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Based on the determination of soil nutrient content and enzyme activity of Jiangxi Camellia oleifera forest at different plantation ages, soil nutrients, enzyme activity features and their relationship were studied. The results showed that: among the test stands, C.oleifera forest soil nutrient content decreased gradually, for catalase, peroxidase and invertase activity ,Summer soil enzyme activity was higher than that in autumn. Along with the C.oleifera forest age increasing, soil nutrient content and soil enzyme activity changed regularly.0-20 cm soil layer, among the 6 kinds of different plantation ages of C.oleifera and control stand, The summer organic matter contents of G50yr were the highest for 3.89%;The autumm organic matter contents of D10yr were the highest for 2.25%. Both the summer and autumn catalase activity of G50yr were the highest, respectively for 2.12, 1.61 mLg-1; the activity of summer peroxidase and invertase activity of C6yr were both the highest among the 6 kinds of different ages, respectively for 2.45 Ug-1,3.43 mLg-1. 20-40 cm soil layer, among the 6 kinds of different plantation ages of C.oleifera and control stand, The summer and autumm organic matter content of G50yr C.oleifera forest were both the highest, respectively for 1.97% and 1.31%, the summer and autumn catalase activity of the G50yr were both the highest , respectively for 1.50, 0.95 mLg-1. the autumn peroxidase and invertase activity of C6yr were both the highest, respectively for 2.22, 1.33 mLg-1. The correlation analysis showed that soil nutrient factors and soil enzyme activity in each layer were significant or extremely significant correlated, Catalase, peroxidase, invertase are the good biological reference indexs to evaluate soil quality and soil fertility.
In this study we analyzed soil physical and chemical properties in the natural grassland and the cultivated oat (Avena sativa) grasslands of 8 (Ⅰ) and 20 (Ⅱ) years in alpine meadow of Maqu. There were significant differences in soil water content, soil organic carbon (SOC), total nitrogen, total phosphorus, available nitrogen and available phosphorus between the natural and the cultivated grassland. The soil bulk density of the natural grassland was significantly higher than that of Ⅱ in the 0 to 10 cm soil layer. The SOC of the natural grassland was 38.66% higher than cultivated grassland in the soil layer from 0 to 60 cm. Total nitrogen, available nitrogen, total phosphorus and available phosphorus of the natural grassland were also significantly higher than those of two cultivated grasslands (P0.05). The total nitrogen, total phosphorus and available nitrogen of cultivated oat grasslands were decreased with the cultivated years increasing. The soil organic carbon had a significant linear relationship with total nitrogen and available nitrogen in the natural and cultivated grasslands.
In recent decades, the ecological environment of grassland in Ali of Tibet has degraded continuously, which has attracted attention of local governments at different levels. Therefore, it is urgent to probe into the causes and improvement techniques of the degradation. In this paper, the overview and types of grassland resources and grazing capacity in Ali of Tibet were discussed. The results showed that the theoretical grazing capacity of Ali region was 2.993 7 million standard sheep and the actual grazing capacity is 3.466 6 million in 2010. Compared with the theoretical grazing capacity, the actual grazing capacity overloaded 15.80%. Based on the grassland resources and grazing capacity, it is suggested that the best suitable measures for local conditions should be taken, such as arranging grazing rationally and utilizing grassland resources scientifically to promote the sustainable development of animal husbandry.
In order to verify effects of different grassland vegetation restorations on species composition, diversity and biomass of poisonous plants in alpine meadow, the sample plots of natural grassland were imposed with sward ripping, reseeding, fertilization and integrated treatments. The results showed that there were significant differences in species compositions and proportions of poisonous plants in different sample plots (P0.05). Compared with the control, the species number and ShannonWiener index of poisonous plants in the communities were reduced significantly by treatments of reseeding, sward ripping and fertilization (P0.05). The order of species number and ShannonWiener index of poisonous plants in different sample plots was reseedingfertilization=integrated treatments sward rippingcontrol and reseedingsward rippingfertilizationcontrolintegrated treatments, respectively. At the same time, reseeding, fertilization and integrated treatments reduced the aboveground biomass of poisonous plants effectively (P0.05), but the sward ripping increased their aboveground biomass (P0.05). The order of aboveground biomass of poisonous plants was reseedingintegrated treatmentsfertilizationcontrolward ripping. In the reseeding plots, Elymus nutans became a single dominant community so that the species number, diversity index and aboveground biomass of poisonous plants were dropped to the lowest points. Thus, to improve the degraded grassland of noxious and miscellaneous grass type, reseeding is regarded as one of the optimal measures for grassland restoration.
