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Effects of arbuscular mycorrhizal fungi on growth parameters, nutrient absorption, and interspecific competition of herbs on iron tailings
WU Hui, CHEN Baodong, ZHU Yongguan, YUE Xianrong, ZHANG Naiming, XIA Yunsheng
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0399 doi: 10.11829/j.issn.1001-0629.2021-0399
[Abstract](159) [FullText HTML] (28) [PDF 1201KB](4)
The greenhouse pot experiment method was used to study the effects of the arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae (FM) and three different planting patterns on growth parameters, mineral nutrient absorption, and inter-species competition of white clover (Trifolium repens) and ryegrass (Lolium perenne) on iron tailings. This study aimed to identify a type of cultivation mode that could not only increase plant colonization but also improve the introduction of pioneer plants in tailings and to provide a theoretical and application basis for plant restoration on iron tailing wasteland. The results showed that FM could establish a symbiotic with the two other plant species and had a higher rhizosphere mycorrhizal infection rate under mixed planting. The rhizosphere mycorrhizal infection rate of mixed planting white clover was the highest, with an average of 47.9%. Inoculation with FM significantly increased the phosphorus concentrations in white clover (168%~357%) (P < 0.05) and the phosphorus concentrations in ryegrass in mixed planting (10.5%) (P < 0.05) as well as the biomass of white clover (by approximately 5–7 times) (P < 0.05) and ryegrass in mixed mode (1.9 times) (P < 0.05). In mixed planting, plant iron concentrations were higher than that in single species. FM inoculation significantly decreased the iron concentrations in shoots of the two plants (P < 0.05), but the iron concentration in their roots increased. FM inoculation significantly increased the iron absorption of white clover and ryegrass under the single mode and significantly decreased the iron absorption of ryegrass under the mixed mode (P < 0.05). In the mixed planting mode, the two plants had higher iron absorption efficiency. FM inoculation significantly increased the iron absorption efficiency of white clover (P < 0.05) and decreased that of ryegrass. The mixed planting mode increased the zinc and manganese concentrations of plants but had no significant influence on the copper concentrations in plants. FM inoculation decreased the manganese concentrations of plants and had no significant influence on the copper or zinc concentrations. The white clover and ryegrass hybrid system has a land equivalent ratio greater than 1, which has a mixed advantage. The interspecific competitive ability of ryegrass compared with white clover was greater than 0, indicating a competitive advantage. Mycorrhizal fungi may improve the competitive ability of white clover. Mixed planting can, therefore, significantly promote the growth of ryegrass, whereas inoculation with FM can enhance the competitiveness of white clover. AMFs have great potential for use with pioneer plants to adapt to the complex adversity of iron tailings and to restore tailings pioneer vegetation.
Effects of alkali stress on the content of mineral elements in different organs of Chloris virgata
XIANG Yue, ZHAO Shuting, WU Hao, LI Zheng, ZHANG Zhenyu, WANG Huan
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0384 doi: 10.11829/j.issn.1001-0629.2021-0384
[Abstract](148) [FullText HTML] (24) [PDF 1050KB](0)
Chloris virgata is a naturally occurring alkali-tolerant halophyte. To explore the physiological mechanism underlying the alkali tolerance of C. virgata, we used 150 mmol·L−1 alkaline salt solution (NaHCO3 ꞉ Na2CO3 = 9 ꞉ 1) to treat C. virgata seedlings for one month. After the alkali stress treatment, we detected different mineral elements (Na, K, Ca, Mg, P, and Fe) and calculated the distribution of each mineral element among different organs (shoots, spikes, and roots). We also observed changes in leaf photosynthesis. The results indicated that long-term alkali stress strongly inhibited leaf photosynthesis and reduced the contents of K, Ca, P, and Mg in different organs. Analysis of the distribution of each element among the three organs showed that the relative contents of Na, K, Ca, Mg, and Fe in shoots were significantly higher than those in spikes and roots under alkali stress(P < 0.05). However, P still largely accumulated in the spike under alkali stress, and the contribution of P to the total element in the spike reached 49.80% under the control condition and 50.02% under the alkali stress condition. Analysis of the contribution percentage of each element to the total showed that K content was much higher than that of other elements in all organs, followed by Ca and P. Under alkali stress conditions, Na was extensively accumulated in all three organs, especially in shoots, where Na accumulation was enhanced from 0.707% to 28.397% by alkali stress. The shoot Na content of the alkali stress treatment was 28.399-fold that of the control treatment. However, under alkaline stress conditions, the spikes of C. virgata maintained a high K content, which supports the normal growth of the spike. In conclusion, C. virgata can complete its life cycle under long-term alkali stress conditions because of its strong ability to regulate Na. C. virgata protects young spikes under long-term alkali stress by enhancing the accumulation of Na in roots and shoots and lowering the accumulation of Na in the spike. C. virgata can also maintain a normal level of P to preserve normal physiological metabolism and relieve the damage caused by alkali stress.
