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2021 Vol.38(2)

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2021, (2): 1-4.
[Abstract](1607) [FullText HTML] (569) [PDF 341KB](27)
Distribution and coupling characteristics of plant nitrogen and phosphorus along desertification gradients in alpine meadows, eastern Tibet Plateau
LIU Tianyuan, ZHOU Tiancai, SUN Jian, WANG Yi, YE Chongchong
2021, 38(2): 209-220. doi: 10.11829/j.issn.1001-0629.2020-0253
[Abstract](2656) [FullText HTML] (646) [PDF 1565KB](27)
Analyses of plant nitrogen and phosphorus and their coupling relationships are important for determining the dynamics and functions of plant communities, as well as ecosystem processes. In this study, we analyzed the characteristics, patterns, and drivers of above- and belowground nitrogen and phosphorus contents and nitrogen: phosphorus ratios along desertification gradients in alpine grassland on the eastern Tibetan Plateau. Our results revealed that plant nitrogen content (mean value: 15.3 mg·g–1) and the ratio of nitrogen to phosphorus (mean value: 5.2) in aboveground vegetation were lower than those in belowground parts (mean value: 28.2 mg·g–1 and 12.5, respectively). With an increase in landscape degradation, nitrogen contents in the above- and belowground portions of plants initially increased and subsequently decreased, whereas there was no clear variation in the phosphorus contents of above- and belowground vegetation. Moreover, it was found that the above- and belowground portions of plants were generally limited by nitrogen, and the relationship between plant nitrogen and phosphorus showed virtually no correlation with desertification stress. Notably, soil water content was found to be a key factor affecting nitrogen and phosphorus contents in the above- and belowground parts of vegetation, with plants enhancing nitrogen and phosphorus contents to adapt to the soil water stress. Our findings will provide a theoretical reference for examining the survival strategies and mechanisms of plants in degraded alpine grassland ecosystems.
Effect of growing season degree days on gross primary productivity and its variation characteristics in alpine shrubland at the southern foot of Qilian mountains
ZHU Jingbin, HE Huidan, LI Hongqin, ZHANG Fawei, LI Yingnian, YANG Yongsheng, ZHANG Guangru, WANG Chunyu, LUO Fanglin
2021, 38(2): 221-230. doi: 10.11829/j.issn.1001-0629.2020-0330
[Abstract](2467) [FullText HTML] (620) [PDF 1486KB](29)
In the context of global climate change, a gradual increase in temperature will have an important impact on the carbon cycle of terrestrial ecosystems. Based on CO2 fluxes measured with the eddy covariance technique, we analyzed the relationship between gross primary productivity (GPP) and growing season degree days (GDD) at different time scales in an alpine shrubland at the southern foot of the Qilian Mountains during the growing seasons from 2003 to 2016. This study has great importance on studying the impact of climate warming on the carbon cycle of alpine ecosystems. The monthly GPP and GDD in the growing season showed a single peak trend over the alpine shrubland ecosystem. The maximum monthly GPP and GDD values all occurred in July or August, whereas the minimum value occurred in May. During the whole growth season scale, GPP and GDD showed high variability, but with a gradually increasing trend (P < 0.05). The mean values of seasonal GPP and GDD for the entire growing season from 2003 to 2016 were 507.11 g·m−2 and 975.93 ℃. On the daily, monthly, and growing season scales, all GPP values positively correlated with GDD (P < 0.05). However, on comparing GPP and GDD in each month of the growing season, no significant correlation was found between GPP and GDD in May and September (P > 0.05), whereas the correlation was strongest (P < 0.01) in July. Overall, the GPP of the alpine shrubland ecosystem indicated a positive reaction to the thermal condition, suggesting that the photosynthetic capacity of the shrubland ecosystem in the Qinghai-Tibet plateau could be improved in the future under the effect of global warming.
