In order to further enhance the competitiveness of China’s oilseed industry and promote its high-quality development， the data of oilseed production， consumption and trade since 2000 were selected， and the competitiveness of China’s oilseed industry from the perspectives of absolute advantage， comparative advantage and enterprise competitiveness were systematically analyzed， the main reasons affecting the competitiveness of China’s oilseed industry were discussed by calculating the contribution rate of oilseed planting technology and the trade competitiveness index. The results showed that China’s oilseed industry was at a disadvantage in all the aspects of absolute advantage， comparative advantage and enterprise competitiveness， and the limiting factors were insufficient resource endowment， low contribution of technological progress， imperfect symbiotic development of the upstream and downstream of the industrial chain and unfavorable domestic and foreign agricultural policy environment. Based on this， targeted opinions and suggestions were put forward from multiple perspectives such as resource development， technological breakthrough and policy support， which provided data references and technical supports for the formulation of the national grain and oilseed development strategy.

Since the reform and opening-up， China’s natural mineral water industry has experienced rapid development， with an increasing diverse range of products. In particular， mineral water enriched with specific nutritional elements has gained significant popularity among consumers. The intake of the trace element strontium has been shown to play effective roles in improving osteoporosis， preventing cardiovascular diseases， and promoting glucose and lipid metablism. However， the strontium intake of Chinese residents has not yet reached the recommended levels. Strontium-rich natural mineral water serves as an important source of strontium supplementation for the human body， indicating a significant market potential in the future. Considering the current state and development trends of China’s natural mineral water industry， the market supply potential of existing strontium-rich natural mineral water resources was analysed. It addressed the development bottlenecks faced by different categories of strontium-rich natural mineral water available in the market and offered suggestions regarding price， quality and labeling， which aimed to effectively foster the sustainable development of China’s strontium-rich natural mineral water industry.

Pollen pore size regulators play central roles in the formation of plant germination pore size. To study the regulation of germination pore development on the pollen surface of wheat and explore the regulatory function of the TaINP1 gene family homologous to OsINP1 in the formation of germination pore size in wheat， 53 members of wheat TaINP1 gene family were identified in the wheat genome using bioinformatics strategies， and their physicochemical properties， promoter cis acting elements and collinearity relationship between genes were systematically analyzed. Tissue expression analysis showed that TaINP2.2 and TaINP2.5 genes were significantly expressed in panicle of wheat， some TaINP1 genes， such as TaINP2.5 and TaINP3.2 etc， were highly induced in pollen after low temperature （10 ℃） treatment. Combined with pollen germination and nano-magnetic bead conversion technology， the RFP reporter gene was successfully introduced into wheat pollen， and the fluorescence intensity of pollen at different low temperatures was observed by laser confocal microscopy， the results showed that the TaINP1 genes played important roles in regulating pollen pore opening and closing. Above results provided basis for the regulation mechanism of wheat pollen pore， and also provided reference for optimizing the efficient transformation system of wheat pollen nanobeads， and also opened up a new way for genetic improvement of wheat molecular breeding.

In order to study the effects of drought stress on physiological characteristics of foxtail millet at seedling stage and the alleviating effect of exogenous abscisic acid （ABA）， different drought tolerant foxtail millet varieties Jigu 22 and Lugu 1 were used as materials to conduct pot experiment. The effects of 20% PEG6000 simulated dehydration stress at seedling stage and spraying 0.1 mmol L^-1 ABA on morphological character， activities of antioxidant enzymes and ascorbate peroxidase （APX）， contents of malondialdehyd （MDA）， proline （Pro）， soluble sugar （SS） and soluble protein （SP） in 2 different foxtail millet varieties were analyzed. The results showed that the relative seedling height of Jigu 22 after drought stress for 4 d was 81.49%，which was higher than that of Lugu 1. MDA content in leaves of the 2 varieties increased after drought stress. On the 7th day of stress， MDA content in Jigu 22 increased by 3.03%， and that in Lugu 1 increased by 33.61% compared with control. The MDA content was significantly reduced after application of exogenous ABA. Exogenous ABA promoted the activities of superoxide dismutase（SOD）， peroxidase（POD）， catalase（CAT） and APX. Osmotic adjustment substances Pro， SS and SP were synthesized in large amounts to maintain osmoregulation and alleviate the damage of drought stress on foxtail millet seedlings. The effect of exogenous ABA on the drought-tolerant variety Jigu 22 was more obvious under drought stress. The effect of exogenous ABA on Lugu 1 was relatively weak， especially on the 7th day of drought stress， and the physiological and growth characteristics recovered slowly. In summary， ABA could effectively alleviate the damage of physiological function and the effect of drought stress on seedling growth of foxtail millet. Different drought resistance varieties foxtail millet had different sensitivity to ABA. The varieties with strong drought resistance were more sensitive to ABA， the mitigation effect of ABA on drought was more obvious. Above results provided theoretical bases for revealing the physiological mechanism of foxtail millet response to drought stress and the application of exogenous ABA.

