Resources and Environment
To determine the relationship between the degree of anthracnose and damage, and to screen the germplasm resources of resistance to anthracnose of southwest glutinous red sorghum, so as to lay a material foundation for breeding resistance to anthracnose. Field spray inoculation was carried out by artificially cultured dominant strain ZG-FS-1 with strong virulence. After inoculation, the resistance level was determined according to disease classification standard. Compared with the uninoculated group, the loss rate of seed weight and germination were obtained. Among the 92 sorghum resources, 10 were highly resistant (HR), 10 were resistant (R), 5 were moderately resistant (MR), 20 were susceptible (S) and 47 were highly susceptible (HS).The average loss rate of spike grain weight of HR, R, MR, S and HS resources were 4.37%, 6.69%, 8.89%, 34.12% and 52.50%, respectively. The average loss rate of 1000-seed weight were 1.81%, 2.98%, 5.59%, 14.56%, 28.89%, and the average loss rate of germination rate were 0.97%, 5.40%, 5.76%, 11.11%, 20.46%, respectively. Sorghum anthracnose can not only greatly reduce the yield of sorghum, but also reduce the germination rate of sorghum seeds. The resistance to sorghum anthracnose could be accurately identified by artificial inoculation and the selected resistant resources could be used as breeding materials for resistance genetic improvement.
To further reveal the past and present situation of cultivated land soil resources in Sichuan agricultural area, taking the rain-fed cropland and irrigated cropland in Sichuan Province as the research objects, the evolution characteristics of the area, spatial distribution and soil resource composition of the two types of cultivated land from 1985 to 2020 were discussed, and the evolution law of their diversity was evaluated. The results showed that: (1) from 1985 to 2020, the overall area of rain-fed cropland in Sichuan Province showed a decreasing trend, while the overall area of irrigated land showed an increasing trend. (2) The area of rain-fed cropland in the hilly areas of eastern and central Sichuan showed a decreasing trend, while that in Panzhihua-Xichang hilly areas showed an increasing trend. (3) The area of irrigated land decreased in the Chengdu Plain, while it showed an increasing trend in the eastern and central hilly areas. (4) The decrease of rain-fed cropland and the increase of irrigated cropland had obvious overlap, and the soil resources in the area of rain-fed cropland mainly belong to Skeletol primitive soils, Ferralisols and Anthrosols. (5) With the change of spatial distribution of rain-fed cropland, purple soil, yellow soil and paddy soil in cultivated land showed a significant decreasing trend. The above results clarified that the transfer of croplands in Sichuan had led to changes in the structure of regional soil resources supply to agricultural production, and also suggested that water supply capacity and soil type changes should be specially considered for water and fertilizer management in farmland on a large scale.
Air negative oxygen ion has the effect of improving human immunity and regulating function balance and is known as “air vitamin”. However, due to the difference of regional ecological environment conditions, it is uncertain to explain the change of air negative oxygen ion reasonably. Thus, it is of great significance to study the characteristics of air negative oxygen ion concentration and its influencing factors in a specific area for further revealing the change mechanism of air negative oxygen ion and carrying out regional air quality assessment. In this study took air negative oxygen ions in Qianshan National Forest Park of Mufu Mountain area of Hubei Province as the research object, and used the long-term dynamic monitoring data to analyze the characteristics of diurnal, monthly and seasonal variations of the concentration of negative oxygen ions in the air and the assessment of the concentration level. The relationship between negative oxygen ion and air temperature, relative humidity, wind speed, PM2.5 and other environmental factors was studied as well, so as to provide scientific basis for environmental quality assessment and ecological service function assessment in this region. The results showed that the distribution of negative oxygen ion concentration showed obvious seasonal variation, with the highest concentration in summer and the lowest concentration in winter, and the overall pattern was summer > autumn > spring > winter. The maximum monthly mean was in August and the minimum monthly mean was in January. The concentration of negative oxygen ions was positively correlated with air temperature, negatively correlated with relative humidity and PM2.5, and had no obvious correlation with wind speed. The mean concentration of negative oxygen ions in Qianshan National Forest Park was 2191/cm3, which had excellent air negative oxygen ion ecological health resources.
