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2020 Vol.37(3)

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2020, 37(3): 1-4.
[Abstract](1618) [FullText HTML] (686) [PDF 351KB](14)
Sustainable grassland management based on grazing system unit: Concepts and models
DONG Shikui, YANG Mingyue, REN Jizhou, SHANG Zhanhuan, ZHAO Xinyue, DONG Quanmin, LIU Wenting, Renqinduanzhi, DOU Shengyun, ZHOU Xueli, Tudanjia, SHI Dejun
2020, 37(3): 403-412. doi: 10.11829/j.issn.1001-0629.2019-0426
[Abstract](3639) [FullText HTML] (1016) [PDF 627KB](64)
Grazing systems are methords of grazing management that divide grazing land into units to create a stable pattern of grassland utilization for livestock and human residence. Subdivision of grasslands into grazing units can serve multiple functions, including support (such as soil conservation), provision (of animal fodder and animal products), regulation (such as climate regulation) and cultural services (heritage preservation). Damage to grassland, livestock, and human residence relationships results from inappropriate grazing management, which can easily lead to ecological and economic problems including grassland degradation and human poverty. Three models exist for rebuilding grazing units based on environmental and socioeconomic conditions: Joint household/farmer cooperative-based modern nomadic grazing patterns, household/small ranch-based settled grazing patterns, farmer cooperative/large ranch-based rotational grazing patterns.
Research progress on prevention and control of turfgrass thatch
ZHANG Ning, ZHOU Yanping, NIU Qichen, CHANG Zhihui
2020, 37(3): 413-422. doi: 10.11829/j.issn.1001-0629.2019-0270
[Abstract](1988) [FullText HTML] (759) [PDF 625KB](34)
Thatch refers to the semi-decomposed and semi-decaying organic matter between the surface and green plants, which is formed through accumulation of the roots, horizontal stems (stolons and rhizomes), and mature leaf sheaths of turfgrass. Thatch exists widely in the lawn ecosystem, and its thickness directly affects the quality and service life of the lawn, as well as its sports quality, such as elasticity, buffer, and trample resistance. Therefore, it is necessary to take appropriate measures to reduce the accumulation of thatch or accelerate the degradation of thatch. We summarized related literature at home and abroad on the relationship between thatch and grass seed selection, cutting, drilling, coring, vertical mowing, ultraviolet radiation, N fertilizer, lime, insecticides, fungicides, growth retardant, earthworm, microbes, enzymes, and biological materials. In this review, we describe the effects of these factors on thatch degradation mechanism from three aspects: improvement of soil physical and chemical properties, effects of soil nutrient content and proportion, and increased number of soil animals, microbes, and active enzymes.
Effects of grazing on leaf traits of four degraded indicator plants in Guinan
WANG Yalin, ZHU Wenyan, HOU Jiangjiang, GAO Qiaojing, ZHAO Xinquan, XU Shixiao, SUN Ping
2020, 37(3): 423-431. doi: 10.11829/j.issn.1001-0629.2019-0338
[Abstract](1682) [FullText HTML] (762) [PDF 629KB](34)
To study the response and adaptation strategies of degraded plants to environmental changes, the effect of grazing disturbance on leaf carbon, nitrogen and phosphorus content and their stoichiometric characteristics, leaf dry matter content, and specific leaf area were analyzed in four degraded indicator plants in the alpine meadow ecosystem of Guinan County, Qinghai.The results showed that the carbon, nitrogen, and phosphorus content and their stoichiometric ratio in the leaves of the four speciesshowed a trend of unchanged carbon content, increased nitrogen and phosphorus content, and decreased stoichiometric ratio (C/N, C/P, and N/P) with the increase of grazing intensity. Furthermore, the growth of plants was limited by nitrogen after heavy grazing. The interaction showed that the change in grazing intensity significantly affected the leaf traits of the four plants (P < 0.01), and had the greatest impact on leaf phosphorus content (P < 0.001). In addition, specific leaf area was the most affected by species, showing species differences among different plants. It was suggested that the four plants showed a trend of increased nutrient storage as grazing intensity increased, but the regulation of specific leaf area showed species specificity.
