To clarify the influence mechanism of biochar types and application rates on rice growth and optimize its field application, this study used four distinct biochar (rice hulls, coffee residue, peanut hulls and soybean straw) as materials, and set 0%-5.0% gradient application rate to analyze its effect on the growth and development of rice (Oryza sativa L. ). The findings demonstrated that biochar significantly promoted rice growth. However, the optimal biochar type and biochar application rate were found to vary. In comparison with the control group, the total dry weight of the biochar treatment group exhibited an average increase of 70.3%, with rice husk biochar and coffee grounds biochar demonstrating the highest increases at an application rate of 5.0%. The impact of biochar on the various growth components of rice plants exhibited variability. The leaf mass fraction generally increased, while the stem and root mass fractions were relatively stable, and the root dry matter content was significantly increased ( e.g., the rice husk biochar treatment group increased by 7.8 % ). In addition, all biochar increased leaf mass per unit area, indicating that they may promote yield increase by enhancing photosynthetic efficiency. Studies have shown that the growth-promoting effect of biochar on rice is regulated by both species and application rate. It is necessary to optimize the application scheme in combination with crop demand and soil conditions to fully tap its sustainable application potential in green agriculture.

In response to the oilseed production capacity enhancement project and to empower the yield improvement initiatives for grain and oil crops, while persistently advancing the industrial development of rapeseed in Sichuan Province, we used the nuclear male sterility line ‘Yi 10AB’ as female parent to cross with the restorer line ‘16-8007’, a hybrid variety ‘Yiyou 46’ with high yield and double-low (low erucic acid and low glucosinolates) was obtained after years of selection and identification. Its average yield in comparative experiment of new varieties in the Sichuan ‘Tianfu Rapeseed’ for two consecutive years (2019-2021) was 3050.25 kg/hm², 8.1% higher than that of the control ‘Deyou 6’. The erucic acid content was 0.0371%, the glucosinolates content was 25.3 μmol/g, and the average oil content was 45.88%. ‘Yiyou 46’ was a superior-quality variety with high yield, stable production, strong lodging resistance, excellent cold tolerance, robust disease resistance, wide adaptability, and suitability for mechanical harvesting. ‘Yiyou 46’ was registered by the Ministry of Agriculture and Rural Affairs in 2022 with the registration number GPD Rapeseed (2022) 510220 and recommended for autumn sowing in winter rapeseed cultivation areas of Sichuan's flatlands and hilly regions.

The purpose of this study is to evaluate the effect of commercial growth regulators on alleviating the harm of low temperaturestress. Tobacco seedlings were treated with artificial climate box at 8℃, and different concentrations of commercial growth regulators ‘Wotaibao’ and ‘Baiande’ were sprayed. The growth of tobacco seedlings before spraying and after spraying 1 time, 2 times and 3 times was investigated. The activities of SOD, POD, PPO and CAT in leaves were detected, and the root activity, MDA and proline content were measured. After low temperature stressat seedling stage, the root activity of tobacco seedlings showed a trend of increasing first and then decreasing; the activity of SOD showed an increasing trend; the activity of POD, CAT, PPO and proline content showed a trend of decreasing first and then increasing. The seedling index, root activity, protective enzyme activity, malondialdehyde and proline content were all increased after spraying the commercial growth regulators ‘Wotaibao’ and ‘Baiande’ at different concentrations.The strong seedling index was effectively improved after spraying ‘Wotaibao’ for 3 times, and the effects of 3 concentrations were not significantly different. Spraying ‘Wotaibao’ diluted 200 times once, and diluted 500 times and 800 times twice had the best effect on improving root activity.Spraying three times with 200 times dilution of ‘Wotaibao’ had the best effect on improving SOD and PPO enzyme activity, malondialdehyde and proline content. The root activity and seedling index were most effectively improved by spraying 750 times dilution of ‘Baiande’ for 2-3 times.The effect of increasing protective enzyme activity, malondialdehyde and proline content was the best after spraying ‘Baiande’ diluted 1500 times for 3 times. The harm of low temperature stress was alleviated through physiological index changes after spraying commercial growth regulators ‘Wotaibao’ and ‘Baiande’.Based on this, it is recommended to use ‘Wotaibao’ diluted 200 times to spray 2-3 times, or ‘Baiande’ diluted 750-1500 times to spray 2-3 times.

