The development of agricultural green science and technology is a strategic fulcrum for achieving the coordinated advancement of food security， ecological protection and farmer’s income growth. It is also the inevitable path for implementing the rural revitalization strategy and promoting agricultural modernization. Therefore， it is necessary to deeply explore the evolution process of agricultural green science and technology development in China， objectively examine the current dilemmas faced by agricultural green science and technology development in China from a realistic logic perspective， and systematically explore the promotion strategies for agricultural green science and technology development in China from a practical logic perspective. The full-chain， multi-level agricultural green science and technology system should be constructed； the full-cycle and multi-dimensional research on agricultural scene applications should be strengthened. And the full-element， multi-subject agricultural green science and technology ecosystem should be improved. Above conclusions provided an operational theoretical frameworks and practical models for solving the systemic problems of agricultural green transformation and cultivating new drivers of sustainable development.

The cuticular wax， a hydrophobic protective barrier covering most aerial plant organs， plays crucial roles in defending against biotic and abiotic stresses. Although the cuticular wax biosynthesis and transport pathway has been progressively elucidated in model plants， with the identification of several structural and regulatory genes， the underlying molecular mechanisms remain largely unknown， particularly in non-model plants. The structure， components， and functions of the plant cuticular wax were introduced，and the mechanisms of cuticular wax biosynthesis and transport were outlined， highlighting the roles of associated structural genes. The regulatory mechanisms underlying cuticular wax biosynthesis at the transcriptional， post-transcriptional， post-translational， and epigenetic levels were critically examined. Finally， the major research trends in this field were discussed，which aimed to provide valuable insights for further research on plant cuticular wax and its implications for agricultural production.

Drought is one of the main stress factors affecting the growth and development of foxtail millet， which seriously inhibits the yield and quality of foxtail millet. Graphene oxide （GO） can effectively improve the resistance of crops to stress. To further explain the mechanism of GO improving the drought resistance ability of millet， 80 mg·L^-1 GO was used to treat Jigu 168 （drought sensitive） seedlings， and the growth， development and physiological and biochemical processes of millet were analyzed. The results showed that 80 mg·L^-1 GO treatment for 15 d could significantly improve the phenotype and root system of foxtail millet， and promote the growth and development of foxtail millet， such as plant height， biomass and root system parameters. After 7 and 15 d of GO treatment， the activity of peroxidase （POD） increased by 42.86% and 66.67%， respectively， and the activity of catalase （CAT） increased by 30.23% and 52.17%， respectively， which indicated that GO could promote the function of antioxidant system and reduce cell damage. In terms of osmotic regulation， GO significantly reduced the Na⁺/K⁺ under drought stress， which helped to maintain intracellular osmotic balance and prevent excessive water loss. In addition， the grain weight after GO treatment was significantly increased by 54.73%. Therefore， a certain content of GO could significantly promote the growth and development of foxtail millet， improve its physiological and biochemical processes， thereby improve the response ability of foxtail millet to drought stress， and ultimately increase the yield. Above results provided scientific basis for GO as soil water-retaining agent to alleviate drought stress during crop cultivation.

Jacalin-related lectin （JRL） proteins belong to the plant lectin family， exhibit specific sugar-binding activity and play crucial roles in processes such as plant stress response. To understand the function of the maize JRL （ZmJRL） gene family， the bioinformatics methods were used to identify and analyze the ZmJRL genes. Additionally， the transcriptomic data from the MaizeGDB website were utilized to investigate the specific expression of ZmJRL genes in various tissues and under different stress conditions. The results revealed that a total of 16 ZmJRL genes in maize were identified， designated as ZmJRL01 to ZmJRL16. They were unevenly distributed on 7 chromosomes of maize. These proteins exhibited structural similarity， possessing jacalin domains and mostly being alkaline-stable proteins. Subcellular localization analysis indicated that ZmJRL proteins primarily localized in the cytoplasm， nucleus and chloroplasts. Phylogenetic analysis divided maize JRL proteins into 3 clades， which were closely related to rice （Oryza sativa L.）. The ZmJRL proteins with same clades had similar motifs. The promoter of ZmJRL genes contained various cis-elements that respond to abiotic stress and hormones. Transcriptome analysis showed that the ZmJRL genes had tissue expression specificity， and the majority of ZmJRL genes could respond to at least one type of adversity stress， such as cold， heat， salt and drought. Above results provided a reference for further study on the biological functions of ZmJRL genes.