Effects of interaction of Epichloë gansuensis and arbuscular mycorrhizal fungi on the seedling growth and cadmium (Cd) tolerance of Achnatherum inebrians
ZHAO Zhenrui, ZHONG Rui, ZHANG Xingxu
2020, 37(3): 432-443. doi: 10.11829/j.issn.1001-0629.2019-0276
[Abstract](23983) [FullText HTML] (1929) [PDF 1177KB](67)
The present study was conducted to measure the colonization rate of arbuscular mycorrhizal (AM) fungi under different growth conditions and to analyze the effects of interaction between Epichloë gansuensis, AM fungi, and Cd2+ on the growth of Achnatherum inebrians seedlings. The results indicated that colonization rate of AM fungi increased first and then decreased with the increase of Cd2+ concentration. AM fungi colonization rate of endophyte-infected (EI) A. inebrians was significantly (P < 0.05) higher than that of endophyte-free (EF) A. inebrians under a high concentration (0.9 mmol·L–1) Cd2+. However, the interaction of Cd and E. gansuensis had no significant (P > 0.05) effect on AM fungi colonization rate. Low Cd2+ concentration (0.3 mmol·L–1) significantly (P < 0.05) promoted plant growth, whereas high Cd2+ concentration (0.9 mmol·L–1) significantly (P < 0.05) inhibited plant growth. E. gansuensis significantly (P < 0.05) alleviated the damage to host plants under a high Cd2+ concentration (0.9 mmol·L–1). AM fungi significantly (P < 0.05) promoted aboveground growth but significantly (P < 0.05) inhibited belowground growth. The interaction of the three factors significantly (P < 0.05) promoted chlorophyll content and aboveground fresh weight, but significantly inhibited root length (P < 0.05). These results showed that both E. gansuensis and Cd2+ affected AM fungi colonization rate, but there was no interaction between them, and the interaction between these three factors affected the growth of A. inebrians seedlings aboveground and belowground.
Screening and analysis of ZjSGR transgenic creeping bentgrass (Agrostis stolonifera)
ZHOU Zhixiang, HAN Liebao, CHAO Yuehui, ZHANG Tiejun
2020, 37(3): 444-450. doi: 10.11829/j.issn.1001-0629.2019-0600
[Abstract](1565) [FullText HTML] (973) [PDF 1035KB](27)
SGR (stay green regulation) are key regulatory genes of chlorophyll metabolism, which play criticial roles in senescence process in plants. In this work, the ZjSGR gene isolated from Zoysia japonica was used to complete the transgenic creeping bentgrass (Agrostis stolonifera) by Agrobacterium-mediated method. A total of 19 regenerated creeping bentgrass plants were obtained after inducing callus, differentiation, rooting, seedling adaptation and planting in soil. By PCR technology, 15 seedlings were confirmed as transgenic plants, with ZjSGR gene inserted into genome successfully. After analyzing with RT-PCR, the ZjSGR gene were proved to be transcribed into mRNA in those plants. The Real-Time Fluorescence Quantitative RT-PCR (qRT-PCR) was used to select transgenic plant with a high expression level of ZjSGR gene, and the result showed that line 10, 13 and 15 had the top three expression levels of ZjSGR, which were selected for further experiments. The analyses of bio-physiology and chemistry in transgenic and WT plants showed that the chlorophyll contents and net photosynthetic rate were drastically decreased in three transgenic plants, while the contents of MDA and soluble sugar were obviously increased. Those results demonstrated that overexpression of ZjSGR gene in creeping bentgrass accelerated plant senescence by degradation of chlorophyll.
Leaf epidermal micromorphology of 14 species of Berberis from Shaanxi
WANG Yu, LIU Panlian, CAO Cuilan, YANG Wenquan
2020, 37(3): 451-458. doi: 10.11829/j.issn.1001-0629.2019-0387
[Abstract](1920) [FullText HTML] (755) [PDF 776KB](20)
The leaf epidermal micromorphology characteristics of 14 Berberis species from Shaanxi (samples were collected from the herbarium of Northwest A&F University) were observed under a light microscope. The results showed that the shapes of the epidermal cells were polygonal or irregular, with anticlinal walls straight and arched or undulate. There were different degrees of thickening in the stratum cuticula of the epidermis. All the 14 species were hypostomatic. The stomata were mainly anomocytic and the shapes of the stomatal apparatus were oval, long oval, or wide oval. These characteristics were related to their drought tolerance. The results of data analysis on the characteristics of the stomatal index, stomatal density, and ratio of stomatal length showed that the stomatal index of the 14 species of Berberis in Shaanxi was quite different, and can be used for identifying Berberis species. Stomatal density was obviously different among specific species, and can be used for identifying specific species in a small range.