In order to explore aluminum tolerance of Axonopus compressus cultivars, 6 traits (total number of secondary branches, total stem length, leaf firing percentage, turf quality, relative shoot dry weight and relative root dry weight) of 19 different geographical distribution of A.compressus germplasm and one cultivar were measured in the study. The results showed that there were significant (P0.05) or very significant (P0.01) difference among different germplasm on 2.1 mmolL-1 aluminum treatment. Coefficient of variation of different indicators ranged from 18.73% to 39.63%, of which the relative shoot dry weight (18.73%) was minimum and turf quality (39.63%) maximum. There were significant correlations（maximal correlation coefficient of -0.920）among different indexes of A.compressus germplasm. Based on six traits, SPSS 16.0 was used to divide carpet grass germplasm into three aluminum tolerance types: aluminum tolerance, intermediate and aluminumsensitive.
230 000 ha grassland accounted for 58.76% of the total grassland area have degraded at Tianzhu County in 2010. At present, the countys natural grassland is still degrading by a rate of 13 300 ha per year. The grassland degradation was caused by both natural factors and human activities. However, overgrazing was a main reason for natural grassland degradation from light to heavy. Therefore, comprehensive countermeasures based on controlling grazing capacity and resolving conflicts between grass and livestock were put forward for natural grassland in the paper, which can help sustainable development of Tianzhu natural grassland and offer technical references for areas of Qilian Mountains on rational utilization of grassland resources and control of degradation.
Genetic diversity of 48 Lilyturfs from different habitats was analyzed by using molecular marker SRAP. 11 effective primer combinations were filtered out and 621 bands with clearly identifiable section were amplified. Each pair of primers could amplify 56.45 bands and the number of polymorphism bands was 621. Moreover, the percentage of polymorphism loci was 100% and genetic similarity coefficient (GS) ranged from 0.058 4-0.936 7 with average value 0.497 5. These showed that the test materials were rich in genetic diversity. Cluster analysis of all materials indicated that the test materials could be divided into six groups at the genetic distance of 0.81 and some materials from the same geographical location could be classified as one group.
Genetic diversity of Sophora alopecuroides germplasm resources was analyzed at DNA level by Random Amplified Polymorphic DNA (RAPD). A total of 314 DNA bands from 22 populations in different habitats were amplified with 31 reliable RAPD primers, of which 285 DNA bands (90.76%) were polymorphic. The Neis gene diversity (H) and Shannon information index (I) were 0.301 5 and 0.453 1, respectively. The genetic distances ranged from 0.114-0.709. The results of RAPD unweighted pairgroup method with arithmetic means (UPGMA) cluster and the principal component analysis (PCA) demonstrated that 22 S.alopecuroides populations were clustered into 6 groups, which means that the genetic differentiations exist among populations.
30 Buchloe dactyloides collected from different geographical origins were put into this research. The basic turf characters, including leafblade length, leafblade width, height, diameter, number of tillers, number of stolon, length of stolon inter node, length of stolon, leaf color, extent of leaf turning yellow were measured and the genetic diversity was analyzed using the ISSR technique. The following results were obtained: 1) The difference of leaf color among these germplasm was significant (P0.05）, and the difference of leafblade length, leafblade width, height, diameter, length of stolon, number of stolon was very significant (P0.01). 2) Seven primers produced 108 polymorphic bands, with an average of 15.6 bands per primer. The percentage of polymorphic bands in average was 82.6%. 3) The Neis genetic similarity coefficient (GS) of the tested accessions ranged from 0.546 to 0.88, which suggested that there was rich genetic diversity among the germplasm of B. dactyloides. 4）These accessions were clustered into five groups. Moreover, there was the positive correlation between the geographical distance and the genetic distance.