To breed short growth period rapeseed varieties， taking the early maturing and excellent breeding germplasm of Brassica napus L. as the research materials， 11 main agronomic traits of 48 materials were analyzed and evaluated through methods including genetic diversity analysis， correlation analysis， regression analysis and principal component analysis under late sowing. The results showed that the genetic diversity index and coefficient of variation range of the 11 quantitative traits were relatively large， indicating that these materials had rich genetic information. Correlation analysis showed that the vegetative growth period， the pod growth period， the pods number per plant， the seeds number per pod， 1 000 seeds weight and flowering duration were closely related to yield per plant. The regression equation for yield per plant was mainly significantly influenced by the pods number per plant， the seeds number per pod and 1 000 seeds weight， with a coefficient of determination of 0.852. The first two principal components extracted by principal component analysis had a cumulative contribution rate of 51.46%， representing most of agronomic traits. Principal component analysis divided 48 germplasm into 4 quadrants， and the first quadrant （Ⅰ） showed that materials with shorter flowering duration， longer vegetative growth period， and longer pod growth period could be used to breed early maturing， short growth period and high-yielding varieties. Above results provided a theoretical basis for the selection of parents and hybrid combinations of early maturing rapeseed with short growth period in the middle reaches of the Yangtze River.

In order to explore the adaptation mechanism of strawberries under suboptimal low temperature， 2 strawberry varieties of Ningyu and Jingzangxiang were taken as materials. The phenotype traits， photosynthetic parameters， rapid chlorophyll fluorescence parameters and leaf ultrastructure of strawberry leaves under different treatments during the reproductive period were determined. The results showed that， under suboptimal low temperature， there was no significant change on plant-type of Ningyu， while the plant-type of Jingzangxiang gradually opened from the intermediate type and the leaf color gradually changed to yellow green. With the prolongation of suboptimal low temperature， the leaf area， leaf thickness and leaf volume of Ningyu significantly decreased， the leaf tissue density significantly increased， the specific leaf area first increased and then decreased， and the leaf dry matter content firstly decreased and then increased. With the prolongation of suboptimal low temperature， the leaf area and volume of Jingzangxiang increased， while the leaf thickness decreased， the leaf tissue density and leaf dry matter content first decreased and then increased， the specific leaf area and density showed a trend of first increasing and then decreasing. With the prolongation of suboptimal low temperature， there was no significant change in chlorophyll content in leaves of Ningyu， however， the chlorophyll a content of Jingzangxiang increased significantly. The net photosynthetic rate， stomatal conductance and intercellular CO₂ concentration of Ningyu leaves all significantly increased after 7 d of stress， and decreased after 14 d of stress. Suboptimal low temperature led to a decrease in water use efficiency， although it increased after 14 d of stress， it was still lower than the control at the same period. For Jingzangxiang， the net photosynthetic rate of leaves significantly decreased after 14 d of stress， while the intercellular CO₂ concentration and stomatal conductance significantly increased after 7 d of stress and decreased after 14 d of stress， the transpiration rate under suboptimal low temperature treatment decreased after 14 d of stress， and the overall trend of water use efficiency was similar to that of Ningyu. Energy transfer of Ningyu leaves was hindered after 14 d of suboptimal low temperature treatment （ΔW_OK>0）， however， the Jingzangxiang had already been hindered after 7 d of stress. The suboptimal low temperature had a significant impact on the oxygen release complexes of Ningyu and Jingzangxiang， and both oxygen release complexes were inactivated （ΔW_OJ>0）. The leaf mesophyll cells of Ningyu and Jingzangxiang under control treatment were intact， and the chloroplast and other structures were intact and clear. Under suboptimal low temperature treatment， the mitochondria in the mesophyll cells of Ningyu were slightly swollen， and a few rough endoplasmic reticulum were slightly dilated. After 14 d of stress， the lamellae and stacking structure of chloroplasts became blurred. After 7 d of stress， Jingzangxiang showed slight cytoplasmic wall separation， chloroplast structure dissolution， unclear outer membrane boundary， and disordered arrangement of lamellar structure. After 14 d of stress， chloroplasts dissolved and denatured， and lamellar structure became blurred. In summary， the leaves of strawberry should adjust under suboptimal low temperature treatment， but long-term suboptimal low temperature could reduce the photosynthetic performance of the leaves and damage the leaf ultrastructure. The damage caused by suboptimal low temperature to the photosystemⅡ reaction center and chloroplasts of Jingzangxiang was greater than that of Ningyu. The plant status， photosynthetic performance and other indicators of Ningyu were relatively stable， and its ability to low temperature was stronger than Jingzangxiang.

