The aims are to objectively select influential and forward-looking global agricultural research frontiers in 2024, reveal the development trends of agricultural research frontiers, gain insight into the competitive situation of countries and institutions in the global agricultural research frontiers, analyze the advantages and disadvantages of the development of China's agricultural research frontiers, providing data support for promoting the improvement of China's agricultural science and technology innovation development strategy. Based on SCI papers from WOS platform, CSCD papers, and EI paper data (2019-2023), 76 agricultural research frontiers from 9 major agricultural disciplines were selected for 2024. Among them, 13 research frontiers were the most forward-looking and had been identified as the forefront of agricultural research.

To breed the double-low (low erucic acid and low glucosinolates) rapeseed variety with the double-high of yield and oil-content, strong stress tolerance and wide adaptability, we used cytoplasmic male line 'Han 3A' as female parent to cross with the restorer line '475R', after selection and identification, we obtained a variety 'Hanyou 23' with high oil content and high yield and multi resistance in Brassica napus L. Its average yield in comparative experiment of new rapeseed varieties in the Yangtze River Basin (the upper, middle and lower reaches) for two consecutive years (2020-2022) was 3167.8 kg/hm², the erucic acid content was 0.105%, the glucosinolate content was 17.48 μmol/g, and the oil content was 47.57%. This variety had resistance to sclerotinia sclerotiorum and viral diseases, strong cold resistance and good lodging resistance. The variety was registered by the Ministry of Agriculture and Rural Affairs in 2024 with the registration number GPD rape (2024) 610234.‘Hanyou 23’was a hybrid Brassica napus variety with high yield and superior quality, strong stress tolerance, wide adaptability and suitability for agriculture mechanization. This paper provided the basis for its popularization and application by introducing the breeding process, characteristics and high-yield cultivation technology.

To investigate the favorable environmental conditions for the seed germination and seeding emergence of Angelica dahurica, and to address the practical issue of the low seedling rate of emergence of Angelica dahurica in field cultivation, the simple and effective methods to enhance the rate of emergence of Angelica dahurica seeds were explored. A two-factor split-plot design was employed under field conditions. The substrates with different ratios, such as peat soil, peat soil:garden soil, and peat soil:garden soil :perlite, as well as garden soil alone, were arranged in the main plots. Seed sowing treatments with no covering, and burial depths of 1 cm, 3 cm, and 5 cm were arranged in the sub-plots. The seed germination, seeding emergence, and growth conditions of Angelica dahurica were determined with different substrates and burial depths. The results indicated that there was a significant interaction effect between different substrates and burial depths. The seed emergence and seedling growth of Angelica dahurica were significantly impacted by the substrates with different ratios. The most suitable substrates were peat soil: garden soil at a 1:1 ratio and peat soil: garden soil: perlite at a 2:2:1 ratio. Furthermore, the effect of burial depth on seed emergence was significant, and the seeding rate of emergence was the highest at 1 cm depth. When cultivating Angelica dahurica in field conditions, a 1:1 mixture of peat soil and garden soil with a burial depth of 1 cm could serve as a simple and effective method to enhance seedling emergence, promote growth, and improve soil structure.

In order to understand the effect of phosphorus and potassium reduction in vegetable fields rich in phosphorus and potassium, the plots with 378 mg/kg available P and 614 mg/kg available K were selected to carry out nine different nitrogen, phosphorus and potassium reduction treatments for three consecutive crops. The results showed that reducing the amount of nitrogen, phosphorus and potassium fertilizer could reduce the contents of the corresponding nutrient elements in vegetables. Reducing the input of phosphorus and potassium fertilizer could effectively reduce the levels of available phosphorus and available potassium in soil. No or less application of phosphorus and potassium had no obvious effect on vegetable yield, but no application of nitrogen could significantly reduce vegetable yield. The vegetable yield of organic fertilizer replacing phosphate and potassium fertilizer was higher than that of conventional fertilization. Nitrogen was the main nutrient element that restricted the growth of vegetables. No or less application of phosphorus and potassium fertilizer in the short term could effectively reduce the accumulation of phosphorus and potassium in soil and reduce the risk of phosphorus loss while keeping the yield from decreasing.

