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2009 Vol.26(10)

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2009, 3(10): 1-11.
[Abstract](1224) [PDF 1387KB](1602)
Poverty divisions and new features of poverty reduction
2009, 3(10): 12-23.
[Abstract](1546) [PDF 2426KB](831)
Regional poverty exists in China rural area. After analyzing the distribution features of poverty area and the factors, the present study divided the 592 poverty alleviation and development counties into 8 poverty region, namely, Karst Mountainous Region, loess plateau region, rangeland region in Xinjiang and Mongolia, alpine meadow region, mountain region in Qinling-Bashan, Valley and mountain region in Hengduan Mountains, mountain region in central China and plain region in central China. According to three successful cases from Karst Mountainous Region, loess plateau region and plain region in central China, the model of three stage poverty alleviation and development was put forward, which is scientific experiment, poverty alleviation pilot and contiguous stretches development. The study proposed 5 new characteristics of poverty alleviation industry: Firstly, poverty in rural area was a key to resolve the rural development issue. Secondly, demonstration experiments had to been carried out in a poverty region. Thirdly, combination of poverty alleviation with ecological restoration. Fourthly, development of agriculture and forestry and husbandry and fishery industry focused on land allocated to a farmer to cultivate for personal consumption and the grassland animal husbandry. Finally, farmer pattern the was base of new rural communities construction and county economy. Based on the new features of poverty alleviation industry, the countermeasures were put forward to alleviate the poverty in this paper.
Interspecific relationships of Vitex negundo var. heterophylla community of Taihang Mountain in Shanxi Province
2009, 3(10): 24-29.
[Abstract](1672) [PDF 1060KB](715)
The interspecific association and correlation of 26 dominant species in Vitex negundo var. heterophylla community were analyzed by using x2test, Pearson's coefficient and Spearman's coefficient. The results showed that those dominant species composed 525 speciespairs; among these speciespairs, the extreme significant association or correlation were 5, 14, 15 respectively; and the significant association or correlation were 10, 6, 13, respectively. Speciespair, showing positive association or correlation, might have similar biological characteristics and similar ecoadaptability and niche overlapping. Speciespairs showing negative association or correlation might have different ecological characters, different adaptation and niche separation.
Study on the genera endemic to China in the angiosperm flora of Gansu
2009, 3(10): 30-38.
[Abstract](1766) [PDF 1992KB](766)
Gansu Province is located in the transitional zone among Loess Plateau, QinghaiTibet Plateau, InnermogoliaXinjiang Plateau and Qinling Mountains. This region has significant diversity in climate types and complexity in floristic elements. Genera endemic to China in the angiosperm flora of Gansu Province accounted to 57 genera, consisting of 72 species, 1 subspecies, 6 varieties and belonging to 38 families. The quantity is superior to ones of other provinces or autonomous regions of the yellow river. In this paper, the divisional scheme used by Lian Yongshan et al. (1997) on arealsubtype infra arealtypes endemic to China was revised. The numbers of genera and the composition of genera type in every arealsubtype on the genera endemic to China in the angiosperm flora of Gansu Province were studied. The results showed that the subtropical species were the dominant, including 24 genera, 42.1% of total genera; Central China species and Hengduanshan Mountains species situated in the first and second for the quantity of genera separately, 15 genera and 13 genera, 26.3% and 22.8% of total genera; the genera with one species, including monotypic genera and oligotypic to moretypic genera only one species distributed in Gansu, were the most important genera type, 47 genera, 82.5 % of total genera. Wen County is undoubtedly the abundance centre of endemism in the Angiosperm Flora of Gansu.
Study on the MODIS NDVI and NOAA NDVI based spatial scaling method A case study in Inner Mongolia
2009, 3(10): 39-45.
[Abstract](1640) [PDF 1405KB](763)
The dominant grassland types in Inner Mongolia were selected as research area and and the annual variation pattern of the relationship between MODIS NDVI and NOAA NDVI was analyzed in growing seasons from 2000 to 2003. The spatial scaling methods between different resolutions datum of remote sensing in largescale spatial extent were studied. At the same time, The MODIS NDVI and NOAA NDVI datum in July and August in 2002 were used to build the spatial scaling model and the model was applied to validate the precision of the model. The result indicated that this spatial scaling method was effective, and the model could be applied to other time quantum. This method could scientifically and effectively analyze and compare the datum of NOAA NDVI and MODIS NDVI.
Monitoring on water resource and ecological environment in Shiyanghe River basin through remote sensing in 10 years
2009, 3(10): 46-51.