In order to explore the differences in cold resistance among different alfalfa varieties under low temperature stress and the changes in the contents of non-structural carbon and nitrogen substances in the roots， the overwintering organs （alfalfa roots） of 12 different fall dormancy alfalfa varieties of the ‘WL’ series planted in Horqin sandy land were dug before overwintering， and the programmable constant temperature and humidity test box was used to simulate the low temperature refrigeration （-20 ℃） treatment，and the low temperature cold storage （4 ℃） treatment was used as the control. The relative conductivity and non-structural carbon and nitrogen substance content of alfalfa root neck were measured， and correlation， clustering， principal component and membership function analyses were conducted. The results showed that the relative conductivity， soluble sugar， soluble protein and free amino acid contents under low temperature refrigeration increased compared to the control， while the starch content decreased. Correlation analysis showed that under low-temperature refrigeration， the relative conductivity of alfalfa root neck was significantly negatively correlated with starch content and significantly positively correlated with soluble protein content （P<0.05）； under low temperature refrigeration， the relative conductivity of alfalfa root neck was significantly negatively correlated with starch and soluble protein contents （P<0.05）. Cluster analysis divided 12 different fall dormancy levels of ‘WL’series into 2 categories. The first category consisted of 3 autumn dormant alfalfa varieties WL168HQ， WL298HQ and WL319HQ. The second category consisted of 1 autumn dormant alfalfa varieties WL329HQ and 8 semi autumn dormant alfalfa varieties. The comprehensive evaluation of the affiliation function showed that the order of the strength of cold resistance of different fall dormancy alfalfa was as follows： WL319HQ>WL298HQ>WL168HQ>WL349HQ>WL329HQ>WL354HQ>WL343HQ>WL358HQ>WL366HQ>WL377HQ>WL363HQ>WL440HQ. In summary， it was suggested to plant low autumn dormant alfalfa varieties with strong cold resistance such as WL168HQ， WL319HQ， WL298HQ in Horqin sandy land.

The YUCCA gene encodes flavin monooxygenase， which plays an important regulatory role in plant growth and development. In order to explore the effect of YUCCA gene on the growth and development of Huperzia serrata， bioinformatics and tissue-specific expression analysis of YUCCA gene family of H. serrata were carried out. The results showed that 18 members of the HsYUCCA gene family were identified in the full-length transcriptome of H. serrata. The amino acid length was 150~544 aa， the relative molecular weight of the protein was 16 105.53~59 058.24 Da， and the isoelectric point was 4.36~9.63. Among them， there were 9 basic proteins， 4 stable proteins， 15 hydrophilic proteins， and 7 proteins with transmembrane structure. The subcellular localization ofHsYUCCA were in the nucleus， cell membrane， cytoplasm， mitochondria， chloroplast and peroxisome. The expression of HsYUCCA4 was the highest in spores， stems and spores， and the expression of HsYUCCA6 was the highest in leaves. HsYUCCA had 35 cis-acting elements such as hormone response， light response and stress response， and had 15 conserved motifs. The physical and chemical properties， subcellular localization， secondary structure， tertiary structure and conserved motifs of HsYUCCA1， HsYUCCA2 and HsYUCCA4， HsYUCCA5 and HsYUCCA6， HsYUCCA7 and HsYUCCA13 were similar， indicating that their biological functions were similar， and the phylogenetic development showed certain homology， and the evolutionary process tended to be consistent. Above results provided a theoretical basis for the future analysis of the possible mechanism of YUCCA gene in the growth， development and reproduction of H. serrata.