Determining the safety threshold of heavy metals in soil is an important measure to ensure the quality and safety of agricultural products in China. By studying the accumulation and transportation characteristics of five heavy metals (Cr, Cd, Pb, As, and Hg) in different organs of corn and wheat in the cities of Jinchang, Zhangye and Baiyin in Gansu Province and establishing the relationship between the effective content of Cr, Cd, Pb, As, and Hg in soil and crop grains, this study identified the safety threshold of effective heavy metals in soil for corn and wheat systems. This study employed the method and principles of species sensitivity distribution (SSD) and derived the safety threshold of effective heavy metals in soil for corn and wheat planting systems based on the cumulative probability distribution curve of the Logistic function distribution model. The results showed that the accumulation pattern of Cr, Cd, Pb, As and Hg in wheat plants was consistent, namely, roots>stems>grains, and similarly, the accumulation pattern of Cr, Pb, As and Hg in corn plants was roots>stems>grains, while the accumulation pattern of Cd was stems>roots>grains. Utilizing the Logistic function distribution model to fit the cumulative probability distribution curve based on the effective content of heavy metals, the safety thresholds of effective Cr, Cd, Pb, As and Hg in wheat soil were determined to be 0.019, 0.771, 35.294, 2.777 and 0.133 mg/kg, respectively. Meanwhile, the safety thresholds of effective Cr, Cd, Pb, As and Hg in corn soil were determined to be 0.296, 7.90, 52.363, 12.462 and 0.119 mg/kg, respectively. The results of this study indicate that estimating the safe threshold of effective heavy metal content based on the cumulative probability distribution curve method was scientific, providing a scientific basis and support for the safe planting and risk control of wheat and corn.

The study aimed to master the soil nutrients, soil environment, soil quality and soil environmental quality of green selenium-rich and germanium-rich production areas in Nanhua of central Yunnan. Based on the 630 surface soil samples data obtained from the 1:250000 land quality geochemical survey in Nanhua of central Yunnan, the soil nutrients, soil environment, soil quality and soil environmental quality of green selenium-rich and germanium-rich production areas in Nanhua County were evaluated according to relevant national or industry standards. The results showed that soil nutrient content in the study area was medium-highly rich, with 37.19% of the soil having sufficient nutrients of the first and second grades, and 42.35% of the soil having sufficient nutrients of the third grade. The overall soil environment was good, with first-grade soil (risk-free) accounting for 80.19%, second-grade soil (risk-controllable) accounting for 19.41%, and third-grade soil (higher risk) accounting for only 0.40%. The comprehensive grade of soil quality was generally high-quality and good, and the proportion of first-grade (high-quality) and second-grade (good) soil reached 60.26%. The proportion of soil that meets the AA grade green selenium-rich production area standard was 2.78%, and the area was 63 km². The proportion of soil that meets the AA grade green germanium-rich production area standard was 28.5%, and the area was 646 km². The proportion of soil that meets the AA grade green selenium-rich germanium production area standard was 2.78%, and the area was 63 km². The soil nutrients in the study area were relatively sufficient, the soil environment was generally good, and it had broad prospects for the development of green selenium-rich and germanium-rich foods. This study provided a scientific basis for the establishment of a green selenium-rich and germanium-rich planting and breeding experimental base and the development of green selenium-rich and germanium-rich agricultural and livestock products in central Yunnan, and contributed to the construction of ecological agriculture, local economic development and rural revitalization in Nanhua area, it also had a certain reference effect on the development of green agriculture and the land use planning in central Yunnan.

High-intensity land conversion and persistent land use activities exert dual effects on soil development, which can significantly influence pedodiversity. We first reviewed the influences of various types of land use on the source of parent materials, microclimate, microrelief, vegetation cover, management practices and soil age. Then based on our systematical analyses of the effects of land use change on soil physical, chemical, and biological properties, we summarized the effects of land conversions on soil genetic, morphological, and diagnostic characteristics. We also comprehensively evaluated soil type evolution trends in different classification categories in response to land conversions. Finally, we proposed three research priorities: (1) an overall understanding of the effect of diverse land use activities on the soil properties and formation processes; (2) deep exploration of dynamic soil genetic responses to land cover conversions and modifications; (3) and development of new technologies for exact and high-efficiency identification of soil type change with land use change.

