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2010 Vol.27(4)

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Continuously developing grassland animal husbandry of China
Jia-Wen LIU
2010, 4(4): 1-3.
[Abstract](2264) [PDF 409KB](689)
The development of grassland animal husbandry in China since 1949 was summarized and China has explored a way with Chinese features to develop grassland animal husbandry. Production level of grassland animal husbandry is continuously growing and more than 30 millions heads of livestock are provided; the structure of grassland animal husbandry production is steadily improving; the development foundation of grassland animal husbandry is more solid. Since 2000, more than 20 billion RMB has been invested for grassland protection. Grassland animal husbandry plays an important role in ecology security and economy development, and the environmental status in some areas has been obvious improved. However, affected by grassland ecological security, swine depended animal husbandry and development capacity in grassland area, the development of grassland animal husbandry is still facing the sever challenges. So, the existing problems and the opportunities should be seriously considered in order to enhance the development of grassland animal husbandry.
Discussion on popularizing the fundamental degree course in university
2010, 4(4): 4-6.
[Abstract](1364) [PDF 455KB](588)
Present study suggests that the academic degree system in China should sever its tie with diploma system, and modern scientific knowledge should break through the shackles of diploma system and gradually popularize through the fundamental degree course teaching. Students should enhance their ability from practice after they master the essential basic knowledge, and they can change their fate at low cost, which will pump fresh energy for China economy.
Effects of grazing intensity on species diversity and structure of meadow steppe community
Xiao-Meng JIN, Guo-Dong HAN
2010, 4(4): 7-10.
[Abstract](2180) [PDF 440KB](1161)
The Stipa baicalensisLeymus chinensis meadow was classified into light, moderate and heavy degradation plots according to the different degradation degrees caused by grazing. The plant community characteristics and diversity index in each plot were measured. Results showed that along with the increasing of grazing intensity, the total aboveground yield of community and middlexerophytes kept similar decreasing trend. That of mesophyte increased first and then decreased but xerophyte showed an increasing tendency. S. baicalensis and L. chinensis were the dominant species and showed a decreasing trend. Species richness index increased first and then decreased. The index of diversity and evenness kept increasing, but the dominance index was contrary.
Effects of grazing on soil organic carbon and total nitrogen in typical steppe
LIU Nan, Yang-Dun ZHANG
2010, 4(4): 11-14.
[Abstract](2220) [PDF 429KB](1139)
The contents of soil organic carbon (SOC) and total nitrogen (TN) under different grazing intensity (light grazing, LG; moderate grazing, MG; heavy grazing, HG; zero grazing and fence, CK) and system in the Leymus chinensis typical steppe near the Xilin River in Inner Mongolia were studied. The result showed that 1)the SOC content of the continuous grazing land was significantly higher than the mixed grazing pasture and the order in continuous grazing pasture was LG>HG>MG>CK. In the mixed utilization pasture, except LG+hay and MG+hay within 20 to 30 cm, the differences between different grazing intensity were not significant. The content decreased with the increase of soil depth. 2) In continuous grazing pasture, the variation pattern of soil TN was similar to SOC, i.e., LG>HG>MG>CK. In the mixed grazing pasture, the pattern was more complex, and the TN content was lower than that in continuous grazing pasture. The TN content decreased with the increase of soil depth. The result indicated that the SOC level in HG was higher than MG which might be caused by more C4 plants with the increasing of grazing intensity.
Current situation and ecotourism development of grassland nature reserve
AI Lin, Xin-Dan LEI
2010, 4(4): 15-19.
[Abstract](1584) [PDF 692KB](793)
Compared with the national nature reserves of other sectors, the number, area and effective utilization of grassland nature reserve were obviously poor. Based on the advantages in terms of large quantity, diverse types and promising market conditions of grassland nature reserve, the necessary of developing ecotourism were analyzed and 5 principles were offered for guiding the construction and management of grassland nature reserve.
Study on the distribution pattern of vegetation litter in fenced watershed in semiarid loess hilly and gully region
Zhong-Ai LIU, Qing-Ke SHU, Gao-Meng KUANG, WANG Jing, LI Ping, DIAO Hui, Lei-Lei- DIAO
2010, 4(4): 20-24.