[Abstract](1601) [PDF 1323KB](729)
Under the background of the climate warming, the ecological environment in the Shiyang River basin has been greatly changed. Based on the quantitative monitoring strategy and key technologies, the factors including vegetation cover, reservoir area and snow cover area were used as the indicators to monitor the ecological environment. The remote sensing imagines were used to calculate the snow coverage, vegetation cover and water resource. The result indicated that the entire area of the glacier snow fluctuated in the Qilian Mountains region with linear increasing trend from 1997 to 2006. In the eastern and middle of Qilian Mountains, the snow coverage showed a decreasing trend, but in the western, its trend was increasing. In general, the vegetation coverage was decreasing in Shiyang River basin. The degradation degrees of the sparse vegetation and density vegetation were the highest. Water resource in the downriver of Shiyang River (Hongyashan Reservoir) decreased, and the maximum reservoir area value was 19.35 km2 in 2005, the minimum value was 7.4 km2 in 2001.
Application of GIS technology in the evaluation of environmental condition
2009, 3(10): 52-58.
[Abstract](2442) [PDF 800KB](788)
Ecological environment is a basis for the living and developing of human being. One of the urgent ecological problems is how to assess the ecological status of the environment in scientific, accurate and effective ways. The indexes of biological abundance, vegetation cover, hydrology, land degradation and environmental quality were selected to calculate the ecological environment quality index by AHP with the administrative region as a unit. The statistical analysis of spatial interpolation tools in GIS was used to get the grid layer, and then the grid calculation was made to get the ecological environmental quality index of each grid, finally to calculate the proportion of the administrative unit at all levels. The result showed that it could resolve the defects of using administrative unit as evaluation unit. This evaluation method focused on the differences among each unit and made the spatial location of evaluation result more precise.
Impact of enclosure on community characters of sowed Elymus nutans grassland in black soil Land
2009, 3(10): 59-66.
[Abstract](1690) [PDF 997KB](758)
The thirdyear and seventhyear sowed Elymus nutans grassland in black soil land in the ThreeRiver region were fenced for 3 years, and the community was surveyed during the middle August in each year. The same grassland outside the fence which was grazed in winter was used as the control. The results showed: 1) the species diversity index of fenced grassland was higher than the grazing grassland, and with the increase of sowed age, the diversity index gradually increased; 2) the change of total coverage, coverage and height of dominant species were same, i.e., they decreased with the increase of sowed age and that of fenced grassland was lower than the grazing grassland; 3) The aboveground biomass was consistently decline with the increase of sowed age, and that of fenced grassland was significantly lower than the grazing grassland.
Study on growth and utilization of alfalfa grown in Cdrich substrate
2009, 3(10): 67-72.
[Abstract](1773) [PDF 1188KB](717)
The improvement of coal mining subsidence land by finding the proper substrates with rich nutrition and suitable soil properties for crop has become the research focus at the case of soil become the scarce resource. Three substrate formulas, including fly ash + sewage sludge (substrate 1), fly ash + lees (substrate 2) and fly ash + furfural residue (substrate 3), were used to study the effect on alfalfa cultivation. The results showed that the alfalfa yield was low and the dry matter based Cd content in alfalfa was over the health standard in the first year due to the high contents of salt and Cd, however, it could be used as fresh fodder for livestock or green manure. Due to the plant absorption and leaching in the first year of, the content of salt in the substrates declined to the normal level and the alfalfa yield achieved the normal level, the Cd content in substrates reduced to 4 to 6 times of environmental quality standards, and the dry matter based Cd content in alfalfa reached the health standard.
Dynamic changes of the aboveground biomass of several forages in karst rocky desertification area
2009, 3(10): 73-79.
[Abstract](1638) [PDF 1017KB](750)
The aboveground biomass dynamic and the relationship between plant height and yield of Cichorium intybus, Pennisetum americanunP.pureum, Zea diploperennis, Lolium perenne, Medicago sativa, Trifolium repens, mixed cultivation of C. intybus, P. americanunP.pureum and Stylosanthes guianensis cv. Reyan No. 2 were studied in karst rocky desertification area to provide a scientific basis for selecting the suitable forage species and cultivating techniques. The results showed that the harvesting height significantly affected the yields of P. americanunP.pureum, Z. diploperennis, L. perenne and T. repens, but little influence on that of C. intybus, the mixed cultivation and M. sativa. The difference of fresh and dry matter yields at different harvest times was significant, indicating that both fresh yield and dry yield had obvious seasonal variation. In which, C. intybus was a high productive forage. P. americanunP.pureum was productive and high quality and suitable fro making silage. The yields of Z. diploperennis in August and October accounted for only 50% and 30% of C. intybus and P. americanunP.pureum respectively. The yield of mixed cultivation was stable compared with the monoculture. L. perenne, M. sativa and T. repens could be used as rotation crops for fully using the land resource and increasing the forage supply in spring and autumn.
