Saline-alkali stress is one of the abiotic stresses in the process of plant growth and development, which can cause water deficit, changes in cell membrane permeability, metabolic disorders and blockage of protein synthesis in plants, resulting in crop yield reduction or death. Finding effective methods to reduce the harm of saline-alkali stress and strategies to improve the saline tolerance of plants are of great significance to the comprehensive utilization of saline land. In this paper, the latest researches on the damage and adaptive mechanism of plants under saline-alkali stress in recent years were summarized, and the physiological and molecular mechanisms of plants responding to saline-alkali stress were summed up. Furthermore, the physiological mechanisms of plants under saline-alkali stress were analyzed, which were mainly regulated by accumulating osmotic substances, increasing the activity of antioxidant enzymes and ionic compartmentalization, etc., and the molecular mechanisms were mainly regulated by signal transduction, transcription factor regulation and the expression of plant salt-tolerance-related gene, etc. This study pointed out the trends and urgent problems in the development of plant adaptation to saline-alkali environments, with a view to providing a certain theoretical basis for the selection and cultivation of saline and alkali tolerant plants.

This study focuses on evaluating the application of anaerobic digestion technology in the treatment of organic waste, conversion into renewable energy and organic fertilizers, and exploring the mitigation effects of that on the environment. The effects of temperature, carbon to nitrogen ratio, organic loading rate, volatile fatty acids, hydraulic residence time and pH on the efficiency and stability of anaerobic digestion were analyzed by literature review. The results show that these parameters have significant effects on promoting microbial activity, accelerating organic decomposition and maintaining stable operation of the system. The effectiveness of anaerobic digestion technology is verified by the typical studies of organic wastes such as corn stalks, livestock manure and food waste, and the structure and function of key microbial communities in the process are elaborated, including the mechanisms of action of bacteria and archaea at different stages such as hydrolysis, acidification, acetogenesis and methanogenesis. In addition, the generation of toxic substances and its management strategies are also discussed. Finally, the findings of this study suggest that improving the efficiency of anaerobic digestion, developing new reactor technologies, and strengthening research on microbial population will help make anaerobic digestion technology more efficient, stable, and widely applied in the future.

Polyethylene (PE), as one of the most used plastics in the world, has widely existed in the natural environment because of its wear-resistant, high molecular weight and indestructible properties. PE would break down into microplastics (MPs) and accumulate in large quantities, and currently MPs has become an important pollutant that affects the ecosystem. Currently, many studies have been demonstrated that PE could be partially degraded, but further research is needed in screening of microorganisms or enzymes that could completely degrade PE and construct a complete biodegradation pathway for PE. Therefore, this paper summarizes the classification, recycle methods and characterization methods of PE, microorganisms and enzymes that degrade PE, biodegradation pathways and influencing factors, and proposes future research directions of PE biodegradation. These findings provide theoretical basis for the degradation mechanism of PE.

To enhance the efficient application of water-soluble fertilizers containing amino-acids in agricultural production, and to promote green, high-quality development of agriculture. The study reviewed the source and production technology of amino-acids raw material, the functional characteristics, the development status, the application in agricultural production and the future development trend of water-soluble fertilizers containing amino-acids. The results showed that water-soluble fertilizers containing amino-acids were widely used in food crops, vegetable crops, fruit crops and cash crops, had positive effects on crop growth, formation of fruit quality and soil improvement. However, the application of fertilizer on different crops needed to be further explored according to the growth and development rules and nutritional requirements of the plant. The water-soluble fertilizers containing single amino-acids cannot satisfy the market demand, it is necessary to develop new types of fertilizers combining function and nutrition of amino acids.

Digital soil mapping is a novel and efficient soil mapping technique that utilizes 3S technology and is theoretically based on soil formation science, geography and mathematics. Domestic and foreign scholars had conducted extensive research on the generation of environmental collaborative variables, the acquisition of sample data, the selection of digital soil mapping models or methods, and the generation and validation of soil maps, especially on mapping methods. This paper introduced five categories of digital soil mapping techniques, including geostatistical methods, deterministic interpolation, mathematical statistics, machine learning, and expert knowledge models. At the same time, the mapping method suitable for the study area was chosen based on the merits of various approaches, from the aspects of target variables, topography and geomorphological features, sample density and distribution status and more. The future development direction of digital soil mapping included incorporating human activity factors into environmental synergistic variables; establishing more effective sampling methods based on machine learning and data mining; the application of new modeling methods (deep learning and multimodal methods).

Modern breeding techniques based on biotechnology have a great impact on crop genetic improvement. CRISPR/Cas gene editing system’s components, mechanisms, breakthrough progresses of gene editing technology in the gene functional verification and crop genetic improvement, current utilization in various vegetable crops such as tomato, watermelon, cabbage, carrot, cucumber, and others, were summarized in this review. The CRISPR/Cas gene editing system stands out as the most extensively utilized gene-editing tool. This review aims to enhance comprehension of the CRISPR/Cas gene editing system and promote its vital role in vegetable crop improvement. This review discusses the factors affecting genetic transformation efficiency, methods to improve genetic transformation efficiency, the defects of the CRISPR gene editing system and the constraints in its current utilization in vegetable crops, including challenges related to the transformation and regeneration processes, and the genotype dependent for certain crops. In conclusion, this review suggests that future research should focus on extensive genotype screening to facilitate easier genetic transformation, the advancement of efficient crop transformation and regeneration systems, and the development of more efficient, innovative, precise, and multi-functional gene editing tools.

In order to explore the effective way to realize the protection of livestock and poultry genetic resources in China, the current situation of the protection of livestock and poultry genetic resources was systematically sorted out, and the realistic difficulties faced by the protection were deeply analyzed. The results show that, at present, the number of protected varieties has been increasing, regulations and policies have been improved, protected areas, seed conservation farms and gene banks have begun to take shape, and the quality of the workforce has been improved. However, it is also faced with the dilemma of not digging deep into the characteristics of resources, and the disconnection between protection and exploitation; the weak support of regulations and policies, and the lack of linkage in the management system; the obsolete facilities in the protected areas, conservation farms and gene banks, and the outdated protection technology; the insufficient financial support, and the single channel of investment. Based on this, the following countermeasures and suggestions are put forward: strengthen the depth mining of resources, improve the level of development and utilization; establish and improve laws and regulations, integrate departmental management resources; strengthen the guidance of fiscal funds and establish a diversified investment and financing system; continue to promote the development and construction of seed conservation farms, protected areas and gene banks.