[Abstract](1945) [PDF 540KB](810)
By determining the amount of vegetation litter in 60 plots in semiarid loess hilly and gully region fenced watershed under different habitat conditions, the affecting factors of the litter and its distribution pattern were studied. Results showed that there was a quadratic regression relationship between slope and litter amount, and the smallest value occurred at 25.5 degree. The litter amount of northern slope was 25.1% more than that of southern slope and that of northern gully was 41.7% more than that of southern gully. The aboveground biomass showed a significant positive relationship with the litter amount (P0.05). The relationship between litter amount and soil moisture was same. The litter amount was highly affected by soil moisture and aboveground biomass.
Population characters of Ligularia narynensis in Kalajun rangeland
LIU Dong, Sha-Zhou AN, Qiang-An KONG, Xian-Hua ZHANG
2010, 4(4): 25-29.
[Abstract](1482) [PDF 534KB](604)
The growth of Ligularia narynensis in Kalajun rangeland of Yili and its difference of sexual reproduction quantitive characters under enclosure and grazing conditions were studied. The result showed that 1) the important value of L. narynensis synchronously changed with its growth period; 2) the difference of population features (coverage, density, number of blooming plants and biomass) varied between enclosure and grazing conditions; 3) the difference of sexual reproduction quantitive characters was significant; 4) the inflorescence length was positively correlated to the plant height (the ratio between them is the sexual reproduction rate); 5) the size of individual plant was negatively correlated to the density.
Application of moving splitwindow technique in quantitative methodologies for edge influence of landscape boundary: a case study of Lespedeza potaniniiArtemisia ordosica community
Xiang-Feng SHI, Dong-Mei HU, Kai-Yang QIU, Ying-Zhong XIE
2010, 4(4): 30-33.
[Abstract](1832) [PDF 441KB](689)
Two transects were set up to study the Lespedeza potaniniiArtemisia ordosica community boundary in south edge of Maowusu Desert. The squared Euclidean distance coefficients of sampling plots along ecotone transect were applied in the moving splitwindow technique for edge influence of landscape boundary position and width in the area across the community. The result showed that while the split form was in size of 4 and 6 units of plots, the curves dramatically varied and the identification of landscape boundary was interfered. While the minimum size of splitwindow was 8 plots the landscape boundary could be properly identified. The emerging peaks appeared between plot 20 and plot 25 in Transect A and B. Therefore, moving splitwindow technique was an effective method for edge influence of landscape boundary and community classification and it was a satisfactory method to show the peaks and widths of communities in small scale.
Study the relationships between the soil and the original vegetationusing nalkane technique
Gao-Wen YANG, ZHANG Fan, Yang-Dun ZHANG, Han-Shu ZHOU, Li-Jun LIN
2010, 4(4): 34-39.
[Abstract](1749) [PDF 505KB](629)
The nalkane technique was used to study the nalkane concentrations in soil of degraded grassland in Bashang area of Hebei Province. The nalkane concentrations were contrasted with dominant species in undegraded grassland to explore the relationships between the soil and the original vegetation. The result showed that the nalkane concentration in soil of Achnatherum splendens plot, sword iris plot, mouse damaged plot and Stellera chamaejasme plot matched well with the nalkane concentration of Leymus chinensis, it could be presumed that the original vegetation of these degraded grasslands was similar with undegraded grassland. The nalkane concentration in soil in Artemisia frigida plot matched poor with the nalkane concentrations of L. chinensis and matched well with that of A. frigida, and it suggested that the change of nalkane concentration could reflect the vegetation change. The nalkane concentration was stable in soil and it suggested that the processes of soil degradation lagged behind the vegetation degradation.
Study on the characteristics of soil carbon accumulation and conversion of carbon sink and source of grassland under different land use types
Yu-Hua KONG, Feng-Jun TAO, FENG Shuang, LIU Yan, Wen-Han DONG, BAI Long
2010, 4(4): 40-45.