Study on the nutrition quality of wild germplasm of Medicago lupulina
2009, 3(10): 80-84.
[Abstract](1693) [PDF 516KB](697)
Thirteen wild ecotypes of Medicago lupulina were collected in the northwest China to test their nutrients using 20 alfalfa varieties, M. scutellata and M. truncatula as the reference. The result indicated that the crude protein contents 13 representative ecotypes varied from 24.26% to 29.36%,the crude fat content ranged from 2.68% to 4.36%,the crude fiber content ranged from 17.05% to 22.61%,the nitrogenfree extract content ranged from 33.79% to 40.25%. These results suggested that the nutrition value of black medic was higher than alfalfa. M. scutellata contained lower crude protein, crude fat and nitrogenfree extract but higher crude fiber. M. truncatula contained higher crude protein, crude fat, crude fiber and lower nitrogenfree extract.
Grey association degree analysis on the main characters of domestic and overseas alfalfa
2009, 3(10): 85-88.
[Abstract](1664) [PDF 445KB](688)
Seventeen alfalfa varieties were used to analyze the relationship among their characters with grey relate degree analysis based on the investigation for 3 years. The result showed that the plant height was the most effective factor affecting the yield, and followed by the growth speed, branch diameter and branch number. The effective factor affecting the quality was the growth speed, branch diameter and branch number. The plant height and growth speed were the key characters for the breeding with purpose of high yield. As for high quality breeding, the growth speed, branch diameter and branch number were the key characters.
Effect of temperature in late autumn on free proline, soluble sugar and POD in alfalfa
2009, 3(10): 89-93.
[Abstract](1847) [PDF 748KB](851)
The effect of temperature in late autumn on free proline, soluble sugar and POD in 9 alfalfa varieties with different fall dormancy was conducted. The result showed that the contents of free proline in 3 different fall dormancy types of alfalfa showed an increasing trend from 10th Sep. to 10 th Oct., and the contents increased with the temperature, in which, the variation extend of free proline in high fall dormancy alfalfa was the largest. The contents of soluble sugar in high and low fall dormancy alfalfa greatly fluctuated and the trends were opposite. This suggested that they were more sensitive to the storage nutrients. Meanwhile, the variation of moderate fall dormancy alfalfa was in the middle. The POD activity showed an increasing trend for different fall dormancy types of alfalfa and the fluctuation of the moderate and high fall dormancy types was greater than the low fall dormancy ones, this suggested that the varieties with moderate and high dormancy were more sensitive to the aboveground temperature.
Analysis on karyotype of Galega orientalis cv. Xinyin No. 1
2009, 3(10): 94-96.
[Abstract](1611) [PDF 479KB](720)
The karyotype and Cband of Galega orientalis cv. Xinyin No. 1 were studied. The results showed that the karyotype was 2n=2x=16=16m. All the chromosomes were median and submedian centromeric. The Cbanding analysis was conducted with HBSG method and the result showed that the Cbanding karyotype is 2n=16=10C+4CI++2T. The karyotype was belonged to 1B type based on Stebbins classification system.
Esterase isozyme analysis of five varieties of Sorghum sudanense
2009, 3(10): 97-102.
[Abstract](1482) [PDF 824KB](653)
Esterase isozyme in leaf and root of 5 varieties of Sorghum sudanense registered in China were analyzed using PEGA technique associated with determination of soluble sugar. The results indicated that the number of bands presented in leaf was less than those presented in roots and varied from 28 to 46. Among 5 varieties, the band color presented in Rf 0.84 in Ningnong was similar to that of Wulate No.1 which was stained in dark brown, this band in Xinsu No.2 and Yanchi was stained to brown, while it was disappeared in Qitai variety. Band numbers in roots in 5 varieties varied from 35 to 49, according to the color characteristics of band presented at Rf 0.84, 5 varieties could be classified into 3 groups. Xinsu No.2 and Yanchi were in group 1and the band color at Rf 0.84 was dark brown. Ningnong and Wulate No.1 were in group 2 and the band color was brown, while it was absent in Qitai. It could be concluded that esterase isozyme analysis was an effective method for identifying the varieties of S. sudanense.