Leaves are the main places for photosynthesis and organic synthesis of cotton.  Leaf shape has important effects on the photosynthetic efficiency and canopy formation, thereby affecting cotton yield.  Previous studies have shown that LMI1 is the main gene regulating leaf shape. In this study, the LMI1 gene (LATE MERISTEM IDENTITY1) was inserted into the 35S promoter expression vector, and cotton plants overexpressing LMI1(OE) were obtained through genetical transformation.  Statistical analysis of the biological traits of T₁ and T₂ populations showed that compared to wild type (WT), OE plants had significant larger leaves, thicker stems and significantly increased dry weight.  Furthermore, plant sections of the main vein and petiole showed that the number of cell in those tissues of OE plants increased significantly.  In addition, RNA-seq analysis revealed differential expression of genes related to gibberellin synthesis and NAC gene family (genes containing the NAC domain) in OE and WT plants, suggesting that LMI1 is involved in secondary wall formation and cell proliferation, and promotes stem thickening.  Moreover, GO (Gene Ontology) analysis enriched the terms of calcium ion binding, and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis enriched the terms of fatty acid degradation, phosphatidylinositol signal transduction system, and cAMP signal pathway.  These results suggested that LMI1 OE plants were responsive to gibberellin hormone signals, and altered messenger signal (cAMP, Ca²⁺) which amplified this function, to promote the stronger above ground vegetative growth.  This study found the LMI1 soared the nutrient growth in cotton, which is the basic for higher yield.

In order to elucidate the response of crop nitrogen absorption and utilization to salt and alkali stress and the regulation mechanisms, based on domestically and internationally research progress, this article summed the effect of salt and alkali stress on crop growth from the aspects of seed germination, seedling growth, root growth, photosynthesis, osmotic regulation system, redox system, and ion balance; discussed the impact of salt and alkali stress on crop nitrogen absorption and utilization and the undying mechanisms from the aspects of soil nitrogen cycling, root nitrogen absorption, and nitrogen assimilation; summarized the regulatory methods on crop nitrogen uptake and utilization under salt alkali stress such as nitrogen efficient variety selection, soil conditioner application, organic matter application, growth regulator application, and endophytic mycorrhizal colonization, and discussed the undying mechanisms. This article pointed out that soil salinization was one of the key soil barrier factors limiting crop production. Increasing nitrogen fertilizer application was an effective way to alleviate salt stress, but improper nitrogen fertilizer application could lead to a decrease in nitrogen utilization efficiency. Further in-depth research on crop nitrogen response mechanisms and regulatory pathways under salt stress from the soil-crop system could be of great significance for crop nutrient management and stable and high crops yield under soil salinization.

The genus Polygonatum Mill, commonly referred to as "Huang Jing," are plants renowned for their medicinal and edible properties. Their active constituents, including polysaccharides, flavonoids, and saponins, exhibit notable pharmacological effects. Recent studies have predominantly centered on the extraction of saponin components from the genus Polygonatum, which are attributed with anti-fatigue, antioxidant, hypoglycemic, lipid-lowering, and immune-enhancing properties. While there has been some advancement in the structural analysis of the genus Polygonatum saponins, their biosynthetic pathways remain underexplored. The synthesis of saponins in the genus Polygonatum occurs via the mevalonic acid pathway and the 2-C-methyl-D-erythritol-4-phosphate pathway, encompassing multiple enzymatic steps. This research indicates that the genus Polygonatum saponins exert diverse biological effects, including anti-tumor, antibacterial, anti-inflammatory, antiviral, and immune regulatory activities, and hold significant potential in medicine, food, cosmetics, and other sectors. Nonetheless, current studies are limited by inadequate structural analysis, an incomplete understanding of biosynthetic pathways, and ambiguous mechanisms of pharmacological action. Future endeavors should prioritize the isolation, structural analysis, synthetic biology, and pharmacology of the genus Polygonatum saponins to advance their scientific investigation and product development, thereby laying a foundation for the creation of novel therapeutic agents.

In recent years, the betel nut planting industry in Hainan Province has developed rapidly. Industrial adjustment and optimization will be the focus of its future development, and a reasonable production area layout is crucial for the sustainable development of the betel nut industry in Hainan. Using regional comparative advantage index and resource endowment coefficient, this study analyzed the spatial-temporal evolution characteristics and driving factors of betel nut production in various cities and counties in Hainan from 2005 to 2022. The results showed that the scale of betel nut cultivation in Hainan had significantly increased, but the yield had significantly decreased. The calculated results of the comprehensive comparative advantage index and resource endowment coefficient showed strong consistency. The central regions of Qiongzhong, Ding'an, Baoting, and Tunchang had stronger comparative advantages in betel nut production, which were key areas for the production layout in Hainan. The leading advantage of traditional planting areas in the east was gradually weakening, while the overall western region lacked comparative advantages but showed a clear upward trend. The production of betel nuts in Hainan presents a pattern of retreating in the east, advancing in the west, and maintaining dominance in the center. The driving factors of spatial-temporal evolution mainly include higher economic benefits, the diffusion of high-yield cultivation and management techniques, and the spread of diseases and pests such as yellowing disease. It is recommended to reasonably adjust the layout of betel nut production, moderately control of planting scale, strengthen socialized services, clarify the regulatory policies for edible betel nut products, and accelerate the transformation and upgrading of the betel nut industry.

In order to effectively control Huanglongbing (HLB) and reduce the loss of HLB to the global citrus industry, this study reviewed the latest research on the control of HLB in recent years. The results showed that there were no effective agents and disease-resistant varieties. At present, the main methods of controlling HLB include traditional ‘three fast methods’, namely planting disease-free seedlings to control HLB from the sources, preventing and controlling Diaphorina citr to block its transmission path, and digging infected trees to eliminate the infection source; expanded physical control technologies include seedling virus-free, light, steam heat treatment, etc.; multi-directional chemical drug control technologies include antibiotics, nanomaterials, immune inducers and antimicrobial peptides; emerging biological control technologies include various probiotics, microbial preparations, etc. Finally, the application prospect of soil amendment and biological control agent combined treatment of HLB and citrus transgenic disease resistance technology based on genetic improvement was prospected, to provide theoretical basis and practical reference for effective control of HLB.