In order to conduct preliminary identification and evaluation of tea tree germplasm resources in southern Henan, 41 clonal varieties from the tea germplasm resources garden in southern Henan were used as materials to analyze genetic diversity and relationships by SSR marker.The results showed that 26 pairs of primers with good amplification were screened from 33 pairs of primers. A total of 102 bands were amplified from 26 pairs of primers, the average number of bands amplified by each pair of primers was 4, the minimum number was 2, and the maximum number was 7. The average number of observed alleles was 2, the average number of effective alleles was 1.8664, the average Nei's genetic diversity was 0.4626, the average Shannon information index was 0.6550, the maximum value of polymorphic information of primers was 0.80, the minimum value was 0.23, and the average value was 0.62. The results of cluster analysis showed that 41 materials were divided into 4 groups at the similarity coefficient of 0.5. Most of the materials with similar geographical origin and genetic background were clustered together, and the genetic distance of the tested varieties was 0.08-1.87. This indicated that the genetic foundation among varieties in the resource garden was relatively broad.
This paper calculated the carbon emissions of Gansu Province and various regions from 2000 to 2020, and selected the proportion of secondary industry, per capita GDP, urbanization rate, energy consumption, energy consumption per 10000 yuan of GDP, scientific and technological input, industrial added value and other influencing factors for principal component analysis. Based on the Probit model, according to the economic development indicators of the 14th Five-Year Plan, three economic assumptions were made for GDP growth in each region, and carbon emissions and peak time from 2020 to 2040 were predicted. The results showed that the carbon emissions in Gansu Province increased continuously from 2000 to 2012, with an annual average growth rate of 7.3%. From 2013 to 2020, the carbon emissions showed a “U” growth rate, with an annual average growth rate of 1.9%. Carbon emissions were positively correlated with per capita GDP, urbanization rate and other factors, and negatively correlated with the proportion of secondary industry and energy consumption per 10000 yuan of GDP. Under the fast economy, only Linxia will achieve carbon peak in 2030 to 2035; under the benchmark economy, Dingxi and other four regions will achieve carbon peak in 2030 to 2035; under the green economy, Lanzhou and other four regions will achieve carbon peak in 2035 to 2040.
With the continuous expansion of orchard planting area in China, the amount of discarded branches of fruit trees is increasing. Discarded branches of fruit trees are rich in minerals and are valuable biological resources, but current improper use of them has caused the waste of resources. This study reviews the utilization and treatment status of fruit tree branches, summarizes the existing problems in the resource treatment of discarded branches of fruit trees, and puts forward suggestions on the problems.The study could provide reference for the in-depth exploration and promotion and application ofdiscarded branch treatment of fruit trees in the future.
Based on the yield data, growth period data and meteorological data of the main highland barley planting areas in Tibet, the hazard index model of the disaster factors, the exposure index model of the disaster-bearing body, the vulnerability index model of the disaster-bearing body, the drought-resistance index model and the corresponding index system applicable to the drought disaster risk assessment of the main highland barley planting areas in Tibet were established, and the comprehensive risk assessment model of the drought disaster in the main highland barley planting areas in Tibet was constructed. On this basis, the risk assessment and zoning of drought disasters were carried out, and the MCI index and comprehensive risk index of drought disasters were verified by using the historical drought frequency data. The results showed that the hazard index model of hazard factors based on MCI index had good applicability in the main highland barley planting areas in Tibet. The comprehensive risk of drought disaster was generally low in the middle and high on both sides. The high risk areas were concentrated in the west of the study area. The secondary high and medium risk areas were distributed in Nimu, Gongga, Sana, Mangkang and other places. The secondary low risk areas were mainly concentrated in Changdu, the middle of Shannan City, Chayu and other places. The low risk areas were concentrated in most of Linzhi City, the west of Changdu City, and the eastern edge of Shannan City.