Effects of copper on antixoidant enzyme activities, antioxidant and non-protein thiol content in Pontederia cordata’s leaves
MA Sisi, XIN Jianpan, CHEN Yidong, HOU Xinxing, TIAN Ru’nan
2020, 37(3): 459-468. doi: 10.11829/j.issn.1001-0629.2019-0340
[Abstract](1398) [FullText HTML] (822) [PDF 901KB](26)
Plants were cultivated in 50% Hoagland’s nutrient solution containing various concentrations of copper (i.e. 0, 5, 10 and 20 mg·L–1) to experimentally characterize the copper tolerance and detoxification mechanism of Pontederia cordata. Changes in antioxidant enzyme activities, and non-protien antioxidant and thiol content in P. cordata’s leaves were analyzed to determine the redox state regulatory activities of leaves under copper treatment. The results showed that the malondialdehyde (MDA) content in leaves increased under copper stress. Superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) activities first increased, and then decreased. Peroxidase (POD) and dehydroascorbate reductase (DHAR) activities increased, and catalase (CAT) activity decreased significantly with the expanded treatment time (P < 0.05). Accumulation of ascorbic acid (AsA) in leaves could be induced in early stages of copper treatment. Low concentration copper treatment (≤ 10 mg·L–1) had no significant effect on the dehydroascorbic acid (DHA) content (P > 0.05). Among the total non-protein thiol (NPT) contents, glutathione (GSH) significantly increased with expanded treatment time . The phytochelatins (PCs) first increased and then decreased. Low concentration (≤ 10 mg·L–1) and short-time copper treatment can enhance redox state regulatory activity in P. cordata leaves, improve the ability of cells to resist oxidative stress, and enhance the tolerance of plants to copper treatment. However, this stimulating effect is destroyed by higher concentrations, and longer copper treatment.
Tissue culture studies, and the plant regeneration system of Sinningia hybrida ‘Isa’s Murmur’
LUO Pengrui, ZHANG Fan, CUI Jie, LIU Qinghong, CHENG Beixi, CAO Ningning
2020, 37(3): 469-476. doi: 10.11829/j.issn.1001-0629.2019-0274
[Abstract](4964) [FullText HTML] (928) [PDF 558KB](83)
The effects of various disinfection methods, the basic medium and exogenous hormone ratios on callus inductions, adventitious bud inductions, proliferation, and rooting were investigated using leaves from Sinningia hybrida ‘Isa’s Murmur’ as explants.We established a regeneration system via tissue culture of S.. The results showed that when leaf tissue of S. was sterilized with 75% ethanol for 10 s followed by 0.1% mercuric chloride for 300 s, the pollution rate was the lowest (15.56%). MS medium with 2.0 mg·L–1 6-BA and 0.1 mg·L–1 NAA exhibited the highest callus inductions rate (91.11%). The 50% MS medium with 2.0 mg·L–1 6-BA and 0.05 mg·L–1 NAA was optimal for adventitious bud inductions, with a adventitious bud induction rate of 88.89%. The optimal medium for adventitious bud proliferation was MS containing 2.0 mg·L–1 6-BA and 0.1 mg·L–1 NAA. The proliferation rate was 2.38. The optimal rooting medium was 50% MS medium containing 0.1 mg·L–1 IBA, with a rooting rate of 87.78%. The survival rate was above 96.67% when plantlets were moved into mixed matrices containing 1 humus: 2 peat soil: 2 river sand. The results of these studies can provide a basis for genetic transformation and large-scale propagation of Sinningia hybrida ‘Isa’s Murmur’.
Effects of slope aspect on component traits, biomass structure and water distribution of Arthraxon hispidus
ZENG Xiaolin, WANG Dawei, LIU Jinping, LIU Li, MA Yong
2020, 37(3): 477-485. doi: 10.11829/j.issn.1001-0629.2019-0347
[Abstract](2061) [FullText HTML] (736) [PDF 483KB](17)
In the study, wild Arthraxon hispidus invaded into degraded lawn of three slope directions was used as the research object. Indexes including the quantitative and qualitative characters of leaves, stems and roots, the biomass accumulation and distribution ratio and water content of plants were measured. The effects of slope direction on component traits, biomass structure and water distribution ratio of A. hispidu was analyzed. The purpose was to study the growth strategy and coping ability of A. hispidu in the heterogeneous habitats. The results showed that: 1) Slope direction had significant effects on light intensity, soil water content and soil thickness (P < 0.05), which resulted in significant differences in the coverage of A. hispidu. 2) Slope direction had significant effect on the traits of leaf, stem and root (P < 0.05). By adjusting the number of leave, tiller and root, A. hispidu changed leaf area, plant height, internode length and root length, which could form components and shapes adapting to the slope habitat. 3) Slope direction had a significant effect on biomass accumulation (P < 0.05). The biomass per plant on sunny slope was significantly larger than that on shady and semi-shady slopes. The biomass on sunny slope was preferentially distributed to stems, while that on shady slope was distributed to the leaves. The adaptability and stress resistance of A. hispidu were increased by adjusting the distribution ratio of biomass. 4) Slope direction had a significant effect on water content of plant. Water content in sunny and shady slopes was greater than that in semi-shady slopes. Water in sunny slopes was preferentially distributed to stems, while that in shady slope was preferentially distributed to roots. In conclusion, the growth strategy of A. hispidu can be adjusted according to the habitat of slope direction. A. hispidu all could form dominant species in three slope directions, which was suitable for popularization and application in planting slope lawn.