An important goal of soil management in the Songnen Plain is improvement of soda saline-alkali soil. Summing up the previous research results on soil improvement, this article summarized the application types, action mechanisms, improvement effects, existing problems of improvers in soil improvement, and looked forward to the application prospects of improvers, in order to provide reference for future in-depth research. The results showed that improvers could be divided into inorganic improvers, organic improvers, and microbial agents. The use of combined improvers was better than that of single improver. The application of improvers improved soil physical and chemical properties, structure, nutrient content, and micro ecological environment, and promote plant growth. The research and development of new organic improvers were the focus of future research.

Vermicomposting is a simple, feasible, low-cost and environmentally friendly bio-microbial coupled organic waste recycling technology. The physicochemical and microbial characteristics of vermicomposting in the treatment of organic waste were summarized. The application research progress of vermicomposting in agricultural production was introduced, and the following suggestions were proposed in view of the problems existing in the practical application of vermicomposting. (1) In order to develop and produce high quality commercial earthworm manure, it is suggested to use the relevant factors affecting the quality of earthworm compost products to carry out mathematical modeling of vermicomposting, so as to efficiently optimize the parameters of vermicomposting, reduce research and development costs and improve production efficiency for large-scale production of earthworm manure; (2) in order to ensure the stable output of high quality earthworm manure, equipment with intelligent control of pH, carbon to nitrogen ratio, temperature and humidity and light should be developed to form automatic and large-scale vermiculture; (3) in order to promote the development of the circular economy of "planting and breeding integration", the effective parts containing humic acid in the process of culturing earthworms can be reused, and the efficiency of vermicompost utilization in agricultural planting and soil remediation should be strengthened.

To analyze the role of native tree species in forestry ecological construction, native tree species and their characteristics were mainly introduced, their role in forestry ecological construction were analyzed, and application strategies were put forward in 3 aspects: scientific planning and planting, protection and breeding technology, ecological education and public participation. Native tree species had the characteristics of strong adaptability, outstanding landscape value and good economy, and their ecological value and landscape value could bring ecological and economic benefits to the local area，and promote the benign development of forestry ecosystem. Native tree species have obvious advantages in forestry ecological construction, which should be full valued, applied and promoted, and scientifically planned and planted according to their growth habits, and research on the protection and breeding of native tree species resources should be strengthened. The awareness of protecting native tree species and the enthusiasm of participating in forestry ecological construction were enhanced by carrying out ecological education activities. The results provided references for optimizing native tree species selection and promoting forestry ecological construction.

Citrus is the largest category of fruit in China, which is widely planted and has many cultivars for fresh fruit market. To extend shelf life, promote intensive processing, improve enterprise’s benefit, current research progresses related to fruit storage and processing have been reviewed. At first, new preservation technologies applied in Citrus fruits’ storage were summarized. Subsequently, innovation technologies for processing products and by-products utilization were discussed. Finally, functional components in Citrus with potential application in pharmaceutical industry were also reviewed. Therefore, depending on different cultivars in production areas, fruit sorting system after post-harvest are recommended for orange and lemon varieties. Meanwhile, the non-thermal processing technology and enzymatic digestion for de-peeling is utilized for tradition processing products, such as sweet orange and tangerine. Functional components in Citrus will be extracted and prepared to medicinal and edible food. In conclusion, new technology for storage and processing are used in Citrus to extendindustry chain, which significantly boost industry development in future.

The herbicide glyphosate is widely used in agriculture because of its high efficiency and low cost, but it also poses certain harm. This paper provided a brief introduction to glyphosate toxicity and mechanism. It was clarified that the harm of glyphosate to water environment was mainly in the aspects of affecting water quality, aquatic organisms and ecosystems. The harm to soil was mainly reflected in the destruction of soil microbial ecology, the destruction of soil microbial community structure and function, and the influence of soil enzyme activity. The research progress of bioremediation of glyphosate-contaminated soil was introduced. The bioremediation of glyphosate-contaminated soil was mainly microbial degradation methods. Compared with non-biodegradation such as adsorption and photolysis, microbial degradation was more environmentally friendly, efficient and promising. Finally, the microbial degradation methods of glyphosate contaminated soil remediation were prospected, in order to provide reference for the application and improvement of glyphosate microbial degradation technology in glyphosate contaminated soil.

China faces significant challenges of large population and limited arable land resources. In recent years, extreme weather events and ongoing soil degradation have significantly influenced China's agricultural production. With advances in agricultural science and technology, incorporating new materials into agricultural practices has been proven to be an effective strategy for adapting to these developments and environmental shifts. Seaweed extract, specifically seaweed oligosaccharides, are natural active substances derived from seaweed using modern technology. They are employed in agriculture as inducers for plant stress and disease resistance, biostimulants, and fertilizer enhancers. With continuous research progresses on the potential applications of seaweed oligosaccharides in agriculture, significant advancements have been achieved in their study and use. To further systematically understand and apply seaweed oligosaccharides, this paper discussed their sources, classification, and production methods. It summarized their impact on bolstering crop stress and disease resistance, fostering growth and development, and improving nutrient absorption, as well as their effectiveness and mechanisms across various crops. This provided innovative approaches and tools for the sustainable and efficient development of Chinese agriculture in the current context.