Responses of root morphological and physiological characteristics of different alfalfa genotypes to phosphorus levels
MA Hong, MENG Jie, LI Ning
2021, 38(2): 231-238. doi: 10.11829/j.issn.1001-0629.2020-0383
[Abstract](3400) [FullText HTML] (789) [PDF 661KB](24)
To clarify the response of the root morphology and physiological characteristics of different varieties of alfalfa (Medicago sativa) to phosphorus levels, the test method of nutrient solution hydroponics was used to analyze a total of six alfalfa plants under the phosphorus levels 0 (P0), 50 µmol·L−1 (P1), 100 µmol·L−1 (P2), 500 µmol·L−1 (P3), 1 000 µmol·L−1 (P4), and 1 500 µmol·L−1 (P5). The response characteristics of root length, surface area, volume, phosphorus absorption efficiency, and acid phosphatase activity to phosphorus level was ascertained. It was found that there were differences in total root length, root surface area, root phosphorus absorption efficiency, and root acid phosphatase activity among varieties at the same phosphorus level. The total root length and root surface area reached a maximum at low phosphorus levels. The total root length and root surface area of the four varieties of Xinmu No.1, Magnum Salt, Zhaodong, and Juneng Ⅱ were higher than those of Longdong and Longmu 801 at low P2 levels. The root volume of each variety was different only in P0, P1 treatment, and the root volume of Longdong was smaller than that of other varieties in the P1, P2, P3, and P5 treatments. The phosphorus absorption efficiency of roots of Xinmu No. 1 and Longmu 801 was higher than that of the other four varieties under low phosphorus conditions. The phosphorus absorption efficiency of the roots of Zhaodong was significantly higher (P < 0.05) than that of the other varieties under P2, P3, and P4 treatments. The root acid phosphatase activity reached a maximum at P1, and there was a significant difference (P < 0.05) among the varieties at the same phosphorus level. Under low phosphorus levels, Magnum Salt and Juneng Ⅱ had significantly higher root acid phosphatase activity than the other four varieties. The comprehensive low-phosphorus tolerance indicators show that Xinmu No. 1 and Magnum Salt have lower phosphorus tolerance than the other varieties are phosphorus efficient varieties, followed by Zhaodong and Juneng Ⅱ, whereas Longdong and Longmu 801 can be classified as phosphorus inefficient varieties.
Effects of different cutting frequency and additives on silagequality and fermentation characteristics of mixed alfalfa
QIN Weina, JIAO Ting, LEI Zhaomin, LI Fei, RAN Fu, LI Xiongxiong, GAO Xuemei, ZHAO Shengguo
2021, 38(2): 239-250. doi: 10.11829/j.issn.1001-0629.2020-0172
[Abstract](1919) [FullText HTML] (558) [PDF 584KB](25)
The purpose of the experiment was to explore the effects of different additives and cutting frequencies on the silage quality of mixed alfalfa. The two alfalfa varieties, ‘Golden queen’ and ‘3010’, mixed in the proportion of 4 ꞉ 1 cutting at different times were used as experimental materials, and five different additives ‘Sila-Max, Sila-Mix, Yaxin-Bio, Baiaomin, Taiwan Xiandeli’ were selected for use in a barrel silage test. Silage made without additives was used as the control (CK). After 60 days, the silage barrels were opened for laboratory evaluation. The results showed that as cutting times increased, the content of silage pH and dry matter (DM) also increased (P < 0.05). Crude protein, lactic acid (LA), and acetic acid (AA) increased at first but then decreased with increased cutting time. The content of acid detergent fiber (ADF), neutral detergent fiber (NDF), and crude ash (Ash) were lowest and water soluble carbohydrates (WSC) and monosaccharides (ESC) highest at the third cutting. Additives also had very significant effects on the contents of soluble protein as a proportion of total protein (SP/CP), DM, ESC (P < 0.01), and other indexes (P < 0.05). The CP, WSC, P, and K contents of the first cutting increased by 1.00%, 32.94%, 2.44%, and 0.99%, respectively, compared to CK, and the LA and AA contents of each cutting were higher than that of any other additives treated with Yaxin-Bio. The CP, SP/CP, and WSC contents of the third cutting increased by 1.37%, 6.39%, and 10.72%, respectively, compared to CK under the treatment of Baiaomin, which also had certain promoting effects on CP, SP/CP, and WSC. Taiwan Xiandeli promoted the increase of neutral detergent insoluble protein (NDIP) and acid detergent insoluble protein (ADIP) (P < 0.05), while Sila-Max and Sila-Mix had no obvious effects on nutrient quality (P > 0.05). In total, according to gray correlation analysis, the quality of MIXed alfalfa silage at the second cutting showed the highest quality, especially when treated with Yaxin-Bio, which could be used in the production practice of alfalfa silage.