Melatonin， as an indoleamine compound， has a wide range of roles in regulating plant growth and development and resisting adversity stress. COMT （caffeic acid O-methyltransferase） is an O-methyltransferase that plays an important role in the phenylpropane metabolic pathway and is a key enzyme in melatonin synthesis. There are 57 GhCOMTs homologous genes in terrestrial cotton， among which GhCOMT28 and GhCOMT55 have the highest homology with Arabidopsis thalianaAtCOMT. In this study， GhCOMT28 was used as an example to parse its biological function， and GhCOMT28 and GhCOMT55 had the highest expression in the roots and stems of cotton， and GhCOMT28 was localized in the cells in the cytoplasm of cell. GhCOMT28 mRNA was induced by drought stress， and silencing of GhCOMT28 （TRV2：GhCOMT28） resulted in reduced melatonin levels in leaves， and the expression of superoxide dismutase （SOD）， peroxidase （POD）， catalase （CAT） and other antioxidant enzymes decreased， free radicals accumulation increased， and plant drought tolerance decreased. Overexpression of GhCOMT28 （35S：GhCOMT28-GFP） in Arabidopsis significantly improved plant drought tolerance. This study revealed that GhCOMT28 had an important role in regulating drought tolerance in cotton seedlings and had potential use for drought-tolerant variety improvement.

Aiming at the limited cultivated soil resources in southern Xinjiang， the effects of mixed salt on cotton seed germination were studied， and the tolerance of cotton to saline-alkali soil environment was discussed.To simulate the complex saline-alkali environment in southern Xinjiang， NaCl， Na₂SO₄， NaHCO₃ and Na₂CO₃ were mixed in molar ratios of 1∶0∶0∶0 （S1）， 9∶1∶0∶0 （S2）， 0∶0∶9∶1 （S3） and 9∶1∶9∶1 （S4）. 5 salt levels （40， 80， 120， 160 and 200 mmol·L^-1） were set to stress the germination period of cotton seeds for varieties Tahe 2 and Xinluzhong 62. The seed germination potential， germination rate， germination rate， salt tolerance critical salinity concentration， and early seedling fresh weight and dry weight were analyzed by using distilled water as control （CK）. The results showed that all 4 salt stresses significantly reduced the germination potential of cotton seeds. At 40 mmol·L^-1， there was no significant difference in germination rate between S1~S4 treatments and CK， but as the salt level increased （≥80 mmol·L^-1）， the germination rate of cotton seeds significantly decreased. At the same salt level， the germination rate of both cotton varieties in the S4 treatment was higher than that in the S1， S2 and S3 treatments. The 4 salt stresses caused a delay in the initial germination time of cotton seeds， and the germination rate significantly decreased. The S1， S2 and S3 treatments at 40 mmol·L^-1 promoted the accumulation of fresh weight and dry weight of cotton seedlings，and with the increase in salt level the fresh weight and dry weight of cotton seedlings gradually decreased， and all levels of the S4 treatment reduced the fresh weight and dry weight of cotton seedlings. Correlation analysis and principal component analysis indicated that germination rate was an important indicator for evaluating the salt tolerance of cotton during the germination period. Under 4 salt stresses， the salt tolerance critical salinity concentration of cotton seed germination rate was as S4>S2>S1>S3. In summary， during the germination period of cotton seeds， there was a certain level of tolerance to 40 mmol·L^-1 of the 4 salt stresses， but as the salt level increased， the 4 salt stresses resulted in a delayed germination time， decreased germination potential， germination rate and germination rate. Xinluzhong 62 showed strong tolerance to NaCl， and Tahe 2 exhibited strong tolerance to mixed salts. Above results provided a theoretical basis for the breeding of cotton germplasm in southern Xinjiang and evaluated important indicators of salt tolerance during the germination period of cotton seeds.