To understand the effects of combined application of organic materials with different sources and clay minerals on the improvement of soil organic matter in newly reclaimed paddy fields, two newly reclaimed red soil paddy fields with different textures, including paddy fields on red sandstone soil and paddy field on yellowish red soil in Zhejiang Province, were selected to explore the mineralization characteristics of different organic materials in newly reclaimed red soil paddy fields by indoor simulation cultivation. The effects of different organic material combination application on soil organic carbon accumulation and composition, as well as the effects of organic materials-clay mineral combination application on organic carbon accumulation in the soils were analyzed. The results showed that the mineralization rate of different organic materials in the soils was different. The application of biochar, weathered coal humic acid, peat and branch compost was conducive to the accumulation of soil organic carbon, and the application of biological manure was conducive to improving soil microbial biomass. The combination of biochar-weathered coal-biological manure, biochar-branch compost-biological manure or peat-straw-biological manure was better for improvement of soil organic carbon. The study on the effects of organic material combinations in different proportions on the accumulation of organic carbon in the soils showed that three proportioning schemes, namely, biochar (2/5)+weathered coal humic acid (1/5)+biological manure (2/5), biochar (2/5)+ branch compost (1/5)+biological manure (2/5), and peat (2/5)+straw (1/5)+biological manure (2/5), were more appropriate for the overall improvement of soil organic carbon quality in new paddy fields. At the same time of applying organic materials, the application of montmorillonite in new sandy loamy paddy field was conducive to the improvement of soil water stability aggregates, and could promote the joint improvement of organic carbon and microbial biomass carbon, and increase the stability of soil organic carbon.

In recent years, the economic benefits of root herbs have continued to rise, the scale of cultivation has been expanding year by year, leading to the rapid development of root herbs planting machinery. However, the planting machinery still has the problems of low planting efficiency, narrow application range, and high planting loss. To address these issues, scholars at home and abroad continue to innovate and optimize, and have achieved certain results. The current situation, development dynamics and constraints of domestic and foreign research on mechanized planting technology and equipment for root and tuber Chinese herbal medicines were reviewed in the article, the structure, their key technologies and types of representative domestic and foreign planting machinery were analyzed and summarized. And the shortcomings of domestic mechanized planting technology for root and tuber Chinese herbal medicines were pointed out, and corresponding countermeasures, suggestions and subsequent development trend and direction were put forward.

In order to study the impact of maximum residue limit standards for agricultural and veterinary drugs on China honey export trade, this article provides an overview of the current agricultural and veterinary drug residue limit regulations and standards in China, the European Union, the United States, Japan, and Australia, as well as the maximum residue limit standards in honey. It also compares and analyzes the relevant limit regulations and standards in China with the aforementioned countries and regions. As a result, China only has limited regulations on 6 pesticides and veterinary drugs in honey in national standards, whereas the European Union, Japan, Australia, and the United States have respectively established limits for 538, 79, 4, and 3 pesticides and veterinary drugs in their respective national standards and regulations. China industry standards have 13 MRL standards for pesticides and veterinary drugs, which have revised and supplemented the National Standard to some extent. However, compared with the standard systems of developed countries, standards for the limit of pesticide and veterinary drug residues in honey are relatively weak in China. Furthermore，There are differences in the types and quantities of MRL standards for agricultural and veterinary drugs in honey between China and other countries and regions such as the European Union, but China's standards are in line with its actual national conditions. In order to avoid the obstruction of honey export, we can refer to the standards of other countries and regions with China honey trade, and provide technical support for the revision of MRL standards for agricultural and veterinary drugs in China.