Multiple mowing improves the yield and nutritional quality of Plantago lanceolata on the Loess Plateau
JIANG Weiqi, YANG Tianhui, HOU Fujiang
2021, 38(2): 251-260. doi: 10.11829/j.issn.1001-0629.2020-0244
[Abstract](1401) [FullText HTML] (495) [PDF 1456KB](24)
Plantago asiatica has a high feeding quality and can improve the protein utilization rate of ruminants. Therefore, a two-year field experiment was conducted with two utilization modes, multiple mowing (simulated rotational grazing) and once mowing (hay harvesting), to evaluate the dynamics of forage yield and nutrient quality of Plantago lanceolata in typical areas of the Loess Plateau. Compared with once mowing, multiple mowing led to a significant increase in dry matter, crude protein (CP), and ether extract (EE) yields (P < 0.05), and a significant decrease in neutral detergent fiber (NDF) and acid detergent fiber (ADF) content (P < 0.05). The dry matter increased with increasing growth time and accumulated temperature (≥ 0 ℃) by multiple mowing. However, there were significant negative linear relationships between CP, EE content, and growth time, and accumulated temperature (≥ 0 ℃; P < 0.05). Based on the growth time and accumulated temperature ≥ 0 ℃, the predictive models (linear and logistic models) showed that for forage yield and quality, the critical accumulated temperature (≥ 0 ℃) was 2 069~2 984 ℃, and the corresponding growth time in the study area was 102~161 d. This study provides a theoretical basis for the management and utilization of cultivated grasslands on the Loess Plateau.
Genetic diversity and population structure analysis of Paspalum vaginatum based on SRAP markers
HONG Jiaqi, SUN Zongjiu, YANG Zhimin
2021, 38(2): 261-268. doi: 10.11829/j.issn.1001-0629.2020-0308
[Abstract](2552) [FullText HTML] (571) [PDF 1435KB](30)
In order to explore Paspalum vaginatum, the genetic diversity of 49 P. vaginatum germplasm resources from different countries was analyzed using SRAP markers, and the population structure and genetic relationships among the germplasm was discussed. Twenty pairs of SRAP primers with stable amplification and good polymorphism were screened out from 100 pairs of primers, and 169 bands were obtained, among which 118 were polymorphic; the percentage of polymorphic sites was 69.8%. The genetic similarity coefficient among 49 P. vaginatum germplasms was 0.52~0.88, with an average value of 0.67, indicating that there were significant genetic differences among the tested germplasms. 49 Paspalum germplasms were divided into two categories by the UPGMA cluster analysis, principal component analysis, and population structure analysis. Forty-four materials showed a more consistent classification under the three methods, and five materials showed a certain degree of variation, indicating that the genetic relationship of the germplasm was stable and could be used in breeding.
Effects of temperature and calcium chloride on seed germination of ryegrass
DU Zhihua, WEN Mei, WANG Yongji, ZHANG Fen'guo
2021, 38(2): 269-276. doi: 10.11829/j.issn.1001-0629.2020-0241
[Abstract](2713) [FullText HTML] (719) [PDF 658KB](20)
To explore the ecological adaptability of ryegrass (Lolium perenne) to the calcium-rich environment in limestone areas, seed germination experiments were conducted. The effects of temperature and calcium chloride on seed germination of ryegrass were studied by investigating the different temperatures and concentrations of calcium chloride. The results showed that under certain temperatures, the germination rate, germination potential, and germination index of ryegrass treated with calcium chloride concentrations (≤ 1.5%) were generally high, whereas high concentrations (≥ 2.0%) of calcium chloride had obvious inhibitory effects (P < 0.05). Temperature had little effect on seed germination of perennial ryegrass under low calcium chloride concentration. The optimal temperature for the seed germination of ryegrass under high concentrations (≥ 2.0%) of calcium chloride was 15 ℃/25 ℃. The results enrich the research on the ecological adaptability of ryegrass, and provide a theoretical basis for ecological restoration, land use, and water and soil conservation in limestone areas.