In order to improve the precise prevention and control level for downy mildew in facility-grown cucumber in spring in Wuhan, this study constructed a disease-promoting meteorological index and suitability grading standards based on meteorological observation data of Wuhan from 1951 to 2021 and disease monitoring data from 2011 to 2021, with identified temperature and humidity as core driving factors. Furthermore, the index accuracy was evaluated and climate risk characteristics of disease occurrence and epidemic were analyzed. The results show that: (1) the disease-promoting meteorological index has an accuracy of 100% in assessing the intensity of the disease, and an accuracy of 75% in predicting the initial day of the epidemic, which can objectively reflect the time and extent of the disease. (2) From 1951 to 2021, the outbreak years of downy mildew and the number of suitable and above epidemic days (DESA) showed a trend of "stable in the first 40 years, and first decreased and then increased in the last 31 years". The outbreak years from 2011 to 2021 doubled compared with 2001-2010, and the growth rate of DESA days from 2006 to 2021 reached 17.2 d/10a, the epidemic risk and intensity of the disease were significantly enhanced. (3) The suitable prevalence period of cucumber downy mildew in Wuhan begins on average on March 19th. It enters the medium-high risk period of downy mildew prevalence in mid-March, the high-risk period after late March, and the highest risk period is from early April to late April. Moreover the disease has a significant trend of early onset in the past 31 years (the proportion of early-onset years increased by 2.4 times). (4) The beginning of the suitable epidemic period of the disease in the facility environment is 1 month earlier than in the open field. The disease-promoting meteorological index constructed in this study can provide a scientific tool for monitoring and early warning of cucumber downy mildew. It is recommended that the plant protection department initiate special monitoring in early March and promptly regulate the temperature and humidity of facilities.

To screen suitable models of green manure intercropping for citrus orchard in Jian'ou City, and explore regulatory effects of different green manures of citruspomelo and soil fertility, the 7-year-old citrus orchard was selected as the experimental subject, the clean cultivation (T₁) was used as control, and the interplant Vicia sativa (T₂), Vicia dasycarpa (T₃), Astragalus sinicus (T₄), Brassica napus (T₅), Medicago sativa (T₆), and Lupinus micranthus (T₇) were served as the six experimental treatments, the impact of the different treatments on citrus fruit agronomic trait, yield, quality, and soil physicochemical property were systematically analyzed in this study. The results showed that the six interplant treatments significantly increased citrus yield by 951.0-3001.5 kg/hm², with the increasing ratio of 5.06%-15.98%, when compared with clean cultivation. Among these, interplant Vicia sativa and Astragalus sinicus achieved the best yield improvement. The interplant green manures enhanced the content of vitamin C, soluble solid matters, reducing sugars, titratable acids, and the sugar-acid ratio, reducing nitrate content by 24.71%-50.57% in the fruit. The interplant Vicia dasycarpa, Astragalus sinicus and Brassica napus obtained higher fresh grass yields under the same conditions. Compared to clean cultivation, interplant green manures increased the content of soil organic materials by 5.96%-14.04%, total nitrogen by 2.58%-12.90%, alkeline-N by 9.79%-21.39%, available phosphorus by 13.28%-21.40%, and available potassium by 16.84%-32.63%. Among these, interplant Vicia sativa obtained the best improvement of soil fertility, followed by Vicia dasycarpa and Astragalus sinicus. In conclusion, interplant green manures in citrus orchard acquire synergistic effects on yield enhancement, quality increasing, and soil fertility improvement. The interplant Vicia sativa exhibits the most comprehensive effectiveness, and could be promoted and applied as the preference pattern of green cultivation in local citrus orchards.