In order to study the effects of meteorological conditions on the internal quality and appearance quality of sunflower seed kernels in Hetao Irrigation District, using the staged sowing experiment to record the development period of sunflowers, and the contents of linoleic acid and oleic acid in sunflower kernels were tested. The incidence of sunflower kernel rust spots, disease index and sunflower borer feeding rate were counted. Using Excel, the numerical relationship between the internal and external quality of sunflower kernel and meteorological conditions was analyzed. The results showed that the sowing date had obvious influence on the inner quality and appearance of sunflower. Considering these two aspects, the best sowing date should be from May 25 to June 2. When the sunshine duration from flowering to maturity was 393.3-396.4.8 h, the content of linoleic acid could be greatly increased and the content of oleic acid could be reduced. When the average relative humidity from flowering to maturity was 58%-59%, the quality of sunflower could be significantly improved. When the average temperature from flowering to maturity was 19.0-20.8℃, the inner quality and appearance of sunflower were obviously improved. Precipitation from flowering to maturity had significant effects on sunflower quality. When precipitation was 42-44 mm, the content of linoleic acid in sunflower was greatly increased. When the precipitation was 46.9 mm, the gnawing rate of moth was the lowest. Precipitation, relative humidity and water vapor pressure at flowering stage were negatively correlated with the occurrence index of sunflower rust spot. With the increase of moisture and humidity, the number of drought-fond pest thrips decreased sharply, so the incidence index of rust spot decreased.

This study explores the changes in nitrogen application rate and the effects of increased CO₂ concentration on wheat yield and biomass in semi-arid areas under different sowing dates. This article used the adjusted APSIM model to set up three different sowing dates of early sowing ESW (March 3rd), normal sowing NSW (March 19th), and late sowing LSW (March 31st), five nitrogen application treatments of N1(0 kg/hm²), N2(52.5 kg/hm²), N3(105 kg/hm²), N4(157.5 kg/hm²), and N5 (210 kg/hm²), and five CO₂ concentrations of C1 (370 ppm), C2 (420 ppm), C3 (470 ppm), C4 (520 ppm), and C5 (570 ppm) for simulation experiments. The results indicated that the APSIM model had good applicability in the experimental area; both nitrogen application rate and CO₂ concentration had an impact on the yield and biomass of dryland spring wheat, and the effects varied under different sowing dates. As the sowing date was delayed, both nitrogen application rate and CO₂ concentration had a positive effect on wheat yield and biomass, with nitrogen application rate having a much greater impact than CO₂ concentration; under specific nitrogen application rates and CO₂ concentrations, the choice of sowing date had a significant impact on yield and biomass. Higher yields were typically achieved during normal sowing periods, while late sowing was beneficial for biomass accumulation. When climate and soil conditions change, adjusting the sowing date can optimize wheat production. When the nitrogen application rate was N4 and the CO₂ concentration was C1, the wheat yield was highest under normal sowing, and the wheat biomass was highest under late sowing. This study holds significant importance in guiding wheat production in semi-arid regions. In practical production, based on local climate and soil conditions, parameters such as sowing dates, nitrogen application rates, and CO₂ concentrations can be adjusted to optimize wheat production and enhance both yield and biomass. Especially in the context of global climate change and the numerous challenges faced by agricultural production, this research provides robust support for the sustainable development of wheat production in semi-arid areas.

Based on the classical IPCC carbon emission calculation theory, the agricultural carbon emissions were calculated in Yunnan Province from 2005 to 2021, considering agricultural material input, soil nitrogen emissions, rice cultivation and livestock and poultry breeding. The influence factor decomposition was analyzed based on Logarithmic Mean Divisia Index. Results showed that: (1) the total agricultural carbon emissions in Yunnan Province tended to increase from 2005 to 2021, showing a relatively obvious three-stage change characteristic of “fluctuating decrease-continuous increase-fluctuating decrease”. The carbon emissions in 2021 increased by 22.38% compared to 2005, with an average annual growth rate of 1.27%. (2) In 2021, the source structure of agricultural carbon emissions ranked as livestock and poultry breeding, agricultural material input and crop farming, average accounting for 73.19%, 14.42% and 12.39% respectively. (3) The LMDI decomposition results showed that agricultural production efficiency, agricultural economic development level and urbanization were emission growth factors, while agricultural industrial structure, employment structure and rural population were emission reduction factors. Therefore, it is recommended to firmly promote the rapid development of urbanization, optimize the agricultural industry structure and employment structure, develop standardized scale breeding of livestock and poultry, and promote the modernization of agriculture and rural development.