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Grazing is the basic measure of land management both at home and abroad, and the grazing land covers more than half of the global terrestrial sphere. As a subsystem of grassland ecosystem, grazing is composed by three elements of human settlement, grassland and livestock, Its core is the soundness and stability of the tripartite system. Grazing may historically be divided into three stages: the primary nomadic period, the transformation grazing period and the morden grazing period. With developing of technology and culture as well as industrial civilization, the grazing management system has constantly take in the technology and culture elements from that civilization and finally completed the transformation, Finally the basic rotational grazing model of human settlement, grasslad and livestock unit established. The rotational grazing is a kind of open agricultural technical system assumed in many submodels so may adapt to various agricultural system and meeting the requirements both of ecology and production as well, so it is significant progress of grassland grazing management. This paper, using the case of the United States, discussed the grazing transformation process which lasted for almost three hundred years. On the other hand, limited by the traditional agrarian culture, China has so many misunderstandings of grazing management system and hardly aware of the morden transformation of grazing, resulted in a serious loss for such a long time. At the present, grazing transformation is one of the most urgent task for China.
The objective of this study was to investigate the rootinvading fungi varieties of alfalfa in various growing seasons. An experiment was conducted to isolate and identify fungi varieties from 31 alfalfa (Medicago sativa) varieties in Henan Province, China. The results of this study showed that the dominant fungi species in three seasons were obviously different, and Alternaria alternata and Rhizoctonia solani were the most common fungal species in three growing seasons and dominant fungal species were different in each season. Rootinvading fungi and their incidence of three growing seasons showed a significant difference among 31 alfalfa varieties. The five varieties with higher incidence of fungi were Alfaking, WL525HQ, Sitel, Siriver, Aohan, respectively, and the five varieties with lower incidence were Algonguin, Vernal, Goldenqueen Grandeur and THG1 when compared to other alfalfa varieties.
The rhizosphere soil under fluecured tobacco continuous cropping for 12 years was used to estimate the autotoxic potential and constituents of autotoxic chemicals for disclosing the development mechanism of successive cropping obstacle of tobacco. The results of this study showed that the continuous cropping encouraged the tobacco rhizosphere soil to produce greatly autotoxic potential to lettuce and tobacco seedlings when compared to control. 7 carbohydrate compounds, 14 acid compounds, 16 ester compounds, and only one the other compound were found in the control soil, but 2 carbohydrate compounds, 3 acid compounds, 8 ester compounds, and 12 other compound were identified in the tobacco rhizosphere soil with continuous cropping for 12 years. Comparing to control, 8 kinds of chemical compounds in the tobacco rhizosphere soil were involved in autotoxic potential, and they were vanillin, digitoxin, cedrol, pentadecanone, tricosene, sitosterol, cholestanol, and Cholestan3one.
An experiment was conducted to examine if raking was an alternative management strategy to replace burning by comparing the effect of burning and raking on soil properties of steppe. This study showed that the burning and the annual mowingraking increased soil temperature by about 2.26 ℃ and 1.48 ℃ at 5 cm and 10 cm depth, and 1.74 ℃ and 0.87 ℃ at 15 cm and 20 cm depth, respectively, and that the burning and the mowingraking significantly reduced the content of soil microaggregate(P0.05), the diameter of which was over 0.25 mm. However, no significant difference in soil microaggregate was found between burning and annual mowingraking. The burning and mowingraking significantly decreased the organic carbon and total N (P0.05), and the burning decreased more soil organic carbon and total N than the mowingraking did. Annual burning reduced soil organic carbon by 11.69 g/kg at the 10 cm depth and 8.00 g/kg at the 20 cm depth, and reduced total N by 0.633 g/kg at the 10 cm depth and 0.752 g/kg at the 20 cm depth, while annual mowingraking decreased less soil organic carbon and total N had than burning did. This study also showed that the burning decreased the C/N ratios of soil at the 10 cm depth（P0.05）, while mowingraking did not affect the C/N ratios of soil.