Study on the role of weeds in the productivity improvement of “raising geese in corn field” system
YU Haoran, GUAN Fachun, MIAO Yanjun, GUO Yonggang, XIE Jiao
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0412 doi: 10.11829/j.issn.1001-0629.2021-0412
[Abstract](242) [FullText HTML] (39) [PDF 981KB](11)
In this study, the effects and status of weeds in the improvement of farmland productivity in the “raising geese in corn field” system were determined by analyzing and comparing the “raising geese in corn field” (GCF) treatment and conventional herbicide treatment (CK). The results showed that the weed diversity under GCF treatment was better than that under CK, and the weed yield was significantly higher than that under CK (P < 0.05). However, the presence of weeds seriously affected the growth of maize (Zea mays), and the leaf area of maize treated with GCF was significantly lower than that under CK before and after grazing (P < 0.01), directly leading to a maize yield reduction of 40.64%. The correlation analysis results showed that both weed yield and diversity were key factors that led to maize yield reduction; the R values were −0.689 and −0.881, respectively, but as the number of geese eating weeds under GCF treatment reached 60.24 t·hm−2, the comprehensive income under GCF treatment was still 137.11% higher than that under CK as the geese ate weeds and turned them into an economically viable product. Therefore, weeds play a vital role in the economic benefits from “raising geese in corn fields,” which indicates a new way for treating weeds in the future.
Effect of Sodium Hypochlorite on Physiological Characteristics of Nitraria tangutorum Open Tissue Culture Seedlings
BIAN Hongying, SU Shiping, LI Yi, WANG Xinxin
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0094 doi: 10.11829/j.issn.1001-0629.2021-0094
[Abstract](242) [FullText HTML] (34) [PDF 1293KB](2)
Taking the tangutorum tissue culture seedlings grown by traditional tissue culture technology as a control, using an open tissue culture method, different concentrations of the bacteriostatic agent sodium hypochlorite were added to N. tangutorum spur medium. According to physiological characteristics, the effects of the bacteriostatic agent were evaluated for tissue cultured N. tangutorum plants. The results showed that with the increase in the sodium hypochlorite concentration, the antibacterial effect on N. tangutorum medium gradually increased. Sodium hypochlorite at a concentration up to 50 mg·L−1 inhibited the root number and root length of N. tangutorum tissue culture seedlings. A sodium hypochlorite concentration of 15–20 mg·L−1 promotes the growth of N. tangutorum tissue culture seedlings. The addition of sodium hypochlorite in the open tissue culture enhances the autogenous metabolism of the tissue culture seedlings and significantly increases the concentration of superoxide anions (\begin{document}$O_2^ - $\end{document}) and hydrogen peroxide (H2O2). Compared with the traditional tissue culture, the accumulation of nutrients was inhibited in the tissue-cultured seedlings of N. tangutorum. Free proline (Pro), soluble sugar (SS), and soluble protein (SP) accumulate at high concentrations; when the sodium hypochlorite concentration is greater than 20 mg·L−1, the activities of antioxidant enzymes catalase (CAT), superoxide (SOD), peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia lyase (PAL) are significantly different compared with the control (P < 0.05). The comprehensive consideration of morphological indicators indicated that a sodium hypochlorite concentration of 50 mg·L−1 is extremely unfavorable for the growth of N. tangutorum tissue culture seedlings. Sodium hypochlorite at a concentration of 15–20 mg·L−1 can be used as a bacteriostatic agent for Nitraria open tissue culture.
Construction of radiation induced mutant population in Origanum vulgare ssp. hirtum
GUO He-feng, HE Yue, YIN Tingchao, CAI Dong, LIU Xinbao, ZHANG Jing, XU Bin
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0558 doi: 10.11829/j.issn.1001-0629.2021-0558
[Abstract](235) [FullText HTML] (31) [PDF 1160KB](0)
In this study, Greek oregano (Origanum vulgare ssp. hirtum) seeds were exposed to 60Co-γ -ray radiation to generate a mutant population for mutant screening with elite traits. The results showed that, with increasing dosage of radiation, the germination rate and germination potential of oregano seeds significantly decreased, and exposure to radiation dosages of 400 Gy or higher led to radical growth stagnation with seedling non-survival. A total of 8,170 M1 mutants were obtained at radiation dosages of 100 ~ 200 Gy. In comparison with the phenotypic traits of untreated control plants in the field, a group of mutants with tall plant height, short internode length, multiple shoot numbers, large leaf size, and varied leaf and flower colors were obtained, thus providing a foundation for breeding new, high-yielding, and high-quality oregano varieties.
Comparison of grassland vegetation coverage extraction algorithms from UAV technology
FU Shuai, FENG Qisheng, DANG Jingyang, LEI Kexin, QIAO Wanxin, LIANG Tiangang, PAN Dongrong, SUN Bin, JIANG Jiachang
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0363 doi: 10.11829/j.issn.1001-0629.2021-0363
[Abstract](235) [FullText HTML] (32) [PDF 5229KB](2)
Vegetation coverage is an objective index and an important parameter that reflects the basic extent of vegetation. In this study, we evaluated and analyzed the effectiveness of eight different visible-light-based vegetation indices for estimating the vegetation cover of different grassland types. Upon comparison of accuracy of these vegetation indices, we found that these vegetation indices were less effective in estimating the vegetation cover of desert grasslands. Therefore, we have proposed a desert vegetation index (DVI) to estimate the vegetation cover of desert grasslands. The effects of different vegetation indices on the vegetation cover estimation of different grassland types were evaluated, and the changes in the threshold values of different grassland types were analyzed. The results showed that: (1) The common vegetation indices could estimate the vegetation coverage in meadow grasslands and typical grasslands with a high accuracy (accuracy > 90%, F1 score > 0.9). The ExG (Excess green index) was the best in estimating the vegetation coverage in meadow grasslands (accuracy > 93%,F1 score > 0.95), and there was no significant difference among the estimation power of vegetation indices when estimating the coverage in typical grasslands. However, the common vegetation indices exhibited low accuracy of vegetation coverage estimation (F1 score ≦ 0.6) in desert grasslands. (2) The DVI proposed in this study has a high estimation accuracy of vegetation coverage in desert grasslands (accuracy > 93%,F1 score reached 0.71), which can effectively compensate for the defects of the above-mentioned vegetation indices. (3) The thresholds of GLI (Green leaf index) and CIVE (Color index of vegetation extraction) were the least sensitive to grassland types; the thresholds of ExG, ExGR (Excess green minus excess red index), VEG (Vegetative index), and WI (Woebbecke index) were less sensitive to the effects of meadow grasslands and typical grasslands, but more sensitive to the effect of desert grasslands; and COM (Combination index) and Lab (Lab index) were the most sensitive to all the grassland types considered in this study.