Study on the inhibition effect of 2propionic acid ammonium to the alfalfa mildew
2009, 3(10): 103-108.
[Abstract](1760) [PDF 1025KB](718)
The inhibition effect of different contents of 2hydroxy propionate ammonium (0.3%, 0.75% and 1.5%) to the alfalfa mildew which was rained two times continuously was studied. The results showed that 2hydroxy propionate could effectively control the growth of mildew and the decomposability of crude protein (CP), crude fat (CF), soluble sugar (SS) and amino acid (AA) of alfalfa. The growth of mildew was found in the control group and Group 1 (0.3%), besides the number of mildew reached maximum on the 6 th day and 8th day respectively and no mildew appeared in Group 2 (0.75%) and Group 3 (1.5%); with time prolonging, the content of CP had no significant change (P0.05), but the content of CF presented obvious downtrend and the decreasing extent was reduced because of mildew inhibitor, in addition, the content of CF was Group 3Group 2Group 1control on the 3rd day, 6 th day,14 th day and the difference was significant between experiment groups and the control group (P0.05); the content of SS was experiment groups control group in early experiment period and it reached the same level in later period; the content of total AA as well as 10 of 17 kinds of AA were improved after adding 2hydroxy propionate ammonium and there was remarkable difference between experiment groups and the control group (P0.05), while the content of Ser, Ala and Gly were fluctuant and the other 4 kinds of AA (Glu, Cys, Met and His) were downtrend.
A primary study on effect of nitrogen fertilization on physiological characteristics of Bromus inermis
2009, 3(10): 109-113.
[Abstract](1975) [PDF 827KB](671)
The three yearaged Bromus inermis grassland was used to study the physiological characteristics of B. inermis under 4 different nitrogen fertilization treatments. The results showed that the chlorophyll content in leaf increased continuously with the increase of nitrogen application amount. The content of soluble sugar under different fertilization treatments was significantly higher than that of control, however, the content of free amino acid showed an opposite trend. The activity of nitrate reductase in moderate and high level fertilization treatments was significantly higher than that of control. The content of nitrate nitrogen was significantly increased only in high level fertilization treatment.
Introduction experiment of silage maize in Zhengzhou
2009, 3(10): 114-121.
[Abstract](1769) [PDF 658KB](754)
Ten single cross hybrids of maize were introduced, and their proper harvesting stage and the correlation among agronomical traits were studied for selecting the varieties adapted to Zhengzhou. The results indicated that the proper harvesting date for silage making was in the stage of wax ripeness in terns of yield, agronomical traits and nutrient contents. The plant height, stem diameter, ear length and ear diameter showed the positive correlation with yield. The CP content was positively correlated with leaf proportion. CF content negatively correlated with CP content. Out of 10 varieties, Ludan 981, Zhengdan 968 and Jundan 18 were better and could be extended in Zhengzhou.
Study on the relationship between vegetative characteristics and aboveground biomass of eight annual forages
2009, 3(10): 122-126.
[Abstract](1650) [PDF 914KB](777)
The outdoor pot experiment was conducted to investigate the relationships between growth characteristics (including plant height, growth rate, leaf weight, leaf area, root length) and aboveground biomass of 8 annual forages. The results showed that the growth characteristics of 8 forages were significantly different. The aboveground biomass was positively correlated with plant height,growth rate,leaf weight,leaf area and root weight except for root length based on the linear regression analysis. While the stepwise regression analysis showed that the aboveground biomass was only positively correlated with plant height,growth rate and leaf area. These results indicated that it was better to consider multiple growth characteristics for exploring the relationship between forage growth characteristics and biomass.
Study on the improvement of seed germination rate of Trifolium pratense cv. Mingshan
2009, 3(10): 127-130.
[Abstract](1684) [PDF 800KB](703)
Effects of H2SO4, NaOH, KNO3 and acetone solution on seed germination rate of Trifolium pratense cv. Minshan were studied. The result indicated that 4 chemicals could break dormancy and increase the seed germination rate of red clover. The solution concentration and soaking time performed different effects on seed germination rate. The best treatment was 40% of H2SO4 solution soaking for 10 minutes and the germination rate was increased by 37%. The germination rates were increased by 34%, 31%, 30%, 30% and 29% respectively under the treatments of 30% H2SO4 solution soaking for 15 minutes, 0.2% KNO3 solution soaking for 12 hours, 40% NaOH solution soaking for 10 minutes, 30% NaOH solution soaking for 15 minutes and 0.2% KNO3 solution soaking for 6 hours. Acetone solution showed the poor effect and the germination rate was increased by only 20%.
