Display Mode： |
The meadows in Dongling Mountain are classified and ranked into 7 communities by TWINSPAN, DCA and CCA that are located at different elevation. The results of the classification and ordination reflect the good relationship between plant communities and environmental gradients that is verified at the twodimension ordination diagram by DCA. The axes of the ordination by DCA reflects the gradient changes in the elevation, the gradient and the number of garbage that altitude, water and heat conditions, the tourism disturbance on plant communities are the major changes in ecological factors. The results of CCA and DCA results are basically the same.
Taking Ewenke Country of Inner Mongolia where the Project of Returning Grazingland to Grass was conducted as the example, the impact of the project on the economic and social efficiencies was studied. The result indicated that total gross value of social product, gross value of products from agriculture, forest, animal husbandry and fishery and the average net income of herdsman increased by 22.9%, 30.6% and 6.9% respectively after the project was carried out. The net benefits of unit area grassland increased 28.69%; the income of the project family from animal production increased by 5.82%, and the cost decreased by 11.70%. The animal husbandry profit of household was also affected by the household itself. In which, the grassland resource and labor showed notable effect. The standardized coefficient of the accessible grassland area reached 0.461. Meanwhile, the experience of leaders and the educational level of headers affected the profit from animal production as well.
The data of ＞0 ℃ annual accumulation temperature (AAT), the annual precipitation (AP), altitude and latitude of 50 meteorological stations from 1971 to 2006 in Qinghai were analyzed and the model for estimating AAT and AP was established. Based on the model and altitude data, the AAT and AP values were obtained by interpolating under the GIS environment, and the resolution was 4 km 4 km. The moisture index of each grid was calculated. And then, the grassland type of every grid was determined by the Integrated Orderly Classification System of Grassland (IOCSG). The results showed that there were 18 classes. In which, the area of frigid perhumid rain tundra and alpine meadow was the most and accounted almost half of the total area of grassland in Qinghai.
As an important ecological variable, the grassland fractional coverage is used in meteorological and ecological analysis and modeling. The precision of the grassland fractional coverage estimation deeply affects the precision of related studies. A number of methods which are used to estimate the grassland fractional coverage and the different opinions were reviewed and analyzed. Focusing on the remote sensing technology, the existing remote sensing based estimating methods were reclassified in order to clear the basic thoughts for estimating the grassland fractional coverage. Moreover, the features, advantage and shortage of each method were analyzed as well.
Annual plant is an important and special eremophyte component with rich species diversity in Hexi Corridor. Based on the survey, there are 142 annual plant species belonging to 81 genera and 25 families in Hexi Corridor. Because of the harsh arid desert environment, the annual plant concentrates in a few families, such as Chenopodiaceae, Cruciferae and Gramineae etc. The distribution features obvious geographical, seasonal characters, and the distribution characters varies in different ground substances and different geological features.
Perennial sowthistle（Sonchus arvensis）was used to evaluate its biological characteristics, forage yield and nutrient contents. The results showed that sowthistle was root sprout plant and presented leaf cluster from 20 April to 10 May after returning green. Branches of first class grew from rootstem, while branches of second class were developed from leaf axil, and the branch number of the rootstem was usually 8 to 15 (some were 19 to 22).The plant height was 98.1 cm after blooming, the highest ones reached 120 cm. Its bearing stage was around 120 days. Hay yields of branching stage, budding stage and blooming stage were 1 165.0 kg/hm2, 2 912.6 kg/hm2 and 3 699.8 kg/hm2 respectively. The dry matter based contents of crude protein and crude fat were 21.99% to 36.42% and 20.40% to 30.45% respectively. The contents of neutral detergent fiber and acid detergent fiber were 21.99% to 36.42% and 20.40% to 30.45%. Contents of calcium and phosphorus were 1.95% to 2.45% and 0.15% to 0.28% respectively.
The dry seeds of 8 alfalfa varieties embarked by satellite Shjian 8 were used to study the cytological effect and the results indicated that the mitosis of root tip cell was increasedl, the biological damage of mitosis was increased and Longmu803 was the highest, Caoyuan 1 was the lowest. At the same time, there were different chromosome aberrations in root tip cells, including chromosome fragment, dissociative chromosomes, chromosome conglutination, lagging chromosome etc, the chromosome fragment was the main aberration type. The chromosome aberration rate of Pleven 6 was the highest and Zhaodong was the lowest. It could be concluded that Pleven6 was the most sensitive and Zhaodong was the most inactive varieties.