S-adenosyl-L-methionine （SAM） is an important bioactive molecule in all living organisms. Regulating the glucose effect of Saccharomyces cerevisiae and directing the carbon flux to SAM synthesis is a challenge for cell factory. The regulating glucose effect by overexpressing SNF1 and introducing SAM synthase gene MetK1 of Leishmania infantum were applied to improve SAM production in S. cerevisiae CGMCC 2842 （2842）. The results showed that the overexpression of SNF1 enhanced the expression levels of genes involved in glucose transport and glycolysis， which improved the glucose utilization and then elevated the levels of glycolytic intermediates. The expression levels of ACS1 and ALD6 and the activity of alcohol dehydrogenase 2 （ADH2） were enhanced， which probably promoted the conversion of ethanol in fermentation broth into acetyl-CoA. The gene expressions involved in sulfur-containing amino acids were also enhanced for the precursor amino acid biosynthesis. Finally， the introduction of MetK1 of L. infantum effectively directed the carbon metabolism flux to SAM synthesis. The SAM production of the stain YPSNF1-MetK1 reached 1.90 g·L^-1，increased by 251.85% compared to that of 2842. Above results laid theoretical foundation for the regulation and application of glucose effect in yeast.

In order to solve the problems of inaccurate prediction of rice moisture content， large hysteresis and low coefficient of determination during the drying process， the response surface methodology （RSM） was used to analyze the main factors affecting the rice moisture content during drying. Genetic algorithm （GA） was used to optimize the traditional BP （back propagation） neural network model， and a prediction model was established based on RSM-GA， which could accurately predict the moisture content of grain during drying. The results showed that the hot air temperature， grain layer temperature and ambient relative humidity had significant effects on the change of moisture content during drying process of rice. The hot air temperature， grain layer temperature and ambient relative humidity were used as the input layers of the prediction model， the rice moisture content was the output layer. The optimal number of intermediate hidden layers of the prediction model was determined to be 10 through empirical formulas， and the neuron structure of the prediction model established was 3-10-1. During model training， the optimal performance was at the 15 th time， the minimum root mean square error was 0.621 84×10^-3， and the optimal Matlab simulation test setting parameters were obtained. When the iterating was to 200 generations， the fitness value was stabilized at 0.019 5. After optimized by genetic algorithm， the coefficient of determination of the prediction model was 0.980， which was 5% higher than the traditional model； the root mean square error was 0.009， which was 17% lower than the traditional model. In summary， the performance of optimized neural network model was improved， which provided a reference for subsequent control strategy research.

To improve the accuracy and reliability of the discrete element method for the design and optimization of sugarcane harvesting machinery， the full-matured sugarcane stalk was taken as the research object， and the Hertz-Mindlin with Bonding model in EDEM was chosen to establish the bonding model of sugarcane stalk by combining the physical test of the stalk and the discrete element simulation method， and the relevant parameters in the simulation model were calibrated. The average value of the maximum shear force of sugarcane stalks in the physical test was 574.5 N. The Plackett-Burman test， Steepest Ascent test and Box-Behnken test were designed to determine the parameters of the sugarcane stalk bonding model using the maximum shear force as the evaluation index， and the reliability of the simulation model was verified by the test. The results showed that the normal stiffness of the sugarcane stalk bonding model was 7.60×10⁸ N·m^-1， the shear stiffness was 4.35×10⁸ N·m^-1， and bonded disk radius was 1.883 9 mm. According to this parameter combination， the average maximum stem shear force obtained by simulation was 562.64 N， and the relative error with the test value was only 2.06%. Above results showed that the sugarcane stalk shear model and calibration parameter results established in this paper could be used for discrete element simulation research， which had guiding significance for the design of sugarcane harvester.

To address the complex scenarios of apple fruit detection in orchard environments， such as target overlapping， uneven illumination and varying scales， and to meet the balance requirement between detection accuracy and computational resources for model deployment， a lightweight apple fruit detection model YOLO-AP based on the improvement of YOLO11n was proposed. Firstly， by integrating GhostModule and dynamic convolution to improve the feature extraction module， a GD_C3K2 module was proposed to enhance the model’s feature extraction capability while reducing model complexity. A global-local dual-stream feature fusion network was designed to reconstruct the neck network by simplifying the bidirectional feature pyramid network and combining the adaptive-downsamping module. Additionally， a global-to-local spatial aggregation module was introduced in the network head to further enhance the model’s global and local spatial modeling capabilities. The lightweight shared convolution head RepCoord-LDH was constructed by combining the coordinate attention mechanism and reparameterized convolution to reduce model complexity while maintaining high detection accuracy. Finally， WiseIOUv3 was introduced as the model’s bounding box loss function to optimize the bounding box regression performance. The results showed that YOLO-AP achieved a precision of 89.1%， a recall of 88.9% and a mean average precision of 96.1%， which were 0.5， 0.1 and 1.1 percentage points improvements compared to the baseline model YOLO11n. Meanwhile， the model’s number of parameters and floating-point operations are 1.4 M and 3.6 G， respectively， which were only 53.8% and 54.5% of the baseline model. In the comparison with mainstream detection algorithms， YOLO-AP also outperformed other algorithms in terms of detection performance and model complexity. In conclusion， the proposed YOLO-AP model provided an effective technical reference for apple detection in complex environments.