In order to clarify the effects of supplementary light quality and substrate water content on the morphological regulation and photosynthetic characteristics of cucumber seedlings， taking greenhouse cucumber seedlings as the research object， the supplementary light quality was set up in 3 treatments including white red ratio 2∶1 （L₁）， full white light （L₂）， white red blue ratio 2∶1∶1 （L₃）， and the substrate moisture content was set up in 3 treatments including 55% （W₁）， 75% （W₂） and 95% （W₃）， and 75% of substrate moisture content under natural light irradiation was used as control （CK）. The effects of different treatments on morphogenesis， growth and photosynthetic characteristics of cucumber seedlings were explored. The results showed that compared with CK， supplementary light significantly changed the morphological indicators， photosynthesis， antioxidant enzyme activity and root activity of cucumber seedlings. Under L₁W₂ treatment， the plant height of cucumber seedlings was significantly higher than CK， but the maximum leaf area was significantly smaller than CK. When treated with W₃， the stomatal conductance， transpiration rate and intercellular CO₂ concentration of seedlings under L₃ supplementary light conditions were significantly higher than those under L₁ and L₂ supplementary light treatments. The activities of superoxide dismutase （SOD）， peroxidase （POD）， catalase （CAT） and the content ofmalondialdehyde （MDA） showed significant differences among different light intensities. The root surface area and root volume increased with the increase of substrate water content under L₁ light conditions， and under L₃ light conditions， the W₂ treatment was significantly greater than the other 2 treatments. Through comprehensive analysis of membership functions， it was found that W₁ treatment had the lowest score among various light quality treatments. Among the same water treatment under 3 different light conditions， L₃ treatment had the highest score， and L₃W₃ treatment had the best comprehensive growth characteristics of cucumber seedlings. Above results provided a reference for the optimization mode of supplementing light and irrigation amount for cucumber seedlings.

Codon preference is present in the genomes of almost all known species. In order to understand the codon use preference of Vitis vinifera genome and improve the efficiency of gene heterologous expression， the characteristics and influencing factors of coding gene codons in Vitis vinifera were studied and analyzed using genome-wide data of Vitis vinifera as the basic material， and the codon preference were compared with other expression systems and plant genomes of Vitis vinifera subfamily. The results showed that， based the chromosome sequence of grape， 21 887 coding sequences were screened out for analyzing the codons preference. The GC content of the codon in encoding gene of Vitis vinifera showed GC₁ （50.19%）>GC₃ （43.92%）>GC₂ （40.36%）， and the last base of codon was preferred to A/U. The 19 optimal codons were identified， including GCA， GCU， GAU， UUU， GGA， GGU， CAU， AUU， CUU， AAU， CCA， CCU， CAA， UCA， UCU， ACA， ACU， GUU， UAU， among which 6 codons ended with A and 13 codons ended with U. The preference of Vitis vinifera genomic codon was influenced by natural selection and mutation， and the natural selection was the main factor. Above results provided a theoretical basis for the study of grape genomics， and also provided guidance for improving the expression of heterologous proteins in Vitis vinifera and the in vitro expression of Vitis vinifera-related proteins.

To explore the structure， function and evolutionary characteristics of chloroplast genome of Polygonum plants， the software of CodonW， SPSS and online programs Galaxy， Genepioneer Bioinformatics Cloud， mVISTA， GENE DENOVO and other tools were used to analyze the codon usage preferences and phylogenetic relationships of the chloroplast genomes of 28 Polygonum plants. The results showed that the codon adaptation index （CAI） and effective number of codon （ENC） in chloroplast genomes of 28 species of Polygonum plants were low， which indicated weak codon usage preference and being mainly influenced by natural selection. The third base of codon mainly ended in A/U， and 9 optimal codons of chloroplast genome all ended in A/U. The correlation analysis between the GC content at different positions of codon， ENC and GC3s， GC3， GC2 revealed that codon preference in chloroplast genome of Polygonum was weak and mainly influenced by the third base composition， while the length of the chloroplast gene sequence had less influence on base composition and codon preference. The phylogenetic tree based on the relative synonymous codon usage （RSCU） was consist with those besed on matk and rbcl gene sequences， 28 species of Polygonum plants were classified into 3 groups， but there were differences in each group， such as P. maackiana was same group with P. tinctoria in phylogenetic tree based on matk gene， while was same group with P. posumbu in phylogenetic tree based on rbcl gene. Above results provided a reference for the utilization， phylogeny， and chloroplast genetic engineering of Polygonum plants.