The relationship between morphological characters (caulis length, internode number and internode length) and fiber content (NDF and ADF) of alfalfa was studied for breeding purpose. The results indicated that the differences of morphological characters, NDF and ADF contents among varieties were significant (P0.05). The coefficients of variation were internode length (29.91%)number of caulis and lateral branch (22.45%)caulis diameter (20.82%)number of lateral branch (19.76%)number of internode (12.57%)caulis length (8.87%)ADF content (4.18%)NDF content (3.24%). The caulis length positively correlated with NDF and ADF contents. Number of caulis and lateral branch positively correlated with ADF content. The rest characters did not show significant relationships with ADF and NDF contents.
The effect of nitrogen and phosphorus fertilizing on quality of red clover (Trifolium pretense cv. Minshan) hay was studied. The results showed that the highest CP and Ca contents were obtained under the treatment of A3B2 and they were 2.5% and 0.14% higher than the control respectively. The highest CA and P contents were obtained under the treatment of A1B3, and they were 1.2% and 0.45% higher than the control respectively. The lowest ADF and NDF content were obtained under the treatment of A1B2 and A1B3 and they were 2.1% and 1.5% lower than the control respectively. Among all treatments, A3B2（N 150 kg/hm2,P2O5 120 kg/hm2）was the best treatment and it had the best hay quality.
Eragrostis pilosa is an important variety of forage and turfgrass. The systematic research works in many countries have been conducted. However, few works were done in China. The research works were mainly focused on seed development and resistance in China. The seed development, utilizing patterns, cultivation methods, drought resistance, effect of nitrogen application rate on yield, photosynthetic characteristics, genetic diversity and so on were conducted in countries out of China. In this paper, the research progress both domestic and abroad on E. pilosa was summarized in order to provide necessary information for improving the research work in China.
Process and control of desertification in Minqin County is one of principal models in China and even in the world. In history, there is an obvious one to one correspondence between acceleration of land desertification and large scale land reclamation, which mainly results from competition and integration of specialized animal production (grazing) and specialized crop production (planting). Based on the spot investigations, analysis of literatures and field experiments, three main problems of current agriculture in Minqin County are summarized as follows: 1) deterioration of environment, mainly including the critical shortage of aboveground water with flow break of Shiyang River, dramatic decline of water table and deterioration of ground water quality; 2) unreasonable planting structure of crop production, mainly including poor crop biodiversity, indiscriminately profit seeking without limitation of water resource utilization and high risk of desertification and the frequent replacement of cash crops; 3) low level of technical support to agroecosystem, including no extension of water saving irrigation, undesirable effects of some high techniques, deficient integration of agricultural systems between desert area and oasis area, unsystematic coordination among all kinds of desertification control measures. Consequently, establishment of pastoral agriculture systems could play a key role in control of desertification in Minqin County through adaptively integrating crop production with livestock production in the light of ecological, productive and economic principles of agricultural structure optimization.
Effects of different allocation patterns of vetiver (Vetiveria zizanioides) and Amorpha fruticosa for slope protection on plant community characteristics were studied from 2005 to 2006. The results indicated: 1) A. fruticosa monocropped pattern increased the number of the plant species, but for V.zizanioides monocropped for pattern on the northfacing slopes, it rejected other plant species. 2) The vetiver dominance was significantly negatively correlated with the community diversity and evenness index but positively correlated with the community ecological dominance index. 3) The role of vetiver was more important than A. fruticosa in intercropped communities, and it was affected by both slope aspect and A. fruticosa. 4) Southfacing slope was proper for the development of vetiver population, but northfacing slope was not. A. fruticosa developed taller, larger stem diameter with less tillers on the southfacing slopes, and it was opposite on the northfacing slopes. 5) In the intercropping community of vetiver and A. fruticosa on the southfacing slopes, A. fruticosa performed better than vetiver and monocropped A. fruticosa, and it was opposite on the northfacing slopes.
The alfalfa growing for 1, 2, 3, 4 and 6 years on experimental farm of Inner Mongolia University for Nationalities were used to study the yield variation and the content of N, P and K in soil. The results showed that the yield decreased along with the growth year and the yield in second year was the highest. The content of total N, available N and P increased along with the growth year. The total P increased at the beginning and then decreased, available K and total K decreased. Nutrient contents within 0 to 40 cm soil layer decreased as the depth increasing. The nutrient contents within 40 to 50cm soil layer were higher than those in 30 to 40 cm layer.
The study on the dynamic plant community characters of recovering degraded steppe under different land preparing methods was studied in southern Ningxia by surveying the fixed sample plots. The results indicated that the heterogeneity of habitat affected the plant community structures with land preparing method of fishscale pit at certain temporal scale. The rest land preparing methods had a little effect on plant community structures. The order of plant diversity in 3 sample plots was fishscale pit 88542 level furrow enclosed natural steppe. As for the enclosed natural steppe for 5 years, the fishscale pit and level furrow methods had a little effect on the plant community and the natural ecological factors had a greater effect.