【Objective】Based on the current “dual carbon” strategic goal, this study aimed to clarify the current characteristics, spatio-temporal pattern and influencing factors of agricultural net carbon sink, so as to provide the important support for accelerating agricultural sink increase and emission reduction.【Method】Based on the scientific reconstruction of the index system, the carbon sink/carbon emission factor method was used to measure and analyze the current situation of China’s agricultural net carbon sink. Then the spatial autocorrelation model was used to discuss the spatial dependence and spatial heterogeneity. Finally, the least-squares method was used to analyze the main factors affecting the change of its intensity. 【Result】From 2005 to 2022, the total amount of agricultural net carbon sink in China was in an obvious upward trend, although there were some interannual fluctuations, and its evolutionary characteristics could be roughly divided into four stages, namely, “continuous rise”, “fluctuating decline”, “rapid rise”, and “slow rise”; the intensity of agricultural net carbon sink was also in an obvious upward trend, with only a slight difference in the trajectory of the evolution, and the difference in its growth rate could be roughly categorized into four stages: “continuous rapid growth”, “slow growth”, “fluctuating ups and downs”, and “slow growth”. 2022, the amount of agricultural net carbon sink had a large interprovincial difference, with Inner Mongolia being the first and Shanghai being the last, and compared with the year of 2005, all the provinces had a significant increase. In 2022, the net carbon sink intensity of agriculture would be the highest in Henan and the lowest in Qinghai, with all provinces showing different degrees of increase compared with 2005. China’s provincial agricultural net carbon sink intensity as a whole showed obvious spatial dependence, but there was also a local spatial clustering phenomenon, more than 70% of the provinces showed obvious spatial clustering characteristics, and the number of provinces located in the high-high clustering and the low-low clustering was approaching. The structure of arable land use, urbanization level, rural residents' income level and the internal industrial structure of agriculture all had a significant impact on the intensity of agricultural net carbon sink; specifically, the higher the ratio of sown area of grain crops, or the higher the urbanization rate, or the higher the income level of rural residents, or the larger the ratio of plantation industry to animal husbandry, the higher the intensity of net carbon sink in agriculture.【Conclusion】The total amount and intensity of China’s agricultural net carbon sink were in a fluctuating upward trend and there were obvious inter-provincial differences. The intensity of China’s agricultural net carbon sink showed obvious spatial dependence and spatial heterogeneity. The intensity of the agricultural net carbon sink was affected by the structure of arable land use, the level of urbanization, the level of rural residents' income, and the structure of the internal industries of agriculture. The measures should be taken to promote the enhancement of sink and emission reductions and to promote the enhancement of agricultural net carbon sink in agriculture, such as establishing a sound policy support system for the development of low-carbon agriculture, strengthening inter-provincial exchanges and cooperation, and increasing financial support for agriculture.

This study aims to screen one or two kinds of herbicides which are suitable for the control of X. sibiricum in Ningxia region. The plant control effects and fresh weight control effects of 5 herbicides, including 2 methyl 4 chlorodimethylamine salt, fluroxypyr, saflufenacil·glyphosate, nitrosulone, topramezone on X. sibiricum, were determined by field experiments. After 21 days, the results of plant control effects showed that among the five herbicides, 2 methyl 4 chlorodimethylamine salt 60% AS with 750 mL/hm², fluroxypyr 200 g/L EC with 900 mL/hm², and saflufenacil·glyphosate 40% OD with 1500 mL/hm² presented excellent plant control effect, and the control effects were 96.62%, 98.31%, and 100%, respectively; the results of fresh weight control effects showed that fluroxypyr 200 g/L EC with 900 mL/hm² and saflufenacil·glyphosate 40% OD with 1500 mL/hm² had remarkable control effects, which were 93.94% and 100%, respectively. Based on the results of control effects, as well as the different crops, the biocidal herbicide saflufenacil·glyphosate can be selected for the control of X. sibiricum in wasteland, forest land, ditches, etc. In the control of X. sibiricum in gramineous crop fields such as wheat and corn, fluroxypyr herbicides were the first choice.

【Objective】Reasonably increasing planting density combined with appropriate nitrogen (N) application rate is an important technical approach for increasing maize yield and resource use efficiency. Understanding the interactive effects of planting density and N rate on maize growth, evapotranspiration (ET) and water use efficiency (WUE) during the growing season, could provide a basis for improving its use efficiency when increasing planting density and controlling N input in maize production. 【Method】Field experiments were conducted during 2022 to 2023 in Jilin Province. Two maize cultivars, Liangyu 99 (LY99) and Demeiya 3 (DMY3), were used in this study. Three planting densities of 50 000, 70 000 and 90 000 plants/hm² and four N application rates of 0, 100, 200 and 300 kg N·hm^-2 were designed to investigate the effects of planting density and N application rate on grain yield and water productivity of different maize cultivars, as well as the dry matter (DM), soil water content, ET and WUE at various growth stages. 【Result】Planting density significantly affected DM and grain yield of maize, but the response trends varied between cultivars. Grain yields of LY99 with 70 000 plants/hm² was 11.1% and 18.3% higher than that with 50 000 and 90 000 plants/hm², respectively. The average yield of DMY3 planted with 70 000 plants/hm² and 90 000 plants/hm² was 10.5% and 9.3% higher than that of 50 000 plants/hm², respectively. Nitrogen fertilization significantly increased DM and grain yield of maize, and also showed significant interactive effects with cultivar or planting density. Compared with N0, grain yields of LY99 were increased by 38.0% to 60.7% under N1, and the yield increases for DMY3 were 24.4% to 38.2%. Notably, the yield responses to N rates were more pronounced for LY99 compared with DMY3. For both cultivars, the yield differences between low N rate and high N rate enlarged with increasing planting density, with LY99 showing a more distinct performance. The water consumption and utilization of maize plants were also significantly affected by planting density, N rate and their interaction. During the growing season, the total ET of DMY3 continually increased with increasing density, while that of LY99 showed the highest values with 70 000 plants/hm² among different densities. In each density condition, the ET of both cultivars increased with increasing N application rates. The WUE of maize plants showed complex responses to planting density and N rate at different growth stages, due to the varied annual precipitation and distribution patterns. The average increase of water productivity of LY99 under planting 50 000 and 70 000 plants/hm² was 8.6% and 10.4% compared with 90 000 plants/hm² respectively_. DMY3 had the highest water productivity when planting 70 000 plants/hm², which increased by 5.8% and 5.3% compared with 50 000 and 90 000 plants/hm², respectively. The water productivity showed different responses to N rate among the three densities. In general, the difference of nitrogen application under low density was small, but it increased significantly under medium and high density. Compared wtih DMY3, LY99 showed higher increases for water productivity when N fertilizer was applied under medium and high density conditions. The correlation analysis showed that interactive effects of planting density and N rate significantly affected maize yield and water productivity by influencing the water utilization at various growth stages. 【Conclusion】Planting density and N rate had significant interactive effects on maize yield and water utilization in the rain-fed region of Northeast China. The two maize cultivars used in this study could obtain high grain yield and water productivity under a moderately higher density of 70 000 plants/hm² combined with 200 kg N·hm^-2 rate.