Effects of rest grazing on vegetation and soil characteristics of alpine steppe and alpine meadow in Tibet
GAO Xiaoyuan, LU Xuyang
2020, 37(3): 486-496. doi: 10.11829/j.issn.1001-0629.2019-0423
[Abstract](2448) [FullText HTML] (828) [PDF 972KB](54)
Rest grazing is one of the primary grazing management and grassland protection strategies in Tibet to restore the vegetation and soil in degraded grasslands and maintain high diversity and biomass through natural regeneration. Considering the alpine steppe and alpine meadow in central Tibet as the research object, the effects of free grazing and rest grazing on plant species diversity, total biomass, balance between aboveground and underground biomass, and physical and chemical properties of alpine steppe and alpine meadow soils were studied through field investigation and laboratory experiment analysis. The results showed that rest grazing reduced Simpson, Pielou, and Shannon-Wiener indices of the plant community and increased the total biomass of vegetation in both alpine steppe and alpine meadow; however, the variations did not achieve any statistical significance. Furthermore, rest grazing increased the balance value of aboveground and underground biomass, thereby contributing to the growth and development of aboveground vegetation. The effect was more obvious in alpine meadow. In addition, no significant difference was observed in the effects of rest grazing and free grazing on soil mechanical composition, soil microaggregates, and soil nutrients in the alpine grasslands. Therefore, rest grazing exerted no obvious effects on vegetation restoration in the alpine grassland of Tibet, and no significant differences were observed between rest grazing and free grazing grasslands in terms of biodiversity of the community, vegetation biomass, and soil physical and chemical properties. As a consequence, the effect of rest grazing remains to be evaluated and studied in the future.
Effect of Rhizobium inoculation on alfalfa under subsurface drip irrigation
Rebigul ·Rehman, LUO Ming, LI Weijun
2020, 37(3): 497-505. doi: 10.11829/j.issn.1001-0629.2019-0223
[Abstract](1153) [FullText HTML] (662) [PDF 695KB](13)
A locally isolated Rhizobium strain (Sinorhizobium meliloti XGL026) labeled with the green fluorescent protein (GFP) gene was used to inoculate alfalfa to quantify competitive nodulation performance and evaluate the effect on yield and quality of alfalfa in the field under subsurface drip irrigation. The results showed that inoculating rhizobia under drip irrigation from the first to third cuts of 4-year-old alfalfa could significantly increase the number and weight of nodules and increase the percentage of nodules (P < 0.05). Compared to controls with only N+P+K and P applications, Rhizobium inoculation treatment increased the average nodule number from the first to third cuts by 16.4 and 21.2 per individual plant, the average nodule weight by 0.029 and 0.033 g, and the average nodulation rate by 49% and 78%, respectively. Rhizobium inoculation could significantly increase the fresh and dry yield from the first to third cuts by 15.8% and 18.9%, respectively, compared with those of the controls. The crude protein content increased by 2.16%, whereas the NDF and ADF decreased by 3.25% and 5.00%, respectively, which indicated that the quality of alfalfa was significantly improved. The effect of applying nitrogen and phosphorus fertilizers and simultaneously inoculating with rhizobia (treatment XGL026+N+P) was better than applying only phosphorus and inoculating with rhizobia (XGL026+P). The results showed that XGL026+N+P had better inoculation effect; it also significantly increased the nodulation capacity, and yield and quality of alfalfa, and reduced the application of chemical fertilizers. This study provides a scientific basis for the application of Rhizobium inoculation to improve the quality and efficiency of alfalfa production under drip irrigation.
Progress in research of grass hemicellulose
CHEN Sihui, XU Hua, HUANG Fei, ZHOU Gongke, CHAI Guohua, DONG Guoqing
2020, 37(3): 506-513. doi: 10.11829/j.issn.1001-0629.2019-0326
[Abstract](1501) [FullText HTML] (953) [PDF 540KB](38)
Hemicellulose is an important component of the cell wall of grasses and can be directly or indirectly used for in food, materials and chemical industries. Hemicellulose of different species contains diverse sucrose such as xylan, xyloglucan, mannan, and their derivatives. These sugars have species- and cell type-specific backbone and side chains with different lengths. In this atical, we have reviewed the structure, biosynthetic process, and roles of hemicellulose components of grasses to lay, a foundation for the comprehensive and in-depth study of grass hemicellulose.