Effects of different ratios of starters of neutral detergent fiber to starch on digestive tract development of lambs
LIU Guohua, ZHAO Haibi, WANG Xiaojuan, PANG Xin, LYU Feng
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0041 doi: 10.11829/j.issn.1001-0629.2021-0041
[Abstract](175) [FullText HTML] (35) [PDF 883KB](3)
In this study, we investigated the effects of neutral detergent fiber (NDF) to starch ratios on the development of the digestive tract of lambs. Sixty male Hu lambs with similar birth weights (3.14 ± 0.05 kg) were randomly divided into three groups with 20 lambs in each group. At 10 days of age, the lambs were supplemented with NDF to starch ratios of 0.50 (group Ⅰ), 0.70 (group Ⅱ) and 1.00 (group Ⅲ). They were weaned at 35 days of age and slaughtered at 56 days of age. Following results were obtained: 1)The height of the rumen papilla, the height and width of the primary crease of the reticulum, and the thickness of the muscular layer in group Ⅱ were significantly higher than those in groups Ⅰ and Ⅲ (P < 0.05), while the height of the rumen papilla in group Ⅲ was significantly higher than that in group Ⅰ (P < 0.01). 2) The crypt depth of the duodenum and ileum in group Ⅱ was significantly lower whereas the thickness of the muscular layer was significantly higher than that observed in groups Ⅰ and Ⅲ (P < 0.05). The crypt depth of the duodenum in group Ⅲ was significantly lower than that in group Ⅰ (P < 0.01). In conclusion, starting diets with an NDF to starch ratio of 0.70 is beneficial for the digestive tract development of lambs. The results of this study can provide a reference for the preparation of starter diets for lambs.
Meta-analysis of the effects of nitrogen and water input gradients on maize yield, nitrogen fertilizer productivity, and water use efficiency in northern China
MO Qishun, QIN Wangfei, ZHANG Qingping, LI Zhou
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0535 doi: 10.11829/j.issn.1001-0629.2021-0535
[Abstract](165) [FullText HTML] (27) [PDF 7573KB](2)
This study was conducted to determine the overall performance of the effects of water, nitrogen, other environmental factors, and agronomic measures on maize (Zea mays) yield, nitrogen productivity (NP), and water use efficiency (WUE) under different environmental and climatic conditions. This study is based on 35 studies on the effects of nitrogen application and water input gradients on maize yield, NP, and WUE, using meta-analysis to explore the relevant factors affecting maize yield, NP, and WUE in northern China, and to quantitatively analyze the relationship between each influencing factor and maize yield, NP, and WUE. The results showed that the average maize yield was 9.19 t·hm−2, and the average of NP and WUE were 55.66 kg·kg−1 and 1.83 kg·m−3, respectively. Water and nitrogen had a significant interaction effect on maize yield. Compared with the control, water input and nitrogen application increased the overall maize yield by 13.43% (P < 0.01) and 10.69% (P < 0.01), respectively. As the input volume increased, water and nitrogen gradually became the main limiting factors for the increase in NP and WUE. In the regression analysis, the effects of water and nitrogen factors, soil organic carbon (SOC), planting density (PD), and available potassium (AK) on maize yield were positive, while that of the mean annual temperature (MAT) was negative. In the structural equation model (SEM), there was a strong positive correlation between SOC and maize yield, and its standardized path coefficient was 0.73. In summary, there is still room for improvement in the water use efficiency and nitrogen productivity of maize in northern China. Based on optimizing water and fertilizer measures, appropriate soil nutrient inputs could increase SOC and AK levels in the soil. Simultaneously, planting density can be increased appropriately, to achieve a win-win situation between high maize yield, water-use efficiency , and environmental protection.
Research progress on rumen microbiota and their regulation
GUO Hong, YANG Huichao, GAO Qiaoxian, XIN Guoshen
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0242 doi: 10.11829/j.issn.1001-0629.2021-0242
[Abstract](163) [FullText HTML] (26) [PDF 914KB](2)
Microorganisms are affected by aspects of the host environment, nutrition, and management, and play an important role in the life and production of ruminants. This review summarizes the establishment and mechanism of four different microflora, as well as their effects on animal metabolism. This review also lists the mechanisms of rumen regulation, which provides a reference for the application of rumen regulation technology, production performance, health improvement, and environmental emission reduction .