A field survey was carried out to investigate the effect of continuous cropping of maize with different years on soil microbes (bacteria, fungus, actinomyces) and main soil nutrients for finding the main obstacle factors of continuous cropping of maize in the Hexi area. This study showed that the quantity of bacteria in 0-20 cm soil layer significantly decreased and the number of fungus increased as the cropping years increased (P0.01). The available P and organic matter were positively correlated to the quantity of bacteria but negatively correlated to the number of fungus. The number of actinomyces increased from the first year to the fifth year, and then decreased after the fifth year. The continuously cropping years did not affect the available K and alkalihydrolygable N. This study suggested that maize continuous planting would destroy the balance of microbe flora in soil, reducing the number of beneficial microbes and increasing the population of soil fungi, which caused the serious disease and reduced the main soil nutrients.
Low available phosphorus in soil is one of the major limiting factors for crop production in the subtropical and tropical regions. A field experiment was conducted to determine the temporal changes of the phosphorus content in latosol soil when 14 tropical legumes were applied into soil in this study. The results of this study showed that the available phosphorus content of soil treated legumes green manures was higher than that of control, indicating that application of green manures to soil increased the available P content in soil to some extent, in which Magnolia lotungensis showed the highest effectiveness and increased available phosphorus content of soil by 339%. 14 tropical legumes showed a different effect on the available phosphorus content of soil as application time increased, but they shared a similar trend. This study suggested that the best time for application of leguminous green manure to latosol was the first month.
To identify the main trace elements of different types grassland from habitat of Przewalskis gazelle in east area of Qinghai Lake, the Fisher Discriminate Analysis was used to quantify the forage value by measuring the copper, manganese, iron, zinc, selenium and molybdenum content of mixed forage samples during summer, autumn, and winter. This study showed that test method was credible and effective, indicating that the molybdenum was the main trace element responding to grassland types except for Artemisis frigida grassland type. The established model could be used to identify the grassland type in the other regions.
on the basis of water balance principle, a linear gradient irrigation experiment was conducted to investigate the influence of soil moistures on turf density, color, texture, uniformity of Kentucky bluegrass in the Xinjiang region. The results of this study showed that Kentucky bluegrass turf showed a better color, uniformity and density when soil moisture was 60%-70% of field water capacity, but the turf texture of Kentucky bluegrass was not different under the different soil moisture, indicating that soil moisture did not affect the turf texture of Kentucky bluegrass. Comprehensive estimation showed that the appearance quality of Kentucky bluegrass turf was better and Kentucky bluegrass grass was health when soil moisture was 60%-70% of field water capacity.
The field observation method was used to evaluate the Rhizoctonia solani resistance of 31 varieties of Kentucky bluegrass in the Beijing region in this study. The results of this study indicated that the R. solani resistance of varieties was different, and their antidisease grade ranged from highinfection to high antidisease. The relative resistance disease index of nine varieties was 0.7 to 1.00, indicating that they were high antidisease varieties; Six varieties with relative resistance disease index between 0.5 to 0.7 was the middle antidisease varieties; Nine varieties was the middleinfection of R. solani because their relative resistance disease index was 0.1 to 0.3; The relative resistance disease index of three varieties were below 0.1 and these varieties was highinfection of R. solani.
Soil enzymes play an important role in the soil ecosystem nutrient cycling and energy flow．Therefore, the study of soil enzymatic activities has important significance to investigate the structure, function and sustainable development of grassland ecosystem．The research of soil enzymes has experienced three different historical periods which were foundation period(Before 1950s), fast development period (1950-1980s) and mutual penetration with other disciplines period (1980s)．Soil enzymes are mainly derived from soil microbe. They can be divided into six categories which were oxidoreductase, hydrolase, transferase, lyase, ligase and isomerase．This paper summarizes several factors affecting soil enzymatic activities of grassland ecosystem, such as degradation levels, fertilization, grazing, soil microbe, season and so on．Based on previous research, we concluded that: 1) soil enzymatic activities tend to decrease with the aggravation of degradation, 2) soil enzymatic activities could be increased to some extent by fertilization, 3) soil enzymatic activities increased by light grazing but reduced by heavy grazing, 4) soil enzymatic activities positively correlated with soil microbe, 5) soil enzymatic activities varied with season. Finally, a prospect to the research and development of the relationship between degradation, restoration and improvement of QinghaiTibet plateau alpine meadow ecosystem and soil enzymatic activities was made.