Crop diseases are major threats for agricultural production， so timely and accurate identification of disease is important for the development of control measures to ensure food security. With the rapid development of deep learning， convolutional neural networks are used more and more to identify crop diseases. This paper compared the advantages and disadvantages of convolutional neural network disease recognition methods from 3 aspects including disease recognition based on different data sets， disease recognition using transfer learning and pre-training， and lightweight of the disease recognition model. It also analyzed the shortcomings of the current methods and put forward the future development trend. It was pointed out that more abundant data sets should be constructed， multi-modal data should be combined， models should be further optimized， and robots should be used to implement automatic detection. It provided important references for reducing food loss， realizing precision agriculture management， promoting agricultural modernization and sustainable development.

Aiming at the unstable problem of single seeding during the sowing process of potato， the basic physical properties of the potato seed were determined with the Enshi selenium-enriched potato seed as the research object. The triaxial dimensions， volume and density of potato seed were measured， and the dimensional structure of the seed displacer was modeled in three dimensions according to the parameters of the seed. The seeding process of the arc-jaw potato seeder was simulated using Recurdyn-EDEM coupled simulation， and the parameters were optimized by response surface test. Taking the effective seed picking length （X₁） and seed scoop width （X₂） as the test factors， and the single-grain rate， multiple-grain rate and empty-grain rate as the test indexes， the quadratic generalized rotary combinatorial design test was conducted with the coupled simulation. The results showed that X₂² and X₂² had significant effects on single grain rate， multi-grain rate and empty grain rate， and X₁ and X₁X₂ had significant effects on multi-grain rate and empty grain rate， while the rest factors had non-significant effects on the index. Using the optimization module to optimize the data of parameters， and the best parameter combination of effective seed length and seed spoon width was determined as 99.74 and 60.02 mm. Under the optimized parameter， the error value between the simulation test and the target value was less than 2% and the single grain rate was greater than 80%， which proved the accuracy of the optimized experimental parameters， and the feasibility of the precision seeding rate.

The most important step of tea residue reuse is drying. In order to optimize the drying process of tea residue dual-axis stirring dryer， Euler-Euler multiphase flow model and component transport model of Fluent software was used to simulate. The results of structure optimization and water content analysis showed that： adding the diversion grille could greatly improve the uniformity and average temperature of the flow field inside the dryer. The change trend of the average temperature inside the dryer increased first and then decreased with the increase of the angle of the diversion grille， and increased first and then decreased with the increase of the number of grilles. The best effect was achieved when 5 grilles were arranged with a spacing of 1 030 mm， and the average internal temperature of the dryer was 429.23 ℃. When the hot air temperature was 500 ℃ and the spindle speed was 300 r·min^-1， the water content of the material at the discharge port of the dryer was the lowest， which was 12.91%. This simulation result provided technical parameters for the design of large double-shaft mixing dryer.

In order to investigate the synergistic effect of different antagonistic bacteria， Streptomyces and their combination with chemical fungicides on Atractylodes macrocephala blight disease， the compatibility of different antagonists and chemical fungicides was measured by dilution plate and drug-containing plate method at first. Then the plate confrontation method and growth rate method were used to evaluate the inhibition effect of antagonists compound solution and antagonists+chemical fungicides compound on Phytophthora sansomeana AMPH-1， which was the pathogen of A. macrocephala blight disease. The results showed that the Bacillus BZX-2， BZX-11 and X-119 strains had good compatibility with dimethomorph. The combination of BZX-2+BZX-11+X-119 had the best inhibition effect， and the inhibition rate reached 75.45%， which was lower than that of the treatment using X-119 alone. When the ratio of antagonist combination of Bacillus strains and dimethomorph was 1∶2， the inhibition effect reached 68.61%， which increased 16.83% and 13.59% compared with dimethomorph treatment and antagonists treatment， respectively. By the pot experiment in greenhouse， it was found that the greenhouse control efficiency of BZX-2+BZX-11+X-119 combination with equal proportion mixing was 72.72% on A. macrocephala blight disease， which was 45.45 percentage points higher than that of BZX-2 treatment. Above results provided effective basis for the new strategy of A. macrocephala blight disease control.