[Abstract](1851) [PDF 638KB](865)
Landuse change is the main affecting factor of soil carbon storage. It is very important to predict the trend of soil carbon release under different landuse patterns so that the soil carbon accumulation and conversion of soil carbon sink and source could be better understand. The organic carbon density and variation patterns of organic carbon storage within 0 to 30 cm soil layer of fenced grassland and grazing land in the southeast of Horqin sandy land were studied from May to November. The results showed that the soil organic carbon content of enclosed grassland decreased significantly with the soil depth, but not for the grazing land. Soil organic carbon density of the fenced grassland within 0 to 30 cm soil layer varied from 2.8 kg/m2 to 4.0 kg/m2. And it was from 3.4 kg/m2 to 4.7 kg/m2 for the grazing land. In general, it was the carbon source process from May to August and from September to November, and it was the carbon sink process from August to September for the fenced land. However, soil carbon storage of the grazing land was more stable, the conversion process of soil carbon sink and source was no significant. It suggested that the reasonable grazing utilization contributed to accumulation of soil carbon and could reduce carbon emission.
Study on characters of soil nutrition of perennial pasture
Wen-Bin DONG, Yu-Shou MA, Quan-Min DONG, Xiao-Di SUN, Jian-Jun SHI, Pan-Long WANG, CHENG Li
2010, 4(4): 46-50.
[Abstract](1679) [PDF 484KB](619)
The contents of soil nutrients of different types and planting times of perennial sown pasture established in grain for green project were measured. The result showed that the contents of soil organic matter, total N, total P, available N and available P decreased with the soil depth, in which, the variation range of total P was small. Compared to the control, the contents of soil nutrients of pasture were significantly increased within 0 to 10 cm and 10 to 20 cm soil layers (P0.05) and the soil nutrients were mainly accumulated in surface layer.
Effect of planting Suaeda salsa on improvement of dredger filled soil
Gui-Mei JU, De-Rong SU, Meng-Yong HUANG, LIU Hu, CA Fei
2010, 4(4): 51-56.
[Abstract](1746) [PDF 684KB](673)
Suaeda salsa was planted to improve the physical and chemical properties of dredger filled soil with 4 plots, the soil samples were collected one year later in layers of 0 to 5cm, 5 to 20 cm and 20 to 40 cm for measuring the physical and chemical properties. The results showed that the treatment could obviously increase the total porosity, reduce the bulk density and increase soil moisture content, while the soil surface water content was obviously increased. The desalination rate of treated soil in surface layer, intermediate layer and deep layer was 50.54%, 43.74% and 27.23% respectively. However, the salinity of the control increased in each layer. Soil organic matter, available nitrogen, available phosphorus, available potassium in treatment group were increased by 17.55 %, 5.03%, 20.54% and 1.49% respectively; and the number of bacteria and actinomycete in each layer was significantly increased and the number of fungi was increased only in the intermediate and deep layers.
Study on the landscape variation of the wetland around estuary of the Yellow River based on RS and GISA case study in Kenli County
Su-Juan TIAN, Wei-Feng CHEN, Su-Feng TIAN, Jin-Xie HU, Zhi-Hua ZHANG, Ru-Yang HOU
2010, 4(4): 57-63.
[Abstract](1891) [PDF 669KB](696)
Based on RS and GIS technologies, the LandsatTM image in 1987 and 2004 were used as data resource to study the dynamic changes of the wetland landscape around the estuary of the Yellow River with Markov model. The results showed that the area of the wetland reduced, especially the natural wetland, reeds, seashore and bottomland by the end of 2010. Compared to that in 1987, the corresponding area decreased by 2 724.7, 19 629.1, 23 737.2 and 3 269.1 hm2. The wetland landscape structure will reach a relatively stable status in the future, i.e., the natural wetland area will only account for 6.8% of total land area and it will be 19.17% for the artificial wetland area.
Evaluation of grassland resources in Jingtai county basod on 3S technologies
LI Yun, Lian-Beng SHU, Xin-Rong CHEN, Wen-Ding CHENG, Jun-Fu MA, Xin-Yuan LI, Xiao-Cun DU
2010, 4(4): 64-68.
[Abstract](1983) [PDF 540KB](638)
The TM image data and field survey were used to investigate and evaluate the grassland resources in Jingtai. The grassland was classified into 4 classes, 5 groups and 7 types based on RS, GIS and GPS technologies and the grass yield estimation model was setup with NDVI (y=0.433 5e0.028 5x, R2=0.56). The area of natural grassland and the theoretical carrying capacity were 391.8 millions ha and 73.5 millions sheep units respectively. The current situation of grassland utilization was evaluated to provide the information for planning, protection and sustainable utilization.