An experiment was conducted to estimate the drought tolerance of alfalfa (Medicago sativa) seedlings of 10 varieties stressed by PEG6000 with the concentrations of 0 (CK)、-0.3、-0.6、-0.9 and -1.2 MPa by measuring cell membrane permeability, malondialdehyde (MDA), free proline (Pro) and carotenoid (Car) concentration as well as superoxide dismutase (SOD) activity. This study showed that the cell membrane permeability, MDA and Car concentration in alfalfa leaves increased and the Pro concentration and SOD activity firstly decreased and then increased as drought stress increased. The maximum range of drought resistance of alfalfa seedlings was at -0.9 MPa water potential around. The subordination function analysis showed that the drought tolerance of 10 alfalfa varieties was German Derby＞Millionaire＞Algonquin＞West blend＞FGZT 106＞Emperor 1#＞Golden Empress＞Affinity＞XinJiang Daye＞Siriver.
This study was to evaluate the physiological changes of Caragana leucophloea and C.aurantiaca seedlings under salt stress. One year old of C. leucophloea and C.aurantiaca seedlings were treated with 0.2%, 0.4%, 0.6%, 0.8% and 1.0% NaCl solution for 7 and 15 days, respectively. Leaf relative conductivity, contents of MDA and proline (Pro) of the seedlings were measured. The results showed that with increased NaCl concentration and longer of stress time, the leaf relative conductivity of C. leucophloea gradually decreased whereas the leaf relative conductivity of C. aurantiaca gradually increased. The MDA content of C. leucophloea decreased at first and then increased; MDA of C. aurantiaca gradually increased when NaCl concentration increased or salt stress was prolonged. When C. leucophloea and C. aurantiaca. plants were subjected to salt stress, the Pro content in leaves went up in order to maintaining the osmosis balance. Ultimately through overall assessment, it was concluded that salttolerance of C. leucophloea was higher compared wit C. aurantiaca.
24 varieties seeds of Italian ryegrass (Lolium multiflourum) were soaked in 0, 23.4, 35.1, 46.8, 58.5 mol/L NaCl solution to evaluate their salt tolerance by measuring germination, growth, water content of leaf. The results of this study showed the relative germination percentage, relative seedling length, relative root length, relative biomass and relative water content of leaf decreased as the NaCl concentration of solution increased and indexes of the accessions in 23.4 mol/L NaCl solution were significantly higher those in 46.8 and 58.5 mol/L NaCl solution(P0.05). Effect of salt stress on parameters of L.multiflourum was in order, the relative root lengththe relative seedling lengththe relative water content of leaf. The remarkable differences in the relative root length and relative biomass under salt stress were found among 24 varieties. Comprehensive evaluation results showed that LM05, LM07，LM10, LM20 and LM23 was strong salt tolerance group and LM03, LM08, LM09 and LM16 was sensitive group to salt.
An experiment was conducted to compare the biological characteristics of 18 species seeds of Carex genera growing at the Beijing mountain area, including introduction and domestication. The morphological characteristics, 1 000seed weight, germination rate were used to estimate Carex planiculmi, C. leiorhyncha, C. lanceolata, C. breviculmis, C. giraldiana, C. neurocarpa, C. heterolepis, C. arnelli, C. hancockiana, C. heterostachya, C. rigescen, C. jaluensis, C. remotiuscula, C. forficula, C. pediformis, C. pediformisect, and KT (Carex spp.). This study showed that difference in morphological characteristics, 1 000seeds weight, and germination rate was found among 18 species. The smallest seeds were C. neurocarpa, C. forficula and C. remotiuscula, and the biggest one was C. giraldiana with 3.3 g 1 000seed weight. The germination rate of KT, C. giraldiana, C. lanceolata and LY6 was 94%, 74%, 74% and 63%, respectively. The germination index of KT, C. leiorhyncha, LY6 and C. lanceolata was 90.27, 56.61, 48.71 and 48.11, respectively. The germination rate of C. hancockiana and C. jaluensis, C. forficula and C. heterolepis was 4%, 2%, 2% and 0.67%, respectively. The seeds of C. arnellii did not germinate during experimental period, and these results would not only provide scientific and basic information for identifying the C.species, understanding the germination characteristics of seeds, selecting good C.germplasm, and extending C.resource.