In order to investigate the effect of biocontrol bacterial on the microecology of ginseng continuous cropping soil， a biocontrol bacterial treatment experiment was conducted in the field. Chemical analysis and high-throughput sequencing technology were used to study the changes in soil physicochemical properties， soil enzyme activities， and bacterial community. The results showed that the application of biocontrol bacteria significantly decreased soil electric conductivity， and increased soil pH， the contents of organic matter， available nitrogen， available phosphorus and the activities of soil urease， soil sucrase， and soil acid phosphatase， with an increase of 9.00% in soil organic matter content and an increase of 19.42% in soil sucrase activity. Bacterial taxonomy analysis divided soil bacterial communities into 39 phyla， 124 classes， 279 orders， 424 families， and 774 genera. Biocontrol bacteria significantly increased the ACE index and Chao index of soil bacteria. Correlation analysis showed that pH， organic matter， available nitrogen， sucrase， urease were significantly positively correlated with Arthrobacter， and significantly negatively correlated with Bradyrhizobium and Microlunatus； available phosphorus content was significantly positively correlated with Candidatus_ Xiphinemabacter， RB41， and significantly negatively correlated with Candidatus_Udaeobacter， Arthrobacter； and there was significantly negative correlation between acid phosphatase and Mycobacterium. In summary， biocontrol bacteria stimulated the growth and reproduction of beneficial microorganisms in soil， increased the fertility and enzyme activity of the soil， and improved the soil nutritional status. Therefore， biocontrol bacteria should be expected to become an effective way to repair degraded soil.

In order to explore the quality change of fish during the hot boiling， rainbow trout （Oncorhynchus mykiss） was as material. the effects of soybean oligopeptide （SOP） and transaminase （TGase） on the quality and protein physicochemical properties of rainbow trout after hot boiling were compared， and the quality （texture， water retention， microstructure） and protein physicochemical properties （myofibril protein， sulfhydryl and carbonyl contents， etc.） of rainbow trout meat were analyzed. The results showed that the addition of SOP and TGase could improve the quality of rainbow trout meat after hot boiling. The hardness， cohesion， elasticity， chewability and water holding capacity of the fish meat were significantly increased. In addition， the addition of SOP and TRase could reduce the loss of myofibril protein， increase the degree of protein cross-linking， stabilize the spatial network structure， and improve the gel properties of fish meat. Above results provided reference for the quality maintenance technology of pre-prepared fish dishes.

Using frozen blueberry as raw material， the deproteinization process of blueberry polysaccharides obtained by ultrasound assisted hot water extraction was studied. Taking polysaccharide retention rate， protein removal rate and data weighted average method as the evaluation indexes， 4 kinds of deproteinization methods including adsorption method，adsorption-salting out method，adsorption-papain-salting out method， adsorption-trichloroacetic acid-salting out method were comparatived the deproteinization effects of crude polysaccharides water extracts from blueberry. At the same time，on the basis of single factor experiment，orthogonal experiment was used to optimize the deproteinization process conditions of crude polysaccharides water extracts from blueberry by adsorption method. The results showed that the deproteinization effect of the adsorption method was the best， the best process conditions for the deproteinization of adsorption method were that the deproteinization temperature was 50 ℃， the sample pH was 3.0， the deproteinization time was 40 min， activated carbon dosage was 1.5%. At this condition， the polysaccharide retention rate was 70.22%， the deproteinization rate was 87.88%， and the comprehensive score was 94.79 points. The adsorption method selected in this study had practical operability， and could effectively remove the protein in the crude polysaccharide of blueberry. Above results provided data supports for further research on separation and purification， chromatographic analysis，structure identification， structure-activity relationship and biological activity research and development of polysaccharides.