Effect of exogenous hormone IAA or 6-BA combined with nitrogen on the above-ground growth and physiological characteristics of Elymus sibiricus
JIN Xin, QI Juan, LIU Wenhui, WU Zhaolin, ZHENG Yuying, YANG Hang, SU Jinglong, LI Ming
2021, 38(2): 277-287. doi: 10.11829/j.issn.1001-0629.2020-0296
[Abstract](2147) [FullText HTML] (523) [PDF 625KB](14)
This study aimed to elucidate the effects of IAA or 6-BA and nitrogen and different ratios of IAA or 6-BA and nitrogen on the above-ground growth and physiological characteristics of Elymus sibiricus and to thus provide a theoretical basis for improving the development of E. sibiricus seedlings. Seeds of E. sibiricus from Qinghai alpine grassland were collected as experimental materials, which were tested using the nutrient solution sand culture method. The results showed that different ratios of nitrogen combined with IAA or 6-BA can better promote the growth of E. sibiricus seedlings than single nitrogen, IAA, or 6-BA. When the ratios of nitrogen and IAA were 5 ꞉ 5, the leaf area, chlorophyll, and soluble protein content of E. sibiricus increased significantly (P < 0.05) compared with the control (12 mg·L−1 single nitrogen). Compared with the control treatment, the leaf area increased by 12.31%, the chlorophyll content increased by 1.2%, and the soluble protein content increased by 17.72%. When the ratios of nitrogen and 6-BA were 5 ꞉ 5, the peroxidase activity of leaves was the highest, and the peroxidase activity of E. sibiricus leaves increased significantly compared with single 12 mg·L−1 or 20 mg·L−1 nitrogen treatment, which increased by 9.1% and 19.72%, respectively (P < 0.05). In addition, when the ratio of nitrogen and 6-BA was 3 ꞉ 7, the leaf area increased significantly by approximately 16.77% and 19.41% than single 12 mg·L−1 or 20 mg·L−1 nitrogen, respectively (P < 0.05). Through principal component analysis and membership function methods, it was found that the ratio of nitrogen ꞉ IAA at 5 ꞉ 5 had obviously affected the above-ground growth and physiological characteristics of E. sibiricus.
Effect of different herbicides on weed control and yield of Panicum miliaceum
FENG Yu, HUANG Guibin, ZHAO Yingnan, WANG Na, GAO Xiaoli
2021, 38(2): 288-295. doi: 10.11829/j.issn.1001-0629.2020-0456
[Abstract](3535) [FullText HTML] (627) [PDF 661KB](18)
This study aimed to explore the control effect of different herbicides on the field and on the yield of proso millet (Panicum miliaceum) and provide a basis for the safe use of herbicides in the proso millet field. The proso millet variety “Yumi-2” was used as the material for the experiment. The pre-seedling herbicide 330 g·L−1 pendimethalin cream and 10% monosulfuron wettable powder were selected after sowing. In the three-leaf stage of proso millet, 36% carfentrazone-tribenuron wettable powder and 55% of two methyl sodium wettable powder were sprayed. Each herbicide was sprayed at the recommended dosage. After 15 days of spraying, the control effect of fresh weight on weeds was investigated. After heading stage, we investigated the effects of herbicides on dry matter accumulation, chlorophyll content of functional leaves, agronomic traits, and yield. The results showed that monosulfuron and two methyl sodium have the best control effects on weeds, and the fresh weight inhibition rate is over 99.7% and over 88.4%; the dry matter accumulation and the relative content of functional chlorophyll in the ground part of proso millet have different degrees of influence. Four herbicides increased the main ear weight of proso millet and significantly increased the yield of proso millet (P < 0.05). Monosulfuron and two methyl sodium levels increased the most significantly, reaching 271.66% and 275.34%, respectively. The herbicide monosulfuron and two methyl sodium had the best weed control, and the fresh weight control effect was higher in the whole growth period, and the yield of proso millet increased significantly. In summary, these two herbicides are the safest herbicides for proso millet fields.
Adaptability of nine Chinese milkvetch varieties (strains) in Hanzhong region
WU Yuhong, WANG Lyu, HAO Xingshun, HE Chunmei, CUI Yuezhen, HUANG Yibin, ZHANG Chunhui, HE Zhongjun
2021, 38(2): 296-303. doi: 10.11829/j.issn.1001-0629.2020-0315
[Abstract](4115) [FullText HTML] (687) [PDF 510KB](26)
A field trial was conducted to select the milkvetch varieties or strains suitable for Hanzhong and provide excellent variety for different planting patterns of rice by comparing the phenological period, agronomic characters, and fresh grass yield of nine Chinese milkvetch varieties. The results showed that the ‘Nanzheng’ variety, ‘yH925’, ‘Ningbodaqiao’, and ‘Xiangzi No.1’ were very early manuring milkvetch cultivars grown in Hanzhong. The ‘yiJ’, ‘848711’, ‘Minzi No.7’ , and ‘Yijiang Zi’ were early maturing milkvetch cultivars, and ‘Xiangzi No.4’ was a medium maturing variety grown in Hanzhong. In terms of grass yield, there is a significant difference between nine varieties. The fresh grass yield of ‘Minzi No. 7’ was the highest with 24192.45 kg·ha−1 followed by ‘yiJ’ with 23494.50 kg·ha−1. The difference between ‘Minzi No.7’ and ‘yiJ’ was not significant but significantly higher than other varieties. The lowest was ‘Nanzheng’ with 12049.80 kg·ha−1, which was significantly lower than that of the other eight varieties. The ‘Ningbodaqiao’ species exhibit excellent characters as green manure in Hanzhong, due to which the plant height, aboveground part, root nodule, and fresh grass yield were better at the flowering stage, and thus can be used in a rice direct seeding mode. The fresh grass yield of ‘Minzi No.7’ and ‘yiJ’ were significantly higher than that of other early maturing varieties and were found to be excellent early maturing varieties.
