Journal of Shenyang Agricultural University

Investigation of Response Thresholds of Cucumber Characteristics to Mixed Phenolic Acids During Different Growth Stages under Protected Cultivation Conditions

[Objective]This study aims to investigate the allelopathic effects and threshold characteristics of phenolic acids on facilitygrown cucumber at different growth stages by applying mixed phenolic acid substances exogenously, and to clarify the allelopathic response threshold and dynamic changes of mixed phenolic acids throughout the entire growth period of cucumber, providing a theoretical basis for agricultural production. [Methods]The experiment involved exogenously applying different concentrations of soil phenolic acid extraction solutions and mixed phenolic acid solutions, measuring cucumber plant height, stem diameter, whole plant biomass, and yield,and analyzing the concentration thresholds that inhibit cucumber growth across its entire growth period using the allelopathic effect sensitivity index(RI). [Results]Mixed phenolic acid solutions in the concentration range of 24-60, 60-121, and 121-243 mg·kg-1significantly inhibited cucumber growth during the seedling, early flowering, and fruit setting stages, exhibiting a clear low-promotion high-suppression phenomenon. The allelopathic effects of phenolic acids mainly manifested as inhibition of cucumber dry matter accumulation and yield, especially during the fruit setting period, where concentrations above a certain threshold led to almost complete crop failure. Additionally, three-dimensional response surface analysis revealed that the allelopathic effects of phenolic acids are influenced by both concentration and growth stage, with the interaction between the two likely dominating the inhibitory effect as the growth stage advances. [Conclusion]This study provides an important theoretical basis for controlling the allelopathic effects of phenolic acids on facility-grown cucumber and helps optimize cultivation management, thereby improving production efficiency.

The Effect of Root Interaction Intensity on Potassium Activation and Uptake in Maize/Peanut Intercropping Systems

[Objective]To investigate the effect of root interactions on soil potassium(K) accumulation and uptake in maize/peanut intercropping, and to provide a theoretical basis for intercropping to improve soil nutrient uptake and utilization.[Methods]A root-box experiment was conducted to examine the impact of varying root interaction intensities(non-partition, partial partition, and complete partition) and K application levels(no K and normal K) on plant growth and rhizosphere soil properties, including pH, organic matter content, and K fractions in a maize/peanut intercropping system. [Results]The aim was to elucidate how intercropping promotes K activation and uptake. Results indicated that normal K application significantly increased total K(by 8.28%–15.85%) and organic matter content(by 22.35%–55.78%) in the rhizosphere, enhancing plant growth, with the effect more pronounced in maize. Compared to complete partition, non-partition treatments exhibited stronger interaction effects in maize. Under no-K conditions, non-partition roots significantly enhanced the activation of non-exchangeable K and organic matter deposition in the rhizosphere, resulting in a34.61% increase in maize K accumulation compared to complete partition and improving system productivity. Partial partition enhanced peanut's interaction effect, leading to a significant increase in available K and organic matter content in the rhizosphere by20.24% and 11.10%, respectively, thus boosting peanut yield.[Conclusion]Maize/peanut intercropping promotes K acquisition, crop K accumulation, and yield through root interactions.

Effects of Reduced Nitrogen Application on Root Morphology, Yield and Quality of Peanut under Alternative Sowing on Small Ridge with Narrow Two-rows

[Objective]Since nitrogen fertilizer was applied excessively leading to low nitrogen fertilizer utilization and decreased yield and quality of peanut production in Liaoning Province, this study explored the effects of reduced nitrogen application on root morphology, yield and quality of peanut under alternative sowing on small ridge with narrow two-rows, so as to determine optimal nitrogen fertilizer reduction rate and provide theoretical reference for local peanut production.[Methods]This study was conducted in Shenyang Agricultural University from 2019 to 2020. Five nitrogen fertilizer levels were set, T0(without nitrogen fertilizer), T1(N82.5kg·hm^-2, conventional nitrogen application), T2(N70 kg·hm^-2, reduced by 15%), T3(N62 kg·hm^-2, reduced by 25%), T4(N54 kg·hm^-2, reduced by 35%) were used to study the effects of nitrogen fertilizer reduction on root morphology, nodule characteristics, yield and quality of peanut by adopting random block design with Qinghua 6. [Results]Appropriate nitrogen fertilizer reduction had effectively promoted optimization of peanut root morphology of alternative sowing on small ridge with narrow two-rows, and T2significantly increased root length, root surface area and average root diameter of peanut, and maintained high root vitality during the growth period. Ultramicroscopic root nodules structure of peanut showed that the reduction of nitrogen fertilizer promoted thalloids growth and liposomes production. Compared with T0, fertilizer application increased peanut pod yield by 3.76%-9.74%. However,nitrogen fertilizer reduction affected yield at different levels. The highest yield was obtained under T2 treatment, with an average increase of 2.17% compared with T1 in two years, while with the average decrease of 0.58% in T3 compared with T1. The effect of nitrogen fertilizer reduction on the quality of peanut seeds was not significant.[Conclusion]Reducing N application by 15%(T2) is suitable to root development and yield improvement, which is the befiting nitrogen fertilizer reduction mode.

