chrysophyllum roxburghii （Family Sapotaceae）, Canthium parviflora Lamk syn. Plectronia parviflora （Lam.） Bedd. （Family Rubiaceae）, Elaeagnus conferta Roxbsyn, Elaeagnus latifolia L. （Family Elaeagnaceae）, Securina leucopyrus syn. Flueggea leucopyrus （Family Euphorbiaceae）, Elaeocarpus tuberculatus Roxb. （Family Elaeocarpaceae）, Nephelium stipulacum Bedd. syn. Doratoxylon stipulatum （Family Sapindaceae） have potential for commercial cultivation. Thus, attempts were made with the objective of recording availability of these species, proximate analysis and their on farm and off farm conservation at Central Horticultural Experiment Station （CHES）. Few plants were also provided to local growers on farm conservation. The continuous depletion of forest and the increasing human disturbance resulted in losses of these species. There is need to conserve these fruits for future.

An Econometric Analysis of Cotton Production Technologies in Harran Plain, Turkey： Translog versus Cobb-Douglas Functions

This research explores the question of how the three production factors, capital, labor, and land may impact the current level of cotton output on the Harran Plain, a major cotton production area in Turkey. The objective of this paper is to estimate a Translog production function and compare the results to those from a Cobb-Douglas specification. Nested tests we performed resulted in the conclusion that the constant returns to scale, weak separability and Cobb-Douglas hypotheses are all satisfied. Thus the Cobb-Douglas specification is a superior functional form yielding results more robust than those from the translog model. Dwelling on Cobb-Douglas estimation results, farm size is found the most influential variable determining cotton output, followed by the variable representing capital as the second influential. Results also demonstrate that the returns-to-scale parameter calculated for this sample is not statistically different from unity, suggesting that cotton production technology in this region exhibits constant returns to scale. This result is consistent with current literature findings that render support to an inverse relationship between farm size and productivity in developing countries.

Bioremediation of Oil-Polluted Cultivated Soils in the Euro-Arctic Region

It has been studied restoration processes in oil products-polluted soils at high northern latitudes （the Murmansk region, Russia）. Mineral and organic fertilizers and a bacterial preparation （based on the local strains of hydrocarbon-oxidizing bacteria） were applied for restore polluted soils. Periods of removing OP （oil products） from soil were determined by the reduction of the pollutant concentration and by soil biological activities--the dynamics of bacteria number and CO2 emission from soil. The soil OP even at such a high concentration （as 10 L/m^2） had stimulated bacterial reproduction. In three summer month levels in the control variant without ameliorators of OP content decreased by 59% from the initial level, in the variant with mineral and organic fertilizers by 86%, in the variant with the bacterial preparation by 84%. Stimulating of indigenous microorganisms activity with additional nutrients was no less effective technique of OP-polluted soil bioremediation, than applying the bacterial preparation, which requires considerable financial investment. Moderately contaminated of OP soil is a source of additional carbon dioxide emission in the atmosphere. Pollution soil with OP caused for increasing of share of potentially pathogenic fungi in the fungal community.

RESPONSES OF WETLAND ECO SECURITY TO LAND USE CHANGE IN WESTERN JILIN PROVINCE, CHINA

By the use of the software of ARCGIS, dynamic changes of the landscape elements, landscape structure, conversion processes of the landscape gradients and the responses of wetland eco-security to land use/cover changes (LUCC) in the western Jilin Province were studied from 1930 to 2000. The results show that the landscape elements of grassland, wetland, forestland and water area shrank rapidly, and wetlands underwent huge losses in the study period due to the conversion from wetland into arable land and grassland in large quantities. The responses of wetland eco-security to LUCC were inverse evolvement of wetland vegetation, loss of biodiversity, water deficiency in wetland ecosystem, the changes of the heterogeneity of wetlands and the fragmentation of the wetland habitats. Suggestions were given for protection of wetlands and the regional sustainable development.