In order to relieve the heavy metal pollution of soil caused by prolonged utilization of organic pig manure fertilizer in vegetable cultivation， a long-term positioning experiment was used to investigate the impact of biochar combined with pig manure organic fertilizer and chemical fertilizer on the accumulation of cadmium （Cd） and lead （Pb） in both soil and plant biomass， as well as alternations in the speciation of Pb ions within the soil matrix. 3 gradients of organic fertilizer treatments including 25% （L）， 50% （M） and 100% （H）， and 4 biochar treatments including 0%（B₀）， 3%（B₁）， 6%（B₂）， 9%（B₃） were designed. The results showed that there was a significant interaction between the organic fertilizer application rate and the proportion of biochar in relation to leaf sweet potato yield and soil Pb content （P<0.05）. The treatments with L and H amount of organic fertilizer with B₃ biochar had the highest yield of leaf sweet potato. The B₁H and B₃L treatments significantly decreased the cumulative Pb content of leaf sweet potato with 31.5% and 37.6%. With the increase of biochar amount， the M treatment decreased the cumulative Cd content of leaf sweet potato. Combined application of organic fertilizer and biochar induced a shift in the chemical forms of Pb within the soil， promoting the transformation of Pb from an acid-extraction and reducible state， which as high bioavailability， to an oxidizable and residue state with reduced bioavailability. In conclusion， combined application of organic fertilizer and biochar could increase the yield of leaf sweet potato， reduce the heavy metal pollution caused by long-term application of organic fertilizer， and improve the soil quality.

Biochar and maize straw can improve soil quality and promote crop growth， but their improvement effects may vary in different crop species. It is of practical significance for agricultural production to explore the difference of response of different crop growth traits and nutrient absorption efficiency to biochar and maize straw. A pot experiment was carried out on Chinese cabbage， agrostis， caryophylla and alfalfa with no material added， biochar added， maize straw added， biochar combined with maize straw， respectively， to analyze the changes of soil nutrients， crop growth and nutrient absorption. The results showed that the contents of soil nutrients （total nitrogen， available phosphorus， available potassium and organic carbon） were affected by biochar， corn straw and their combined application in the range of -28.78%~40.41%， -17.85%~53.20% and -3.45%~62.51%， respectively. The combined application of biochar and maize straw significantly affected the growth of 4 crops，and the above-ground dry weight increased by 23.74%~80.89%. The root length increased by 22.51%~77.91%， 25.86%~80.45% and 45.93%~149.24%， and the nutrient absorption efficiency increased by 3.40%~143.73%， 1.07%~188.80% and 9.82%~290.32%， respectively，under the treatments of biochar， corn straw and their combined application. The application of biochar and maize straw significantly improved the growth of the 4 crops. Biochar and maize straw increased the soil nutrients， promoted the nutrient absorption of crops， and promoted the above-ground and root growth of crops. Above results provided a theoretical basis for the extensive utilization and popularization of biochar and straw.

The combined application of controlled release nitrogen fertilizer and urea can realize the light and simplified fertilization of rice. In order to study the appropriate amount of nitrogen fertilizer under the combined application of controlled release nitrogen fertilizer and urea in early rice production in red soil area， field plot experiments were arranged. Pure nitrogen 69 （N69）， 104 （N104）， 138 （N138）， 173 （N173） and 207 kg·hm^-2 （N207） were applied according to the combined application ratio of 60% controlled release nitrogen fertilizer and 40% urea， and took no nitrogen application （N0） as control. The rice yield and nitrogen fertilizer agronomic efficiency， as well as the dynamic changes of ammonium nitrogen in surface water after basal fertilizer application were analyzed， and the quantitative relationship between ammonium nitrogen in surface water and rice yield was discussed. The results showed that the controlled release nitrogen fertilizer and urea mixed application could significantly increase rice grain yield （P<0.05）， and with the increase of the amount， rice grain yield increased by 15.6%~30.6%， while the nitrogen fertilizer agronomic efficiency gradually decreased. After the application of controlled release nitrogen fertilizer and urea， the content and total amount of ammonium nitrogen in surface water increased significantly， and reached the peak on the second day after the application of nitrogen fertilizer， and then gradually decreased with time. The content and total amount of ammonium nitrogen in surface water were significantly positively correlated with the amount of controlled release nitrogen and urea applied after fertilization 1~7 d. The slope of the fitting equatio showed that when the nitrogen application rate increased by 1 kg·hm^-2， the content and total amount of ammonium nitrogen in surface water increased the most at 2 d after fertilization， which were 0.06 mg·L^-1 and 1.28 kg·hm^-2. Considering the rice yield and the agronomic use efficiency of nitrogen， it was recommended to control the total nitrogen application rate at 104 kg·hm^-2 in early rice fields in red soil area according to the fixed proportion of 60% controlled release nitrogen and 40% urea. At the same time， avoid drainage at 2 d after fertilization to reduce the loss of nitrogen. Above results could provide technical support for reducing nitrogen application rate and increasing efficiency in early rice production in red soil area.