Development prospect of mixed planting of legume and gramineae forage in winter fallow field in the Yangtze-Huaihe region
ZHOU Yaxin, YUE Xiangpeng, WEI Zhenwu, JIANG Zhou, YAN Tianfang
2021, 38(2): 304-315. doi: 10.11829/j.issn.1001-0629.2020-0108
[Abstract](2388) [FullText HTML] (606) [PDF 679KB](24)
With the rapid growth of animal food demand and the implementation of “grain to feed” policy, it is imperative to promote the adjustment of agricultural industrial structure and the comprehensive development of herbivorous animal husbandry. As an important grain production base and animal husbandry development base in southern China, the Yangtze-Huaihe region can completely utilize its winter fallow fields’ production potential, carrying out the cultivation mode of both grain and forage, and therefore provide high-quality forage suitable for local winter production. The production approach of mixed planting of Gramineae and legumes in the winter fallow field can effectively improve productivity and enhance the sustainability of the land. It plays a positive role in increasing farmers' income and promoting the development of herbivorous animal husbandry and the transformation of agricultural ecology in southern China. This study analyzes the development prospect and current situation of forage grass planting in the Yangtze-Huaihe Region, expounding the advantages of the mixed planting of legumes and grass. Mixed planting of high-quality bean and grass and its ecological and economic benefits are also described to provide a reference for grass planting in winter fallow fields in the Yangtze-Huaihe region and similar areas.
Comparison and comprehensive evaluation of summer-planting silage maize varieties in Henan Province
ZHOU Bo, HAN Xiaohua, LI Xiaohong, WANG Yanzhao, LIU Kang
2021, 38(2): 316-326. doi: 10.11829/j.issn.1001-0629.2020-0277
[Abstract](4773) [FullText HTML] (821) [PDF 680KB](38)
The aim of this research was to select silage maize varieties suitable for planting in Henan province. A total of 20 silage maize hybrids were collected and used as test materials, and were evaluated in terms of dry matter yield, corn silage quality (protein, starch, acid detergent fiber, neutral detergent fiber, and relative feed value), stress resistance (lodging rate, lodging rate of corn stalks, and stem rot), and agronomic traits (plant height, ear height, and duration). The results showed that: 1) the dry matter yield of Yuqing 386, Yuqing 506, Beinongqingzhu 368, Yuqingyu No.3, Xinke 910, Yayu 04889, Xianyu 1658, Zhengqingzhu No.1, Jiuxin 631, Beinongqingzhu 3740, and Zhengqingzhu No.2 were higher than those of Yayuqingzhu 8 (the control variety). The grain yield of Xianyu 1658 and Jiuxin 631 was higher than that of the control variety Zhengdan 958. 2) There were significant differences in the quality indicators among the 20 varieties of maize (P < 0.05). We obtained two groups of maize through a cluster analysis of these quality indicators, of which the maize variety group I was a higher quality group. Among the maize variety group I, all grades of maize varieties were the top level or first-class, except for the maize variety Yongyou 1573. With a lower neutral detergent fiber (NDF) and acid detergent fiber (ADF) content, and a higher starch content, the value of maize variety group I for silage was relatively high. 3) Yuqingyu No.3, Yuqing 386, Ninghe 0709, Yuqing 506, Quchen 19, Yayu 04889, Dajingjiu 26, and Yongyou 1573 had weak lodging resistance. All the analyses showed that Beinongqingzhu 368, Xinke 910, Xianyu 1658, Zhengqingzhu No.1, Jiuxin 631, Beinongqingzhu 3740, and Zhengqingzhu No.2 were suitable for planting in the Henan Province, and had higher dry matter yield, higher quality silage, and a higher level of stress resistance.