Morphological characteristics and the relationship between morphological variation and geographic origin in 68 accessions of white clovers (Trifolium repens) were estimated. These white clovers were at latitude of 1.02 N-55.8 N, at longitude of 87.12 E-8.9 W, in elevation of 2-2 804 m and belonged to 29 countries. The results showed that the largest variation was found in leaf area, followed by inflorescences per unit area and plant height, and the less variation was found in height of fertile tillers and florets per inflorescence. Mantel test showed that changes of three characters, including plant height, inflorescences per unit area and florets per inflorescence, existed significant spatial correlation, while the correlation was not significant between leaf area (or height of fertile tillers) and spatial distribution. Cluster analyses showed that there was significant correlation between morphological variation and geographic origin of white clovers and different origin of white clovers had similar genetic differentiation. The morphological variation in white clovers originated in European showed different evolutionary direction
In order to provide necessary cytology information on germplasm identification, origin analysis, species succession and breeding, the chromosome number and karyotype of Cosmos bipinnatus were studied. The results showed that the chromosome number of C. bipinnatus was 2n=24, and its karyotype formula was 2n=2x=24=18m (1sat)+6sm (1sat). The average relative length of chromosomes was 6.20% to 9.06%. Ratio of the longest to the shortest chromosome was 1.47%，16.7% of chromosomes showed long arm/short arm2∶1. The karyotype of C.bipinnatus belongs to 2A type. As the asymmetry coefficient was 43.25%, chromosome of C.bipinnatus should be a more symmetric type.
Seeds of twentyeight perennial ryegrass varieties introduced from Germany were irradiated by 60Co with 400 Gy, 500 Gy. The effects of radiation treatments on the germination potential, number of tillers, plant height, fresh weight and heading date were observed and analyzed in the field. The results showed that the low dose caused death of Gordo, Ligrande and Barmultra, while the high dose caused death of Remy and Bartissimo. Furthermore, gamma beam causes changes of the perennial ryegrass minute tiller number, height, growth characters, fresh weight and earing period. The tiller numbers of Zarastro, Barfort, Tosca and Orlando mutagenesis material increased signficantly after radiation, The height and the fresh weight of Lolita mutagenesis material increased by 20%. These results indicated that radiation is a good and fast way to improve the quality of forage, which could be used in further breedings.
In this study, leaf ultrastructures of Potentilla chinensis, P.discolor, P.leucophylla and P.verticillaris under drought stress were investigated by transmission electron microscopy. The results showed that with the drought stress strengthening, the damage of chloroplast and mitochondria gradually increased, the number and the volume of osmiophilic also gradually increased, and the chloroplast,s area gradually decreases and slightly increase in the number. Through the comparison of chloroplast and mitochondrial damage of four kinds of plants in same drought stress gradient, it was found that the ability of drought stress was in the following order: P.verticillarisP.leucophyllaP.discolorP.chinensis. Therefore, the degrees of plant chloroplasts and mitochondria structural damage are related to drought tolerance, which can be used to evaluate the strength of drought resistance of morphological traits of genus Potentilla.
The temporal dynamics of seed rain and the characteristics of sexual reproduction of Agropyron michnoi in the semifixed dune and the fixed dune of Hulun Buir desertification grassland were studied in this paper. Results showed that the seed rain of A.michnoi lasted 45 days from August 8 to September 22. There was a linear regression between the seed rain intensity fluctuation of A.michnoi and the maximum wind speed. Among different habitats, the seed rain intensity of A.michnoi in the semifixed dune was always significantly higher than that in the fixed dune. The panicle length, panicle width, per panicle weight, the number of spikelets per panicle, and 100 grain weight of sexual propagules of the semifixed dune were significantly higher than those of the fixed dune. The ratio of seed rain number and seed production were 29% and 10% respectively in the semifixed dune and the fixed dune. Sand microhabitat changes do not affect the spread period and fluctuation of A.michnoi seed rain, but have a significant impact on morphological features of its sexual propagules.
In this paper, the method of gray correlation was used to perform the comprehensive evaluation of 20 wild Medicago ruthenica materials from 13 regions of Inner Mongolia. Plant height, growth duration, growth rate of plant height, D/WRatio, wet matter yield, dry matter yield and seed yield were used as indicators to constructed the model to evaluate the production performance of various materials. The results showed that M4 from Huitengliang County, M8 from Tongliao City, M5 from Xisu County and M6 from Tongliao City showed relatively better production performance. In contrast, M20 from Damao County, M19 from Wulanchabu Siziwangqi, M3 from Xilinhot and M10 from Chifeng City showed low production performance. The weight of each trait indicator were in the following order: plant heightgrowth durationgrowth ratedry matter yieldwet matter yieldD/WRatio.