Body deformation， occlusion and other factors will generate during pig aggression， and this makes it difficult to recognize the identity of pigs. This study proposed a deep learning algorithm based on improved YOLOv9 to recognize pig identities under aggression situation. 18 000 frames were generated from 600 labelled 1 s aggressive videos as the dataset. Firstly， DualConv was used to replace the subsampling of YOLOv9 network， which reduced the computation on the base of maintaining the accuracy. Secondly， the neck part of YOLOv9 was improved by integrating bidirectional feature pyramid network （Bi-FPN） to improve the feature extraction capability of the model under aggression scene. Then， the partial self-attention （PSA） mechanism was introduced behind RepNCSPELAN4 layer of backbone to enhance the ability of model to capture local features. Finally， the improved YOLOv9 was used to recognize pig identities. The results showed that the average accuracy of this improved YOLOv9 model was 93.6%， which was 3.7 percentage point higher than that of the benchmark model， and the detecting speed was 31.58 f·s^-1. Above results indicated that the improved YOLOv9 could effectively improve the identification accuracy of pigs in aggression scene， and helped refine the aggression recognition from the group level to the individual level.

To identify the pathogen of anthracnose on Capsicum annuum L. in Jize and Guangzong county in Hebei province， diseased pepper fruits were collected. 71 strains were isolated， in which 32 strains from Jize county， and 39 from Guangzong county. By morphological and molecular identification， 24 strains were identified as Colletotrichum scovillei and 8 strains were as C. truncatum in 32 strains from Jize county， acounting for 75.00% and 25.00%， respectively， 32 strains were identified as Colletotrichum scovillei and 7 strains were as C. truncatum in 39 strains from Guangzong county， acounting for 82.05% and 17.95%， respectively. Fungicide difenoconazole was employed to assay the sensitivity of 46 tested strains， the median effect concentration （EC₅₀） were ranging from 0.143 0 to 0.434 8 μg·mL^-1， with average of 0.289 8 μg·mL^-1. Above results identified the pathogen of pepper anthracnose in south of Hebei province， and provided theoretical basis and fungicide recommendation for the prevention and control of pepper anthracnose caused by C. scovillei.

In order to explore the characteristics of the grasshoppers community structure and its influencing factors in Yili River Basin desert grasslands， the combination of route surveys and typical sample plots were used to determine the occurrence of grasshoppers， and revealed the main influencing factors of the grasshopper community structure in desert grasslands by using statistical methods of quantitative ecology. The results showed that the number of desert grasshopper species in the Yili River Basin desert grasslands was 20 species， which belonged to 12 genera and 4 families. The dominant grasshoppers were Calliptamus italicus， Calliptamus barbarus， Notostaurus albicornis Oedaleus decorus decorus and Dociostaurus tartarus. There was no significant difference in Shannon-Wiener index of grasshopper alpha diversity among different plant functional groups. The S?rensen index of grasshoppers in the Gramineae functional group were significantly higher than that in the Asteraceae functional group by 61.00% （P<0.05）， and there were no significant differences between other plant functional groups. The results of permutational multi-variance analysis further showed that there were significant differences in grasshopper density among different plant functional groups （F=4.37， P<0.05）. The structural equation model and random forest model showed that average annual temperature， sunshine duration and vegetation coverage were the main influencing factors that drived the density of grasshopper communities under different plant functional groups in the desert grasslands of Ili River Basin. Above results provided a theoretical basis for sustainable management of grasshoppers in desert grasslands of Ili River Basin.