Biotechnological Strategies for Phytoremediating Triazinic Herbicides in the Humid Pampa （Argentine）

In agricultural producer countries, the use of chlorinated herbicides （atrazine）, associated to intensive farming practices, overflows the ecosystems natural attenuation capacity. Thus, herbicide residues contaminate the soils and water sources, increasing the risk for human health and wildlife. Humid Pampa is the main agricultural region in one of the world＇s largest herbicide consumer countries; hence, technologies to remediate its residues are needed. In this context, phytoremediation is an effective, environmental friendly and publicly accepted option. Accordingly, the objective of designing biotechnological strategies for phytoremediating triazinic herbicide residues in an integrated approach to the ongoing Humid Pampa agricultural trend is raised. In this way, strategies according to the edaphic, topogeographic and fanning practices characteristics of this region where established. In those strategies, the adequate selection of plant species is essential. For that purpose, atrazine tolerance assays were performed in simple （semisolid agar medium） and complex （microcosms） experimental systems implanted with Lolium multiflorum, Lotus sp. and Quenopodium quinoa. L. multiflorum was selected and evaluated via atrazine dissipation assays with soil. Atrazine soil content was determined by solvent extraction and subsequent HPLC-UV analysis, observing statistically significant attenuation levels at 21 days. According to the observed results, a strategy for scaling up the application to field conditions is proposed.

Soil and Water Conservation Ecological Technology in China

Analysis of the development of research and technical application is a critical basis for the identification and evaluation for suitable soil and water conservation ecological technology（SWCET） in China. Among instruments for analyzing the development of research and technical application, bibliometric statistics and visualization tools such as Cite Space have been widely applied. To analyze the domestic development of SWCET, we applied Cite Space to the CNKI（China National Knowledge Infrastructure） database on Chinese research literature（from Jan 1985 to Mar 2017） and patents（Jan 2002 to Feb 2017）. The circulation of research after 2002 and quantity of patents after 2010 increased rapidly. Research institutions, people and interests were dispersed, a strong center of research has not been formed and cooperation among research institutions is weak. The number of patented inventions in western regions of China suffering serious soil erosion is far lower than that in eastern regions such as Jiangsu, Beijing, Shandong and Guangdong. Vegetation restoration, ecological slope protection and protective cultivation are relative hotspots according to technical measures： the Loess Plateau, stony desertification（area） and dry-hot valley according to research area, and expressway, side slope and sloping cropland according to application area. Research hotspots mainly appeared several years after the number of published papers increased in 2002. In the past five years, only stony desertification has emerged as a focus. We argue that further studies on the identification and evaluation of SWCET should be focused on certain technical measures, regions and areas.

Production of Biochar for Soil Application:A Comparative Study of Three Kiln Models

Biochar has potentials for soil fertility improvement, climate change mitigation and environmental reclamation, and charred biomass can be deliberately incorporated into soil for long-term carbon stabilization and soil amendment. Many different methods have been used for biochar production ranging from laboratory to industrial scales. However, in countryside of developing countries, biomass is generally used for cooking but not charred. Biochar production techniques at farmer scale have remained poorly developed. We developed and tested biochar production kilns for farmers with a dimension of 50.8 cm × 38.1 cm （height × diameter）, using three different setups for optimizing oxygen （02） limitation and syngas circulation： airtight with no syngas circulation （Model I）, semi-airtight with external syngas circulation （Model II） and semi-airtight with internal syngas circulation （Model III）. A comparative assessment of these biochar production kiln models was made considering biochar pyrolysis time, fuel to biomass ratio, biochar to feedstock ratio and thermogravimetric index （TGI）. Among the models, the best quality biochar （TGI ---- 0.15） was obtained from Model I kiln taking the longest time for pyrolysis （12.5 h） and the highest amount of fuel wood （1.22 kg kg-1 biomass）. Model III kiln produced comparatively good quality biochar （TGI = 0.11）, but with less fuel wood requirement （0.33 kg kg-1 biomass） and shorter pyrolysis time （8.5 h）. We also tested Model III kiln in a three times larger size under two situations （steel kiln and pit kiln）. The biochar to feedstock ratio （0.38） and quality （TGI =0.14） increased slightly for the larger kilns. Quality of biochar was found to be mainly related to pyrolysis time. The costs for the biochar stove and pit kiln were US$ 65-77, while it was US$ 154 for the large size steel kiln. Model III kiln can potentially be used for both cooking and biochar production at farmer scale.

Pulling growth technique towards rare earth single crystals

Pulling growth technique serves as a popular method to grow congruent melting single crystals with multiscale sizes ranging from micrometers to centimeters.In order to obtain high quality single crystals,the crystal constituents would be arranged at the lattice sites by precisely controlling the crystal growth process.Growing interface is the position where the phase transition of crystal constituents occurs during pulling growth process.The precise control of energy at the growing interface becomes a key technique in pulling growth.In this work,we review some recent advances of pulling technique towards rare earth single crystal growth.In Czochralski pulling growth,the optimized growth parameters were designed for rare earth ions doped Y_3Al_5O_(12)and Ce:(Lu_(1-x)Y_x)_2Si O_5on the basis of anisotropic chemical bonding and isotropic mass transfer calculations at the growing interface.The fast growth of high quality rare earth single crystals is realized by controlling crystallization thermodynamics and kinetics in different size zones.On the other hand,the micro pulling down technique can be used for high throughput screening novel rare earth optical crystals.The growth interface control is realized by improving the crucible bottom and temperature field,which favors the growth of rare earth crystal fibers.The rare earth laser crystal fiber can serve as another kind of laser gain medium between conventional bulk single crystal and glass fiber.The future work on pulling technique might focus on the mass production of rare earth single crystals with extreme size and with the size near that of devices.