To implement the strictest farmland protection system and further standardize the balance management of arable land occupation and compensation, Danjiangkou City had carried out the survey and evaluation of arable land reserve resources in the whole region. Taking the base map data of farmland reserve resources survey and evaluation in Danjiangkou City issued by Hubei Province as the research object, according to the evaluation criteria in the “Work Plan for the Survey and Evaluation of Cultivated Land Reserve Resources in Hubei Province” (EZZB [2021] No.15), the evaluation of farmland reserve resources in Danjiangkou was carried out, and further risk assessment was carried out on the plots that were evaluated as suitable for cultivation. The evaluation results showed that the total suitable arable land area of the survey and evaluation of cultivated land reserve resources in Danjiangkou City was 106.5 hm2, accounting for 43.15% of the area of the assessment base map. Among which 56.2 hm2 was grassland and 50.3 hm2 was bare land. The areas suitable for cultivation were at or below the middle risk, and the area of low risk was only 4.9 hm2, accounting for 1.97% of the area of the assessment base map. The area of lower risk was 74.5 hm2, accounting for 30.18% of the area of the assessment base map. The area of medium risk was about 27.1 hm2, accounting for 10.99% of the area of the assessment base map. The reserve cultivated land in Danjiangkou City had a large area with medium ecological risk, which was mainly distributed around the reservoir area of the South-to-North Water Diversion Project, and required appropriate ecological protection and restoration.
The paper aims to explore the linkage relationship of colour of pepper organs. 18 botanical traits of 113 pepper cultivars were investigated and statistically analyzed. Correlation analysis showed that corolla colour, style colour and filament colour had high correlation, while ovary colour, young fruit colour, immature fruit colour and mature fruit colour had no significant correlation. Phylogenetic clustering analysis indicated that purple immature fruit colour was linked to fruit shape and filament colour, stem pubescence was linked to disease-resistance. In this study, we elucidated 18 botanical traits of 113 pepper germplasm, especially the correlation between immature fruit colour and mature fruit colour, which laid a solid foundation for the subsequent research on the genetic law of fruit colour and the gene mapping of fruit colour in pepper.
To study the characteristics of soil nutrients and the ecological stoichiometric ratios of carbon (C), nitrogen (N), phosphorus (P) and potassium (K) under different land use types, the distribution of soil nutrients in the surface layer (0-20 cm) of paddy fields, drylands, grasslands and woodlands and the differences were analyzed by bibliometric methods. The results showed that the four land use types were relatively rich in total potassium and fast-acting potassium, but generally deficient in total phosphorus, with significant differences (P<0.05); soil total nitrogen was positively significantly correlated with total phosphorus (P<0.05), and negatively significantly correlated with adequate phosphorus (P<0.05), soil organic matter showed a highly significant positive correlation with total nitrogen (P<0.01), and total soil phosphorus showed a highly significant positive correlation with total potassium (P<0.01). Soil C:N values were highest in paddy fields, soil C:K, C:P and N:K values were highest in grasslands, N:P values were highest in woodlands and P:K values were highest in drylands; based on the integrated soil nutrient pool index, it could be concluded that the overall soil nutrient levels of the four different land use types showed paddy fields>grasslands>drylands>woodlands. The four land use types effectively presented the differences between soil nutrient content and ecological stoichiometric ratio of elements, which could provide theoretical support for the revegetation and soil improvement of different land-use types.
Based on the daily meteorological observation data of seven meteorological stations in southern Tibet from 1980 to 2021 (April-October), the temporal and spatial variation characteristics and influencing factors of dry and wet index (AI) in the growing season of major grain producing areas in Tibet were studied by using climate propensity rate, Mann-Kendal test, Morlet wavelet analysis, GIS hybrid interpolation method, Pearson correlation coefficient, contribution rate analysis and other methods. The results showed that the average AI in the main grain producing areas of Tibet was 1.7, which belonged to the semi-arid area, and the overall trend was decreasing (humidifying) (-0.036/10 a). The linear decreasing trend was different in different regions, and the area around Lazi County was the most significant (-0.26/10 a). AI had no obvious mutation, and had long and medium term oscillation characteristics of 24 a, 6 a. The spatial distribution was uneven, and had the characteristics of ‘shrinking the dry area and expanding the wet area’. the contribution rate of the main climate influencing factors of AI varied in different regions. In general, the contribution degree after quantification was as follows: precipitation (34.9%)> relative humidity (28.4%)> sunshine (19.9%)> maximum temperature (12.4%).