Effects of different sowing methods on the agronomic and productive properties of alfalfa in the agricultural arid area of Eastern Qinghai
GANG Yonghe, ZHANG Haibo, NIU Yong, DU Jiang, CHEN Yonglong, Sarenhua
2021, 38(2): 327-334. doi: 10.11829/j.issn.1001-0629.2020-0312
[Abstract](2713) [FullText HTML] (600) [PDF 535KB](24)
In order to select suitable sowing methods of alfalfa in the arid area of Eastern Qinghai, three alfalfa varieties, Longdong alfalfa, WL343, and Gold empress, were selected and planted using three sowing methods (broadcast sowing, drilling, and precision hole sowing). The results showed that: 1) the overwintering rate among the three varieties was significantly different (P < 0.01), and the overwintering rate of WL343 was 78.74%, which was 7.86% and 13.16% higher than that of Longdong alfalfa and Gold empress, respectively; there were no significant differences between the three sowing methods (P > 0.05). 2) There were significant differences in plant height, growth rate, and stem leaf ratio among WL343 and Gold empress and Longdong alfalfa (P < 0.05), no significant difference in branch number per plant compared with Gold empress alfalfa, but a significant difference in branch number compared with Longdong alfalfa (P < 0.05); the plant height under precision hole sowing method was significantly higher than that of drilling and broadcast sowing and the number of branches per plant was significantly different between precision hole sowing and broadcast sowing. The stem leaf ratio was significantly lower than that of sowing and drilling. 3) There was no significant difference between the fresh grass yield of WL343 alfalfa of the second year, and that of Gold empress was 10.57% higher than that of Longdong alfalfa; there was no significant difference between the fresh grass yield of precision hole sowing and drilling, but a significant difference in precision hole sowing and broadcast sowing. The average forage yield of WL343 alfalfa with precision hole sowing was 39.86 t·hm−2, which was higher than that of other varieties and among sowing methods. 4) The crude protein content of WL343 alfalfa was 19.20%, which was 2.65% and 6.12% higher than that of Gold empress and Longdong alfalfa, respectively, 20.41% and 7.83% for crude fiber, and 17.23% higher than Gold empress for nitrogen free extract. Based on the agronomic characteristics and production performance analysis, the combination of WL343 alfalfa with precision hole sowing performed much better in in the eastern agricultural arid area of Qinghai Province.
Dynamics of sap flow of Populus euphratica and responses to environment variables in the southeast of the Kumtag Desert
HUANG Yaru, MA Yingbin, LI Yonghua, XIN Zhiming, ZHAO Naqi, YANG Zhan, MA Yuan, WU Jing, DONG Xue, LI Shuai
2021, 38(2): 335-347. doi: 10.11829/j.issn.1001-0629.2020-0380
[Abstract](1878) [FullText HTML] (564) [PDF 1312KB](21)
In this study, the PS-TDP8 tree stem sap flow monitoring system was used to study the sap flow of Populus euphratica (the Euphrates or desert poplar) in the southeast of the Kumtag Desert from April to October in 2018 (spring April, summer July, autumn September). Correlation analysis and stepwise regression method were used to analyze the influence of meteorological factors (total solar radiation, air temperature, wind speed, relative air humidity) on the sap flow of P. euphratica. The results showed that the diurnal sap flow variation trend of P. euphratica displayed a "broad peak type". Sap flow in summer had the earliest start time, and the sap flow started at 06:00 in the morning, while the sap flow started at the latest in autumn. There was high sap flow velocity in all seasons at night. The trunk sap flow velocity was positively correlated with solar radiation, air temperature, wind speed, and saturated water pressure difference, while negatively correlated with air humidity. The main meteorological factors that affected the flow velocity of P. euphratica in spring and autumn were total solar radiation and air temperature, while those in summer were total solar radiation and relative air humidity. The response of P. euphratica sap flow velocity to air temperature, air relative humidity, wind speed, and saturated water pressure difference was clockwise in different seasons, and the asymmetry of the response to solar radiation was counterclockwise. The response of P. euphratica sap flow velocity to meteorological factors difference is different in different seasons, indicating that P. euphratica has different strategies to cope with water deficit to maintain water balance, and reduce water loss through stoma regulation under certain conditions (e.g., extreme drought in summer). The current results are of great significance for clarifying the water transpiration response of P. euphratica to environmental factors in arid desert environments and for a deeper understanding of the water use strategy of P. euphratica to adapt to arid environments.