Comprehensive Evaluation and Evolutionary Characteristics of Eco-Environment Quality in Qilian Mountain National Park
YANG Lei, SHAN Shuyao, SANG Chen, LIU Yue, XU Haojie
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0392 doi: 10.11829/j.issn.1001-0629.2021-0392
[Abstract](174) [FullText HTML] (36) [PDF 2004KB](5)
Qilian Mountain National Park serves as a vital ecological security barrier in Western China, but mining, hydroelectric development, and overgrazing have resulted in serious ecological and environmental damage. Using remote sensing as well as meteorological and socio-economic statistical datasets of 14 counties in Qilian Mountain National Park from 2000 to 2018, this study established an assessment indicator system for eco-environmental quality. We also employed the principal component analysis method to determine the contribution of each indicator, which was then used to develop a new eco-environmental quality index (EQI). The spatiotemporal variations in the EQI and its influencing factors were examined. The results showed that the spatial distribution of mean annual EQI was characterized by low values in the west and high values in the east of Qilian Mountain National Park. The EQI varied significantly for the different counties. During the study period, the EQI of the national park showed a significant increasing trend (P < 0.05). The smaller the average EQI, the slower the rate of increase. Natural factors were the major driving force for the temporal variation of eco-environmental quality, followed by economic and social factors, showing a contribution of 52%, 28%, and 20%, respectively. The mean annual temperature and precipitation, annual average radiation, vegetation coverage, enhanced vegetation index, leaf area index, net primary productivity, gross output value of forestry, amount of livestock raised, grain planting area, value-added index of primary industry, per capita GDP added value index, natural population growth rate, the number of educated people, urban and rural household savings, per capita net income of rural residents, and non-agricultural population played a positive role. Value added index of secondary industry, value-added index of tertiary industry, agricultural population, and other indicators played a negative role. Our findings suggest the need for further implementation of natural forest protection, returning farmland to forest, and forbidden grazing programs in the future. Decision-makers need to improve the ecological compensation mechanism and eco-environment supervision. Strict limits on the intensity of human activities in the central and western parts of the national park should be set to promote the restoration of a fragile ecological environment.
Effects of grassland utilization on Microbial community structure in Hulunbeier grassland
WANG Deping, SONG Qian, LIU Zhongkuan, ZHAO Kun, LIU Yuling, XIAO Hong, CAO Jing, RONG Yuping
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0334 doi: 10.11829/j.issn.1001-0629.2021-0334
[Abstract](802) [FullText HTML] (295) [PDF 695KB](17)
Grassland soil microorganisms are key elements in maintaining the nutrient cycle function of ecosystems, and are sensitive indicators of changes in grassland ecosystems. Based on the study of soil microbial community composition and soil physicochemical properties under four utilization modes, namely enclosure, mowing, grazing, and reclamation in the Hulunbeier grassland, the effects of grassland utilization mode on grassland microbial communities were expounded. The results showed that: 1) After grassland reclamation, the soil total carbon (TC) and nitrogen (TN) content decreased by 41.45% and 45.08%, respectively, whereas the conductivity (EC) and available phosphorus (AP) content increased by 371.93% and 139.93%, respectively, and the phospholipid fatty acid (PLFA) content of the farmland microbial community was limited by carbon and nitrogen. 2) Compared with enclosed grassland, grazing grassland, and farmland, mowing significantly increased the PLFA of soil bacteria, fungi, actinomycetes, gram-positive bacteria (G+), gram-negative bacteria (G), and microbial communities. 3) According to the comprehensive analysis of the four grassland utilization modes, TC and TN were positively correlated with PLFA content of soil bacteria, fungi, actinomycetes, G+, G, and other microbial communities, while AP, pH, and EC were negatively correlated. Therefore, grassland reclamation resulted in soil carbon and nitrogen nutrient loss for farmland and further reduced the amount of PLFA in the microbial community. Considering the reduction in soil nutrients and PLFA in microbial communities, it is not recommended that hulunbeir grasslands be reclaimed as farmland.
Estimation of genetic parameters and breeding value of body weight at different stages of Hu sheep growth and development and genetic correlations with key feed efficiency indices
ZHAO Yuan, ZHANG Deyin, ZHANG Yukun, ZHANG Xiaoxue, LI Xiaolong, SONG Qizhi, ZHOU Bubo, LIN Changchun, ZHAO Liming, WANG Jianghui, XU Dan, CHENG Jiangbo, LI Wenxin, WANG Weimin
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0116 doi: 10.11829/j.issn.1001-0629.2021-0116
[Abstract](278) [FullText HTML] (33) [PDF 1040KB](1)
In this study, we sought to determine variance components and genetic parameters for the body weight traits of Hu sheep at different stages of growth and development, thereby providing a reference for Hu sheep breeding. In 2018 and 2019, we selected new-born male Hu lambs with complete pedigree records, and used the birth weight, weaning weight, and 100- and 180-day body weights to determine the feed intake from 100 to 180 days of age. Variance components were estimated based on a restricted maximum likelihood algorithm using ASREML-R, and body weight breeding values were estimated based on the best linear unbiased prediction at each test period. The results revealed that the variance of maternal permanent environmental effects was significant at different body weight stages (P < 0.05). The estimated heritabilities of birth weight, weaning weight, and body weight at 100 and 180 days of age were 0.43 ± 0.06, 0.27 ± 0.15, 0.46 ± 0.16, and 0.41 ± 0.12, respectively. The genetic and phenotypic correlations between different body weights ranged from 0.38 to 0.97 and from 0.25 to 0.84, respectively. The genetic and phenotypic correlations between feed conversion rate and body weight were 0.09 ~ 0.74 and 0.05 ~ 0.51, respectively, whereas the genetic and phenotypic correlations between residual feed intake and body weight ranged from −0.04 to 0.26 and from −0.15 to 0.039, respectively. We concluded that in Hu sheep, maternal effects have an important influence on the growth rate of lambs. Medium and high body weight heritability were identified at different growth stages, whereas we detected large differences among the genetic and phenotypes correlations between selected feed efficiency traits and body weight at different growth stages. Accordingly, careful selection at an early stage is necessary to reduce potential losses in economic benefits. If selection is practiced at an age of 100 days, improvement would be seen at an age of 180 days.