In order to explore the optimum sowing date of alfalfa (Madicago sativa) in seasonal planting system in Huai River region, effects of autumnal sowing date on growth characteristics and forage yield were investigated in field experiments at Funan and Huaian from September 2009 to June 2011. The results showed that in the seasonal planting system (autumn sowing and twicecutting in next spring), growth characters and forage yield reduced gradually with the autumn sowing date delayed. The average plant height at the early bloom stage in the first cutting was 91.91 cm for the sowing date of September 6, which was near double that of October 22 (42.90 cm) on the Huaian experiment site. Accordingly, the forage yield on the sowing date of September 6 was the highest, 4.37 kgm-2 in fresh weight and 1.05 kgm-2 in dry matter. Forage yield was positively correlated (P0.01) to plant height, shoot number and dry weight per plant (P0.01). According to the path analysis results, plant height and dry weight per plant were the most primal factors for alfalfa forage yield. The results implied that the earlysowing in autumn improved the dry matter yield of alfalfa by increasing the plant height and dry weight per plant. The optimum sowing date of alfalfa for seasonal cultivation along Huai River region should be in September to early October.
Hebei Bashang region is located in the farmingpastoral ecotone in north China. A compound management of agriculture and animal husbandry is a main way of agricultural production. In order to improve the situation of poor quality of forage and lack of forage resources for ruminants in the region, effects of applying contents of Urea Formaldehyde (20%, 30% and 40%) and Nitrogen (30, 60, 90, 120, 150 and 180 kgha-1）in slowrelease Nitrogen fertilizers on maize silage quality were studied by using randomized experiment design. The results showed that nutritive quality of the silage treated with 40% Urea Formaldehyde was better than those with 30% and 20%, but the organic acid content was opposite. Compared to slowrelease Nitrogen fertilizers of different N contents, the maize silage treated with 120 kgha-1 N had higher contents of crude protein, dry matter and organic acid and lower of neutral and acid detergent fiber than those of other treatments; and the quality of silage was better as well.
Effects of boric fertilizer application on seed yield and germination of Paspalum atratum cv. Reyan 11 were studied by a pot experiment in this study. The experiment included 9 different boric concentration treatments (0~4.0%). Each treatment was divided into 3 applications. The results showed that seed yield reached the highest of 1 124.4 kgha-1 with 3.0% boric treatment. 3.0% boric treatment significantly raised seed yield components, including fertile tiller nubmer per pot, floret number per spikelet, fertile floret number per spikelet and thousand grain weight . The fertilizer also raised seed germination rate, germination potential, germination index, seedling height and weight. Seed germination rate under 3.0% boric treatment reached to 20.17% and 30% increase compared with control.
In order to investigate effects of sand burial depths on Kengyili rigidula seedling emergence and growth under natural conditions, a simulation study was conducted with six sandburial depths (0, 1, 2, 3, 4 and 5 cm). The results showed that the sand burial depth had significant effects on seed germination, seedling emergence and seed dormancy of K.rigidula. The seedling emergence rate of K.rigidula decreased with increasing of sand burial depth. It was 13.6%, 78.4%, 63.2% and 63.6% when the burial depths were 0, 1, 2 and 3 cm, respectively. It could be concluded that a sandburial depth of 1-3 cm might be more suitable to the seedling emergence and growth of K. rigidula, while the burial depths of 0 and 4 cm might be unfavorable to the seedling emergence and growth.
A mowing height growth linear model was established in the present paper. Based on the model, the relationship between growth status of individual plants, including dynamic changes of individual plant height, tillering and per unit yield, and total biomass of Sorghum sudanense (HayKing) with different cutting treatments was analyzed. The results showed that unit yields of monocropping grassland of S.sudanense (HayKing) with different cutting treatments were stable in its growth cycle. There was a significant negative correlation between plant individual growth rate and growth potential under different cutting treatments. These results indicated that the monocropping grassland of S.sudanense (HayKing) has ability to maintain unit yields with a certain stability during its life span through balancing the relationship between the growth rate and the growing potential of individuals.