Productive performance of oat rotation in spring fallow in Wumeng Mountain Area
XU Lijun, LIU Qian, XIAO Shiliang, RAO Yanzhang, ZHAO Dongqi, SUN Qizhong, WANG Bo
2020, 37(3): 514-521. doi: 10.11829/j.issn.1001-0629.2019-0287
[Abstract](1216) [FullText HTML] (680) [PDF 502KB](17)
To solve the problem of idle spring fields and low yield per unit land area in Wumeng Mountain area, China, a comprehensive evaluation test of the production performance and nutritional quality of 12 oat varieties was carried out. The results showed that, among the 12 oat varieties, Aiwo, Yanwang, and Lingxiu had the best performance in terms of hay yield at 14.42, 14.13, and 12.13 t·ha–1, respectively. In terms of nutritional quality, Muwang and Beile No.2 showed the highest crude protein content, the highest neutral detergent fibers content, and low acid detergent fibers level. Through calculation of the protein yield per unit area of the different oat varieties, it was concluded that Yanwang, Muwang, Aiwo, and Meida performed the best, with protein yield of up to 1.22, 1.16, 0.96, and 0.92 t·ha–2. Yanwang and Muwang had the largest weighted correlation and the best comprehensive production performance. They can be used as the main varieties in the idle spring fields of Wumeng Mountain area.
Effects of Epichloë endophyte on the growth and nutritional quality of different geographic populations of Festuca sinensis
WANG Kai, WANG Weilin, WANG Haobang, PEI Tianyue, DONG Xin, LIN Weihu, TIAN Pei
2020, 37(3): 522-531. doi: 10.11829/j.issn.1001-0629.2019-0312
[Abstract](1650) [FullText HTML] (680) [PDF 811KB](19)
To investigate the effects of Epichloë endophyte on the growth and nutritional quality of different ecotypes of Festuca sinensis, six ecotypes of endophyte-infected (E+) and endophyte-free (E−) Festuca sinensis were established. The plant seeds were obtained from Qinghai and Sichuan provinces and compared for their growth (tiller, stem diameter, leaf width, plant height, fresh weight, and dry weight) and nutritional quality (crude fat, crude protein, crude ash, and moisture content) under pot cultures in a greenhouse. The results are as follows: 1) Epichloë endophyte had a significant impact on the height, tiller, stem diameter, fresh weight, crude fat, crude protein, and moisture content of ecotypes (P < 0.05), and these effects were different for different ecotypes. The height of ecotype 84 E+ was significantly higher than that of E− plants (P < 0.05), while the crude fat content of ecotypes 41 E+, 57 E+, and 141 E+ was significantly higher than that of the corresponding E− plants (P < 0.05). The crude protein content of ecotypes 41 E+, 99 E+, and 141 E+ plant was significantly higher than that of the corresponding E− plants (P < 0.05), and the moisture content of the ecotype 99 E+ was significantly higher than that of E− plants (P < 0.05). Moreover, tillering number was significantly lower for ecotype 57 E+ than that for E− plants (P < 0.05), while the stem diameter of ecotype 99 E+ was significantly lower than that of E− plants (P < 0.05). The height of ecotypes 57 E+ and 99 E+ was significantly lower than that of the corresponding E− plants (P < 0.05), and the crude protein content of ecotype 57 E+ was significantly lower than that of E− plant (P < 0.05). 2) Significant differences were reported in tiller, stem diameter, plant height, fresh weight, crude fat, and crude protein content among different geographical populations, while the performance of various groups was different (P < 0.05). Among the six endophyte-free (E−) F. sinensis populations, the tiller number of ecotype 57 was significantly higher than that of the ecotypes 84 and 99 (P < 0.05), and the crude protein content was significantly higher for ecotype 57 than that for the other five ecotypes (P < 0.05). The height of ecotype 111 was significantly higher than that of ecotypes 84 and 99 (P < 0.05), and the crude fat content of ecotype 111 was significantly higher than that of the ecotypes 41 and 99 (P < 0.05). Among the six endophyte-infected (E+) F. sinensis populations, ecotype 111 had significantly higher tiller number and stem diameter than the other five ecotypes (P < 0.05). Both fresh weight and dry weight of ecotype 141 were significantly higher than those of ecotypes 41 and 84 (P < 0.05), while the crude fat content of ecotypes 111 and 141 was significantly higher than that of ecotypes 41, 84, and 99 (P < 0.05). Comprehensive analysis of growth and nutrition indicators showed that ecotypes 57 and 111 were the best among the six endophyte-free (E−) F. sinensis populations, while ecotypes 111 and 141 were the best among the six endophyte-infected (E+) F. sinensis populations. In summary, the endophytic fungi promoted growth (84) and improved nutritional quality (41 and 141) or restrained growth (99) and reduced nutritional quality (57). Thus, the host genotype had a significant impact on the growth and nutritional quality of Epichloë endophyte-F. sinensis symbiont (P < 0.05).