A field trial was conducted to select the suitable varieties for the west Fujian by comparing the economic characteristics and phenological period of new species or lines for Chinese milk vetch. This study indicated that the yield of Chinese milk vetch Mingzi No.6 and 8410441 and 8324411 was over 40 500 kg/ha, and was higher than that of control. New varieties showed a higher height and faster growth than control Chinese milk vetch, including Ningbo Daqiao, Yi Jianzi and Yujian Daye. However, Ninbo Daqiao and Yujiang Daye showed higher winter survival ratio than others. This study suggested that all lines of Chinese milk vetch did not perform well and showed their intrinsic growth potentials because they were affected by extreme weather.
Torrid Zone teosinte (Zea mexicana）is shortday plant, and does not bloom and produce seed in the longday area of north China. An experiment was conducted in the long day area to estimate the reproduction property and hybrid selection possibility of a new germplasm teosinte Lumu No.2 with photoperiod nosensitivity, which was selected from nature variance plant by systematical breed. This study showed that the new germplasm was able to produce seeds in longday area, and its florescence date was in early or medium August and the seed mature date was in early October. The fresh grass and seed yield was 45 930 kg/ha and 1 595.5 kg/ha, respectively. The successful rate of hybrid selection was 72.7% when Lumu No.2 was used as father plant. This study suggested that the new germplasm could plant in longday area, which would amplify the germplasm of hybrid selection and reduce cost of corn seed production.
On the basis on data from the ground meteorological station and remote sensing, and differences in maximum light utilization efficiency, the CASA mode was used to estimate the net primary production (NPP) by the ARCGIS 9.2 and ENVI 4.5 in Henan Province, China. The results of this study showed that NPP in Henan Province was 34.87 Mt C, and its spatial distribution was closely related to vegetation type, indicating that NPP of forest was the biggest, NPP of shrub came to the second, and NPP of grassland and cropland was the third and the fourth. NPP in December, January, and February was the lowest, accounting for 1.38% of annual NPP, and those in May, July, and August were was the biggest, which was 56.84% of annual NPP. Compared to Miami, Montreal, Chinkugo model, this study was similar to results from Miami, and order of vegetation types was similar to order from Chinkugo. This study suggested that the CASA mode predicted well the NPP in Henan Province, and was suitable for simulating the NPP.
A field survey was carried out to describe the species diversity distribution pattern of alpine grassland communities along an altitudinal gradient at the Ritunbu Mountain of Nyainqentanglha Range, Naqu regions in the Northern Tibet. The results of this study showed that aboveground biomass and total coverage of plant communities increased firstly and then decreased as the altitude gradient increased, and peaked at 4 623 m. The species richness index, ShannonWiener index and Pielou evenness index showed a unimodal pattern, and peaking at intermediate levels of altitude.
Based on simultaneous data of Elymus nutans growth and meteorological factors, the phenological variation of E. nutans during recent 20 years at the side slope conditions in the Northeast region of QinghaiXizang Plateau was determined by the SPSS 13.0 statistical software in this study. This study showed that the phenological phase of E. nutans appeared earlier, in which the date of ear and bloom showed the obviously earlier by 1.50 d/a and 1.58 d/a due to global warming, and the maturate date of E. nutans seed did not change. The growing season in the Hezuo region during recent 20 years prolonged by 1.5 d/a, correspondingly, the growing season of E. nutans in Hezuo prolonged by 3.4 d/10a.
To understand the growth rhythm of natural forage grass growing at the typical steppe regions, the observational data from the Xilinhot national climate observatory for many years were used to describe the growth rhythm and meteorological index of phenological phase of Stipa kryloyii, Leymus chinensis, Cleistogenes squarrosa by statistical principle. This study showed that the height, cover, and yield of three kinds of grass at growing season showed a similar trend, peaking at the late August. Regreen time was from late April to early May, and seed mature was from middle August to early September. The fastest growth rate of herbage was found at heading period. The phenophase was significantly related to daily average geothermal temperature at 40 cm. Herbage growth showed an own growth rhythm and ecological environment changes restricted this growth rhythm.