Based on the meteorological data of Yingshan National Meteorological Station from 2013 to 2021, taking Yingshan tea as the research object, the Changchong Tea Factory was selected as the observation area, the change characteristics of the growth period and yield factor index in different tea rounds were analyzed. The correlation analysis and significance test were used to explore the correlation between meteorological factors and yield at different growth periods. The results showed that the duration of growth period of different rounds of tea was the first round tea> the third round tea> the second round tea. Bud density, average 100 bud weight and theoretical fresh leaf yield all were three round tea> two round tea> first round tea, while the actual fresh leaf yield was two round tea> three round tea> first round tea. The average temperature and relative humidity during the key growth period of different rounds of tea in Yingshan was the third round tea> the second round tea> the first round tea. The precipitation was the third round tea> the first round tea> the second round tea. The sunshine was the second round tea> the first round tea> the third round tea. The number of foggy days reached 50%. The above conditions were suitable for tea plant growth. The precipitation, relative humidity, temperature and sunshine hours of the first round tea decreased with the change of the year. The precipitation, relative humidity and sunshine hours of the second round tea decreased with the annual change, while the average temperature increased. However, the precipitation and temperature of the third round tea showed an upward trend with the change of the year, while the relative humidity and sunshine hours showed a downward trend. Through correlation analysis, it was found that temperature was the first important meteorological factor affecting the growth, development, yield and quality of tea, followed by precipitation and relative humidity, while sunshine played the opposite role.
Rice-planting soils are the most important agricultural soils in China. It is a group of soils with hydroponic maturation in which human beings have cultivated rice for a long time, and a specific soil profile structure has been formed. “Chinese Soil Classification System” and “Chinese Soil Taxonomy”, two current soil classification systems in China, regard rice-planting soil as an independent soil type, which is called paddy soils and stagnic anthrosols, respectively. This group of soils is gradually formed under periodic irrigation-drainage, fertilization, cultivation and rotation. Its main soil formation processes include periodic redox alternation and iron-manganese leaching, base leaching and base restoration actions, and strong fixation and accumulation of organic carbon. At present, the quantitative research on this group of soils has been gradually improved. There is a more in-depth understanding of its distribution law in geographical space and genetic characteristics affected by terrain and soil parent material. However, the mechanism of vertical differentiation of iron oxides in the soils, the setting of some soil subgroups, soil quantitative identification standards, field investigation and mapping technology and the evolution of soil types caused by the change in utilization mode need to be further studied.
Based on daily temperature data in Heilongjiang Province from 1991 to 2020, this study explored the temporal and spatial variations of the critical temperature of ≥10℃ at the beginning and the end of the day, as well as the parameter relationship and spatial-temporal distribution characteristics between the effective accumulated temperature of ≥10℃ and the longitude, latitude and altitude. The results showed that the correlation between the effective accumulated temperature ≥10℃ and the latitude, longitude and altitude in Heilongjiang Province had reached a very significant level, and the effective accumulated temperature geographic calculation model had a good simulation effect. During the study period, the initial date of the critical temperature ≥10 ℃ was in advance, the trend of advance was mountainous>plain, and the final date was delayed, the trend of delay was plain>mountainous. The advance of the initial day and the delay of the final day were conducive to the accumulation of effective accumulated temperature; during the study period, the effective accumulated temperature ≥10℃ showed an increasing trend, and its distribution showed obvious regional characteristics. In general, it gradually decreased from south to north, and gradually increased from mountains to plain.
To effectively and rationally utilize the ancient tea tree resources, the morphological and genetic diversity of the ancient tea tree resources in Wa Autonomous County of Cangyuan in Yunnan Province were analyzed. Based on the individual investigation and analysis of 634 ancient tea trees, the results show that the main germplasms of ancient tea trees in Cangyuan are Dali tea (Camellia taliensis) and Pu-erh tea (C. assamica). The average ground diameter of ancient tea trees is 26.729 cm, the average diameter at breast height is 18.816 cm, the average trunk height is 1.184 m, the average tree height is 5.655 m, and the average crown width is 2.931 m, respectively. According to the strength of the growth potential, the trees are divided into three groups: strong, medium and weak, and the growth of most ancient tea trees is of medium level. For tea trees of 500-year-old or above, the average genetic variation coefficient is 46.505%, and the Shannon-Wiener index (H') ranges from 0.873 to 1.858, indicating that the genetic diversity of ancient tea trees is rich, and the availability of ancient tea trees is high in the selection of excellent resources. The average traits of 42 investigation sites were divided into three categories by cluster analysis, and the genetic regional characteristic of each trait is not significant. The ancient tea trees in Cangyuan are Dali tea and Pu-erh tea. The individual plants of ancient tea trees are distributed in the shape of small settlements, and there is a large genetic diversity of phenotypic traits among individual plants. The results can provide reference for tea tree breeding and help the conservation and utilization of ancient tea tree resources.