To analyze the components of Ascophyllum nodosum， Ecklonia maxima， Lessonia trabeculata （LF）and Lessonia nigrescens （LN） and evaluate their nutritional value and further explore their processing and utilization potential， the basic nutrients， amino acids， fatty acids and inorganic elements of 4 brown algaes were analyzed and evaluated. The results showed that the 4 brown algaes were all high protein， low fat and high dietary fiber， and the insoluble dietary fiber content of Ecklonia maxima was as high as 48.60%. The alginate， mannitol and iodine contents of Lessonia nigrescens （LN）， Ecklonia maxima， Lessonia trabeculata （LF） and Ascophyllum nodosum were 48.99， 48.31， 47.48 and 40.88 g·100 g^-1. And the 4 brown algaes contained 18 amino acids and 8 essential amino acids， and the amino acid score （AAS） was higher than the standard shown by Food and Agriculture Organization of the United Nations and World Health Organization， which indicated that the amino acid composition of 4 brown algae was reasonable and balanced. According to the essential amino acid index （EAAI）， Lessonia nigrescens （LN） had higher nutritional value with higher saturated fatty acids/total fatty acids and unsaturated fatty acids content. The 4 brown algaes were rich in inorganic elements such as Na， K， Ca， Fe and Zn， and the content of heavy metal elements was within the limit range except for Pb content in Ascophyllum nodosum. In conclusion， the 4 brown algaes had high nutritional value and great potential in the development of seaweed chemical industry and nutritional health food.

In order to study the extraction process of polysaccharides from Perilla leaves and its antioxidant activity in vitro by ultrasonic-assisted hot water reflux method， the effects of different solid-liquid ratio， extraction temperature and extraction time on the yield of polysaccharides from Perilla leaves were detected. Response surface method was used to optimize the extraction process of polysaccharide from Perilla leaves， and the scavenging ability of polysaccharides from Perilla leaves to 3 different kinds of free radicals was determined to evaluate its antioxidant activity in vitro. The results showed that the optimal process were as follows： solid-liquid ratio 1 g∶36 mL， extraction temperature 77 ℃， extraction time 4 h， under these conditions， the yield of polysaccharides from Perilla leaves was 9.76%. The scavenging rates of Perilla leaves polysaccharides to 1，1-diphenyl-2-picrylhydrazy free radical （DPPH·）， 2，2’-azinobis-3-ethylbenzthiazoline-6-sulphonate，^{free radical（ABTS+·） and hydroxyl free radical（?OH） were 93.04%， 88.31% and 72.30%， respectively，and the semi-inhibitory concentration of DPPH·， ABTS+· and ?OH were 0.800， 0.945 and 0.665 mg·mL-1， respectively，indicating that Perilla leaves polysaccharides had good free radical scavenging ability. Under the optimal condition， the yield of Perilla leaves polysaccharides was 9.76%， which was basically consistent with the predicted value， and the extraction effect was good， indicating that the method was suitable for extracting polysaccharides from Perilla leaves. Above results provided theoretical basis for further development of Perilla leaves products.}

The north China plain is the cornerstone of our country’s food security. Intensive agricultural production has led to heightened concern over the safety of its cultivated land. To evaluate the safety of cultivated land production and enhance its production potential， 15 indicators were selected from 4 aspects： location， soil， climate and production conditions for assessing the safety of cultivated land production. And the analysis of limiting factors for cultivated land production safety were conducted based on a restrictive index model. The results showed that the overall production status of cultivated land in the north China plain was good， with the comprehensive index of production safety ranging from 0.55 to 0.93. It was classified into 5 levels. Level 1 （0.85~0.93） and Level 2 （0.80~0.85） together occupied 21.79% and 57.14% of the total cultivated land area in the study area， respectively， distributed in the eastern part of the study area. Level 3 （0.75~0.80） covered 10.73% of the cultivated land area in the study area. Level 4 （0.70~0.75） and Level 5 （0.55~0.70） accounted for 4.83% and 5.51%， respectively， distributed in mountainous areas in the west and northwest. The overall degree of comprehensive restriction on cultivated land production safety in the north China plain was mainly moderate （71.22%） and slight （23.19%）. Most regions had factors that could be significantly improved， with large improvement potential. Areas without restrictions （0.12%） and severely restricted areas （5.47%） had very low proportions. The zoning for enhancing cultivated land production potential could be divided into continuously enhancing areas， key enhancement areas， protected enhancement areas and restricted enhancement areas， accounting for 49.42%， 15.39%， 28.65% and 6.54%， respectively. Different stages of management could be carried out for areas with different production potential enhancement， adhere to the principle of balancing cultivated land development and ecological conservation through differentiated rectification measures.