Correlation and path analysis of major agronomic traits and yield-related characteristics in blueberry F₁ hybrids were conducted to clarify the characteristics and relationships between key agronomic traits and per-plant yield. This study aimed to explore the heterosis potential of blueberry hybrids and provide a reference for formulating appropriate breeding objectives. Using 21 blueberry hybrid progenies as test materials, 13 agronomic traits were investigated under subtropical climatic conditions. Correlation analysis revealed that stem diameter (X₄) exhibited a significant positive correlation with per-plant yield, while east-west canopy width (X₁), north-south canopy width (X₂), leaf number (X₅), fruiting branch number (X₁₀), and total fruit set (X₁₁) showed highly significant positive correlations with yield. Other traits displayed varying degrees of correlation. Path analysis indicated that the contribution of each trait to per-plant yield ranked as follows: total fruit set (X₁₁)> single-fruit weight (X₈) > fruit longitudinal diameter (X₇)> north-south canopy width (X₂)> hundred-fruit weight (X₉)> fruiting branch number (X₁₀)> east-west canopy width (X₁)> plant height (X₃)> fruit transverse diameter (X₆)> average fruit set per branch (X₁₂)> stem diameter (X₄)> leaf number (X₅). Through dimensionality reduction via multiple linear regression, 12 agronomic traits were consolidated into new variables represented by fruit longitudinal diameter (X₇), single-fruit weight (X₈), and total fruit set (X₁₁). The adjusted coefficient of determination for these new variables reached 0.971, and the established regression equation Y=-0.4091-0.0057X₇+0.2177X₈+0.0022X₁₁ effectively explained the influence of relevant factors on per-plant yield. Total fruit set (X₁₁) of blueberry F₁ hybrids demonstrated a highly significant positive correlation with yield, and the top three direct path coefficients were ranked as total fruit set (X₁₁), single-fruit weight (X₈), and fruit longitudinal diameter (X₇). These three traits adequately explained the impact of correlated factors on yield. During the selection of blueberry F₁ hybrids, the selection criteria for total fruit set, single-fruit weight, and fruit longitudinal diameter could be appropriately relaxed. Lines 29-2-2, 33-30-A and 30-29-B exhibited F-values of 1.99, 1.65 and 0.96, respectively, achieving the top three comprehensive scores and warranting further investigation.

The aim is to clarify the optimal irrigation method for daylily in Datong City, Shanxi Province, and provide reference for local daylily cultivation and irrigation management. Four plots of daylily with different irrigation methods were selected by the methods of geographical location selection and irrigation method selection in Yunzhou District, the main production area of daylily in Datong City, Shanxi Province. The selected plots of daylily had a growth age of more than five years, and other field management methods were the same. The development period of each selected sample plant was consistent. Samples were taken at fixed points and times for determination. The differences in growth indicators, material accumulation and yield structure of daylily under drip irrigation, sprinkler irrigation, ordinary water irrigation and dry land were compared and analyzed. Based on meteorological data from 1981 to 2023, the characteristics of temperature and precipitation changes in the main production areas of daylily, as well as the changes in temperature, precipitation, water requirement and water deficit during the growth period (from emergence to the end of flowering) of daylily were analyzed. The results showed that there were differences in growth indicators, material accumulation and yield structure of daylily under different irrigation methods. Among them, the drip irrigation method resulted in the fastest growth, the most material accumulation, the highest yield and the greatest contribution rate of irrigation. The temperature in the main production areas of daylily has increased, while the precipitation and effective precipitation of more than 10 mm during the growth period have decreased, leading to an increase in the times of irrigations during the growth period of daylily. Comprehensive analysis indicated that the precipitation during the growth period of daylily could not meet the growth requirements. In normal precipitation years, three times of irrigations were needed, while in drought years, six to seven times of irrigations were required, and in severe drought years, ten or more irrigations were needed. Drip irrigation is the optimal irrigation method for daylily production in Datong, Shanxi Province, with the best economic benefits.

This study focused on carbon footprint and nitrogen fertilizer utilization in agricultural production, providing theoretical support for low-carbon production of dry rice. The carbon footprint (CFP) of the production process of upland rice was calculated by using life cycle assessment (LCA) methodology. The results showed that the carbon footprint of 1 kg Jilin upland rice from planting to product processing was 0.4721 kg CO₂-eq. The carbon footprint of upland rice was mainly derived from nitrogen fertilizer production (39.71%) and land emission (20.41%). In conclusion, compared with rice, upland rice had no methane emission and had emission reduction effect. Optimization of fertilizer selection, rational reduction of nitrogen fertilizer application, application of controlled release fertilizer, addition of nitrification inhibitor, and rational substitution of organic fertilizer for fertilizer were important ways to further achieve carbon emission reduction of upland rice.

Satellite remote sensing has a wide range of applications in estimating corn residue cover and evaluating the implementation of conservation tillage methods. This study took Lishu County, Jilin Province as the study area to invert the inter-monthly and inter-annual straw coverage conditions from 2020 to 2024. The results showed that from the end of autumn harvest (late October) to the beginning of spring sowing (early April), the straw coverage rate in the whole county continued to decrease, and the low coverage areas significantly increased, and the inter-annual differences were significant. The dynamic change analysis of straw coverage in Lishu County based on the inversion of tillage index could accurately indicate the spatial and temporal distribution of straw coverage and give insights to the protective tillage practices of black soil.