The most critical factor for wetland restoration is the surface water and the artificial precipitation enhancement is one of direct ways to gain water resources at present. Based on the experimentation data and experiences in Yushu of Qinghai Province, the technical feasibility of artificial precipitation enhancement for the wetland restoration was analyzed. The results indicated that the effect of artificial precipitation enhancement on rainfall, wetland biomass and the soil moisture was significant. The precipitation, forage yield and soil moisture within 0 to 10 cm were increased by 10.73% (or 33.8 mm), 9.02% (or 10 g/m2) and 39% respectively.
The demands and optimum proportion of N, P and K of hybrid Pennisetum purpureum cv. Guimu No.1 grown in field bund were studied with 3414 design. The results showed that its response to formula fertilizing was good. Among the treatments, the best one is N2 P2 K2 (N 414 kg/hm2, P2O5 138 kg/hm2, K2O 276 kg/hm2) and its yield was the highest [(256.811.18） t/hm2], and the difference with the low level treatments was significant (P0.01). The yield was increased by 16.6% compared with the check. Based on the analysis of the effect prediction model, the estimated highest yield was 259 t/hm2 and the relevant fertilizing formula was 414 to N 621 kg/hm2, P2O5 140 kg/hm2 and K2O 204 kg/hm2. The best economic formula wasN 414 kg/hm2, P2O5 140 kg/hm2 and K2O 172 kg/hm2, and the relevant yield was 256 t/hm2.
Conventional tillage management in orchard features the laborintensive, fertilizer costing, bare ground in winter and dust in spring. The technology of natural grass cover could increase soil organic matter content, reduce evaporation, increase drought resistance, improve peach quality, save labor and reduce environmental pollution. The survey results in Pinggu shown that the soil organic matter content was increased by 10.4% to 38.1%, the single weight of peach was increased by 2.8% to 5.4% and the soluble solids in peach was increased by 0.65% to 1.35%.
The stochastic exponential growth model and birthdeath process model were established to analyze the extinction risk and population viability with detected data of wild Pere Davids deer populations. The first model showed that the stochastic factors performed a significant impact on population dynamics. The probability of extinction gradually increased as the increasing of variance. It had little effect on the probability of extinction to keep stocking a small number of deer under the condition of stable variance. In addition, the calculated population doubling time was 10 years with birthdeath process model while the birth rate was 16.13% and the death rate was 7.13%. At the same time, the population doubling time on 95% confidential level was calculated with different fertility and mortality.
In the formulation of rations and the feed evaluation systems it is assumed that nutrients from different feeds are additively on the base of their assigned nutritive value, irrespective of feeding level or other components of the diet. However, these assumptions are not always valid because there are interactions in the digestibility or in the efficiency of the utilization of dietary energy caused by mixing the components of the diet. The interactions of feeds can affect the nutritive value, so the additivity is not always effective. Interactions among feeds are of economic importance but they can rarely be identified by conventional analyses of feeds. This emphasizes the need to make greater use of animal based feed evaluation systems and to manipulate the interactions correcting the negative ones and exploiting the positive ones, when developing livestock feeding systems based on the imbalanced feed resources (crop residues and byproducts) available in China. In this paper the associative effects of feeds on the digestion of nutrients and the balance among absorbed nutrients as well as the possible mechanism of these effects were discussed.
In order to understand the resource allocation pattern under clipping and grazing conditions, the biomass of root, stem, leaf and flower (seed) of Seriphidium transiliense was measured. The results showed that the clipping treatment increased the biomass allocation to root but reduced that to stem and leaf, and with the increase of clipping intensity the ratio of biomass allocation to root increased by 8% to 20% with the increasing clipping intensity, the ratio to stem and leaf relevantly decreased by 5% to 14% and 3% to 6% respectively. The grazing treatment showed the same impact. The biomass allocation pattern was root stem leaf flower (seed), the biomass allocated to root accounted as much as 45% to 67%, and biomass for sexual growth was less than 1%. The priority of biomass was given to reserve organ (root) under clipping and grazing conditions.
By analyzing the correlation between the area of grasshopper occurrence and 74 characteristic indexes of atmospheric circulation in Xinjiang from 1986 to 2003, the factors of atmospheric circulation which were significant related with grasshopper occurrence were selected. And then, 4 models for predicting the area of grasshopper occurrence were established by using the successive regression and tested. The area of grasshopper occurrence in Xinjiang from 2004 to 2006 were predicted with these models, then the predicted and actual results were compared and a model, its accuracy rate for prediction was more than 85%, was selected. Meanwhile, the relationship between the factors of atmospheric circulation and the area of grasshopper occurrence were analyzed.