Soil active organic carbon can reflect the dynamic characteristics of soil carbon as an important part of soil carbon pool. In order to reveal the distribution of active organic carbon components in forest soil， broad-leaved forest， coniferous and broad-leaved mixed forest， coniferous forest and shrubwood in Wangyedian forest farm of Inner Mongolia were taken as the research objects，the contents of easily oxidizable organic carbon （EOC）， particulate organic carbon （POC） and dissolved organic carbon （DOC） at different soil depths of different stand types were investigated. The distribution characteristics of soil EOC， POC and DOC and their correlation with terrain factors， stand factors and soil physicochemical properties were analyzed using analysis of variance， correlation analysis， redundancy analysis and grey correlation analysis. The results showed that soil EOC， POC and DOC contents were the largest at 0 to 10 cm soil layer， and decreased as the depth increased. At 0 to 10 cm soil layer， there was no significant difference of EOC content between coniferous and broad-leaved mixed forest and broad-leaved forest. At 10 to 30 and 30 to 50 cm soil layer， EOC content of coniferous and broad-leaved mixed forest was significantly greater than that of the other 3 forest stand types. The highest POC content was found in all soil layers of the broad-leaved forest. The DOC content was similar in broad-leaved forest and coniferous and broad-leaved mixed forest， but higher than that in coniferous forest and shrubwood. As for the 4 stand types， the main physicochemical properties affecting the soil active organic carbon components were pH， total nitrogen and readily available potassium， and altitude and canopy density also had great effects. Therefore， soil active organic carbon content decreased with the increase of soil depth， and different active organic carbon components at varied soil depths showed different responses to stand variation. Soil pH， total nitrogen， readily available potassium， altitude and canopy density were the main factors affecting soil EOC， POC and DOC contents. Above results provided a scientific basis for carbon sink function evaluation in Wangyedian forest farm.

To investigate the effect of pyrolysis temperature on the characteristics and structure of biochar， biochar was prepared by using straw as additive and municipal sludge as raw material at 300 and 700 ℃ according to the mass ratio of 0∶100， 15∶85， 30∶70， respectively. The role and effect of biochar prepared under different conditions analyzed as a soil amendment for iron tailings sand， and the biochar was mixed with iron tailings soil for a rye grass pot experiment. The results showed that the addition of biochar could decrease pH of iron tailings sand and keep pH stable. Compared to biochar prepared at different temperatures， biochar prepared at 300 ℃ significantly reduced soil pH， the soil pH was closer to neutrality. After adding biochar， the soil cation exchange capacity， catalase activity and urease activity were all improved to varying degrees， the sludge biochar prepared with 15% straw addition under high-temperature pyrolysis condition and the sludge biochar prepared with 30% straw addition under low-temperature pyrolysis condition showed good plant growth effect.

To investigate the relationship between photosynthesis and yield of winter wheat in northern Xinjiang and the amount of drip irrigation， and to screen out the suitable drip irrigation amount for high-yield cultivation of drip irrigated winter wheat in northern Xinjiang， Xindong 22 was used as the test material， and 8 drip irrigation treatments were set under the condition of automatic rain-proof dry shelter for 2 consecutive years， including 3 450 （W1）， 3 900 （W2）， 4 350 （W3）， 4 800 （W4）， 5 250 （W5）， 5 700 （W6）， 6 150 （W7）， 6 600 m³·hm^-2 （W8）. The effects of drip irrigation amounts on photosynthetic physiological characteristics， dry matter and distribution， yield and irrigation water use efficiency of winter wheat plants were analyzed. The results showed that， with the increase of drip irrigation amount， the SPAD value， leaf area index， net photosynthetic rate， transpiration rate， stomatal conductance and dry matter accumulation of winter wheat increased firstly and then decreased， reached the maximum in W7 treatment， and the intercellular CO₂ concentration decreased firstly and then increased， and was the lowest in W7 treatment with 244.09 （2023） and 294.82 μmol·mol^-1 （2024）， respectively. The drip irrigation amount and yield of winter wheat showed a parabolic relationship with the opening downward， and the simulation equation was y=-0.000 3x²+3.935 7x-4 468.8 （2023）， y=-0.000 3x²+3.799 5x-6 921 （2024）， and the production were the highest with 6 150 m³·hm^-2 drip irrigation amount. The average yield in 2 years was 7 201.04 kg·hm^-2， which increased by 40.67%， 37.17%， 28.67%， 25.33%， 7.88%， 14.89%， 17.15% compared with W1， W2， W3， W4， W5， W6， W8 treatments， respectively. Considering comprehensively， the drip irrigation amount of 6 150 m³·hm^-2 could maximize the yield of winter wheat in northern Xinjiang， and achieved the unity of high yield and water saving.