Effects of silage fermentation promoter and harvest stage on nutrient quality of whole silage maize
FAN Kaili, SU Yajun, WU Jianping, LI Yu, DOU Siyuan, ZHANG Rui, LI Zemin, JIA Li, LEI Zhaomin
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0095 doi: 10.11829/j.issn.1001-0629.2021-0095
[Abstract](257) [FullText HTML] (35) [PDF 962KB](4)
This study aimed to investigate the effects of silage fermentation promoters on the nutritional quality of whole-plant corn silage at different harvest stages. In 2018, ‘Yu silage 23’ was used as the test material, and three treatments (control, MAX, and MIX) were set at 1/2, 2/3, and 3/4 milk-line periods, repectively. After 60 days of silage, open-bag sensory evaluation and sampling were conducted to determine nutritional quality. The results showed that the silage fermentation promoter had no significant effect on the sensory evaluation of the whole plant silage corn (P > 0.05), which significantly affected ammonia nitrogen (NH3-N), lactic acid (LA), acetic acid (AA), dry matter recovery (DMR), dry matter (DM), crude protein (CP), and water-soluble carbohydrate (WSC) content (P < 0.01), as well as the pH, butyric acid (BA), and starch (ST) content (P < 0.05). The delayed harvest period had a significant impact on the whole plant corn silage LA, AA, BA, DMR, DM, CP, ether extract (EE), crude ash (Ash), neutral detergent fiber (NDF), acid detergent fiber (ADF), ST, WSC, 48h in vitro dry matter digestibility (IVDMD48 h), 48 h in vitro neutral detergent fiber digestibility (IVNDFD48 h), and total digestible nutrients (TDN) (P < 0.01), as well as the pH (P < 0.05). The gray correlation results show that the stage when the milk-line is at 2/3 is suitable for harvesting, and the silage fermentation promoter Sila-MIX is suitable for promotion and use in production practice.
Effects of degradation degree on plant communities and soil water holding capacity of Maqin alpine meadow
ZHANG Yuheng, ZHANG Li, ZHANG Xiujuan, YANG Yongsheng, WANG Junbang, XU Xingliang, HUANG Yuru, ZHAO Qiudong, LI Yingnian, ZHOU Huakun
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0388 doi: 10.11829/j.issn.1001-0629.2021-0388
[Abstract](330) [FullText HTML] (81) [PDF 1174KB](14)
To explore the influence of the degree of degradation on the success of plant communities and the water conservation capacity of alpine meadows in the Three Rivers Source Region, this study selected Maqin alpine meadow sample land with different degradation degrees in the source area of the Three Rivers on the Qinghai-Tibet Plateau. Through a combination of field monitoring and indoor tests, this study analyzed the effects of different degradation degrees on plant coverage, height, species number, biomass, soil bulk density, soil saturated hydraulic conductivity, and water holding capacity. The results showed the following: 1) The alpine meadow is in the process of continuous degradation, and the average height and coverage of plants in the Maqin alpine meadow decreased significantly by 41.1% and 58.5%, respectively (P < 0.05); the species number, richness, diversity index, and evenness index of vegetation decreased gradually, and the dominance index was the highest (0.18) in mildly degraded plots. 2) The aboveground, belowground, and total biomass decreased significantly with an increase in the degree of degradation (P < 0.05). Compared with the original vegetation sample plot, the aboveground, underground, and total biomass decreased by 49.8%, 71.1%, and 70.0%, respectively. 3) The effect of the degree of degradation on the soil water holding capacity and saturated water conductivity of alpine meadows decreased with increasing depth, and the effect on soil water holding capacity and saturated water conductivity of the surface layer (0 − 5 cm) was the most significant. Compared with the native vegetation, the 0 − 5 cm soil water capacity, field water capacity, capillary water capacity, and saturated water conductivity of the severely degraded alpine meadow decreased by 41.7%, 42.9%, 41.4%, and 84.4%, respectively. With an increase in the degree of degradation, the soil bulk density of the 0 − 5 cm soil layer of alpine meadow increased significantly (P < 0.05). In conclusion, as the degree of degradation increased, the species richness, diversity, evenness, and dominance of alpine meadow vegetation communities decreased. At the same time, the influence of the degree of degradation on the soil water holding capacity of alpine meadows is primarily concentrated in the 0 − 5 cm layer, and the surface matting of alpine meadows is the key to maintaining the water conservation function of this region.