Impact of manure and urea on the fresh yield ofDactylis glomerata after snow disaster
2009, 3(10): 131-133.
[Abstract](1639) [PDF 365KB](672)
The impact of manure and urea on the fresh yield of Dactylis glomerata after snow disaster was studied in 2007 and 2008. The results showed that the fresh yields among 6 manure and urea treatments were significant different after 20 days snow disaster. The yields of manure treatment (30 000 kg/hm2) and urea treatments (75 kg, 175 kg, 275 kg) were significant higher than the control. The fresh yield in the treatment of manure (30 000 kg/hm2) + urea (175 kg/hm2) was the highest. And the economic fertilization formula was 30 000 kg/hm2 of manure + 75 kg/hm2 of urea.
Technical regulation on propagation and renewal for forage germplasm resources
2009, 3(10): 134-139.
[Abstract](1695) [PDF 888KB](799)
According to the Technical Regulation on Characterization and Documentation for Crop Germplasm Resource, and based on the experience got from the work on establishment of national medium term gene bank of forage germplasm and the national nursery of perennial forage, The Technical Regulation on Propagation and Renewal for Forage Germplasm Resources was established aimed at the existing problems to provide the technical guidance for conservation and utilization of genetic germplasm.
Response of seed germination of three Caragana species to temperature and soil moisture
2009, 3(10): 140-145.
[Abstract](1757) [PDF 1224KB](779)
Caragana leucophloea, C. pumila and C. acanthophylla are xeric shrubs, which have potential value in vegetation restoration. Effects of alternated temperature and soil moisture on seed germination and germination phenology of 3 species were studied. Alternating temperature regimes of 10/6, 15/6, 20/10, 25/15 and 30/20 ℃ were used while the photoperiod condition was 12 h/12 h. The results indicated that the soil moisture to trigger the germination was 2.5% for 3 species. The germination speed of C. leucophloea and C. pumila were fast and the germination could complete at the same year of the seed maturation, and could finish the emergence. But the seedling emergence was long for C. acanthophylla because of hard seeds.
SWOT analysis on grouphousehold grassland managementin Maqu and strategies for future development
2009, 3(10): 146-149.
[Abstract](1497) [PDF 713KB](857)
Exploring the patterns of grassland utilization is the key to realize the sustainable development of the grassland resources. In order to offer the advocates and policy makers a new view on grassland utilization, the SWOT tools were used to analyze two grassland management patterns in Maqu, i.e., the individual household contract and grouphousehold contract. The results showed that the grouphousehold management was better. Under the grouphousehold management, the usage right of grassland belongs to a group of household and it could avoid the grassland overusing without supervision and limit the unreasonable action under the individual household management. It showed many advantages, such as high ecology efficiency, low cost of livestock production and balance between livestock demand and forage supply, and abound social resources. At present, the grouphousehold management is commonly accepted in Maqu and very successful. And it should be the grassland management pattern in the future.
Grass endophyte research 10Seedling properties of Neotyphodium endophytehost complexes
2009, 3(10): 150-154.
[Abstract](1861) [PDF 538KB](814)
Some endophytic fungi involved in gramineous plants could provide better resistance to pests and plant pathogens, better tolerance to drought, better plant growth and tillering of the host. In this study, the seed germination, seedling growth and aphid resistance of several varieties of tall fescue (Lolium arundinaceum), perennial ryegrass (L. perenne) and wheat grass (Roegneria kamoji) containing endophytic fungi at different levels were tested both in growth chamber and pot. More tillers and better aphid resistance were significantly observed from both tall fescue and perennial ryegrass varieties containing higher levels of endophytic fungus in the seeds, while seedlings of wheat grass infected higher level of endophytic fungi had higher seed germination rate, better growth and more tillers. However, endophytic fungi infected in wheat grass did not cause better aphid resistance of the host. These indicated that the application of these endophytic fungi in agriculture was promising.
Control effect of Metarhizium anisopliae complex preparation agent on grassland locust
2009, 3(10): 155-159.