Functional Study of the Rice Sheath Blight Resistance Related Gene OsDUF

[Objective]Rice sheath blight is one of the major diseases in rice. Due to the wide host range of Rhizoctonia solani and the lack of resistant rice resources, it causes serious losses of rice production. Previous study, we investigated the roles of rice sheath blight-responsive hormones and the candidate resistance gene OsDUF, providing the theoretical basis for the prevention and controlling rice sheath blight. [Methods]The susceptible variety Yanfeng 47 and the resistant rice variety Gangyuan 8 were selected for inoculation with the rice sheath blight fungus to identify the disease resistant candidate gene OsDUF, bioinformatics analysis and subcellular localization of OsDUF were conducted. Resistance of CRISPR-Cas9-generated OsDUF mutants were compared to wildtype plants. Yeast two-hybrid assays were performed using OsDUF as bait protein, and changes in the expression levels of OsDUF genes were detected under exogenous hormonal treatments, furthermore changes in the expression levels of defence genes and hormone-related genes were detected under treatment with R. solani. [Results]Phylogenetic characterization revealed that OsDUF,encoding a cytoplasm-localized protein possessing the DUF1645 domain characteristic of stress-responsive proteins, exhibits closest evolutionary relationship to japonica rice accessions(Oryza sativa subsp. japonica). Bioinformatics interrogation further identified ten putative rice interactors through domain architecture analysis, though subsequent experimental validation remains required.Identification of resistance in isolated leaves showed that the mutant was more susceptible to the disease than the wild type, indicating that OsDUF positively regulates rice sheath blight resistance, and one-to-one interaction validation did not reveal that OsDUF interacted with the predicted candidate proteins. Under exogenous hormone treatments, the genes OsDUF were up-regulated by indoleacetic acid, ethylene, and jasmonic acid, and down-regulated by gibberellin, abscisic acid, and salicylic acid. After inoculation with R. solani, the expression levels of defence related genes(OsAOS1, OsPAL1) and hormone-related genes(OsERF063, LOX2) were significantly higher in the wild type than in the mutant. [Conclusion]The results suggest that OsDUF may be involved in the resistance of rice to R. solani through the way of modulation of defence genes and hormone signaling pathways.

Effect and Optimization of Amino Acid Fertilizer as a Nitrogen Substitute in Greenhouse Tomato

[Objective]To address the challenges of soil nitrogen accumulation, yield reduction, and quality decline caused by excessive nitrogen fertilizer application in greenhouse tomato cultivation, the effects of substituting chemical nitrogen fertilizer with amino acid fertilizer and the optimization of application strategy were studied. [Methods]The effects of substituting chemical nitrogen fertilizer with amino acid fertilizer at varying ratios on soil nitrogen dynamics, tomato yield, fruit quality, and nitrogen use efficiency through greenhouse tomato pot experiments were investigated. The maximum substitution potential and optimal replacement ratio were determined by comprehensively analyzing the yield and nitrogen use efficiency. [Results]The results showed that under equivalent nitrogen conditions, the treatment with 40% amino acid fertilizer substituting for nitrogen fertilizer(M4N6PK) increased the soil ammonium nitrogen and nitrate nitrogen content, total plant nitrogen uptake, agronomic nitrogen efficiency, and nitrogen fertilizer use efficiency by 39.18%, 11.39%, 68.37%, 162.76%, and 89.27%, respectively, compared to the control(NPK); the yield of tomatoes was the highest, with an increase of 40.61% compared to the control, while significantly reducing the content of nitrate(26.14%) and nitrite(49.76%) in fruit, and enhancing the content of soluble sugar, organic acids, soluble protein, and vitamin C in fruit. Compared with the control(NPK), the treatment with 80% and 100% of amino acid fertilizer replacing nitrogen fertilizer(M8N2PK and M10N0PK) significantly reduced soil nitrate content, tomato yield, nitrate content in fruit and nitrogen use efficiency, while significantly increased the content of soluble sugar and vitamin C in fruit. Through model optimization, the maximum potential for amino acid fertilizer substitution was 66.20%, with the optimal substitution ratio being 35.25%, which could achieve a 42.86%increase in tomato yield and a 91.36% increase in nitrogen fertilizer use efficiency. [Conclusion]In greenhouse tomato cultivation,amino acid fertilizer replacing nitrogen fertilizer can significantly increase crop yield, quality and nitrogen use efficiency This study provides a theoretical basis for the technology of reducing chemical fertilizers and increasing the efficiency in protected tomato cultivation in cold regions.