Response of soil physical and chemical properties of zokor mounds to grazing management modes in an alpine meadow
ZHANG Qian, YAO Baohui, YANG Jing, CAI Zhiyuan, SUN Xiaomei, SU Junhu
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0042 doi: 10.11829/j.issn.1001-0629.2021-0042
[Abstract](214) [FullText HTML] (53) [PDF 1233KB](6)
The aim of this study was to study zokor (Eospalax baileyi) of different mound ages (one-year (ZM1), two-year (ZM2), three-year (ZM3), and Multi-year (ZMM)) and control meadow (CM) under four grazing management modes (rotational grazing (RG), growing season grazing (GSG), continuous grazing (CG), and prohibition grazing (PG)). The study was performed to evaluate the effects of grazing on soil physicochemical properties during the succession of zokor mounds and provides references for grazing management in alpine meadow. The results showed that GSG significantly increased the soil water content of ZM2 and ZM3 in 0 − 10 cm layers compared with PG. In addition, total nitrogen content of ZM3 in 0 − 10 cm, 10 − 20 cm, and 20 − 30 cm layers significantly increased (P < 0.05), respectively. Compared with CG, GSG significantly increased the total phosphorus content of ZM1 and ZM2 in 0 − 10 cm layers (P < 0.05), and RG significantly increased the soil C/N ratio of ZM2 in 0 − 10 cm and 10 − 20 cm layers (P < 0.05), respectively. Structural equation model analysis revealed that different management regimes had a positive effect on the soil water content, total nitrogen, and organic carbon of ZM3 and had positive effects on soil organic carbon and C/N ratio of ZMM. Therefore, GSG can better restore the soil nutrient content of zokor mounds compared with other grazing management modes.
Histochemical characteristics and differentiation of the belowground buds of Medicago archiducis-nicolai during overwintering
YANG Xiaoxia, WEI Jiake, XIA Jianqiang, FANG Qiang’en, ZHANG Bo
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0074 doi: 10.11829/j.issn.1001-0629.2021-0074
[Abstract](219) [FullText HTML] (52) [PDF 1479KB](4)
To determine the mechanisms underlying belowground bud overwintering in Medicago archiducis-nicolai, we examined the histochemical characteristics and differentiation of buds during the period of overwintering, based on the histochemical staining of paraffin sections. Observations revealed that the starch content in overwintering buds is stored primarily in the cortex, pith, the peripheral young leaves and basal tissue of bud tips, and in the basal part of the leaf primordium, whereas protein is mainly stored in the growth cone of bud tips, apical leaf primordia, and cambium of the bud body. At the cold-adaptation stage in late autumn, the bud body was observed to undergo rapid elongation and starch in the buds began to undergo degradation, although total starch contents remained at a high level during this stage. At the beginning of winter, there was a retardation in both bud differentiation and elongation, concomitant with a reduction in temperatures. At the freezing-stress stage in winter, there was a cessation of growth in both the bud cone and bud body, and at this stage, the starch content of buds had been almost completely degraded. Thereafter, in response to gradually increasing temperatures, the bud body slowly began to resume growth, although meristematic growth of the bud cone did not recover fully until the growing stage in spring. In conclusion, our findings indicated that in belowground buds of M. archiducis-nicolai, the transition to a dormant state is characterized by growth stagnation and a reduction in the starch contents of buds, and that dormant buds can withstand cold stress during the period of overwintering on the Qinghai–Tibet Plateau. This cold tolerance can be attributed to the degradation of starch in buds, which, by increasing the concentration of soluble sugars in cells, contributes to reducing their freezing point.
Exploration of the stereo development mode of ecological grass-based livestock husbandry in Yunnan-Guizhou Plateau- An example from the Yongshan County, Yunnan Province
SUN Jiamei, LIU Zhiquan, ZHONG Jin, WANG Tianwei, WANG Xiangquan, SUN Changrong, GAO Shuqin, PAN Qingmin
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0371 doi: 10.11829/j.issn.1001-0629.2021-0371
[Abstract](200) [FullText HTML] (47) [PDF 1291KB](5)
The development of ecological grass-based livestock husbandry is an important part of the structural adjustment of agriculture in the new era. There are 4.7 × 105 km2 hill grasslands in southern China, with abundant light, heat, water, and soil resources. Grass has a long growing season, high productivity, and huge potential for the development of ecological grass-based livestock husbandry. Moreover, vegetation and climate show obvious vertical differences due to complex terrain conditions. However, grass-based livestock husbandry development in hill grasslands in southern China has rarely been reported. Therefore, we conducted technology demonstrations in Yongshan County, Zhaotong City, Yunnan Province. Accordingly, three modes were explored based on climate and vegetation characteristics at different elevations. At high elevations (above 2 500 m), the mode centered on grazing; at middle elevations (1 500–2 500 m), the mode centered on both grazing and house feeding; and at low elevations (below 1 500 m), the mode centered on house feeding. This stereo development mode system has been formed in the region. Therefore, we made suggestions for the development of ecological grass-based livestock husbandry in southern China and can provide a basis for future decision-making.
Analysis of phenophase and morphological traits of perennial ryegrass germplasm
ZHANG Chenchen, ZENG Lingshuang, ZHANG Jing, XU Bin
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0365 doi: 10.11829/j.issn.1001-0629.2021-0365
[Abstract](182) [FullText HTML] (41) [PDF 966KB](5)
To evaluate and screen the germplasm resources of perennial ryegrass (Lolium perenne) for excellent characteristics, 99 perennial ryegrass germplasm resources were selected to observe and analyze their phenological periods and eight morphological traits, and principal component analysis and cluster analysis were performed based on the morphological indicators. The results showed that the whole growth period of the tested germplasm was 252.0 – 310.0 days, their morphological characteristics showed abundant variation with a coefficient of variation of 22.63 – 44.11%. Based on the cluster analysis of eight morphological characteristics, perennial ryegrass germplasms were divided into four groups with obvious morphological differences. The germplasms of groups I and IV can be further investigated as parent breeding materials or released as new varieties for forage- or turf-type breeding objectives. In summary, there are rich variations in the morphological characteristics of the perennial ryegrass germplasms used in this study, among which, germplasms of groups I and IV can be used as elite parental materials to breed new forage and turf-type varieties.