The productivity of natural grassland in Sichuan Province during the period 2006-2009 was estimated by combing the field survey and remote sensing monitoring methods. This study used the vegetation index (EVI) to establish the estimation model for predicting the yield of main grassland types by many times modification and verification. This estimation model was used to assess the grassland production during 2007-2009 in Sichuan Province, and indicating that the averaged unit yield of grassland was 4 752 kg/ha, the total palatable fresh forage yield was 8.391010 kg (equivalent to 2.531010 kg hay yield), and the theoretical stocking rate was 29.69106 sheep unit. This study further showed that the estimation yield from model was in accord to those from field survey in each region, and suggested that this model could be applied to grassland yield estimation in the large range scale in Sichuan Province.
To understand the soil animal communities of the frost soil regions in the upper area of Shule River, a field survey was carried out to investigate the largersize soil animals from different habitats during June to July, 2010. A total of 453 animals (belonging to 3 classes 9 orders 13 taxonomic groups) were identified in this study, in which the larval Coleopteran (beetles), larval Diptera and adult Coleopteran were dominant groups. Compared with former related record at other regions in the northwest of China, the quantity and diversity of soil animal in the upper reaches of Shule River was lower due to the extremely arid conditions. Although the species composition of the soil animals differed significantly in different vegetation types, the animal biomass and diversity had no obvious correlations with quantified vegetation indices (P0.05). The biomass, individual numbers and ShannonWiener diversity of soil animals was not significantly different between permafrost and seasonal frost (P0.05); however, the diversity in the transition zone of permafrost were significantly higher than those in the permafrost and seasonal frost (P0.05).
After discussion on the currently practiced animalfeed balance system, this study pointed out that the currently practiced animalfeed balance system suffered from the defeats of timedelay in reporting and missing of control target. Some unsuitable considerations for animalfeed balance control were also proposed and further commented. Finally, this study proposed some suggestions for improving the animalfeed balance control system, based on the local experiences and statistical data provided by the concerned local bureaus.
A field experiment was conducted to select the optimal pesticides from 24 pesticides for control Bazaria turensis. This study showed 10 pesticides among 24 pesticides performed well, and they were Pseudomonas pseudoalcaligenes SC, 10% Cyfluthrin EC, 25% Profenophos EC, 4.5% Cypermethrin EC, Gynaephora ruoergensis chou et yin Nuchear polyHedrosis rirus SC, 2.5% Deltarmethrin EC, 3% Cypermethrin EC, 5% CypermethrinAdmire EC, 1.8% Avermectin EC and 10% Imidacloprid WP, in which Pseudomonas pseudoalcaligenes SC, G.ruoergensis chou et yin Nuchear polyHedrosis rirus SC, and 1.8% Avermectin EC showed a lower toxicity and higher efficiency and long effective period, and they had the priority for controlling the larva of B. turensis. The 10% Cyfluthrin EC, 25% Profenophos EC, 4.5% Cypermethrin EC, 2.5% Deltarmethrin EC, 3% Cypermethrin EC, 5% CypermethrinAdmire EC and 10% Imidacloprid WP showed a faster control effect on B. turensis. Application of selecting 10 pesticides together postponed the time of pesticides resistance of B. turensis.
The successful experiences of colleges and universities in the United States of America (UAS) includes the stable systems of colleges and universities, responsible systems under democratic management, strict supervisory mechanisms of society, competitive mechanisms, social evaluation and feedback mechanisms, and so on. This study proposed some suggestions on the education reform of colleges and universities and the development of Pratacultural Science in China by learning lessons and advanced experiences from colleges and universities of USA.