Extracellular polysaccharides （EPS） produced by microorganisms， as an environmentally friendly green agent， have broad application prospects in promoting plant growth. The EPS produced by Sphingomonas sp. CX7 fermentation was used as the research object to analyze its primary structure， and explore its promoting and stress resistance effects on barley seedlings. The results showed that EPS produced by CX7 was a heteropolysaccharide composed of glucose， mannose， rhamnose， fucose， ribose， glucuronic acid， galactose， galacturonic acid， arabinose and xylose， with a mass ratio of 5.68∶3.25∶1.99∶1.62∶1.00∶0.81∶0.27∶0.06∶0.02∶0.01. By spraying barley leaf， the optimal EPS dosage for barley growth was 2 g·L^-1. At 2 g·L^-1 EPS， the root length， plant height， fresh weight and dry weight of barley increased by 47.45%， 19.28%， 18.15% and 37.88%， respectively， the contents of chlorophyll， soluble sugar， soluble protein， proline and the activities of peroxidase， catalase increased by 52.47%， 25.55%， 27.36%， 94.44% and 82.81%， 97.91%， respectively. In summary， the EPS produced by Sphingomonas sp. could promote plant growth and enhance plant stress resistance， which provided a certain reference basis for green biological agents to replace traditional agricultural foliar fertilizers.

A pot experiment was conducted to assess the impact of various formulations of water-soluble fertilizers containing humic acids （WSF） on acidified brown soils in Yantai city with non-fertilizer treatment serving as control group（CK）. 6 topdressing treatments， including Market No. 1 （HJ）， Market No. 2 （GL）， Market No. 3 （LD）， Market No. 4 （XZ）， self-developed No.1 （NY） and self-developed No.2 （NE）， were applied at 2 application rates per fertilizer of 0.4（-0.4）or 2.0 mL·kg?1 soil（-2.0）. The impacts of different treatments on maize seedling height， stem diameter， biomass， cadmium （Cd） content， as well as soil physicochemical properties and available Cd content were compared. The results indicated that， compared to CK， the application of NY， XZ and NE elevated soil pH by 0.57~0.61， 0.55~0.62 and 0.49~0.64 units， respectively. The total exchangeable acidity of the soil treated with NY-0.4， NE-0.4 and XZ-2.0 decreased by 28.0%， 23.3% and 12.5%， respectively， accompanied by a corresponding decrease in exchangeable aluminum content by 51.2%， 29.1% and 18.0%. These outcomes were indicative of the potential to mitigate soil acidification and alleviate aluminum toxicity. The application of WSF generally augmented soil organic matter content， reduced soil electrical conductivity， improved the availability of soil nutrients， lowered soil cadmium availability， and fostered the growth of maize seedlings while inhibiting Cd absorption. These improvements collectively contributed to enhancing soil quality and crop quality. Soil acidity emerges was a pivotal factor influencing the activation， absorption and accumulation of Cd in the soil-maize seedling system. A comprehensive analysis of maize seedling growth and soil improvement revealed that the XZ product outperformed the other tested formulations. Above results provided valuable insights into the effects of WSF product properties， compositions and dosages on fertilizer efficacy， offering a reference for optimizing maize fertilization strategies and ameliorating degraded soils.