Soil phosphorus bioavailability assessed by XANES and Hedley sequential fractionation technique in a glacier foreland chronosequence in Gongga Mountain, Southwestern China

The primary productivity of terrestrial ecosystems is influenced by soil phosphorus bioavailability, which depends largely on chemical fractions of phosphorus. The sequential fractionation technique developed by Hedley et al. or its subsequent modification is a well-known method to determine soil phosphorus forms. Hedley sequential fractionation technique separates the phosphorus into fractions based on their different chemical solubilities in extractants with certain chemical properties. Recently, synchrotron-based X-ray absorption near edge structure(XANES) spectroscopy has been employed to measure soil phosphorus species directly and non-invasively. The XANES method provides information concerning local structure and chemical information of target elements at a molecular level. Thus, it can distinguish phosphorus fractions bound by metal oxides or hydroxides(such as Fe, Al, and Ca). In this present work, the phosphorus speciation of topsoil along a glacial foreland chronosequence in Gongga Mountain is determined using these two methods. The changes in soil phosphorus bioavailability along the 120-year-old chronosequence are assessed based on comparisons of the results obtained by these two methods. The results indicate that Hedley sequential fractionation technique shows a greater ability to determine soil bioavailable phosphorus(Resin-P and NaCHO3-P), while XANES is effective in distinguishing phosphorus bound by metal compounds. In the chronosequence, Ca- and Al-bound phosphorus were derived mainly from primary minerals, whose phosphorus contents decreased within 120 years of moraine weathering and soil development. The content of soil bioavailable phosphorus increased rapidly after 30 years since deglaciation. The increasing phosphorus bioavailability promoted the colonizing and primary succession vegetation.

An in-situ Technique for Producing Low-Cost Agricultural Biochar

Application of biochar to agricultural soils is effective to sequester atmospheric carbon and improve soil quality, but current pyrolysis and transportation costs are high, making biochar too costly to be used at the field scale. This study developed a new in-situ technique, burning and soil covering(B-SC), which can be used by farmers for production of biochar with crop residue. In this study,the air-dried feedstocks, elephant grass and corn residue, were burnt in situ for biochar production in the field. After approximately 90% of the leaves were combusted, the burning process was dramatically slowed down by covering the feedstock with soil. The biochar yield averaged 18.0 ± 1.3(n = 15) and 13.7 ± 1.3(n = 10) kg per 100 kg air-dried feedstock for the elephant grass and corn residue,respectively. The biochar properties were suitable for soil improvement. The inputs for biochar production of the B-SC process only included low labor force, open field, feedstock(e.g., grass and crop residue), and simple tools. The operation time for processing 10 kg of the corn residue by an individual farmer was 24.4 ± 4.1 min(n = 10). As compared with the conventional field burning process, the B-SC process drastically shortened the time for biomass burning and generated a significantly lower emission of smoke and thermal energy. This simple technique can be particularly practical and effective for farmers to improve the soils of poor quality in China.

Nutrient Recycling from Industrial Solid Wastes and Weeds by Vermiprocessing Using Earthworms

Vermicomposting is a biotechnological process that enables the recycling of organic waste materials into manure through the combined action of earthworms and mesophilic microorganisms. In this study, a 13-week experiment was carried to vermiprocess food industry sludge mixed with different bedding materials including two weeds, water hyacinth and parthenium, as well as cow dung, in different combinations employing earthworms of the species Eisenia fetida. Eight vermibins containing one kilogram of the waste mixtures （dry weight basis） were established for vermicomposting. Vermiprocessing significantly increased nitrogen, phosphorous, and potassium contents of the mixtures. However, a decrease in pH, organic carbon, and C：N ratio was observed after vermiprocessing. The heavy metal contents in the vermicomposts were higher than the initial values but within permissible limits. These results indicated that the studied wastes can be converted into good quality manure by vermiprocessing, which indicated their agricultural values as a soil conditioner if mixed with weeds in appropriate ratios.