As an alien invasive plant, Eupatorium catarium is paid attention to due to its ecological and economic impacts in China．The column chromatograph technology was used to determine the chemical constituents of E.catarium for providing useful information for reutilization of this alien invasive plant. In this study, 10 chemical constituents were isolated from E.catarium, and they were identified as quercetin（Ⅰ）、3Omethylquercetin（Ⅱ）、luteolin（Ⅲ）、apigenin（Ⅳ）、7,4dihydroxy5,6dimethoxyflavone(Ⅴ)、caffeic acid（Ⅵ）、friedelin(Ⅶ)、24ethyl5cholesta722(E)dien3one（Ⅷ）、Stigmasterol(Ⅸ) 、sitosterol(Ⅹ) by their physicochemical property and spectroscopic features. All these compounds were firstly isolated from the species and the compoundⅡ、Ⅳ、Ⅴ、Ⅷ were also firstly separated from Eupatorium genus. Except for compound V and compound Ⅷ, the other 8 compounds showed a utilizable value in medicine and agriculture, these would provide basic data for developing E.catarium products with high valueadded products.
The different proportions of Medicago sativa and Roegneria turczaninovii were ensiled to optimize the proportion of mixed silage by measuring the nutrition constituent, which was used to estimate fermentation quality. The results of this study showed that the silage increased the content of DM and NDF and decreased the CP, ADF, WSC of alfalfa products, and that the silage increased the content of DM, NDF, CP and ADF, and decreased the EE and WSC of R. turczaninovii. The CP and Ca content of mixed silage was significantly higher than R. turczaninovii silage and lower than alfalfa silage, and the content of DM, NDF, ADF was significantly lower than R. turczaninovii silage. As the proportion of R. turczaninovii increased in mixed silage, the pH decreased, and the content of lactic acid accounting for total acid in mixed silage was between two single silages. The content of acetic acid accounting for total acid in the mixed treatment of alfalfa and R. turczaninovii (3∶7) was 33.9%, and was significantly higher than other treatments(P＜0.05), and butyric acid in mixed treatment was little. The content of ammonium nitrogen accounting for total nitrogen in mixed silage was significantly lower than alfalfa silage(P＜0.05)，and was significantly higher than R. turczaninovii silage(P＜0.05). Counts of lactic acid bacteria in all treatments after ensiling reached 106 cfu/g（FM）, and was higher than nonensiling, and counts of lactic acid bacteria and mould in mixed treatments was high than two single silage. The score of fermentation quality of R. turczaninovii silage was 97, and the content of ammonium nitrogen was low; therefore, R. turczaninovii silage was optimal treatment.
The in vitro gas production technique was used to evaluate associate effects of mixed with two ruminants forages of silage cornstraw, alfalfa green hay and oat green hay with 0∶100, 25∶75, 50∶50, 75∶25 and 100∶0 in the Qinghai plateau. This study showed that 48 h gas production and theoretical maximum gas production were positively related to the content of NDS/CP(P＜0.001), OM(P＜0.01), NDS(P＜0.05), and negatively related to the content of ADF(P＜0.001), NDF(P＜0.05), CP(P＜0.05). Gas producing velocity were positively related to the content of OM(P＜0.001), NDS(P＜0.001), NDS/CP(P＜0.01), and negatively related to the content of ADF(P＜0.001), NDF(P＜0.001). The lag times of gas production were positively related to the content of ADF(P＜0.01), NDF(P＜0.05), and negatively related to the content of OM(P＜0.01), NDS(P＜0.05), NDS/CP(P＜0.05), and these results showed the fermentation level of combined forages in vitro gas production were mainly affected by the proportion of nonstructural carbohydrates and crude protein. When the forages are mixed, combination proportion of silage cornstraw and alfalfa hay by 25∶75, silage cornstraw and oats by 50∶50, alfalfa green hay and oat green hay by 50∶50 were relatively appropriate, and with the increase of fermentation time, associate effects quantity of each combinations showed a gradually decreasing trends.
Grass pea (Lathyrus sativus) is easy to become creeping due to thin and soft stem, which often causes the decomposition of lower leaf and stem. An experiment was conduct to determine the effect of humping support and pinching on the yield and of grass pea in this study. This study showed that the combination of the humping support and pinching significantly increased the yield and the pinching at the flowering stage increased the yield by 20.2%. The Spearman analysis result indicated that the branches per plant, one hundred seed weight, and pod number per plant were main factors affecting the yield. This also showed that the humping support and pinching increased the yield of grass pea by increasing the branch number of main stem and pod number per plant.