Effects of Biochar Incorporation on Rice Yield and Nitrogen Fertilizer Use Efficiency in China

[Objective] This study aims to elucidate the efficacy, key determinants, and regulatory mechanisms of biochar application in Chinese rice production systems. [Method] Through a comprehensive literature analysis, we evaluated biochar's impact on rice yield and nitrogen use efficiency(NUE) in China. Quantitative assessments identified the relative contributions of soil properties,biochar characteristics, and agronomic practices to the observed effects. [Result] The results indicate that biochar incorporation increased rice yields by an average of 9.70% and enhanced NUE by 12.00% nationwide. Key biochar properties—raw material, C/N ratio, pH, and pyrolysis temperature—significantly influenced performance, with crop residue-and husk-derived biochar demonstrating superior efficacy. Biochar was most effective in alkaline(pH>7.5) and acidic(pH<6.5) soils with fine to medium textures. A positive dose-response relationship existed, with notable yield improvements at application rates exceeding 10 t·hm~(-2),however the efficacy declined over time. Meanwhile, the agronomic practices, particularly alternate wetting and drying irrigation and high nitrogen fertilization(>250 kg·hm~(-2)), optimized biochar performance. Regional analysis highlighted greater benefits in southern rice-growing areas. Machine learning revealed a hierarchical influence pattern, with soil properties exerting the greatest impact,followed by biochar characteristics and agronomic practices. [Conclusion] Strategic biochar implementation offers a viable pathway to enhance productivity and resource efficiency in Chinese rice systems. Optimizing biochar selection, application dose, and management practices based on site-specific soil conditions can simultaneously boost yields and NUE, thereby advancing low-carbon,environmentally sustainable rice production in China.

Regional Differences and Spatial-temporal Evolution of Financial Services for Comprehensive Rural Revitalization

[Objective]Exploring regional differences and spatial-temporal evolution of financial services for comprehensive rural revitalization can provide support for optimizing financial support and improving agricultural work in the new era. [Methods]Utilizing panel data from 30 provinces in China from 2013 to 2021, the study employs the entropy weight TOPSIS method to construct a fivedimensional evaluation index system for financial services in rural revitalization. The Dagum Gini coefficient and Kernel density estimation are used to analyze regional, temporal characteristics, and evolutionary trends nationwide and across four major regions.Additionally, the Moran index and Markov model are applied to examine the trends in the evolution. [Results]The levels of all dimensions rise, with a distribution pattern of East > Central > West > Northeast, and the improvement speed of Central > Northeast >West > East. Nationwide, total disparities have expanded, revealing unevenness, with inter-group differences being a key contributor to the overall disparity. The absolute disparities in development levels among provinces are increasing in the national, eastern, and central regions; the absolute disparity in the western region remains relatively stable, while the northeastern region shows a decrease.Polarization has also been observed in varying degrees across all four major regions. Additionally, the probability of upward mobility regarding financial services for rural revitalization exceeds the probability of downward mobility. [Conclusion] The level of financial services for comprehensive rural revitalization is on an upward trend, exhibiting significant spatial agglomeration and spillover effects.In the future, it is essential to control inter-regional differences, promote balanced development and strengthen cooperation to provide strong financial support for comprehensive rural revitalization.