Preliminary study on prediction of green period of grassland in Qinghai Lake region
Yong-Lin WEI, Li-Meng SONG
2010, 4(4): 69-72.
[Abstract](1612) [PDF 477KB](712)
he grassland ecosystem in Qinghai Lake region is an important component of tourism resources.The green period of grassland would affect its utilization and management,which closely depends on the weather conditions. The long term meteorological data were used to predict the start and end date of green period of grassland and the prediction model was established as well. The results predicted with prediction model fitted the real situation and could be used in grassland utilization and management.
Effects of irrigation amount on alfalfa productivity in south of Beijing
WEN Xia, Xiang-Yang HOU, Fu-Ban MU
2010, 4(4): 73-77.
[Abstract](2048) [PDF 544KB](633)
Four irrigation treatments (0,25,50,75 mm per time, 3 times in a year round) were designed to study the productivity response of alfalfa planted 3 years ago in south of Beijing through measuring the yield, leaf to stem ratio, plant height in early flowering stage and dry matter of single plant of second and third harvests. The results showed that if enough water was supplied in last winter, the irrigation treatment did not affect the yield of the first harvest, but the second harvest, third harvest and annual yield increased with the irrigation amount. However, the yield of fourth harvest was reduced. Plant height in all harvesting times showed the same trend with the yield. In addition, the irrigation did not significantly affect the leafstem ratio of the first and fourth harvests. Stemleaf ratio and weight of single branch in the second and third harvesting times increased with the irrigation amount. Therefore, irrigation should be performed after the first and second harvests. it should not be irrigated at the growing period after third harvest and the stage of turning green if irrigated in last winter. The best annual irrigation amount was 150 mm while the rainfall in growing season was 390 mm.
Study on the effects of different row spacing of alfalfa on Cenchrus pauciflorus control
DIAO Yan, Lin-Wei LV, WANG Wei, Zhi-Song HAN, LU Yan, Xiang-Zhi LUO
2010, 4(4): 78-81.
[Abstract](2084) [PDF 499KB](762)
A biological treatment trial on effects of different row spacing of alfalfa on controlling seriously invaded Cenchrus pauciflorus was conducted. The results showed that the row spacing treatment could reduce the number of C. pauciflorus and the best was 30 cm which decreased the density to around 1 200 hm2. But the effects on the morphological and reproduction characteristics of C. pauciflorus were difference, these characteristics showed a stressed status in the treatments of 30 cm and 40 cm row spacing. It showed the lower height, fewer branches and seeds. But in treatment of 50 cm row spacing, the average number of branches was over 9, the number of seed setting was over 180 and the reproduction ability was still strong. It could be concluded that 30 cm of row spacing was the best for the control of C. pauciflorus.
Effect of three different mutation treatments on germination and seedling growth of Cichorium intybus cv. Puna seeds
Ceng-Zhen- WANG, Shi-Cu BAI
2010, 4(4): 82-88.
[Abstract](1874) [PDF 651KB](583)
The seeds of Cichorium intybus cv.Puna were treated by ray, NaN3 and space radiation and the seed germination and seedling growth characters were determined in laboratory. The results indicated that 60Co ray、NaN3 and space radiation showed stimulation effects. The order of germination index of 3 treatments was NaN3 60Co ray space radiation; as for main root length, it was space radiation NaN360Co ray; and for root fresh weight, it was space radiation 60Co rayNaN3; for stem and leaf fresh weight, it was space radiation NaN3 60Co ray.
Effect of drought stress on three physiological indexes in alfalfa seedling
Hua-Min HE, Tian-Meng HE, Pei-Zhi YANG, Wei-Ze SUN, Yun-Hua HAN
2010, 4(4): 89-92.
[Abstract](2342) [PDF 460KB](721)
The seedling of alfalfa (Golden Empress) were treated for 0 to 6 hours with the improved airdrought method and the AsA content, MDA content and POD activity in aboveground and underground parts were tested. The results showed that under the condition of slight drought stress in a short time, the MDA content and AsA content increased along with the progress of drought stress. The POD activity also increased in underground parts, however, there was no significant change in aboveground parts. The underground parts were more sensitive to drought stress than aboveground parts. The improved airdrought method was proper to simulate the drought stress conditions.