The allelopathy between weeds and alfalfa were studied andthe results showed that Calamintha graclis, Cerastium sp., Alopecurus aequalis and Youngia japonica showed allelopathy to alfalfa. The seed germination of alfalfa treated with soak solution of C. graclis was significantly lower than that of the control; A. aequalis had a significant negative impact on seedling length of alfalfa; both the seed germination and seedling length of alfalfa treated with the soak solution of C. sp. and Y. japonica were lower than those of the control. The allelochemics of C. graclis, C. sp. and Y. japonica, A. aequalis were water soluble and ethanol soluble respectively. The response of different alfalfa varieties varied, FGC901 was more sensible than GT 13R+FD8.
Scince Eichhornia crassipes has been a disaster in southern China, its occurrence pattern in Chuanzihe River was studied for finding the reasonable and economical control techniques. The result indicated that the main biomass was got from June to mid September and affected by the climate and water conditions, it was also affected by the water pollution level because its biomass in heavily polluted Chuanzihe River was higher than that in lightly polluted pools.
The morphological characters and ISSR of 14 materials, including variants, control and other cultivars of Cynodon dactylon, were analyzed. The results indicated that the difference of internode length was significant between variants and the control, and the difference of internode diameter were also significant except HN016. The green period of HN015 was longest and HN010 was shortest. Ten primers were screened from 38 arbitrary primers of ISSR, 14 genomic DNA of C. dactylon materials were amplified, the results showed that the genetic similarity was from 0.585 to 0.776 between variants and the control and their genetic variability was remarkable.
The dynamic variation of nitrogen and phosphorous movement in soil of golf course which is close to Tiegang Reservoir in Shenzhen and its impacts on water quality were studied under simulative conditions. The results indicated that the eluviated matters shown little impact on pH of water. The eluviating speed of organic matters in soil was very slow but it was fast for phosphorus and along the time the phosphorus was absorbed by soil. Nitrogen in soil could be rapidly eluviated than phosphorus. The total contents of nitrogen and nitrate increased gradually along with the time, which were three times more than that of water in the reservoir. Considering the low content of nitrogen and phosphorus in submerged soil, as well as the practical conditions and the natural factors in the time when the reservoir was submerged, the reservoir will come to a new dynamic balance after water was stored through water cycling. So it could be concluded that the eluviated nitrogen and phosphorous from soil of Shenzhen Tycoon Golf Course would not negatively affect the water quality of Shenzhen Tiegang Reservoir.
The competition between zoysia and overseeded perennial ryegrass was studied in Xian, a representative city in north transitional climatic zone, from April to May in 2008 through observing the dynamic change of coverage and density of zoysia and perennial ryegrass. The results indicated that the community pattern of overseeding compound community changed in 2 periods. From April to June, zoysia replaced perennial ryegrass and became the dominant species gradually. After September, the coverage and density of perennial ryegrass increased gradually and became the major species again. Pick and Bige were suitable perennial ryegrass varieties for overseeding and 3.5 g/m2 was the suitable overseeding rate. The competition was mainly affected by the turfgrass genetic characteristics and the external environment and the temperature played a critical role. High frequency and short stubble of mowing changed the light and shadowing conditions and strongly influenced the competitiveness of turfgrass.
Along with the fast development of express highway, a large area of slope became bare and it results in water and soil erosion. Spray seeding could achieve threedimensional greening with shrub and grass. Taking Nanjing Changzhou Express Highway (Section in Nanjing City) as the example (where the gradient of rocky slope was 60 to 700 degrees, the average height was 20 m and the ground substance was very hard), the materials, equipments, key techniques and construction standards were summarized. It could be concluded in this example that spray seeding was an efficient approach to rapidly establish vegetation cover on rocky slope.
The typical black soil beach type of heavily degraded grassland in Zeku was selected as the sampling area to study the integrated improving approaches from 2006 to 2007. On the basis of fencing and rodent control, the degraded grassland was treated with 4 methods, including a) plough + clean culture with perennial grass, b) plough + mixed grasses sowing, c) heavily harrowing + mixed grasses sowing, d) enclosure. The integrated approaches were provided as follows: rodent control, organic manure application, plough, chemical fertilizer application, grass sowing, harrow and enclosure.
The origin and development of university course of Grassland Management in animal husbandry developed countries and the development history in China were reviewed and the current situation was analyzed. The view for the course reform was provided based on the purpose of high education. Taking the teaching experience in Shenyang Agricultural University as an example, the construction, reformation and development of Grassland Management were introduced.