Studying the spatio-temporal variation characteristics of temperature in Qingxu County will provide reference for future meteorological services and climate change for agricultural production, and promote sustainable local economic development. Data of temperature and grain yield from 1960 to 2019 in Qingxu was selected and analyzed by the climate propensity rates, moving average calculations methods, Mann-Kendall trend tests and mutations. The results showed that: the annual average temperature in Qingxu was on the rise, and the trend rate of air temperature was 0.27℃/10 a. In the 1990s, there was an obvious line between the cold period and warm period. The interdecadal variation trend was “significant increase—steady—significant increase—gradual increase”, and there was an obvious catastrophe point in 1991. The average temperature in the four seasons also showed an upward trend, with a significant rise in spring. The interdecadal change showed a fluctuating warming trend. The average temperature in spring, autumn and winter had obvious mutation points, with the time of 1996, 1994 and 1980, respectively. The total annual grain output and the annual autumn grain yield were significantly correlated with the annual average temperature, but the annual summer grain yield was uncorrelated. Based on these, reasonable proposals for development and utilization of agricultural resources were put forward.
In order to select salt-tolerant soybean germplasm as the foundation for salt-tolerance breeding, 52 soybean genotypes were exposed to 0.4% of NaCl and 0.8% of NaCl, and the germination indices and some seedling stage indices were investigated for salt tolerance. The results showed that the germination potential, germination rate, hypocotyl length and diameter of the population were decreased significantly under 0.8% of NaCl treatment, compared with the control and 0.4% of NaCl treatment, but there were significant differences among individuals in the population. Salt-intolerant soybean germplasm had significantly lower chlorophyll content and leaf relative water content under 0.4% and 0.8% of NaCl stress than salt-tolerant soybean germplasm. The ability of holding Na+ in the roots in salt-intolerant germplasm was decreased under 0.8% of NaCl stress, while Na+ contents in the stems were higher than that of salt-tolerant germplasm. A total of 18 salt-tolerant soybean germplasm materials, 23 intermediate soybean germplasm materials and 11 salt-intolerant soybean germplasm materials were screened by membership function method.
To clarify the impact of straw returning ratio on rice yield and nitrogen utilization, a field plot positioning experiment was conducted in Tangtou Town, Sinan County of Guizhou Province during the rice growing season from 2019 to 2021. Six treatments were set up in the experiment: CK was no fertilizer, S0 was conventional fertilizer, S1 was conventional fertilizer + straw returning 5 t/hm2, S2 was conventional fertilizer + straw returning 10 t/hm2, S3 was conventional fertilizer + straw returning 15 t/hm2, and S4 was conventional fertilizer + straw returning 20 t/hm2. The results showed that from 2019 to 2021, the yield of S3 treatment was the highest, increased by 20.16%, 8.66% and 14.40% respectively compared with that of S0 treatment, and the yield increase in 2019 was the highest. The reason for the yield difference was that straw returning to field improved the number of effective panicles, the number of grains per panicle, 1000-grain weight and seed setting rate of rice, and then significantly increase the yield. The fitting analysis of straw returning and rice grain yield showed that the highest grain yield was achieved by straw returning amount of 15.43 t/hm2. Straw returning could improve the nitrogen partial factor productivity and nitrogen harvest index between years. In 2019, the nitrogen partial factor productivity of S3 treatment was the highest, while the nitrogen harvest index of S4 treatment was the highest, which were 42.81% and 24.30% higher than those of S0 respectively. In 2020, the nitrogen partial factor productivity and nitrogen harvest index of S3 treatment were the highest, with an increase of 55.98% and 22.61% over those of S0 treatment respectively; and in 2021, the nitrogen partial factor productivity and nitrogen harvest index of S3 treatment were also the highest, with an increase of 21.75% and 15.88% over those of S0 treatment, respectively. Straw returning increased the physiological utilization rate of nitrogen between years, and S3 treatment had the best effect, with an increase of 72.97%, 76.14% and 52.98% respectively compared with that of S0 treatment from 2019 to 2021. Moreover, year and straw returning treatment significantly improved the physiological utilization rate of nitrogen and agricultural efficiency of nitrogen. Therefore, considering rice yield, straw returning fitting results and nitrogen utilization rate, S3 treatment is more suitable for straw returning.