To study the effects of different tillage measures on soil active organic matter and carbon pool management index, five treatments were set up through field positioning test, including rotary tillage (RT), no-tillage (NT), deep loosening of 35 cm, deep loosening once every 2 years in the fall, and no tillage and tillage alternately (ST₂), deep loosening of 35 cm, deep loosening once every 3 years in the fall, no tillage and tilling alternately (ST₃), deep loosening 35 cm, deep loosening once a year, deep loosening + tilling, and all the straw returning to the field when tilling (STS), with rotary tillage (RT) as the control to compare and analyze the content of high active organic matter (H-LOM), medium active organic matter (M-LOM), low active organic matter (M-LOM) and none-active organic matter (N-LOM), and the variation characteristics of carbon pool management index (CMI) of different soil layers (0-10, 10-20, 20-30, 30-40 cm). The results showed that the STS treatment increased the total soil organic matter (TOM) by 19.73% on average compared with the RT treatment; rotational tillage and straw return significantly affected the percentage of active organic matter fractions, and the STS treatment increased the content of H-LOM, M-LOM and L-LOM by 20.65%, 34.52% and 32.69% on average, respectively compared with the RT treatment; the carbon pool index (CPI) of the NT, ST2, ST3 and STS treatments was higher than that of RT treatment and with different degrees of increase in organic matter content; compared with RT treatment, the carbon pool management indexes of NT, ST2, ST3 and STS treatments with high, medium and low active organic matter were greater than 100, and STS treatment had the highest CPI up to 421.21. Comprehensive analysis, the STS treatments could be used as an effective tillage method to increase soil organic matter content on a large scale.

The soil structure and microbial community characteristics of long-term sugarcane cultivation in the national geographical indication agricultural product origin of ‘Taoshan sugarcane’ in Ruian, Zhejiang Province were analyzed. This project used wet-screening method to determine the composition and stability of soil water-stable aggregates, and Miseq high-throughput sequencing was adopted to measure soil microbial community, and then the relationship between soil structure and microbial abundance and diversity was explored. Based on the content of >0.25 mm water-stable aggregate, mean weight diameter (MWD) and geometric mean diameter (GMD) of aggregate, the structural stability of sugarcane soil was divided into three levels: high (HS), medium (MS) and low (LS). The pH and organic matter content of HS soil were significantly higher than those of MS and LS soils, while there was no significant difference in available phosphorus, hydrolyzed nitrogen and available potassium among soils with different structures. The HS soil had significantly higher microbial carbon (MBC) and nitrogen (MBN) content relative to MS and LS soils. The analysis of microbial community structure showed that soil structure significantly affected the OTU quantity, alpha diversity index, and community composition of microorganisms. The HS soil with higher contents of stable aggregate and organic matter provided a suitable microbial habitat for microorganisms. Soil structure also affected the abundance of dominant microbial genera. Redundancy analysis (RDA) showed that soil structure affected the abundance of dominant microbial genera by altering soil physicochemical properties. A good soil structure could provide a more suitable habitat for microorganisms. The research results had preliminarily revealed the soil structure and microbial community characteristics of long-term sugarcane plantation soil, as well as their interrelationships. This provided a reference for studying the regulation of sugarcane soil structure, optimization of microbial diversity and function in order to enhance soil health function. This result also provided scientific basis for the management and sustainable utilization of long-term sugarcane plantation soil.

The reclamation of cultivated land reserve resources is an important source for supplementing cultivated land, and it is also a significant measure for ensuring food security and promoting the sustainable utilization of land resources. The rational development and utilization of these resources are of great significance for promoting economic development and implementing the policy of balancing the occupation and supplementation of cultivated land. Taking the reserve resources of cultivated land created through reclamation in Fujian Province as the research object, this study selected 12 influencing factors from four dimensions: terrain, soil, location and plot, to analyze their quantity and quality from the perspectives of mountainous and coastal areas. And a hot spot analysis was conducted to explore the coordination of their quality and quantity in spatial distribution. The research results showed that the quantity of reserve resources of cultivated land created through reclamation in Fujian Province varied greatly in spatial distribution, presenting a spatial distribution characteristic of “more in the east and less in the west”, and mainly concentrated in coastal areas, mainly consisting of orchards and tea gardens. The quality of reserve resources of cultivated land created through reclamation in Fujian Province was generally high, and except for the soil dimension, the quality in coastal areas was better than that in mountainous areas. This was mainly due to the advantages of flat terrain, convenient transportation, and regular plots in coastal areas. Among various types of land, the quality and quantity of reserve resources of cultivated land created through reclamation in orchards, tea gardens, and pond surfaces had a significant positive correlation in space. Specifically, the quality and quantity of reserve resources of cultivated land created through reclamation in coastal areas were high, while they were low in mountainous areas. In addition, the distribution of reserve resources of cultivated land created through reclamation with high quality but low quantity, and low quality but high quantity was relatively small. This indicated that the quality and quantity of reserve resources of cultivated land created through reclamation in Fujian Province are relatively coordinated, and high-quality resources tend to be concentrated together. There were significant differences in the quality and quantity of reserve resources of cultivated land created through reclamation between mountainous and coastal areas in Fujian Province. Exploring the characteristics of their quantity, quality, and coordination were of great significance for the rational development and utilization of reserve resources of cultivated land, optimizing resource allocation, promoting coordinated regional development, and protecting cultivated land.