With a variety of excellent features, Lespedeza has a very broad application prospects. The research explored the genetic diversity from morphology, biochemistry, chromosome and molecules levels in Lespedeza. It also summarized application values of feeding, ecology and medicine for providing some references for Lespedeza germplasm resources further study.
tanding milkvetch (Astragalus adsurgens) is an important leguminous forage and soil conservation plant. Harmful insect is one of the limiting factors to forage production. Crapholita shadawana (Tortricidae) and Melanagromyza adsurgenis (Agromyzidae) are the stemboring insects of the plant. Occurrences of the two insect species were investigated in four age pastures (established in 2003, 2002, 2000 and 1998) at Huanxian, Gansu province in August or September of 2004, 2005 and 2006, and in May (late regreening), June (branching) and August (early flowering) of 2005. The occurrences were associated with pasture age, year and seasons. The two kind of insects feed A. adsurgens plants that older than 3yearold and younger than 8yearold, percentage of damaged plants was 20.0%-100.0% and 52.0%-100.0%, respectively, in which 100% plants were damaged by the first insect and the second insect in 2005. Amount of each insect varied in different year, in which amount of C. shadawana larvae per 100 plants (ALPP) in both of the oldest (established in 1998) and youngest (established in 2003) pastures in 2006 was significantly (P0.05) higher than each of 2005 and 2004, and in other pastures was fewer (P0.05). The maximum of C. shadawana amount in three years was 65.8 larvae per 100 shoots (i.e., 65.8% shoots were damaged, 2004 data from 1998established pasture). ALPP of M. adsurgenis in the youngest pasture in 2006 was significantly (P0.05) higher than in 2004 and 2005, and in the oldest pasture in 2006 was significantly (P0.05) fewer than in other two years. The maximum of ALPP of M. adsurgenis in three years was 38.8 larvae per 100 shoots (i.e., 38.8% shoots were damaged, 2004 data from 2000established pasture). Based the relationship between pasture ages and ALPP, although it fluctuated in different year, ALPP of both of insect species increased as the age increased, reaching the peak at 7yearold and 8yearold, and then decreased rapidly as the majority of plants died. Among a year, the two kind of insect began fed in June (not found in May), however, C. shadawana was only found in the oldest pasture in June, 2005, and M. adsurgenis in June was found in all pastures and its ALPP reached the maximum. Furthermore, ALPP in June was higher than in August in each of pastures. The two kind of insect had not live in a same shoot even two larvae of same species. Since there were no differences were found between damaged shoots and nodamaged shoots, examination on insect body, boring holes and frass after splitting stems should be a reliable method to diagnose if boring insects in shoots. Gansu province is the new distribution region of the two insects.
Based on comparative advantage methods, industrial concentration degree and costrevenue methods, the competitive powers of livestock products including mutton and beef were calculated in Gansu province. The result showed that the beef had no advantage of scale and mutton had a little, but there was obvious advantage of output for both beef and mutton. Under the combined action of advantages of scale and output, the comprehensive comparative advantage of beef was becoming much more remarkable and the mutton advantage improved steadily. The value of industrial concentration degree of beef was 57.932 6% in 2008, but only 48.918 7% for mutton. It could be concluded that the regional advantage was weak for mutton and remarkable for beef. In addition, the advantage areas, where beef and mutton were produced, were agglomerating towards the Hexi region and areas inhabited by the minority nationalities. Both selling prices and production costs of beef and mutton in Gansu have strong competitive advantages compared with levels of the national average and the major western animal husbandry provinces. Finally, some countermeasures and suggestions are put forward in order to raise the comparative advantages of distinctive livestock products.
Grassland animal husbandry is the leading industry in Hezuo City and it was restricted by natural conditions and socioeconomic development. The complementarity between agriculture and animal husbandry was poor， The internal structure of animal husbandry was similar and regional division of labor was not obvious. The commercialization process of livestock is extensive, low quality and inefficient and enterprises category of processing animal products was incomplete, small, poor driving. As a general shortage of intermediary forms of institutions and associations, selforganizing capacity of farmers and herdsmen is poor. Furthermore, lack of market resulted in the slow process of industrialization of animal husbandry. Therefore, on the premise of protecting grassland ecological environment, actively promoting base construction, developing leading enterprises and strengthening the agricultural service system could achieve the transformation from grassland animal husbandry to a modern animal husbandry.
By using the retrieval platform of CNKIs CAJD, this paper makes the mapping knowledge domains on the years distribution, organizations cooccurrence analysis and key words cooccurrence analysis of the papers published in PRATACULTURAL SCIENCE since founded. Finding that the research focus on sustainable development of pastoral agriculture, adaptability evaluation of forage.And there is an extensive cooperation among the organizations.