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The relationships between grazing managements and soil carbon, nitrogen, phosphorus storage and their variations were studied in the degraded alkali-saline grassland by comparative study between fencing and grazing on time series. The results showed that aboveground biomass of degraded grassland decreased by 10.3%, 52.6% and 80.7% after 5, 6 and 8-years continuous grazing, respectively, however, the aboveground biomass of degraded grassland increased by 33.9%, 72.4% and 92.2% after 5, 6 and 8-years fencing, respectively. The underground biomass had similar response with aboveground biomass to grazing managements. Continuous grazing increased the soil pH and bulk density and reduced soil nutrient concentration whereas fencing reduced soil pH and bulk density and increased soil nutrient concentrations. With fencing, organic carbon and total phosphorus storage in surface layer soil gradually increased, however, total nitrogen storage firstly decrease and then increased. With grazing, soil carbon, nitrogen and phosphorus storage in surface layer soil all firstly increased and then decreased. After 5 years for fencing, the soil carbon, nitrogen and phosphorus storage was lower than grazing due to decreasing soil bulk density. The soil organic carbon significantly responded to aboveground biomass which suggested that the aboveground vegetation can be used as an effective indicator for soil carbon storage.
Precipitation is one of the key factors that influence the soil respiration. A simulated precipitation experiment focused on effects of precipitation on soil respiration was conducted in the steppe in southeastern Gansu Province in 2012. The results showed that: soil respiration rate (Rs) increased sharply after 15 mm and 30 mm precipitation and Rs was 9.0 times and 10.3 times higher than that of no-precipitation treatment in sunny aspect. Rs of grassland with 30 mm precipitation was higher than that of with 15 mm precipitation significantly (P0.05). In shady aspect of grassland, Rs increased 5.2 times and 8.0 times compared with no-precipitation treatment when precipitation was increased 15 mm and 30 mm, respectively. None significant differences of Rs were found between precipitation and no-precipitation treatments after 5 hours. Soil CO2 emissions were increased 2~3 times after the precipitation. The excitation effects of precipitation on Rs should be considered when evaluating the amount of CO2 emitted from soil. It is essential to adjust the soil CO2 emission data based on precipitation.
The distribution and relationships of the ground vegetation, soil seed bank, soil water content and the effects of micro-landform on types of species, species density, diversity and similarity of soil seed bank and aboveground vegetation were studied by investigating the ground vegetation, soil seed bank and soil water content in different micro-landform units of fixed sand in Yanchi desert steppe. The number of species, density, similarity, the soil seed bank species richness index and the soil water content, ground vegetation, soil seed bank decreased in the following order: Bottom slope＞Lower side slope＞Middle side slope＞Upper side slope＞Crest slope. The soil water content, ground vegetation and soil seed bank are significantly positive interrelationships(P0.05). The soil seed bank species diversity index and uniformity coefficient showed a fluctuated with slope position.
In order to study the influences of salt tolerant plants on the saline soil, field experiments were conducted to investigate the pH, water-soluble salt, soil nutrient in growing season of Sesbania cannabina, Medicago sativa, Sorghum sudanense, Suaeda salsa in coastal saline soil. The pH of soil with four different salt-tolerant plants increased compared with the soil without plants. Four tested plants treatments have obvious function of restraining salt accumulation in 0―20 cm soil layer. The average reduced salt percentage in 0―20 cm soil layer compared with control without plants was 37.12%～45.97%. Soil organic matter, available nitrogen, available phosphorus, available potassium content compared with control without plants increased by 3.45%～15.5%, 1.37%～22.2%, 13.7%～18.5%, 0.76%～4.30%, respectively. The cultivation of salt tolerant plants has positive effects on improving soil fertility level. The effects of fertilization and plowing treatment on soil nutrient were better than the single plowing treatment although both of the two treatments were significantly better than the control.