To investigate the contents of soil dissolved organic carbon and soil organic carbon in the rhizosphere of several tree species in different sampling places in a forest ecosystem, the factors affecting the spatial heterogeneity of soil dissolved organic carbon and soil organic carbon in forest ecosystem were analyzed. This project was carried out in the subtropical montane moist evergreen broad-leaved primary forest ecosystem in Ailao Mountains of Yunnan Province. Seven dominant tree species in the primary soil area of forest ecosystem with high altitude in three sampling watersheds were selected as the research objects to investigate the contents of soil dissolved organic carbon and soil organic carbon in the 0-10 cm topsoil. The results showed that the contents of soil dissolved organic carbon and soil organic carbon in the rhizosphere of 5 tree species, including Lithocarpus hancei (Bentham) Rehd., Castanopsis rufescens (Hook. f. et Thoms.) Huang et Y. T. Chang., Lithocarpus xylocarpus (Kurz) Markg., Symplocos ramosissima Wall. ex G. Don and Schima noronhae Reinw. ex Bl. Bijdr, were significantly higher than those in the rhizosphere of the other 2 shrub species, namely, Camellia forrestii (Diels) Coh. St. and Vaccinium duclouxii (Levl.) Hand.-Mazz.. Among the 5 tree species, the contents of soil dissolved organic carbon and soil organic carbon in the rhizosphere of L. hancei and S. noronhae were significantly higher than those of the other 3 species, indicating that different tree species could apparently affect the spatial heterogeneity of soil dissolved organic carbon and soil organic carbon. The contents of soil dissolved organic carbon and soil organic carbon as well as the proportion of soil dissolved organic carbon in soil organic carbon in the rhizosphere of the 7 sampling tree species respectively reached the maximum value in the Laojunshanshen watershed, and decreased to the corresponding lowest value in the Sankeshu watershed, indicating that the environmental factors in different sampling watersheds could also obviously affect the contents of soil dissolved organic carbon and soil organic carbon as well as the ratio between them. The research results of this project fully proved the complexity of the spatial distribution of soil dissolved organic carbon and soil organic carbon in forest ecosystems and the diversity of environmental controlling factors, and could provide new scopes for the research on soil organic carbon composition and carbon storage in various types of forest ecosystems in the world.
Cultivated land is the basis of food production, and the quality of cultivated land affects the comprehensive production capacity of cultivated land. The central and local governments have repeatedly pointed out the need to protect the red line of cultivated land and to stabilize the policy, area and yield of grain production. The area of mountainous and hilly areas in the Xiangjiang River basin is widely distributed, and it is important to study the quality level of cultivated land in mountainous hilly areas to deepen the protection of cultivated land and improve the land productivity of cultivated land in the basin. The cultivated land in Dong'an County, a typical mountainous and hilly area in the upper reaches of the Xiangjiang River basin, was selected for quality evaluation. The results were analyzed by overlaying the soil map, current land use map and administrative division map of Dong’an County on the ArcGIS platform. The index weight was determined by hierarchical analysis, and the affiliation degree was determined by fuzzy mathematics, after the comprehensive weights were derived. The results showed that according to the evaluation standard of “quality grade of cultivated land” GB/T 33469—2016, the evaluation result was that the quality of cultivated land in Dong’an County was divided into 6 grades. Among them, the area of the third grade was 12793 hm2, accounting for the highest proportion of the total area, which was 37.4%; followed by the wide distribution area of the second grade and the fourth grade, which were 8648 hm2 and 6985 hm2, respectively, accounting for 25.3% and 20.4%; the area of other grades of land was relatively small. The content of effective phosphorus, fast-acting potassium and organic matter of cultivated land in Dong’an County was mostly at the middle level, and the area of cultivated land with soil nutrient characteristics of Grade I, Grade II and Grade III was widely distributed, which required some targeted measures to enhance the production capacity of cultivated land.
Resources and Environment