Selection of high-yield and good-quality oat varieties in the eastern agricultural area of Qinghai Province
ZHAO Yiwei, MA Xiang, ZHANG Ran, MA Huiling
2020, 37(3): 532-541. doi: 10.11829/j.issn.1001-0629.2019-0252
[Abstract](3338) [FullText HTML] (877) [PDF 499KB](39)
To select good-quality oat varieties suitable for planting in the eastern agricultural area of Qinghai Province, eight local main oat varieties were studied. The agronomic characteristics, yield, and quality of the tested varieties were analyzed and compared, and their adaptability is evaluated by membership function. The results showed that the forage yield and quality of the eight oat varieties in the flowering stage were as follows from high to low: Qinghai 444 > Qinghai Sweet oat > Qingyan No.1 > Qingyin No.1 > Jiayan No.2 > Baiyan No.7 > Qingyin No.2 > Lena. The grass yield of Qinghai 444 was the highest at 39 091.29 kg·ha–1, whereas Qinghai Sweet oat ranked the second, and they both have low fiber content, which led to better palatability. The grass yield and crude protein content of Qingyan No.1 were higher than those of the other tested varieties. Therefore, it is suggested to plant Qinghai 444, Qinghai Sweet oat, and Qingyan No.1 for harvesting forage. The order of the eight oat varieties in terms of seed yield and forage quality were as follows from high to low: Baiyan No.7 > Qinghai Sweet oat > Qingyan No.1 > Lena > Qinghai 444 > Qingyin No.2 > Jiayan No.2 > Qingyin No.1. The crude protein content (3.74%) of Baiyan No.7 was the highest, but its seed yield (5 528.01 kg·ha–1) was lower than that of Lena (5 888.69 kg·ha–1). The seed yield of Qingyan No.1 was low. Thus, it is suggested to plant Baiyan No.7, Qinghai Sweet oat, and Lena for high seed yield.
Effects of cattle and sheep grazing on the community stability of grass/Trifolium repens grasslands Yungui Area
WANG Wen, HU Tinghua, LIU Huijin, ZHAO Yijun, XU Zhen, MAO Wenya
2020, 37(3): 542-549. doi: 10.11829/j.issn.1001-0629.2019-0275
[Abstract](1415) [FullText HTML] (630) [PDF 680KB](35)
Grass/Trifolium repens grassland is one of the main grazing and mowing pastures in the karst areas of southern China. To clarify the influence of vegetation composition and community stability of grass/T. repens grasslands grazed by different livestock grazing, which will reveal its vegetation succession characteristics to a certain extent. The plant community characteristics, species diversity, biomass composition and community stability of grass/T. repens grasslands under cattle and sheep grazing were quantitatively analyzed in this study. The results showed that: 1) the biomass of dead matter and the number of plant species on the grasslands were GC > GS, while the species Simpson index was GS > GC. 2) the aboveground biomass components of the lawn grasses (Lolium perenne, Dactylis glomerata and native grasses), native dicotyledon (Verbenaceae, Plantaginaceae, Oxalidaceae and Cruciferae) and medium palatability herbages were GC > GS; while the seeding white clover composition was GS > GC. In addition, the aboveground biomass dominated by grasses (77.20%) for GC and by grasses (51.79%) and leguminous (28.02%) for GS. 3) the content of K in the grassland soil was GC > GS. 4) the species Raunkiaer frquency histogram of GC was inversely J-type, and community succession value was GS (45.45)> GC (37.08). The research shows that the community of GC is relatively stable, while GS is in a higher stages of succession, and for the maintaining of community stability and species diversity of grass/T. repens grasslands, cattle’s grazing is more benefited than the sheep. Therefore, mixed grazing or rotation grazing of cattle and sheep can be implemented to improve the stability and productivity of grass/white clover grasslands.
Genetic diversity analysis of the main agronomic traits and nutritional in 18 oat cultivars introduced to Lhasa
ZHOU Qilong, Duojidunzhu, Tudengqunpei, LIU Yunfei, Yixiyangzong
2020, 37(3): 550-558. doi: 10.11829/j.issn.1001-0629.2019-0335
[Abstract](2414) [FullText HTML] (826) [PDF 628KB](21)
This study aimed to elucidate the genetic diversity of the main agronomic traits in 18 oat (Avena sativa) cultivars introduced to Lhasa. A total of 18 agronomic traits were calculated by diversity analysis, clustering analysis, and principal component analysis. The results showed that the diversity index was from 1.458 to 2.054, and the average diversity index reached 1.87. The introduced oat cultivars showed abundant genetic diversity, showing large differences in the same characteristics and high coefficient of variations in different characteristics. Large coefficients of trait variation were observed for dry grass yield (52.354%) and flag leaf length (51.946%). Based on cluster analysis, 18 oats were classified into four groups. Group Ⅰ included 11 different cultivars, that belonged to the high stem group. Group Ⅱ included one cultivar that belonged to the high dry grass yield group. Group Ⅲ consisted of two different cultivars that belonged to high nutrition and more grains group. Group Ⅳ included four different cultivars that had better performance in different indicators and suitable for introduction to Lhasa. According to principal component analysis, the first five components (leaf yield and seed yield factor, ADF and NDF factor, ash factor, stem leaf ratio and crude protein factor, and plant height factor) contributed 79.592% to the variation. We constructed a comprehensive evaluation model by using the five principle components and calculated the integrated score, and screened Baler Ⅱ, Haymaker, and Haiwee as oat cultivars suitable for planting in Lhasa.