The maximum entropy (MaxEnt) species distribution model combined with the existing geographic distribution record of alfalfa was employed in the present study. Ten variables correlated with growth of alfalfa (Medicago sativa) were selected for analysis which included 7 climate variables (annual precipitation, global radiation, temperature of the coldest month, mean annual temperature, the lowest temperature of green period, average temperature in August, air humidity in August) and 3 three soil variables (soil pH, soil thickness, soil organic matter content). The percent contribution of variables for alfalfa suitability and the dominant factors were calculated by Jackknife module of maximum entropy model. The results showed that AUC value of training data and test data were 0.913 and 0.889, respectively, which reached in “Accurate” level. Maximum entropy model can simulate the geographical distribution of alfalfa. The most suitable area(P＞0.50) for alfalfa cultivation were 9.8×103 km2 which mainly distributed in the south and southeast Xilin Gol and accounting for 7.7% of the total area. Meanwhile, our study also showed that the dominant factors affecting the geographic distribution of alfalfa were annual precipitation, temperature of the coldest month, the lowest temperature of green period, air humidity in August.
The characteristics of original spectra, spectra without envelope and the first derivative spectra of 8 desert range plants which growing well on the Seriphidium transiliense degradation desert were analysis and compared in the present study. For spectral reflectance characteristics, there were significant differences among different plants at a specific band with a maximum different value of 40% in reflectance between 760 nm and 930 nm. The reflectivity decreased in the following order: Seriphidium transiliensePolygonum aviculare＞Peganum harmala＞Eragrostis pilosa＞Petrosimonia sibirica＞Trigonella arcuata＞Ceratocarpus arenarius＞Petrosimonia sibirica. The maximum moisture absorption spectral reflectance values was 27% near 1400 nm and the value decreased in the following order: S. transiliense＞K. scoparia＞C. arenarius＞E. pilosa＞P. aviculare＞T. arcuata＞P. harmala. The red edge position (P) of P. aviculare was 708 nm and the values of the other seven plants were same as 718 nm. The amplitude (K) of S. transiliense, P. aviculare, P. harmala, E. pilosa, K. scoparia, T. arcuata, C. arenarius and P. sibirica was 0.925 4, 0.685 4 , 0.799 8, 0.441 6, 0.183 9, 0.538 7, 0.132 7 and 0.188 5, respectively. Spectral red edge and peak and valley characteristics without envelope were more clear and obvious compared with the original spectral curves which suggest that the first derivative played an important role in accurately extracting the Red edge parameters of spectrum characteristics of grassland plants.
Changes in land-cover and landscape pattern are significant components of studies on ecological and environmental changes within nature reserves. Here, we applied change rate and transform matrix model with GIS to analyze Huihe nature reserve land-cover, based on 4 periods of Landsat TM images during 1995-2010. Then, we studied landscape pattern changes with a set of landscape indices such as mean patch area and cohesion index. The results showed that high coverage grassland and marshland are major land-cover types within Huihe nature reserve, which all decreased from 1995 to 2010 (-379.38 km2 and -39.25 km2). As to the landscape pattern, all landscape indices of high coverage grassland and marshland fell down, especially the mean patch area index and average shape index of marshland. Considering the changing periods, the degradation of land-cover and landscape pattern mainly happened from 1995 to 2004, whereas it slowed down after 2004. Our results approved that the situation of the grassland and wetland had changed better because of the establishment of national administration, as well as improving management actions.
Eight plants of Crassulaceae and Commelinaceae were evaluated by measuring their morphological changes, soil water content, leaf relative water content, electrolyte osmotic rate, malonyldialdehyde (MDA) content, superoxide dismutase (SOD) activity and water soluble carbohydrate content under the simulated drought condition. The eight plants were Sedum lineare, Sedum alfredi, Sedum emarginatum, Sedum polytrichoides, Setcreasea purpurea, Tradescantia spathacea, Murdannia loriformis and Callisia repens. The physiological and biochemical indices performed differently after stress in which soil water content and leaf relative water content decreased, electrolyte osmotic rate, MDA content and water soluble carbohydrate content increased and SOD activity increased firstly and then decreased. The comprehensive evaluation using membership functions showed that the order of drought resistance from strong to weak was Callisia repens＞Sedum lineare＞Sedum polytrichoides＞Tradescantia spathacea＞Sedum alfredi＞Setcreasea purpurea＞Sedum emarginatum＞Murdannia loriformis. The plants had little changes after 14 days water stress and can restore after 35 days water stress when it regained watering which suggested that the plants could be used as lawn-style roof greening materials in Guangzhou area.