Study on pollen viability and stigma receptivity of three species of Allium
Jin-Hua DIAO, Jing-Feng LI, Ren-Tu-Ya NA, SHI Qin
2010, 4(4): 93-96.
[Abstract](2062) [PDF 482KB](698)
TTC (2,3,5triphenyl tetrazolium chloride) method, pollen staining method and BenzidineH2O2 method were used to study the pollination characteristics of 3 wild species (Allium mongolicum, A. polyrhizum and A. tenuissimum) in terms of pollen viability, pollen fertility and stigma receptivity. The results showed that all the 3 plants had high pollen viability and pollen fertility. Pollen viabilities were 73.40%2.94%, 71.23%4.39% and 80.62%4.11% for A.mongolicum, A. polyrhizum and A. tenuissimum, respectively, and the pollen fertilities were 79.44%2.83%,84.32%1.63 and 70.93%4.86% respectively. The pollen viabilities decreased quickly and pollen longevities were about 8 hours for 3 plants. Optimal pollination time was 3 to 4 hours after flowering. The stigma receptivity of 3 plants was around 5 days. Optimal rpollination period lasted around 2 days.
Cloning and sequence analysis of Actin gene fragment of Microula sikkimensis
 Tun-Chu-Juan, Yi-Gong ZHANG, Li-Jing ZHANG, FU Hua
2010, 4(4): 97-101.
[Abstract](1579) [PDF 744KB](646)
Total RNA of Microula sikkimensis was extracted from leaf. The actin gene fragment was amplified by reverse transcription polymerase chain reaction RTPCR and then cloned into pGEMT vector. The gene fragment was sequenced after identifying the positive clone by PCR. The results revealed that the actin gene fragment from M. sikkimensis contains 599 bp and encodes a protein of 199 amino acids. Similarity comparison with other actin gene sequence in the GenBank showed that it shared over 84% of nucleotide sequence similarity and over 95% of amino acid sequence similarity with other actin, which suggests that actin gene of M. sikkimensis was highly conservative.
Research and development of forage germplasm resource database based on GIS and VB.net
Meng-Hu ZHANG, Jing-Beng ZHOU, Qi-Qing FENG, WANG Wei
2010, 4(4): 102-105.
[Abstract](1852) [PDF 498KB](585)
Present study explained how to estabish the forage germplasm resource database in Qinghai Province through the utilization of Map Objects in Geographic Information System (GIS) software, the programming language of Microsoft Visual Basic.net 2.0 and ACCESS database system. The database was aimed to achieve the objectives of search, manage and print out of information on forage germplasm. And it consisted two components: the forage germplasm resource database which was for the data search, information display, report generation and print; and the spatial database which was for the search of geographic information.
RAPD analysis based identification of Dichondra repensgermplasm resources
FU Wei, Cheng-Bin TANG, Jia-Hai TUN, Xiao-Li WANG, You-Min AN, Jian-Bei ZHANG, CHEN Wei
2010, 4(4): 106-111.
[Abstract](1713) [PDF 567KB](824)
RAPD molecular markers were used to detect the genetic diversity among 16 materials of Dichondra repens with 22 primers which were selected from 100 random primers. The results indicated that there were 246 polymorphic loci out of totally 269 loci and the polymorphic rate was 91.45%. Genetic distance of D. repens was calculated by Nei method and it ranged from 0.0336 to 0.6097. The RAPD dendrogram suggested that 16 materials of D. repens could be divided into 3 groups at 0.74 of genetic distance, which could screen the excellent materials out and it was similar with the result of landscape evaluation.
Effects of solar light and temperature on fall dormancy of alfalfa in Beijing area
Da-Wei XU, Xin-Dan LEI
2010, 4(4): 112-116.
[Abstract](1564) [PDF 427KB](610)
The regrowth height of 11 alfalfa varieties with different fall dormancy rates were measured in order to find out the relationships of regrowth height with sunshine time and average temperature. The results showed that the fall dormancy of alfalfa appeared in October in Beijing. Photoperiod and average temperature showed impacts on the fall dormancy of alfalfa. The critical threshold conditions of different fall dormancy types were that the sunshine time was less than 11h and the average temperature was less than 7.8 ℃. The critical threshold conditions of different fall dormancy rates were that the sunshine time was less than 10.4 h and the average temperature was less than 7.8 ℃.