In order to explore the effects of microbial fertilizer and humic acid compound fertilizer on the growth， photosynthetic characteristics， and bulb quality of Lilium， and to determine suitable fertilization amounts， a field micro-plot experiment was conducted using Lilium tissue-cultured seedlings. 8 treatments were set up， including humic acid compound fertilizer at 10 （F-1）， 30 （F-2）， 50 g·m^-2 （F-3）， microbial fertilizer at 30 （J-1）， 60 （J-2）， 90 g·m^-2 （J-3）， humic acid compound fertilizer 30 g·m^-2+microbial fertilizer 30 g·m^-2 （H）， and a water control（CK）. The effects of different treatments on the growth and photosynthetic characteristics of Lilium plants were compared and analyzed. The results showed that， compared with CK， the application of microbial fertilizer and humic acid compound fertilizer promoted the growth and development of both the aboveground and underground parts of Lilium to varying degrees. Among them， the H treatment significantly increased the circumference， fresh weight， root length， number of lateral roots and stem thickness of Lilium bulbs， which were 1.76， 3.78， 1.61， 1.85 and 1.58 times that of CK， respectively. The application of microbial fertilizer and humic acid compound fertilizer significantly increased the chlorophyll content and net photosynthetic rate （P_n） of Lilium， with the H treatment having the highest chlorophyll a and chlorophyll b contents， which were 2.31 and 2.64 times that of CK， respectively， and the P_n of J-2 and J-3 treatments being the highest， 148.72% and 172.96% higher than that of CK. The stomatal conductance （G_s）， transpiration rate （T_r） and water use efficiency （WUE） of the microbial fertilizer-treated plants were significantly increased compared to CK， while the intercellular CO₂ concentration （C_i） was significantly reduced， with the G_s and T_r of J-2 treatment being the highest， 50.00% and 65.47% higher than that of CK. The application of microbial fertilizer and humic acid compound fertilizer effectively increased the sucrose， starch， and soluble protein contents of Lilium bulbs， with the sucrose and protein contents of F-3 treatment being the highest， and the starch content of J-3 treatment being the highest， increasing by 17.97%， 15.41% and 9.20% compared to CK， respectively. Through principal component analysis and membership function analysis， it was concluded that the comprehensive evaluation of Lilium indicators was best under H treatment. In summary， microbial fertilizer and humic acid compound fertilizer could effectively promote the growth and photosynthetic rate of Lilium， and improve the yield and quality of bulbs. When both were combined， the growth effect on Lilium ws the best. Above results provided a theoretical basis and technical support for the fertilization of Lilium bulbs.

Low temperature disaster in spring is the main meteorological disaster affecting tea trees in Guizhou. Climate risk assessment and zoning of spring low temperature disasters of tea trees could provide technical support for the scientific and reasonable layout of Guizhou tea industry， reducing losses caused by low temperature disasters， and designing low temperature meteorological index insurance products. Based on the theory of natural disaster risk， risk assessment and zoning of spring low temperature disasters of tea trees in Guizhou province were conducted using daily average temperature and daily minimum temperature data from 84 meteorological stations from 1961 to 2020， as well as tea planting area and yield data from 1999 to 2017. Mathematical statistics， information entropy weight method， analytic hierarchy process， and geographic information system （GIS） spatial analysis methods were used to assess the risk. The results showed that the risk index of low temperature induced disasters was closely related to geographical factors， and high value areas mainly distributed in high altitude areas in space. The overall sensitivity index of the pregnant disaster environment showed a decreasing trend from west to east. The high-risk area of low temperature disasters of tea trees in Guizhou was 9.07×10⁵ hm²， accounting for approximately 5.15%. The medium to high risk area was 3.16×10⁶ hm²， accounting for approximately 17.96%. The low risk area was 3.49×10⁶ hm²， accounting for approximately 19.81%. High risk and medium to high risk levels were mainly distributed in Weining county， Hezhang county， Nayong county， Dafang county， Shuicheng district， western part of Duyun city， central part of Leishan county， northern part of Jiangkou county， the southern part of Yinjiang county， Meitan county， and the western part of Fenggang county， the western and eastern parts of Zheng’an county and the western part of Wuchuan county. The low-risk areas were mainly distributed in the southwest of Beipan river basin， the north of Chishui river basin， and the southeast of Duliu river basin.

To explore the sap flow characteristics of Salix psammophila with different diameter classes and its relationship with environmental factors， the sap flow rate of Salix psammophila was continuously monitored by plant sap flow meter （EMS62）， and the meteorological factors and soil factors were monitored simultaneously by small weather station （HOBO U30） and water potential sensor （TEROS 21）. The results showed that the diurnal variation of sap flow rate at each diameter class showed a ‘single peak’ curve. With the change of time， the flow rate of >10 mm diameter class increased first and then decreased， while the flow rate of ≤10 mm diameter class decreased continuously， and the start-up and end time of flow were different. The sap flow rate of Salix psammophila in sunny day was higher than that in rainy day. The change of sap flow in sunny days showed ‘single peak’ curve， and the change of sap flow in rainy days showed ‘single peak’ or ‘double peak’. Solar radiation was the primary factor affecting the change of Salix psammophila sap flow. With the expansion of time scale， the interpretation rate of sap flow change decreases， while the number of affected factors increased. In conclusion， during the growing season， the sap flow of Salix psammophila increased with the increase of diameter class， but there were differences in the sap flow changes of different diameter classes.