[Abstract](1410) [PDF 588KB](750)
Metarhizium anisopliae, an important entomopathogenic fungus, is used for biological control. Two groups, 2.5% of M. anisopliae complex preparation agent (clBioc) and 4.5% of Cypermethrin, were designed to test the control efficiency on grassland locust. And each group included 3 concentration levels (450 mL/hm2, 600 mL/hm2, 750 mL/hm2). The results indicated that the M. anisopliae agent showed excellent control efficiency at 3 concentration level. The control efficiency of 4.5% Cypermethrin at 450 mL/hm2 of concentration was not significantly different from that of M. anisopliae agent, so the latter could be used while the locust density was lower. The control efficiency of 4.5% Cypermethrin at 600 mL/hm2 of concentration was not significantly different from that of M. anisopliae agent at 750 mL/hm2 of concentration, so the latter could be used while the locust density was higher.
Research review on herbicide activity of phytopathogeny mycotoxins
2009, 3(10): 160-164.
[Abstract](1635) [PDF 549KB](821)
Mycotoxin with herbicide activity could be excreted by many plant pathogenic fungi. It can make weeds be albino and wilting, restrain the growth of weeds or kill weeds. Fermentation solution or crude toxins of many biocontrol agents to weeds also have weed controlling activity. The utilization of mycotoxin became one of the hot topics of researches on microbial herbicide in recent years. Different kinds of mycotoxin have different bioactivity, chemical structure, action site and mechanism and this could be a new approach for researchers to find out new herbicides. In this paper, the plant pathogenic mycotoxin as biocontrol agent was discussed in its herbicidal activity, control objects, mechanisms and biocontrol effect on weeds and the role for new herbicide development.
Study on evapotranspiration of three coldseason turfgrasses by using SPAC
2009, 3(10): 165-170.
[Abstract](2020) [PDF 792KB](824)
The evapotranspiration dynamic of three coldseason turfgrasses (Lolium perenne, Poa pratensis, Festuca arundinacea) were studied in Beijing area using field test combined with laboratory analysis. The results showed that the evapotranspiration dynamic of 3 coldseason turfgrasses with 15 days interval kept a similar tendency. The evapotranspiration of L. perenne was higher than others except for the period from late April to early May. The evapotranspiration of 3 turfgrasses was obvious different among different seasons, the highest value appeared in mid June, and followed by that in late August and mid September, and the lowest value appeared before winter. The KC of L. perenne was the largest (1.03), and followed by F. arundinacea (0.89) and P. pratensis (0.87).
Regulation effects of PP333 on extension of tall fescue(Festuca arundinacea)
2009, 3(10): 171-176.
[Abstract](1931) [PDF 859KB](861)
Effects of PP333 on shoot extension and root feature of tall fescue (Festuca arundinacea Schreb.) were conducted under insidedoor pot condition.The results showed that, while the concentration of PP333 was from 100 to 1 900 mg/L, it suppressed growing speed, shoot extension, accumulation of aboveground biomass and root growth, elevated root area, volume, rootshoot ratio, tillering and accumulation of underground biomass of tall fescue; and significant correlations existed among these indexes and PP333 concentration. The tillering slowed when the concentration of PP333 over 1 000 mg/L; it had a little effects on extension distance of aboveground,coverage area and aboveground biomass when concentration of PP333 over 1 300 mg/L. The highest underground biomass, root volume and rootshoot ratio were obtained while the concentration of PP333 was 1 300 mg/L.
Control of brown spot by mixed cultivation of Medicago sativa and Elymus nutans
2009, 3(10): 177-180.
[Abstract](1666) [PDF 506KB](686)
The cultivating mode greatly affected the morbidity and extent of harm from brown spot in alfalfa. By contrast test between the mixed cultivation of Medicago sativa and Elymus nutans and the monoculture of M. sativa, the results indicated that the morbidity and severity of brown spot in alfalfa under the mixed cultivation were reduced by 7.02 and 16.8 percentage units respectively comparing with the monoculture, and it was an efficient ecological method to control the brown spot in alfalfa.
Effect of different irrigation amounts on alfalfa yield
2009, 3(10): 181-181.
[Abstract](1669) [PDF 0KB](402)
The fresh yield of alfalfa (Medicago sativa) and economic efficiency under different irrigation amounts were studied for exploring the watersaving and high yield irrigation patterns in Jingtai. The result indicated that the proper soil moisture within 20 to 40 cm in the growth period was 30% and the yield increased along with the increasing of irrigation amount, however, while the total irrigation amount reached 5 400 m3/hm2, the effect was not significant. The economic efficiency reached the highest while the total irrigation amount was around 5 400 m3/hm2.