Taiwan loach is an excellent breeding species, and the mechanism of salinity on its hatching rate and emergence rate during artificial breeding is not clear. In order to clarify the optimal salinity for hatching and emergence of Taiwan loach, and to screen the optimal salinity range suitable for hatching of Taiwan loach fertilized eggs and emergence of larvae, it provides technical support for large-scale seedling breeding in Anyue area. The fertilized eggs of Taiwan loach were used as experimental materials, and different salt addition gradients of 0‰, 2‰, 4‰, 6‰, 8‰ and 10‰ were set to carry out artificial hatching experiments. The water temperature was controlled at 21℃ and pH 8.0. Three parallels were set in each group to determine the hatching rate and emergence rate under different salinity conditions. The results showed that salinity had a significant effect on the hatching rate and emergence rate of Taiwan loach, showing the rule of ‘low promotion and high inhibition’. When the salinity was in the range of 0‰ - 2‰, the hatching rate and emergence rate reached the highest level, and the hatching rate of 2‰ salinity group was 50‰, which was significantly higher than that of other treatment groups. The emergence rate of the salinity group reached 46%, which was also the highest in each treatment group. When the salinity exceeded 2‰, the hatching rate and emergence rate continued to decrease with the increase of salinity, and the emergence rate decreased to 0 when the salinity was ≥ 8‰. The suitable salinity range for the hatching of Taiwan loach fertilized eggs and the emergence of larvae is 0‰ - 2‰. This salinity condition can effectively improve the efficiency of seedling breeding and provide guidance or reference for the hatching and emergence of Taiwan loach.

In order to study the warming effect of different plastic film mulching methods on early spring corn in Wuhan, ensure safe sowing and increase yield per unit, a comparative observation experiment was conducted on three covering methods with ‘Etianyu No5’ as test material in Hannan District of Wuhan, including open field sowing, single-layer plastic film covering, and single-layer plastic film + small arch shed. The results showed that plastic film covering significantly increased the ground temperature by 10 cm, increased the effective accumulated temperature by 9.9%-22.1% compared to open field sowing, shortened the entire growth period by 5-13 days, and increased the seedling emergence rate by 20%-30%. Among them, the warming effect of plastic film + small arch shed treatment is the most significant, and the effect of promoting early market is the best; the open field sowing method is not suitable for promotion due to the high risk of low temperature and cold damage during the sowing period. Under the methods of plastic film covering and plastic film + arch shed, the average earliest suitable sowing period could be 8 days and 19 days earlier than open field sowing, respectively. In terms of selecting a safe sowing period, if continuous low temperature is forecasted, the germination rate could be improved by delaying sowing or adding small arch sheds, thereby reducing the risk of low temperature and cold damage.

The study scientifically evaluates the quality of rural human settlement in Hunan Province and provides countermeasures and scientific basis for its improvement. This paper constructs an evaluation index system for the quality of rural human settlement in Hunan Province, consisting of four subsystems: economic environment, infrastructure, public services, and ecological environment. By employing methods such as the entropy method and geographic visualization, it explores the spatiotemporal evolution characteristics of rural human settlement quality in Hunan Province from 2015 to 2024. Over the past decade, the overall quality of rural human settlement in Hunan Province and the quality of each subsystem have significant improvements. There are significant spatial differences in human settlement quality, with the eastern region, represented by the Changsha-Zhuzhou-Xiangtan area, leading in terms of scores, while the western region scores relatively lower. In the governance of rural human settlement in Hunan Province, it is necessary to narrow regional spatial differences and continuously improve the quality of rural human settlement environment in various regions of Hunan Province from the four aspects of economic environment, infrastructure, public services, and ecological environment, based on actual conditions and tailored to local circumstances.