The global warming rate and the frequency of extreme high temperature weather are continuously increasing, which could bring catastrophic impacts to rice production. To further clarify the response mechanism of rice to high temperature, this article summarized the research progress in the direction of rice heat damage from high temperature, focused on the impact of high temperature on rice production, and deeply analyzed the physiological (photosynthetic characteristics/antioxidant system) and gene molecular mechanisms of rice’s response to high temperature. We concluded that the heat tolerance characteristics of rice were formed by the interaction between varieties and the environment. Results showed that, the photosynthetic characteristics of rice were influenced by both stomatal and non-stomatal limiting factors, and the antioxidant process was achieved by enhancing the activity of antioxidant enzymes and reducing the content of malondialdehyde; rice improved plant heat adaptability by activating the expression of key genes and stimulating the transduction of heat signals within the plant; by optimizing “Before production-During production-After production” comprehensive management and monitoring system, we could explore innovative cultivation systems, and thoroughly investigate the high temperature defense mechanisms of rice. Therefore, this study aimed to clarify the physiological and molecular mechanisms of rice in response to high temperature stress, providing a scientific reference for future heat-tolerant rice breeding work and improving rice sustainable production.

Seed shattering is a major factor limiting rice production, and breeding new rice varieties with moderate seed shattering is a key challenge faced by rice breeders worldwide. Rice is the most important cereal crop in China, plays a vital role for national food security. Seed shattering is one of the most important traits during rice domestication, and the abscission zone is the important region to control seed shattering. Compared with wild rice, cultivar has eliminated the seed shattering with partially developed abscission layer. Seed shattering not only has a direct impact on the yield, but also affects the way of its mechanical harvest. In order to breed rice varieties with moderate seed shattering in agricultural production, it is necessary to mine and utilize important seed shattering genes and introduce them into excellent rice varieties for genetic improvement, so as to breed new rice varieties suitable for mechanical harvesting with moderate seed shattering. Several seed shattering genes had been identified by map-based cloning, such as SH4/SHA1, qSH1, OsSh1/ObSH3, and their functional mechanisms had been analyzed. At the same time, new rice materials with moderate seed shattering have been successfully developed through CRISPR/Cas9 gene editing technology, gamma ray mutagenesis technology and gene introduction methods. Seed shattering has an important effect on grain yield and rice harvesting methods, in this paper, we reviewed the methods, physiologic basis, the identification of seed shattering genes and genetic mechanism of seed shattering in rice. At the same time, it is proposed that by using the important genes in excellent rice germplasm resources, could provide reference for exploring the mechanism of rice seed shattering, and breed new rice varieties suitable for mechanical harvesting with moderate seed shattering.

[Purpose/Significance] AI literacy is becoming increasingly important, not only to adapt to the future development of higher education and the needs of future society, but also to cultivate innovative thinking and problem-solving skills, to enhance decision-making abilities and, most importantly, to emphasize ethical education to avoid the abuse and misuse of AI technology. Existing research emphasizes the importance of AI literacy, with a focus on discussing AI literacy frameworks and pathways. Although some scholars have classified and discussed the AI literacy for teachers and students, there has not been a comprehensive analysis of the skill requirements for different roles in the context of "AI + higher education". [Method/Process] AI literacy education is a multidimensional and multi-level systematic problem. Based on 18 application cases, this study analyzes the specific application scenarios of AI in the educational process, summarizes the development characteristics of "AI+higher education", and analyzes its AI literacy requirements for university teachers, students, managers, and teaching assistants. Therefore, four-role framework for AI literacy is constructed to provide a theoretical reference for future AI literacy education in higher education. [Results/Conclusions] In the context of "AI + Higher Education," future higher education will continue to develop towards ubiquitous teaching, personalized learning, diversified evaluation, and scientific management, ultimately achieving the complete intellectualization of higher education. For teachers, the skills required are innovative teaching and technological integration; for students, active learning and diversified skills; for administrators, forward-thinking leadership and data-driven decision-making; and for educational support staff, intelligent integration of services and resources. The core elements of AI literacy can be summarized as four key components: thinking, knowledge, skills, and attitudes. In specific educational scenarios, the AI skills of teachers, students, administrators, and educational support staff have similarities but also exhibit differences. Due to space limitations, this study did not construct an AI literacy education pathway. In future research, we will continue to deepen the connotation of AI literacy and propose targeted AI literacy education pathways based on the skill requirements of different roles.

【Objective】Genetic improvement for efficient utilization of maize nutrients represents a crucial method to ensure national food security. Exploring quantitative trait locus (QTL) and related candidate genes of nitrogen use efficiency can provide a theoretical basis for improving the efficiency of nitrogen fertilizer in maize and cultivating high-yield and high-efficiency maize varieties. 【Method】In this study, QTL mapping analysis in one recombinant inbred line (RIL) population constructed by KA105 and KB024 was performed for grain yield under two different nitrogen treatments, including the derived traits partial factor productivity from applied nitrogen (PFPN), low nitrogen tolerance coefficient (LNTC) and nitrogen agronomic efficiency (NAE). Concurrently, integrating the seedling transcriptome data of the parent KA105 under nitrogen treatment, differentially expressed genes were identified, and candidate genes associated with maize nitrogen use efficiency were mined through co-expression analysis. Subsequently, the selected candidate genes were validated using qRT-PCR. 【Result】Through mapping analysis, a total of 36 QTLs distributed across different chromosomes were detected, explaining 1.63% to 17.26% of the phenotypic variation. Among these, eight major QTLs with a phenotypic variation explanation rate exceeding 10% were identified, along with seven genetically stable QTLs commonly identified across different traits or environments. Notably, qNNGYP1 located on chromosome 1 has been repeatedly detected in previous studies, with a phenotypic explanation rate of up to 11.73%. Additionally, other QTLs (qNNGYP1, qPFPN1) co-located in this interval across different environments, suggesting it as a focal region for further investigation. Combining transcriptome data of seedlings under low nitrogen stress, 39 differentially expressed genes within these QTL intervals were identified, and 6 key genes were identified through co-expression network prediction. The result of qRT-PCR indicated that the expression trends of the candidate genes under both nitrogen treatments were consistent with the transcriptome data. Specifically, GRMZM2G366873 was involved in the regulation of auxin homeostasis and may participate in maize responses to low nitrogen stress, drought stress, and boron stress through auxin signal transduction, also regulating ear length. GRMZM2G414192 was involved in the response of the photosynthetic system to low nitrogen stress and was regulated by brassinosteroids. GRMZM2G414043 was associated with maize grain length and biomass, while GRMZM2G040642 may be involved in the long-distance signal transduction of nitrogen. 【Conclusion】In summary, a total of 36 QTLs were identified, distributed across chromosomes 1, 4, 5, 7, 8, and 9, including eight major QTLs (PVE>10%). The candidate genes GRMZM2G366873, GRMZM2G414192, GRMZM2G414043, and GRMZM2G040642 were identified as potential genes for maize nitrogen efficiency.