Ornamental grasses are new superior landscape material with high ornamental value, ecological effects, low cost of management and protection, strong resistance and widely used in China nowadays. In the present paper, the application of ornamental grasses in the golf course was reviewed and some common species in Gramineae and their characteristics were summarized. The existing problems for the application of ornamental grass in golf course were analyzed to provide theoretical reference for researches about ornamental grasses applications. Ornamental grass can be widely used in sub rough area, the cart path side, lakeside and other landscaping areas. However, the biological invasion, ecological balance and other issues should be paid more attentions.
The allelopathy of aqueous extracts of 44 different garden plants and volatile oil of Mentha haplocalyx which was the strongest allelopathic plant on radish (Raphanus sativus) were studied in Petri dishes in laboratory. And the allelopathy of Magnolia denudata was validated through pot experiment. Meanwhile, the effects of several in vitro allelopathic testing methods were compared in the present study. M. haplocalyx, M. denudata and Pterocarla stenoptera had the strongest allelopathic inhibitory effects, and the synthetic effect (SE) were -0.72, -0.65 and -0.38, respectively. Pittosporum tobira, Sophora japonical and Ginkgo biloba had the strongest allelopathic promoting effects, and the SE were 0.47, 0.41 and 0.26, respectively. With the 0.5 mg·mL-1 concentration, the volatile oil of M. haplocalyx had significant inhibitory effects (P0.05) on seed germination and seedling growth and root growth (P0.01) of R. sativus. The different testing methods had significantly different effects on allelopathy which was related to the test plant. This study will provide some reference for systematic study on the allelopathy of garden plants.
This paper reviewed the influences of phosphorus (P) on turf. Phosphorus can accelerate turf germinating and forming and promote the growth of aboveground and underground. Except with the good effects on physiological property, such as increasing the intracellular chlorophyll content, activating the enzymes of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), phosphorus also plays an important role in regulating the nutrition metabolism and improving the physicochemical and biochemical soil properties. However, phosphorus has poor mobility which resulted in low utilization rates and excessive application in the practical production. The over-use of P led to serious environmental problems ranging from the soil phosphorus enrichment to point and non-point source phosphorus pollution which bring heavy metals accumulation in the soil. The present paper described the influences of P on turfgrass growth and summarized P application in turfgrass to provide a reference for the efficient using of P in the future.
A wide variety of invasive plants have caused ecological and economic problems in China. We explored the efficiency of molecular identification for the 17 popular aggressive invasive plant species and their relative species using ITS2 DNA regions. The results showed that ITS2 sequences possessed low intra-specific divergences and considerable inter-specific variations. ITS2 sequences could identify 95.5% of 300 invasive plant and related species samples correctly at the species levels. The constructed NJ tree displayed that different invasive plant species separated well and the same invasive species clustered together. The secondary structures of ITS2 sequences are also important for the systematic and taxonomic study. Molecular identification based on ITS2 sequences might be a useful tool for the identification of invasive species.
Dormancy appeared during germination of Corispermum patelliforme seeds. The aim of the study was to explore seed viability and the optimal temperature for seed germination and seedling length. The dormancy was broken during the course of seed storages and the optimal seed storage method was selected for dormancy-breaking. The results showed that seed viability did not change after stored at different conditions. If stored at RDS (Room dry storage) and RSS (Room sand storage) conditions, the optimal temperature for seed germination was 20 ℃ and 25 ℃, 25 ℃, respectively. Germination rate increased after storage with the following order: CDS (Cold dry storage)FSARDSRSSFSS (Field sand storage). The optimal temperatures for seed germination and seedling growth ranged within their optimal seed storage temperatures for RDS and RSS which suggested that CDS was the best storage method among these five studied seed storage methods for C. patelliforme.
In order to explore the mechanism of drought-tolerance of Pittosporum pentandrum, the growth and physiological and biochemical characteristics of 1-year-old P. pentandrum seedlings were analysis under four levels of drought stress including optimal water content(CK), mild drought stress(LD), moderate drought stress(MD)and heavy drought stress(HD) which were controlled by weighing the soil and pots. With the increase of drought stress, the heights and biomass of the seedlings decreased but the root/shoot ratio increased; net photosynthesis rate (Pn), transpiration rate (Tr), stomatal conductance(Gs), stomatal limitation(Ls)and water use efficiency(WUE)decreased while intercellular CO2 concentration (Ci)increased; the contents of K+ and Mg2+ decreased while the content of Ca2+ firstly increased and then decreased; the contents of soluble sugar and soluble protein increased while the content of proline firstly increased and then decreased; the contents of malondialdehyde and membrane permeability increased but the activity of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and ascorbate peroxidase enzyme (APX) firstly increased and then decreased. These results indicated that the membrane lipid peroxidation increased and the growth was inhibited under drought stress. However, P. pentandrum protected the membrane structure and maintained normally physiological activity through improving the activities of the antioxidant enzymes system and accumulating osmotic regulation such as soluble sugar, proline ,soluble protein and Ca2+ which improve its tolerance to the drought stress.