Effects of different barely/common vetch diets on nutrient digestibility and greenhouse gas emission of sheep
LIU Fuyao, ZHANG Cheng, WANG Chunmei, HOU Fujiang, NAN Zhibiao
2020, 37(3): 559-565. doi: 10.11829/j.issn.1001-0629.2019-0204
[Abstract](1588) [FullText HTML] (701) [PDF 516KB](34)
Here we evaluate the effects of different proportions of common vetch (Vicia sativa) diets on the digestibility and metabolism as well as greenhouse gas emission of sheep. Twelve 6-month-old hybrid rams weighing 30 ± 1 kg were chosen and randomly assigned into two groups. The animals from the two groups were fed with different diets supplemented with different proportions of common vetch. Dietary barely∶common vetch was in the ratio of 8∶2 or 6∶4. The pre-test period lasted for 15 days, and the trial period lasted for 9 days, after which the sheep were transferred to metabolic cages for digestion and metabolism trial using total urine and fecal collection method. The result revealed no significant differences in dry matter intake and nutrient digestibility between the two groups (P < 0.05). The daily O2 consumption per kilogram body weight BW0.75 in the 6∶4 group tended to be higher than that in the 8∶2 group (P = 0.083). No significant difference in CH4 and CO2 daily emission was observed between the two groups (P < 0.05). Thus, the feeding effect of 20% common vetch and 40% common vetch on nutrients digestion and greenhouse gas emission of sheep was similar.
Effects of fermented rapeseed meal on growth and serum indices in white male muscovy ducks
CHEN Xiaolian, ZHAN Jinshun, ZENG Yanbing, ZHOU Quanyong, ZHAO Pin, LIU Linxiu, SONG Qiongli, ZOU Zhiheng
2020, 37(3): 566-573. doi: 10.11829/j.issn.1001-0629.2019-0427
[Abstract](1784) [FullText HTML] (746) [PDF 461KB](13)
To study the effects of supplementing diet with varying doses of fermented rapeseed meal on growth and serum indices in white male muscovy ducks, four-hundred and eighty 28-day-old white male muscovy ducks all of the same hatching cohort and of similar body weight were randomly divided into 4 groups, with 6 replicate subgroups of 20 ducks each. Ducks in the control group were fed a corn-soybean basal diet. Ducks in the experimental groups were fed the basal diet supplemented with 12%, 16%, or 20% fermented rapeseed meal. The experimental period was 21 days. The results are as follows: 1) the final body weight and average daily weight gain in the control group and the 16% group were significantly higher than those in the other groups (P < 0.05). The average daily feed intake in the control group was significantly higher than that in the other groups (P < 0.05). 2) Serum total protein, total cholesterol, high-density lipoprotein, and low-density lipoprotein were significantly lower in the 16% group than in the 12% group (P < 0.05). Alanine transaminase and alkaline phosphatase activities were significantly higher in the 16% group than in the 12% group (P < 0.05), but tetraiodothyronine concentrations displayed an opposite trend. 3) Superoxide dismutase activity was significantly lower in the 16% group than in the control group (P < 0.05). No significant differences were observed in other indices of antioxidant functions. In conclusion, fermented rapeseed meal can be added to the diet without negatively impacting the growth performance of ducks. Supplementation with 16% fermented rapeseed meal had good efficacy in this study.