Effects of concentrate supplementation amount on slaughter performance and organ development of Tibetan sheep
WANG Cailian, WU Jianping, LIU Lishan, LANG Xia, SONG Shuzhen, WANG Fei
2021, 38(2): 348-357. doi: 10.11829/j.issn.1001-0629.2020-0225
[Abstract](2398) [FullText HTML] (603) [PDF 632KB](16)
The object of this research was to investigate the effects of concentrate supplementation amount on the slaughter performance and organ development of Tibetan sheep. Forty nine-month-old Oura-type Tibetan sheep (OTTS) (plateau type) (30.21 ± 1.42) kg were selected and randomly divided into 4 groups with 10 replicates in each group. Every day 0, 0.1, 0.2 and 0.3 kg concentrate supplementation was provided for each sheep after grazing. The experiment included a 15-day pre-trial period and a 195-day trial period. The results showed that supplementary feed significantly improved the slaughter performance of OTTS (P < 0.05). The percentage of body weight of the head, skin+wool, heart, liver, lungs, kidneys, and large intestine increased, whereas the stomach, small intestine, gastrointestinal tract, and gastrointestinal contents decreased as the amount of concentrate supplementation increased (P > 0.05). The percentage of stomach contents in the total contents of the gastrointestinal tract and that of large intestine contents in the total contents of the intestinal tract increased as the amount of concentrate supplementation increased (P > 0.05). The intestinal length, proportional to body length decreased and stomach volume increased as the amount of concentrate supplement increased (P > 0.05). The preliminary results showed that supplementary feed could improve slaughter performance, stimulate organ development, and change the distribution of gastrointestinal contents of OTTS in the cold season. This study provides a theoretical basis for the development of the Tibetan sheep industry, improvement of organ development, and regulation of gastrointestinal content distribution in Tibetan sheep in high-altitude areas.
Growth curve fitting for plateau-type Tibetan sheep
ZHANG Junxia, FANG Decheng, HE Na
2021, 38(2): 358-363. doi: 10.11829/j.issn.1001-0629.2020-0289
[Abstract](2766) [FullText HTML] (612) [PDF 797KB](12)
Nonlinear fitting models for growth curves can be used to predict the growth and development rate and changes in the growth curves of livestock. In this study, we fitted early growth and development curves for plateau-type Tibetan sheep using three types of nonlinear fitting model, namely the Gompertz, Logistic, and Von Bertalanffy models. The results showed that the growth of plateau-type Tibetan lambs could be well fitted using the three growth curve models (R2 > 0.99). Among the three models, the fitting effect of the Von Bertalanffy model was found to be better than that of the other two models. The age in months and weight at the inflection point, as well as the best gain of ram lambs were 1.35, 12 kg, and 246.67 g·d−1, respectively, whereas those for ewe lambs were 1.36, 11.96 kg, and 239.33 g·d−1, respectively. The growth curves for the early growth and development stage of plateau-type Tibetan sheep established using the Von Bertalanffy model can provide a theoretical basis for early selection and breeding.
Effects of Ageratina adenophora on amino acid and fatty acid contents in the muscles of Jianchang black goats
SHAO Chenyang, WANG Siqi, HU Yanchun, GAO Pei, CUI Yujing, XIE Lei, SHU Gang, REN Zhihua, DENG Junliang
2021, 38(2): 364-370. doi: 10.11829/j.issn.1001-0629.2020-0376
[Abstract](2391) [FullText HTML] (618) [PDF 538KB](13)
This study aimed to examine the effects of Ageratina adenophora on amino acid and fatty acid contents in the muscles of Jianchang black goats. Jianchang black goats were fed with A. adenophora freely, and the contents of amino and fatty acids in their muscles were analyzed using an automatic amino acid analyzer and the chloroform-methanol extraction method, respectively. The contents of essential amino acids, non-essential amino acids, total essential amino acids, and flavor-related amino acids in the muscles of Jianchang black goats fed with A. adenophora decreased compared with the control group. At the same time the content of saturated fatty acid (SFA) decreased, while the content of monounsaturated fatty acid, polyunsaturated fatty acid, and unsaturated fatty acid (UFA) increased, and the UFA/SFA (U/S) ratio increased. The fatty acids that are proportional to the smell of mutton increased, and those that were inversely proportional to the smell of mutton decreased, indicating that A. adenophora reduced the nutritional value of amino acids and improved the nutritional value of fatty acids in meat, which had a certain effect on the flavor of meat. The results showed that A. adenophora fed ruminants had certain nutritional value, but the toxicity of A. adenophora changed muscle fatty acid and amino acid contents, which decreased the meat quality.