Switchgrass (Panicum virgatum) has the potential to produce biofuel from its lignocellulosic feedstock. A field experiment was conducted to evaluate the dynamic change of biomass yield and qualities of switchgrass (P. virgatum cv. Alamo) in different growing seasons in Beijing, China. The results showed that the aboveground biomass of switchgrass was highest in late August, and gradually decreased by 23% (from 20.3 to 15.2 t·ha-1) in late October and decreased by 30% in late November. There were significant dynamic various for switchgrass qualities in different growing seasons. The nitrogen and chlorine concentrations increased firstly and then decreased with a peak value at anthesis stage in late August. The heat value, volatile, hemicellulose, lignin contents increased, and the water, ash, fixed carbon, cellulose, phosphorus, potassium, sulphur contents decreased. The offtake of all elements measured in this experiment reached the peak value in late August which suggest that late October was optimal for harvest with better qualities and higher biomass yield for Alamo in Beijing.
Effects of super absorbent polymers type and dosage and the nitrogen fertilizer on oats yield and hay production in different growth stages were studied with orthogonal design with 3 factors and 3 levels at arid and semi-arid region. The results showed that the influence on oats yield decreasing in the following order: nitrogen fertilizer, super absorbent polymers dosage and super absorbent polymers type. The optimal treatment was Soil Conditioner Warer with dosage of 60 kg·ha-1 and 60 kg·ha-1 nitrogen fertilizer which can increase the yield, yield performance and economic benefit of Avena sativa cv. Qingyan No.1.
Asymmetrical competitions play an actual role in population co-existence of permanent mixed pasture. Perturbation experiments was conducted on 20yr old binary mixed pasture, which composed of white clover with cocksfoot/red fescue, to study the mechanism of coexisted population. The net production of white clover increased after removal of company grass at both mixtures which suggested that company grass had a competitive effect on white clover. The competitive intensity varied in different seasons, with a low value at beginning of growing season and a high value at the late stage. However, company grass responded differently which decreased after the removal of white clover with the intensity values between -0.023～-0.394 and suggested that nutricism benefits exceeded competitive effects from white clover. In the current system with moderate grazing, asymmetrical competitions is very important for all components dynamically balanced over a long term.
Forage straw is the main feeding source in Loess Plateau, however, optimal selection of forage straws have become important work of establishment and development of animal husbandry. Principal component analysis and cluster analysis were employed to comprehensively evaluate the quality of forages straw in the Loess Plateau with 10 indices including available water (AW), crude protein (CP), ether extract (EE), crude fiber (CF), acid detergent fiber (ADF), neutral detergent fiber (NDF), ash (ASH), nitrogen free extract (NFE), water soluble carbohydrates (WSC), organic matter digestibility (OMD). The order of principal component analysis evaluation of forages straw quality was as following: milletsoybeanpeassmall millethighland barleyoatsorghumpotatomaizewheat.The results of cluster analysis were millet, soybean,peas and oat clustered in a group, small millet and potato clustered in a group, wheat, maize and sorghum clustered in another group, and highland barley alone clustered a group.
For rational developing and utilizing the resources and promoting the sustainable development of ecological animal husbandry in Guizhou karst mountainous area, the quality of characteristic shrub Sophora davidii after silage with individual additives or combination which including lactic acid bacteria, cellulose enzyme, formic acid, sucrose and combination of lactic acid bacteria + cellulose enzyme and lactic acid bacteria + cellulose enzyme + formic acid + sucrose were studied to select optimal ensiling conditions which provide technical supports for the extension and storage of the forage resources in Guizhou karst areas.The results showed that the silage had good sensory qualities with low pH (3.97～4.73), ammonia nitrogen (3.76%～12.23%), acid detergent fiber (30.70%～42.16%), neutral detergent fiber (48.37%～61.84%) and total tannins (0.63%～0.89%) and high crude protein (16.83%～20.10%). The additives improved ensiling and sensory quality which decreased the pH and ammonia nitrogen content. The optimal additives for S. davidii was sucrose which achieved the best silage with good sensory qualities, low pH (3.97) and ammonia nitrogen (5.67%), and high crude protein (19.89%).