Hyperspectral remote sensing is an important technology for crop research. In order to promote the healthy development and basic research of crop growth cycle, improve the application level of remote sensing technology in crop research, this paper summarizes the analysis algorithms of hyperspectral in crop research, focus on the research progress of hyperspectral in crop growth, crop information monitoring, and crop information extraction. This paper systematically reviews the studies on leaf area index, biomass estimation, nitrogen monitoring, chlorophyll monitoring, pest and disease monitoring, heavy metal monitoring, crop carbon to nitrogen ratio, and water content, which still need to be further developed. Analysis shows that the combination of hyperspectral technology and artificial intelligence has achieved initial results in crop research which is still difficult to meet the intelligent needs of modern agriculture. If the new generation of information technology and large models are used to empower, enormous research potential will be unleashed.

To explore the growth differences among different green manure varieties and their effects on rice yield, nutrient accumulation and soil properties after turning over, the winter fallow field (CK) was used as the control, three common green manures (Astragalus sinicus L., Vicia villosa var. and Vicia sativa L.) were selected to conduct field experiments to analyze the differences in the characteristics of green manures during the growth period and their effects on rice yield, nutrient accumulation and soil properties after turning over. The results showed that the performance of plant height and biomass in the three types of green manure was as followed: Vicia villosa var. > Vicia sativa L. > Astragalus sinicus L., with Vicia villosa var. being the best and suitable for planting in the region. After turning over green manures, the rice yield significantly increased compared to CK, with the yield under Vicia villosa var. reached 10.47 t/hm², which was 58.88% higher than that of CK. Green manure turning over could improve the taste value and nutrient accumulation of rice. Compared with CK, the taste value of rice treated with Astragalus sinicus L., Vicia villosa var. and Vicia sativa L. increased by 5.58%, 9.46% and 11.16%, respectively, and total potassium accumulation in rice straw increased by 50.88%, 42.87% and 67.70%, respectively, the total nitrogen accumulation in rice grains increased by 17.25%, 45.62% and 47.74%, respectively and the total potassium accumulation in rice seeds increased by 17.96%, 54.28%, and 48.88%, respectively, the total phosphorus accumulation in rice shoots increased by 11.32%, 62.16% and 27.41%, respectively, the total accumulation of total potassium increased by 45.53%, 44.73% and 64.64%, respectively, with the best comprehensive effect being the Vicia villosa var. and Vicia sativa L.. Green manure could improve soil properties and had the potential to improve soil fertility. Among them, the treatment of Vicia sativa L. had a pH increase of 2.96%, organic matter increased by 10.05%, and total nitrogen content increased by 4.41% compared to CK. The treatment of Astragalus sinicus L. had an organic matter increase of 1.43%, total nitrogen content increase of 24.25%, total phosphorus content increase of 9.20%, and available phosphorus content increase of 10.95% compared to CK. In summary, the biomass and nutrient accumulation of Vicia villosa var. and Vicia sativa L. were both high, and their flipping could improve the yield, taste value and nutrient accumulation of rice. Therefore, they were recommended as green manure varieties for planting in this region; Astragalus sinicus L. and Vicia sativa L. had the potential to increase soil fertility through tillage, while Vicia sativa L. had a better effect. This study could provide a theoretical basis for the utilization of green manure and sustainable agricultural production in the northern Jiangsu region.

With the continuous improvement in rice cultivation techniques, China has maintained a high rice production level of about 210 million tons over the past decade. Direct-seeding rice cultivation technology, recognized for its efficiency and simplicity, has been favored by Chinese farmers. However, controversies persist regarding direct-seeding rice compared to transplanted rice in national-scale production. Thus, this study employed meta-analysis techniques to quantify disparities in grain yield, economic benefit, rice quality, lodging characteristic, and greenhouse gas emissions between direct-seeding rice and transplanted rice. Our results indicated that direct-seeding rice significantly reduced grain yield by an average of 6.3% relative to transplanted rice, which was main due to the reduced total spikelet (-3.8%) and filled-grain percentage (-1.8%). In different planting systems in China, the yield of direct-seeding rice had significantly decreased compared to transplanted rice, and the direct-seeding rice-induced reductions in yield of single rice (-10.9%) and late rice (-13.1%) were higher than those of middle rice (-4.8%) and early rice (-4.4%). The grain yield reductions for direct-seeding rice were from 10% to 20% in Jilin, Liaoning, Xinjiang, Ningxia, Shandong, Jiangsu, and Zhejiang provinces, meanwhile Heilongjiang and Jiangxi provinces saw reductions of 5% to 10%, but it had no significant effect in other provinces. Direct-seeding rice resulted in comparable net economic return relative to transplanted rice (p> 0.05). Direct-seeding rice reduced milled rice rate (-3.1%) and gel consistency (-3.5%), improved appearance quality (chalkiness percentage and chalkiness degree, which decreased by 25.3% and 22.5%, respectively), whereas no significant effects were observed on nutrition quality and taste value. Direct-seeding rice increased lodging index at base of the first (+12.4%) and third (+10.3%) internodes, but not at the second internode, indicating an increase in risk of lodging relative to transplanted rice. In terms of greenhouse gas emissions, direct-seeding rice fields showed reductions in methane emissions (-42.8%), global warming potential (-36.2%), and greenhouse gas intensity (-41.1%) compared to transplanted rice fields, while promoting nitrous oxide emissions (+29.1%). In addition, a review was recounted on nitrogen utilization and its loss, water and energy use efficiency, and weed incidence. Finally, the recommendations for the future advancement of direct-seeding rice were proposed, main focusing on rice variety breeding, rice cultivation technique optimization, rice planting area layout, as well as policies and services with the goal of technological innovation and regionalized application of direct-seeding rice cultivation technology in China.