Developmental duration and life table of Aphis craccivora with Vigna unguiculata ‘Minnan’ as food source at different temperatures
LI Chunyan, JI Jie, CHEN En, CHEN Zhitong, YING Zhaoyang
2021, 38(2): 371-377. doi: 10.11829/j.issn.1001-0629.2020-0250
[Abstract](2366) [FullText HTML] (568) [PDF 569KB](9)
The developmental duration, fecundity, and life table of Aphis craccivora at different constant temperatures were studied to verify whether Vigna unguiculata ‘Minnan’ is a suitable host plant for A. craccivora. The results showed that the developmental duration of A. craccivora decreased with increase of temperature from 17 ℃ to 33 ℃. The fecundity of A. craccivora was significantly different at temperatures from 17~33 ℃, being highest at 21 ℃ (103.90) and lowest at 33 ℃ (4.40). The net reproductive rate decreased with the increase of temperature, being lowest at 33 ℃ (1.378) and highest at 21 ℃ (54.649). The intrinsic increase rate was above zero at 17~33 ℃, lowest at 33 ℃ (0.041) and highest at 25 ℃ (0.338). The finite rate of increase varied with temperature increase, being highest at 25 ℃ (1.403) and lowest at 33 ℃ (1.042). The time for population doubling was lowest at 25 ℃ (2.049 d). The results indicated that V. unguiculata ‘Minnan’ can be used as a banker plant for producing A. craccivora, supplying enough food for natural enemies, for example ladybugs or parasitic wasps, in ecosystems.
Effect of conservation tillage on soil microbial diversity in China: A Meta-analysis
WANG Yazhi, QI Peng, WANG Xiaojiao, JIAO Yapeng, GUO Gaowen, MA Juanjuan, ZHANG Qi, WANG Junxia, GAN Run, WANG Liwen
2021, 38(2): 378-392. doi: 10.11829/j.issn.1001-0629.2020-0302
[Abstract](2610) [FullText HTML] (586) [PDF 969KB](38)
A Meta-analysis of 42 published studies was conducted to ascertain the effects of conservation tillage [no-tillage with no straw returning (NT), tillage with straw returning (TS), no-tillage with straw returning (NTS)] on soil microbial diversity under different climatic types, soil quality, and test durations in China. The study examined the response of soil microbial diversity to conservation tillage, and at the same time evaluated the factors affecting soil microbial diversity. The results showed that compared with conventional tillage, conservation tillage significantly improved the Shannon and Simpson indices of soil microorganisms (P < 0.05), among which no-tillage with straw returning demonstrated the greatest increase in diversity, with an increase of 8.4% and 3.7%, respectively, compared to the control. The Shannon and Simpson diversity indices of bacteria in conservation tillage soil were higher than those in traditional tillage, and the Shannon and Simpson diversity indexes of fungi increased significantly in no-tillage with no straw returning soil, with an increase of 4.4% and 5.3%, respectively (P < 0.05). Soil microbial diversity is significantly affected by annual mean temperature and planted crops under traditional tillage with straw returning. No-tillage treatment in non-neutral soil with better soil environmental quality significantly increased soil microbial diversity (P < 0.05), and the effect of no-tillage on soil microbial diversity in the northern region of China was greater than that in other regions. Therefore, it is suggested that a conservation tillage system with no tillage as the core should be constructed in northern China, and straw returning management measures should be selected according to local conditions in different regions. Furthermore, the diversity of soil fungi and more indices of soil microbial diversity under conservation tillage should be studied.
Exploration and thinking on the “Double-supervisor Three-Stages System” training mode for professional degree graduates in the animal husbandry: Taking Lanzhou University as an example
LI Fei, LI Fadi
2021, 38(2): 393-398. doi: 10.11829/j.issn.1001-0629.2020-0085
[Abstract](3740) [FullText HTML] (1034) [PDF 453KB](35)
Professional degree graduates in the animal husbandry field are an important way to transfer talents to the agriculture. Further improving the training mode for graduates in this field is of great significance to meet the needs of industrial talents and the career choices of graduate students. The current professional graduate training process in the aquaculture field has problems such as the mismatch between training methods and industry needs, weak practical ability of the mentor teams, and the lack of standards for the training model of “Double-supervisor Three-stages System”. This article explores and tries from the perspectives of improving the professional practice ability of mentors, systematically designing a “two-mentor three-stage system” training model, and cultivating graduates' innovative and entrepreneurial abilities, which provides a reference for improving the theoretical, practical, and innovative and entrepreneurial abilities of professional degree graduates in the animal husbandry field.