Effects of different enclosure methods on early community vegetation structure and stability of alpine meadows in northwest Sichuan
HE Li, HUANG Chao, CHEN Dechao, DENG Dongzhou, YAN Wuxian, WU Shilei, LI Honglin, LIU Yuping, ZHANG Li
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0158 doi: 10.11829/j.issn.1001-0629.2021-0158
[Abstract](199) [FullText HTML] (61) [PDF 1202KB](3)
This research explores suitable management measures for alpine meadows in northwestern Sichuan. In this study, grazing prohibition and grazing restrictions (grazing prohibition in growing season + grazing in non-growing season) and typical alpine meadow plots under the management of forage and animal husbandry were used as the research object for this research. Degraded grassland vegetation outside the fence was used to create a control group. Using a combination of field surveys and lab-based analyses, species diversity and stability of the alpine meadow plant community in Northwest Sichuan was examined. This research explored the relationship between species diversity and plant community stability immediately following enclosure of research plots to determine preliminary recommendations for an appropriate grassland management model. The results showed the following: 1) In the initial stage of implementation of the three enclosure management methods, grasses such as Elymus nutans Griseb. are the dominant species in the plant community, with important values of 9.14, 13.52, and 8.17, respectively. No absolute dominant species were recorded in the degraded grassland community, with Potentilla anserina L., Anemone rivularis Buch. Ham. ex DC., and Anaphalis flavescens Hand. Mazz. being the main plant species observed. 2) Provision of fencing increased community species diversity. Sites where prohibition of grazing had been implemented had the highest species diversity. The lowest species diversity was recorded for the forage-livestock balance plant community. Simpson’s diversity index and Pielou evenness index of were slightly higher in the degraded grassland communities in comparison to grasslands where grazing was restricted. 3) The stability of the community in each plot is expressed as grazing restriction > forage-livestock balance > grazing prohibition > degeneration. Reasonable grazing can therefore improve grassland stability. 4) The relationship between community species diversity and stability was found to be negative. Species diversity is mainly affected by the type and quantity distribution of species, while community stability is closely related to the stability of dominant species. Therefore, taking into account the structure and stability of the plant community, grazing prohibition and grazing restriction management are effective measures for the ecological restoration of alpine meadow vegetation in northwest Sichuan.
Comprehensive analysis of production performance and nutritional value of 14 alfalfa varieties in the Ningxia Yellow River diversion irrigation area
MA Xiaoxia, BI Yixian, CHEN Hongliang, ZHANG Long, YAN Ya, QU Hailong, LANG Fenghong
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0343 doi: 10.11829/j.issn.1001-0629.2021-0343
[Abstract](205) [FullText HTML] (59) [PDF 989KB](5)
A comparative experiment on filed performance and nutritional value of 14 alfalfa varieties was conducted in 2017–2019 to select Medicago sativa varieties suitable for cultivation in the Ningxia Yellow River diversion irrigation area. In this study, the filed performance parameters (plant height, number of stems per plant, hay yield, fresh/dry ratio, and stem/leaf ratio) and nutritional indicators (content of crude protein, neutral detergent fiber, acid detergent fiber, ether extract, and crude ash) of alfalfa at early bloom were measured for three consecutive years. The dataset was then analyzed using the grey correlative system to assess varieties comprehensively. Results showed that the hay yield of AmeriStand 407 was the highest of 16.68 t·hm−2 in three years, and the average hay yield of 4020MF, BR4010, Magnum Ⅶ and 55V12 were 16.47 ~ 16.63 t·hm−2. The crude protein content of 54V09 was the highest at 19.46%. The neutral and acid detergent fiber content of WL316HQ were the lowest at 35.12% and 28.85%, respectively. The comprehensive analysis results show that 4020MF, Phabulous, WL363HQ, and BR4010 perform excellently in the Ningxia Yellow River irrigation area, with potential for more extensive use as a pasture crop in the region.
Evaluation of the safety of imazapic for alfalfa crops
SU Wangcang, LI Huilong, LEI Haixia, FENG Changsong, SUN Lanlan, XU Hongle, WU Renhai
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0231 doi: 10.11829/j.issn.1001-0629.2021-0231
[Abstract](208) [FullText HTML] (59) [PDF 1226KB](1)
This research aims to determine the safety, quality, and weed control effects of imazapic on alfalfa (Medicago sativa). Alfalfa crops that had been planted for 4 years and 10 months were used for the study. The safety level, quality index, and weed control effects of these alfalfa crops were surveyed by spraying different doses of imazapic 10 days after mowing them. Results showed that 7 and 14 days after treatment, treatment with imazapic at the doses of 100.8 and 129.6 g·ha−1 significantly reduced the plant height and fresh weight of the alfalfa (P < 0.05). Inhibitory effects on alfalfa plant height and fresh weight were significantly reduced 28 days after application of 100.8 g·hm−2 of imazapic (P < 0.05). Treatment with imazapic at the doses of 129.6 g·ha−1 still had a significant effect on the plant height, fresh weight, and number of nodules present on the alfalfa plants (P < 0.05). The number of nodules on old alfalfa plants was less than those present on younger alfalfa plants. After 28 days, the plant control effect and fresh weight control effect of imazapic at the doses of 86.4, 100.8, and 129.6 g·ha−1 were both higher than 80%. Treatment with imazapic at the doses of 129.6 g·ha−1 significantly affected the yield. The crude protein content was found to have decreased significantly (P < 0.05). The experimental results showed that imazapic had a good control effect on weeds in the dose range of 86.4 ~ 100.8 g·ha−1. Use of this dosage had no adverse effect on the growth and quality of alfalfa and significantly increased the yield. It therefore has good promotion value in the context of agricultural production.