The combining questionnaire survey and participatory interview were explored to investigate 105 herdsman families in Sangke Township of Xiahe County, Gansu Province. The investigation contents including family basic situation, production status, living conditions and ecologic regime were analyzed to find the problems in the process of community livestock development. With the participation of technical staff and community herdsmen, the problems arising from the grassland management were recognized and the resolutions were put forward to improve the living conditions of herdsman, coordinate the economy and ecology in pastoral area and utilize sustainable resource.
In order to improve the DUS testing system, through the Guidelines for the Conduct of Tests for Distinctness, Uniformity and Stability Stylosanthes, 192 germplasm of Stylosanthes were tested by 24 measured traits.We transfermed test results as code to conduct cluster analysis. And cluster analysis showed that 192 germplasm could be divided into 11 class when the similarity coefficient was 0.770. Combined with the source of the germplasm, breeding background and results of diversity analysis, explanation of six testing characteristics were to be supplement, the pod beak was to be rejected, the color of coleoptile and the wool of stipule were to be increased. And the test standard varieties were determined. Explored the revision of the guidelines for the conduct of tests for distinctness, uniformity and stability Stylosanthes, can provide more powerful basis for the examination and approval of new varieties and species identification in Stylosanthes.
Alfalfa is the king of the forage whose comprehensive nutritional value is significantly higher than that of food crops like corn and wheat. At present there is a huge gap between supplies and demands of alfalfa although it has vital significance for the development of dairy industry in our country. The present paper analysed the inputs and outputs of alfalfa industry and estimated the technical efficiency of alfalfa production in eight major producing provinces from 2011 to 2013 using the parametric estimation method, then estimated the rate of technical progress and its contribution rate. The results showed that the technical efficiency was high and increased year by year with the value of 89.3% in 2013 and the contribution rate of technical progress was 49.4% which indicated that the development of China’s alfalfa industry is in a state between “extensive” and “intensive” growth. In conclusion, the suggestions about raising the seed cost, labor and machinery and improving the scale of alfalfa production were put forward.
The grass yield and nutrient quality of Festuca arundinacea grass clippings after silage with or without additive or crushed and pellet with corn flower were analysis to investigate its feed potential. The fresh and dry yields of grass mowing 5 times per year were 13 269.3 and 4 120.7 kg·ha-1, respectively. Grass clippings were easy to ensilage whose quality could be improved by compound bacteria additives. Crush grass clippings individual or mixed with corn and other additives were easy to pellet whose digestibility of dry matter can be improved by additives to 75%. These results suggested that grass clippings had great potential to develop as a high quality forage resource.
Field plot experiments were employed to investigate fertilizer effects of whole plastic-film mulching overlying soil and bunch planting of dry-land hulless oat(Avena nuda). Compared with no-mulching cultivation(CK), whole plastic-film mulching overlying soil and bunch planting(WFM) increased fertilizer use rate remarkably which lead N, P, K fertilizer use rate to 36.0%, 20.0% and 31.8% , respectively, and increased by 8.2%, 5.7% and 6.4% compared with CK. The techniques of WFM also increased hulless oat fertilizer use efficiency remarkably which lead N, P, K fertilizer use efficiency to 12.0,20.0 and 11.0 kg·kg-1 , respectively, and increased by 29.0%, 39.9% and 25.0% compared with CK. The techniques of WFM also increased the relative-yield of N, P, K nutritional deficiency zone remarkably which lead the relative-yield of N, P, K nutritional deficiency zone to 65.4%,59.6% and 90.5%, respectively, and increased by 11.6%, 9.6% and 4.2 % compared with CK. The techniques of WFM decreased N, P, K fertilizer adherence remarkably which lead N, P, K fertilizer adherence to 34.6%, 40.4% and 9.5%,respectively, and decreased by 25.1%,19.2% and 27.6% compared with CK. Therefore, this technique made a key breakthrough for highly efficient fertilizer utilizing techniques in dryland hulless oat.