Adaptability and performance of C4 forages in northern subtropics
Dian-Chao HOU, Xiang-Lin LI, Li-Jiang MO, HE Feng
2010, 4(4): 117-121.
[Abstract](1736) [PDF 562KB](646)
In order to screen the high quality grasses adapt to northern subtropics, 4 gramineous grasses (Paspalum wettsteinii, Pennisetum clandestinum cv. Whittet, Setaria sphacelata cv. Narok and Brachiaria decumbens cv. Basilisk) were introduced and tested in Qiannan area from May to November in 2009. Under 5 times of clipping, the results indicated that the hay yields of B. decumbens cv. Basilisk and S. sphacelata cv. Narok were significantly higher than P. wettsteinii and P. clandestinum cv. Whittet (P0.05). The crude protein yield of S. sphacelata cv. Narok was the highest. The quality in vegetative stage was better than that in flowering stage. S. sphacelata cv. Narok was the best among the tested varieties.
Effects of long term interplanting forage on soil humus content in orchard
Xu-Hui LUO, Fu-Shui RUAN, Dun-Jie CHEN, DAN Jie, Xi-Xiang WANG, Yi-Bin HUANG
2010, 4(4): 122-126.
[Abstract](1769) [PDF 536KB](642)
Archis pintoi cv. Amarillo and Chamaecrista rotundifolia cv. Fuyinn No.1 were interplanted in hilly orchard for water and soil conservation in subtropical red soil region in Fujian Province in 1996. The contents of humus organic carbon and the combining between organic matter and minerals were measured in 2007. The results showed that the humus organic carbon content in surface soil (0 to 15 cm) of treatments interplanted A. pintoi cv. Amarillo and C. rotundifolia cv. Fuyuan No. 1 were increased by 2.56 g/kg and 1.90 g/kg respectively compared with the control (clean tillage). But the change of humus organic carbon content in subsurface soil (15 to 30 cm) was weaker than surface soil. The combining degree of original soil in surface was 83.09% to 96.75%, higher than that in subsurface (77.73% to 92.14%). And the increased combing degree in surface soil of interplanting treatments was 70.52% to 83.42%. Among different treatments and control, the order of combining degree was clean tillage interplanting A. pintoi cv. Amarillo interplanting C. rotundifolia cv. Fuyuan No. 1. The treatment of interplanting A. pintoi cv. Amarillo showed better performance than C. rotundifolia cv. Fuyuan No. 1, and the increased combing degree was 83.42% which was 12.9% more than latter.
Comprehensive analysis of salt tolerance of 30 introduced barley varieties or lines in seedling period
Song-Feng JIE, Aly Kansaye, Xiang-Gong DU, Xiao-Jun NIE, Gui-Yang FANG, Jian-Chao YANG, LI Kang-, Bao-Jun ZHANG, Wei-Ning SONG
2010, 4(4): 127-133.
[Abstract](2286) [PDF 617KB](634)
MDA content, SOD activity, CAT activity, Pro content and chlorophyll content, photosynthesis rate, stomatal conductance and transpiration rate were measured under different salt stress at seeding stage. Salt tolerance in 30 introduced materials of Hordeum vulgare was comprehensively analyzed by principal component analysis and subordinative function. The results showed that MDA content, chlorophyll content, photosynthesis rate, stomatal conductance and transpiration rate decreased with the increasing of NaCl concentration except SOD activity, CAT activity and Pro content. The sequence of salt tolerance for 30 materials was 22252230DH116TabighaModaba2255DH552228TarpgolborKoRvKHEMUSSteptoeHarringtonClipperJrbidCpyrusDH66PriorMorex2243TObarleyBarbican2242DH40SchoonerDH127KerabSloopYahudiyaDH126.
Study on proline accumulation patterns of six plantspecies under adversity stress
Min-Xia LIU, Jian-Jie MA
2010, 4(4): 134-138.