【Objective】Analyzing the yield and yield related traits of Sichuan wheat varieties from 2000 to 2020, providing reference for genetic improvement of yield in Sichuan wheat varieties. 【Method】From 2019 to 2022, a community trial design was used to measure the yield and related traits of 145 wheat varieties in Sichuan Province since 2001 to 2016, as well as 60 high-yield wheat varieties (Varieties with top yields in regional trials in Sichuan Province over the years) since 2000 to 2020. This data was used to analyze the trend of yield and yield related trait changes in Sichuan wheat cultivars cultivated from 2000 to 2020. 【Result】145 Sichuan wheat varieties from 2001 to 2016 have an average annual genetic gain of 37.20 kg·hm^-2 or 0.66% in yield. Grain number per spike and effective spike number per unit area showed an increasing trend, while thousand grain weight and plant height showed a decreasing trend. Correlation analysis showed that effective spike number per unit area was positively correlated with yield. Path analysis showed that the continuous increase of effective spike number per unit area (annual increase 0.42×10⁴/hm² or 0.13%) was the main factor for the increase of yield potential of high-yielding varieties. The average annual yield genetic gain of 60 high-yield wheat varieties from 2000 to 2020 was 61.10 kg·hm^-2 or 0.89%, the effective spike number per unit area showed an increasing trend, the plant height showed a decreasing trend, and the grain number per spike and thousand grain weight had almost no change. Correlation analysis shows that there was a significant positive correlation between yield and the number of effective ears per unit area. Path analysis showed that the continuous increase in effective spike number per unit area (with an average annual increase of 1.80×10⁴/hm² or 0.51%) was also a major factor in improving the yield potential of 60 high-yield wheat varieties in Sichuan from 2000 to 2020. 【Conclusion】The improvement and breeding of wheat yield heritage in Sichuan Province has made some progress, especially the improvement effect of high yield breeding is remarkable, and the yield level of wheat varieties in Sichuan Province is gradually increasing. The continuous increase in effective ears per unit area was the main factor for improving the yield potential of Sichuan wheat varieties. High grain number per spike and thousand grain weight are important foundations for high yield in Sichuan wheat, but their genetic improvement is in a bottleneck period. Increasing the effective spike number per unit area is the key to furtherly improve the yield of wheat in Sichuan.

【Objective】FWL (Fruit Weight2.2-Like) gene is a negative regulator of cell proliferation, which not only regulates plant organogenesis and organ size, but also participates in the regulation of metal ion transport accumulation and signal transduction. Analyzing of the function of OsFWL3 gene is helpful to reveal the transport mechanism of trace metal elements in crops. It provides theoretical support for reducing heavy metal accumulation and improving crop quality. 【Method】The gene information, genome structure and phylogenetic tree of OsFWLs family were analyzed by bioinformatics method, and the expression profile of OsFWL3 gene was predicted. Two OsFWL3 knockout lines were obtained using CRISPR/Cas9 gene editing technology. Then wild type and Osfwl3 mutants were treated with ZnSO₄ at seedling stage and filling stage, respectively. The phenotypes of plants and grains after treatment were analyzed, and the content variation of metal elements such as Zn was determined to explore the effects of OsFWL3 on the transport and accumulation of metal ions and seed quality. 【Result】The gene function of OsFWLs family is similar to some extent. OsFWL3 gene is highly expressed in anther and panicle, indicating that it is closely related to reproductive development of rice. The number of primary branches, grian length, grain thickness and 100-grain weight of Osfwl3 mutants are significantly larger than WT. OsFWL3 affects the content and distribution of Zn and other metal ions in rice seedlings and grains. The deletion of OsFWL3 gene affects the competitive transport of Zn, Cd and Mn from underground to above-ground, lower grain to central grain and husk to brown rice. 【Conclusion】OsFWL3 gene affects the distribution of Zn and other metal ions in rice grains and plants, and it plays an important role in regulating the growth and development of rice plants and grain size.

Lasioderma serricorne is a common pest in tobacco leaf processing and cigarette production. In order to understand the occurrence and damage characteristics of Lasioderma serricorne and take appropriate prevention and control measures for different scenarios, the research progress on the biological characteristics, damage, monitoring and control methods of Lasioderma serricorne were reviewed. The results showed that the reproductive generation and peak activity period of Lasioderma serricorne varied in different regions. The degree of damage in southern regions was higher than that in northern regions, and the degree of damage in high quality tobacco was higher than that in low quality tobacco. The methods for pest monitoring included manual statistics based on traps, image recognition, and electronic nose monitoring. There were 3 methods for the prevention and control of pest: physical control, chemical control, and biological control. Physical control included low-temperature treatment, high temperature treatment, vacuum conditioning, controlled atmosphere treatment, microwave treatment, and ultraviolet light trapping. Chemical control included fumigation, hormones, chemical insecticides, plant-derived insecticides, and plant essential oils. Biological control included bacterial control, fungal control, parasitic natural enemy control, RNA interference technology, and attractant. The research provides references for the integrated control of tobacco beetle.

【Objective】Exploring the genetic loci and related genes that control cottonseed size traits to lay a foundation for subsequent study on the molecular mechanism cottonseed size formation. 【Method】The upland cotton recombinant inbred line (RIL) population composed of 300 lines was used as the research material. Seven phenotypic traits including cottonseed index (SI), seed length-cutting acreage (SLA), seed length-cutting perimeter (SLP), seed length (SL), seed width (SW), length-width ratio (LWR) and seed roundness (SR) were evaluated in four environments. The RIL population was genotyped by liquid phase chip strategy. The high-quality single nucleotide polymorphism (SNP) markers and phenotypic data were subjected to perform genome-wide association study (GWAS), and quantitative trait nucleotides (QTNs) associated with cottonseed size-related traits were mined. The genetic effects of QTNs were analyzed to identify candidate genes. 【Result】Seven cottonseed size-related traits showed a continuous normal distribution in four environments, which expressed a sizable phenotypic variation. The coefficient of variation ranged from 1.82% to 10.70%. The influencing effect on trait formation were basically as genotype>environment>genotype × environment, indicating suitability for GWAS analysis of these results. Correlation analysis showed that the seed index was significantly correlated with SLA, SLP, SL and SW, and LWR was significantly correlated with SR, indicating the possible existence of pleiotropic loci. GWAS was performed using the 3VmrMLM model, and a total of 47 QTNs were associated with these seven traits. A total of 11 QTNs were associated on chromosome A07, of which three physical loci in the region of 71.99-72.87 Mb, A07:71993462, A07:72067994 and A07:72198802 were very close and simultaneously associated with SI, SLA, SLP, SL and SW in four environments. The average value of R2 between markers was>0.8 (P<0.001), showing a large linkage disequilibrium. Genetic effect analysis showed that there were two haplotypes in this region. Among these cottonseed size relating traits, haplotype Ⅱ and haplotype I were significantly different, indicating that these loci directly affected cottonseed size traits and could be used for molecular marker-assisted selection. The expression patterns of the genes in the interval were analyzed using TM-1 transcriptome data. The results revealed that Gh_A07G1767 was preferentially expressed and Gh_A07G1766 specifically expressed at the stage of cottonseed development. These results speculated that these genes may play an important role in the growth and development of cottonseed.【Conclusion】47 QTNs were identified, and two candidate genes related to cottonseed development were screened.