Vegetation composition and interspecific associations of alpine meadow under different utilization rates on the northeast Qinghai-Tibet Plateau
XUAN Wenting, Zhao Yijun, LI Yizhuang, LIU Jinyin, WANG Xianzhi, YU Yingwen
, Available online  , doi: 10.11829/j.issn.1001-0629.2021-0402 doi: 10.11829/j.issn.1001-0629.2021-0402
[Abstract](517) [FullText HTML] (170) [PDF 1138KB](28)
The vegetation community structure and interspecific association are the main evaluation indices of grassland stability and community succession. It is important to study the vegetation composition and interspecific association under different utilization rates for grassland management and revealing the mechanism of stability maintenance in alpine meadow. This study analyzed vegetation composition, inter-species relationship and community stability under the annual average grassland utilization rate of 60%-70% (moderate utilization grassland, MG), 80%-90%(heavy utilization grassland, HG) and >90% (extreme utilization grassland, EG) in the northeastern Qinghai-Tibet Plateau. It aimed to explore the relative suitable grassland utilization rate in the northeastern Qinghai-Tibet Plateau. The results showed that 1) MG grassland dominated by grass (Elymus nutans, Stipa krylovii and Poa crymophila) and HG grassland dominated by Elymus nutans, Kobresia humilis and Stipa krylovii, while the EG grassland dominated by Kobresia humilis; 2) With the increasing of utilization rate, plant species richness decreased, and the β diversity index, Shannon-Weiner diversity index and Simpson dominance index showed a declining trend, reaching the lowest in EG grassland; the aboveground biomass proportion of sedge increased, while the aboveground biomass proportion of grass decreased; 3) Compared to EG grassland, MG and HG grasslands had a closer interspecific association and stronger community stability, and EG grassland showed a trend of degradation. The study concluded that the moderate utilization rate under the rotational grazing pattern was beneficial to maintain the vegetation community stability in alpine meadow.
, Available online  , doi: 10.11829/j.issn.1001-0629.2019-0257 doi: 10.11829/j.issn.1001-0629.2019-0257
[Abstract](1831) [PDF 0KB](6)
The effects of different herbicide mixtures on the alfalfa (Medicago sativa L.) yield and weed control effect were explored by applying different herbicide mixtures. The results showed that the weed control effects of different herbicide combinations was quite good; the dry weight of alfalfa with imazethapyr alone was as high as 1762 kg×hm-2; the dry weight of alfalfa with benazolin-ethyl alone was higher, which was 1897 kg×hm-2; and the dry weight of alfalfa with imazethapyr and bentazone mixture was the highest, 2175 kg×hm-2. Although the weed control effect was poor, the dry weight of alfalfa was 1882 kg×hm-2 when only haloxyfop-P-methyl (CK2) was applied. Except for bentazone, there was no significant difference in the yield of alfalfa among different dose of the same herbicide alone. The herbicide and related mixtures can be used at alfalfa five-trifoliate growth stage in Ar Horqin Banner as follows: imazethapyr 1050 mL×hm-2 + bentazone 1200 mL×hm-2+ haloxyfop-P-methyl 600 mL×hm-2;benazolin-ethyl 300(or 750)mL×hm-2 + haloxyfop-P-methyl 600 mL×hm-2,imazethapyr 1050 mL×hm-2 + haloxyfop-P-methyl 600 mL×hm-2,If the density of broadleaf weeds redroot pigweed (Amaranthus retroflexus L.) is not high enough, also haloxyfop-P-methyl 600 mL×hm-2 can be applied.
, Available online  , doi: 10.11829/j.issn.1001-0629.2019-0198 doi: 10.11829/j.issn.1001-0629.2019-0198
[Abstract](2001) [PDF 0KB](139)
In order to clarify the characteristics of the 7 fungi Phialocephala mycorrhizal fungi which isolated from the roots of bilberry in Daxinganling, and were named as JUN-1to JUN-7. The growth characteristics and microstructure were analyzed, and its ability to dissolve phosphorus and the ability to secrete IAA and iron carriers were quantitatively analyzed. The results showed that these 7 mycorrhizal fungi have certain ability to dissolve phosphorus, secrete iron carrier and secrete IAA. Among them, the strongest ability to dissolve phosphorus is JUN-5, followed by JUN-4. The phosphorus solubilizing capacity of these two bacteria is significantly higher than other strains. The phosphorus concentration in the solution is 80-95 mg·L-1 higher than that of CK. The strongest ability to secrete IAA is JUN-7, and the concentration of IAA in the solution is increased by 57.90 mg·L-1 compared with CK. The ability to secrete iron carriers of JUN-4 and JUN- 6 is stronger than other strains . The ratio of the dissolved phosphorus circle to the colony radius can reach 2.5 times or more. The comprehensive analysis indicated that the ability of JUN-4 to dissolve phosphorus and the ability to secrete iron carrier were very strong, and its growth-promoting ability and growth-promoting mechanism could be further analyzed. The results of this study can provide a theoretical basis for the development of rhododendron fungi and the cultivation of blueberry.