[Abstract](1754) [PDF 595KB](779)
The accumulation and variation patterns of free proline in 6 plant species (Potentilla fragarioides, Leontopodium nanum, Kobresia humilis, Oxytropis kansuensis, Stellera chamaejasme and Potentilla fruticosa) distributed in subalpine meadow of Gannan were studied at different environmental gradients. The results indicated that along with the change of environment (including soil water, temperature and sunlight) from the shade slope to sunlight slope, the concentration of free proline in leaf of 6 species increased in certain degree. The increasing range of free proline concentration among different species was different. The contents of praline could be used as an indicator for the resistance of plant.
Seasonal changes of soluble sugar contents of Dactylis glomerata in mowing pasture under different intensities of simulating grazing
Rong-Hua ZHANG, Mo-Lin WANG, Sha-Zhou AN, Qing-He SU, LI Hai
2010, 4(4): 139-143.
[Abstract](1951) [PDF 549KB](740)
The different simulatant grazing intensity were designed on Zhaosu Horse Farm to study the change of soluble sugar contents in roots and leaves of Dactylis glomerata in mowing pasture. The results showed that the soluble sugar content in leaf was increasing before the cutting. It was high after returning green but low after heading stage. The roots of soluble sugar contents on growth prophase was not significant (P0.05). It was rapidly decreased after cutting, and then raising up until late September. The coimpacts of season and grazing intensity on the soluble sugar content were significant (P0.01). The effect of the grazing intensity on the soluble sugar content was significant, but its affecting patter was not obvious due to season and climate.
Impact of cutting frequency on the productivity of Medicago sativa cv. Zhaodong
XU Hui-, LIU Rong-, Hui-Jing- LIU, Guo-Wen CUI
2010, 4(4): 144-148.
[Abstract](1894) [PDF 539KB](702)
Cutting is the main harvesting way for alfalfa and the cutting frequency affects not only the hay yield and quality but also the overwintering rate. Medicago sativa cv. Zhaodong is the main variety in Harbin and it is important to determine its cutting frequency for the alfalfa production. In twoyear cutting experiment, the hay yield, crude protein yield and overwintering rate were measured. The data of different cutting treatments were comprehensively evaluated by the gray relevancy analysis method. The results indicated that the proper cutting frequency in Harbin was 2 times per year. The correlation analysis result indicated that the cutting frequency significantly negative correlated with the productivity.
Methods for maize top rot sampling and its economic loss assessment
MENG Fei, Mo-Cang LI, Hui-Qin GENG, YANG Feng
2010, 4(4): 149-153.
[Abstract](1772) [PDF 525KB](866)
The field survey on occurring rate of maize top rot of 24 varieties (lines) and the evaluation of their resistance with cluster analysis methods were conducted. The results showed that all varieties could be clustered into 5 diseaseresistant groups, which was similar to the field survey. The disease occurring rate of diseases which do not cause no harvest (including maize top rat) could not be directly used as the crop loss rate or to calculate the economic loss. It was proper to sample and determine the theoretical yield according to the disease level of crop varieties with different disease resistant levels. The correlation between the theoretical yield and actual yield was not significant by 2 test and this suggested that the methods for the survey sampling and assessment of crop yield loss were practical.
Some thinking on grass culture
Ke-Chang LI
2010, 4(4): 154-159.
[Abstract](1564) [PDF 862KB](670)
As one of basic objects which the human social activities dealing with, the grass has been utilized in various social activities and the grass culture has been developed at the same time. During this developing progress, other types of cultures were formed and developed which promoted by the grass culture, and then to be an important part of Chinese culture and even the world culture. The concept, connotations, types, boundary, features, development history and research methods of grass culture were introduced and discussed in this paper.
Guiding role of the theory of four production levels of pastoral agriculture ecological system on sustainable development in Subei County
Yong-Jing CHAI, Zhi-Zhong CAO
2010, 4(4): 160-164.
[Abstract](1863) [PDF 705KB](683)
The grassland pastoral ecosystem is characterized by four production levels, i.e., preplant production level, plant production level, animal production level and ultrabiological production level. The productivity of the system could be enhanced through closer coupling between different levels. The theory plays an important guide role to sustainable development of pastoral area. Properly dealing with the relationships among the four production levels could promote the social transformation of animal husbandry in pastoral areas (from traditional extensive livestock production to modern intensive livestock production). The theory is also important for the ecological civilization of rangeland, harmonious development between human and nature and the sustainable development of economy and society.