Fusarium oxysporum (Fo) is a soil-borne fungal disease that causes crop wilting, which is a serious constraint to the sustainable development of agriculture. Effectors are key factors in pathogen-plant interactions, and their mechanism of action can be analyzed to provide effective strategies for controlling plant diseases. When Fo infects crops, it secretes a protein in the xylem of vascular bundles, which is called Secreted In Xylem effector protein (SIX). In order to study the role of SIX effectors between Fo and plants, the structural characteristics of SIX on the Fo genome were analyzed. The functional attributes of SIX in identifying different formae speciales and physiological races of Fo, influencing the pathogenicity of Fo, and affecting the immune response of plants were summarized. It was pointed out that SIX had toxic effects on plants and could interact with plants in an incompatible manner to influence the invasion of pathogens. The results of this study reveal the effects of SIX on plants in different aspects and provide theoretical support for the study of the molecular mechanism of plant disease resistance and the selection and breeding of disease-resistant varieties.

Feed efficiency (FE) is a crucial economic trait that significantly impacts profitability in intensive sheep production, and can be evaluated by the residual feed intake (RFI) and feed conversion ratio (FCR). However, the underlying genetic mechanisms that underlie FE-related traits in sheep are not fully understood. Herein, we measured the FE-related traits of 1280 Hu sheep and conducted the phenotype statistics and correlation analysis, the result showcase that there was a large variation for FE-related traits, and RFI was significant positive correlation with average daily feed intake (ADFI) and FCR. Moreover, a genome-wide association study (GWAS) was conducted using whole-genome resequencing data to investigate the genetic associations of ADFI, FCR and RFI. For ADFI and FCR traits, two and one single nucleotide polymorphisms (SNPs) exceeded the genome-wide significance threshold, whereas ten and five SNPs exceeded the suggestive significance threshold. For RFI traits, only four SNPs exceeded the suggestive significance threshold. Finally, a total of eight genes (LOC101121953, LOC101110202, CTNNA3, IZUMO3, PPM1E, YIPF7, ZSCAN12 and LOC105603808) were identified as potential candidate genes for FE-related traits. Simultaneously, we further analyzed the effects of two candidate SNPs associated with RFI on growth and FE traits in enlarged experimental population, the results demonstrated that these two SNPs was not significantly associated with growth traits (P > 0.05), but significantly related to RFI traits (P < 0.05). These findings will provide valuable reference data and key genetic variants that can be used to effectively select feed-efficient individual in sheep breeding programs.

In order to further understand the demand and benefits of agricultural meteorological services, the supply and demand of agricultural meteorological service product content, product time effect, service form and service channel are compared and analyzed from the two dimensions of agricultural meteorological service user demand and service supply through statistical analysis, and the contribution rate and economic benefits of agricultural meteorological services are measured on this basis. The results show that: (1) meteorological service for agriculture has a strong decision-making service attribute, and the government/administrative agencies or institutions are the current service subjects. Planting, agricultural insurance and agricultural management are the main service areas of meteorology serving agriculture, especially planting. (2) Agricultural users have a strong demand for meteorological services, the vast majority of agricultural meteorological products can meet user needs, and a few products still have a certain gap with user needs in terms of content, timeliness, service methods and channels. (3) The benefits of agricultural meteorological services are remarkable. The contribution rate of agricultural meteorological services was 4.84%, and the benefit value of national agricultural meteorological services was 347.26 billion yuan. On this basis, four suggestions are put forward in order to provide reference and support for meteorological departments to optimize the supply of agricultural meteorological services.

【Objective】 The rice-crab co-culture is a predominant three-dimensional ecological cultivation model in northern Chinese rice fields. The water-soil interface is a key area for material cycling within this system. In this paper, studying the diversity and structure of microbial communities at this interface aimed to understand its evolution and support research on the ecological health of water and soil in rice-crab co-culture systems. 【Method】 Eight long-term rice monoculture systems and eight long-term rice-crab co-culture systems (>20 years) were selected in a typical rice-crab co-cultivation area in Panjin, Liaoning province. Based on measurements of physicochemical indicators of rice field water and soil, as well as high-throughput sequencing technology of the 16S rRNA gene, the study compared the effects of two rice cultivation systems on the properties and bacterial community structures of the water-soil interface in paddy fields. 【Result】 (1) The introduction of crabs significantly reduced the unique microbial communities at the water-soil interface. Specifically, the number of unique operational taxonomic units (OTUs) in surface water and interfacial soil decreased by 27.0% and 71.2%, respectively. However, the introduction of crabs had no significant effect on alpha diversity in surface water, but it reduced the richness of bacterial communities in interfacial soil. (2) The introduction of crabs significantly altered the structure and composition of the water-soil interface bacterial community. The introduction of crabs significantly increased the relative abundance of Proteobacteria (30.4%) and decreased the relative abundance of Acidobacteria (39.9%) in surface water. Simultaneously, it increased the relative abundance of Planctomycetes (21.1%) and decreased the relative abundance of Ignavibacteriae (15.1%) and Nitrospirae (21.7%) in interfacial soil. (3) Proteobacteria and Bacteroidetes were not only core species at the water-soil interface of rice field systems, but also key species in co-occurrence networks, playing important roles in stabilizing ecological networks. (4) The introduction of crabs into rice fields increased the complexity and stability of the bacterial co-occurrence network in the interface soil, but decreased it in the paddy field water. (5) Linear regression analysis showed that NO₃^-- N concentration in surface water and interface soil pH were the main driving factors influencing the diversity and stability of their respective bacterial community structures. 【Conclusion】 The introduction of crabs significantly altered the microbial community structure and diversity at the water-soil interface in rice fields. The increase in nutrient salts in the water posed a risk of reducing the stability of the aquatic microbial community. However, the rice-crab co-culture shaped a more stable bacterial community in the interface soil, which facilitated nutrient cycling and enhanced crop nutrient utilization efficiency.