Study on the structural characteristics of plateau zokor tunnels based on ground-penetrating radar
ZHANG Wuzhao, MA Yujun, LI Xiaoyan, WANG Lei
2020, 37(3): 574-582. doi: 10.11829/j.issn.1001-0629.2019-0339
[Abstract](1348) [FullText HTML] (716) [PDF 917KB](23)
Plateau zokor (Eospalax baileyi) is a small cave dwelling animal peculiar to the Qinghai-Tibet Plateau. Quantifying the structure of plateau zokor tunnels can provide a foundation for future studies on the effect of its disturbance on the ecological environment. Ground-penetrating radar (GPR) can acquire the structural characteristics of underground tunnels in a nonvisible, nondestructive, and highly efficient manner. In this study, the depth, diameter, and direction of plateau zokor tunnels were investigated using the GPR method, and compared with those obtained with the traditional digging method. The results showed that the tunnel position obtained by GPR was consistent with that obtained by excavation, and there was no significant difference between these two methods in tunnel diameter and depth (P > 0.05), indicating that the GPR method was able to obtain accurate results. The depths of plateau zokor tunnels ranged from 1.6 cm to 19.8 cm, with an average value of 11.9 cm; the diameters of the tunnels ranged from 2.1 cm to 14.4 cm, with an average value of 9.1 cm; the underground tunnels fluctuated slightly, but was generally distributed in the same horizontal plane. Moreover, there was a good correspondence between the location of the underground tunnels and the distribution of land surface mounds; the tunnels under the new mounds were more continuous and the tunnels under the old mounds were more fragmented. In general, the structural characteristics of plateau zokor tunnels were successfully obtained by GPR, and we were able to study the mechanism of its influence on soil properties and vegetation characteristics, and to further comprehensively assess the role of plateau zokor in the entire ecosystem.
Evaluation of the silage quality of ramie mixed with rice and/or maize straws
CHEN Jikang, DONG Guoyun, YU Chunming, CHEN Ping, GAO Gang, CHEN Kunmei, WANG Xiaofei, ZHU Aiguo
2020, 37(3): 583-591. doi: 10.11829/j.issn.1001-0629.2019-0389
[Abstract](2345) [FullText HTML] (667) [PDF 575KB](31)
In this study, the feasibility of producing a mixed ramie silage was investigated and its feed value was determined by sensory and nutritional evaluations. Fresh ramie was mixed with dried straws of maize and/or rice at the weight ratios of 1∶1∶0 (ZY), 1∶0∶1 (ZD), 2∶1∶1 (ZH), and 1∶1∶1 (ZL), or with sucrose at the weight ratio of 99∶1 (ZT), and whole fresh ramie silage was used as the control. The results showed that ramie alone (the control) could be used for silage, having improved feed value in terms of decreased neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents and increased dry matter intake and relative feed value. However, 23.6% of the crude protein (CP) was lost during ensiling, and a bad fermentation quality was acquired owing to the high pH and poor texture. Exogenous sucrose supplementation played a positive role in decreasing the CP loss but a negative role in improving the feed value. Although the silages of ramie mixed with maize and/or rice straws had lower CP losses, enhanced fermentation quality, and balanced nutrient components, their feed values were decreased owing to the increased NDF and ADF. The mixed ramie and rice straw silage (ZD) had a better feed value but worse fermentation quality and more CP loss than the mixed ramie and maize straw silage (ZY). The ZD and ZY silages showed better feed values than the ZH and ZL silages. We concluded that mixed silage preparations containing fresh ramie should be an effective way to tap into the feed value of the roughage, and further studies on regulating the NDF and ADF contents should be conducted.
Research progress of biological nitrification inhibitor (BNI) in improving nitrogen use efficiency in agricultural production systems
WANG Li, Saman BOWATTE, HOU Fujiang
2020, 37(3): 592-602. doi: 10.11829/j.issn.1001-0629.2019-0190
[Abstract](2128) [FullText HTML] (839) [PDF 823KB](44)
Fertilization is one of the main methods to improve agricultural productivity. Improving nitrogen use efficiency is one of the core issues in chemical fertilizer application. Nitrate-nitrogen leaching and nitrous oxide (N2O) emissions caused by nitrification and denitrification are the main reasons for low nitrogen utilization rate, and N2O is a greenhouse gas that causes a sharp rise in global temperatures. Biological nitrification inhibition refers to the ability to release a natural compound that inhibits nitrification from the roots of plants. The released natural compound is called a Biological nitrification inhibitor (BNI), which specifically inhibits the activity of microorganisms in soil nitrification. BNIs can significantly increase the yield of rice, corn, and other crops by approximately 5%~10% and corn utilization of nitrogen by 3.1%, as well as decrease emission of greenhouse gases, such as N2O, by 90% compared to those in non-BNI plants. The BNI “Brachialactone”, which is released by Brachiaria plants, exerts nitrification-inhibitory effect, inhibiting 60%~90% of the total nitrification. The above findings show that BNIs play an important role in inhibiting nitrification, increasing nitrogen utilization, increasing crop yield, and decreasing greenhouse gas emission. This paper reviews the plants known to release BNIs and plants known to inhibit soil nitrification but with unknown BNIs, and further discusses the important role of bio-nitrification inhibition in agricultural systems.