In order to understand the microclimate variation of the poplar agroforestry， and provide important basis for the rational selection and cultivation of understory crops，the 3-year-old poplar （Populus deltoides ‘Nanlin 3804’） plantation with the spacing of 6 m × 6 m， and the understory radish （Raphanus sativus） in Baimahu farm， Huai’an City， Jiangsu province， China were selected as the study materials in the agroforestry system. The dynamic changes of light intensity， air relative humidity， soil temperature and other indexes at different sites of the agroforestry system were investigated. The results showed that the light intensity inside the poplar plantation was about 71.0% lower than that outside the plantation； the average daytime light intensity in the plantation was about 6 500 lx in September， which was difficult to satisfy the light saturation point of the sunny plants， but it could satisfy the light saturation point of the shade plants. The daily variation of light intensity， air temperature， air relative humidity and surface temperature in the plantation changed considerably， while the daily variation of soil temperature and soil humidity at 5 cm depth was relatively small. There were insignificant differences in microclimate between different sites （0， 2， 3 and 4 m away from poplar） in the plantation， which indicated that the microclimate in the study poplar plantation had tended to be homogenized in the horizontal layer. The correlation among light intensity， air temperature， air relative humidity， and surface temperature in the plantation was relatively strong， while the correlation among soil temperature and humidity at 5 cm soil depth， and other microclimate indexes was relatively weak. It was considered that in the leafy stage of poplar， the light intensity in the plantation was weak， which was difficult to satisfy the requirements of sunny plants， but it could satisfy the requirements of shade plants. Therefore， shade-tolerant plants must be selected as understory crops； thinning and pruning were necessary for improving the light intensity in the agroforestry system. Above results provided a theoretical basis for further understanding the microclimate characteristics of agroforestry ecosystems and guiding the sustainable development of agroforestry.

The long-term use of conventional plastic mulch has led to increasing “white pollution” in agricultural fields. Biodegradable water-permeable mulch has environmental friendliness with water infiltration and aeration properties. However， its yield-enhancing mechanisms and varietal compatibility in early-maturing regions remain unclear. In response to the national strategy promoting eco-friendly mulching across 9 provinces in northwestern of China， a field experiment was conducted to evaluate the effects of 4 treatments， including no mulch （CK）， transparent biodegradable mulch （T1）， black biodegradable mulch （T2） and conventional plastic mulch （T3）. And the growth and yield of the early-maturing potato cultivar Wotu 5 under different treatments were analyzed. The results showed that， compared to CK，T1 treatment significantly increased yield by 14.9%， T2 treatment increased only 0.8%， while T3 reduced yield by 6.5%. Further analysis revealed that T1 treatment had significantly higher number of tubers and effective branches per plant than other treatmens. In summary， the transparent biodegradable mulch improved individual plant productivity through a dual mechanism of ‘cooling by infiltration and root promotion via aeration’. Above results established compatibility database between biodegradable mulch and potato， which provided reference for film selection in northwestern of China.

To investigate the effect of exogenous phosphorus fertilizer on the quality of ginseng in continuous cropping soil， the soil of the continuous cropping ginseng land was as the experimental material， and 4 phosphorus application treatments were set including 0.00 （CK）， 0.44 （P1）， 0.62 （P2）， 0.80 g·kg^-1 （P3）. The saponins content of cultivated ginseng and the physicochemical properties， soil enzyme activities in rhizosphere soil of different treatments were determined. The correlation analysis and principal component analysis were combined to clarify the patterns of changes in cultivated ginseng ginsenosides and soil properties with the growth period. The results showed that the fresh and dry weights of ginseng increased with the increase of phosphate fertilizer application amount， and P1 and P2 treatments had a positive effect on the contents of soil alkaline nitrogen， available potassium and organic matter. The accumulation of ginsenosides and total saponins was positively regulated by low level of exogenous phosphorus. Soil conductivity， available potassium and soil protease had a positive regulatory effect on ginsenoside accumulation. The principal component analysis extracted 2 principal components， which the cumulative contribution rate reached 94.726%. The comprehensive analysis indicated the cultivated ginseng of P1 treatment （0.44 g·kg^-1） showed better growth， accumulated more ginsenoside effective components， and the soil environment was more suitable for ginseng growth. Above results provided scientific basis for the rational application of phosphorus fertilizer to the soil improved old ginseng land.