Optimization of Negative Pressure in MoldHole of Axial Flow Air Suction Seed Metering Drum Based on RSM and CFD

[Objective]To address the issue of poor seed suction caused by low suction negative pressure in axial-flow air-suction seed meters, this study optimizes the structural parameters of key components to increase negative pressure stability and suction efficiency,thereby improving seeding accuracy and operational performance for precision agriculture applications. [Methods]Based on the combination of RSM(Response Surface Method)and CFD(Computational Fluid Dynamics), BBD(Box-Behnken Design) simulation experiment was carried out to optimize the key structural parameters of axial-flow air-suction drum-type seed metering device. The pressure value at the entrance of the mold hole of the test model was numerically calculated using FLUENT software. The obtained data set was imported into Design expert13 software and predicted and optimized by response surface method. The reliability of the prediction results of RSM was verified by numerical simulation test and bench test. Taking tomato seeds as the experimental object,the seed suction performance of seed metering device was tested.[Results]The combination of optimal parameters for the key structure of the axial-flow air-suction drum-type seed metering device obtained is: hole draft angle of of 12.59 °, fan blades thickness of 2.26mm, and fan blades number of 9. Then the objective function predicts that the negative pressure at the inlet of the orifice was 64.61Pa. The suction seed singling rate of tomato seeds was 75% when the fan rotation speed was 1 500 r · min~(-1). According to the structural parameter combination optimized by RSM, a three-dimensional model was established for CFD numerical simulation, and the simulation result was 64.08 Pa, so the error between the prediction result of response surface method and CFD numerical simulation was 0.82%. The negative pressure at the entrance of the original model was 45.85 Pa, and the negative pressure of the optimized model was increased by 39.76% compared with the original model, and the optimization effect is remarkable. The negative pressure bench test of the mold hole showed that the negative pressure at the inlet of the mold hole was 62 Pa when the rotating speed of the fan blade was 1500 r·min~(-1), and the error between the bench test and the numerical simulation test was 3.35%. [Conclusion]The bench test of seed suction performance showed that the suction seed singling rate of tomato seeds was 75.22% when the fan speed was 1 500 r·min~(-1), which was 15.72% higher than that before optimization. Considering the inevitable errors caused by simplified structure and 3D printing, it was considered that the results meet the requirements and the optimized experimental design is reliable.

Design and Experiment of Trenching and Soil Covering Shovel for Straw Deep Returner

[Objective]In order to solve the problems of the complex structure of the trenching and soil covering parts, the inability to carry out automatic soil covering after ditching, and the high power consumption of the existing straw deep burial returning machine,an trenching and automatic soil covering shovel designed. [Methods]Through theoretical analysis, the main structural parameters of the straw deep burial returning machine were determined. Taking the penetrating angle of the shovel tip, the width of the shovel body and the forward speed as the key test factors, the simulation analysis was carried out based on discrete element software, to explore the influence of the 3 test factors on tillage resistance and soil covering rate. The effects of the interaction terms of each factor on the tillage resistance and automatic soil covering rate of the trenching and soil covering unit were analyzed using multi-factor experiments.Through experimental analysis, the optimal range of the three factors and the optimal combination of the three factors for minimum tillage resistance and maximum soil covering rate are obtained. [Results]The simulation results show that the optimal parameters of the trenching shovel are as follows: the penetrating angle of the shovel tip is 24 °, the shovel width is 420 mm, the forward speed is 1.48 m·s~(-1),then the tillage resistance is 2 875 N, and the automatic soil covering rate is 87.76%. [Conclusion]According to the optimal combination of parameters of the simulation results, the design and field performance test of the trenching and soil covering shovel of the straw deep burial returning machine were carried out. Finally, it is concluded that the stability of the trenching depth of the trenching shovel is 98.84%, the consistency of ditching width was 96.35%, the automatic soil covering rate was 86.47%, and the tillage resistance was 2 856 N. The simulation test results and field test results meet the design requirements.

Screening of Soybean Germplasm for Source-sink Relationship at Bulging Stage and Identification Indexes of Grain Wrinkles

[Objective]The bulging stage is a critical period for grain formation and filling in soybean germplasm. The co-ordination of source-sink relationships directly affects the rate and fullness of seed filling. The study of the relationship between source-sink relationship and grain wrinkling at the bulging stage of soybean germplasm can help to reveal the physiological mechanism of wrinkling grain formation, so as to in provide breeders with more precise breeding goals and strategies. [Methods]355 soybean germplasm resources from different sources were used as test materials, and indicators such as source-sink relationship at grain filling stage and seed wrinkling at maturity were determined. [Results]355 soybean germplasm could be classified into five wrinkling grades,namely grade 0(9), grade 3(321), grade 5(3), grade 7(21) and grade 9(1), and the higher the grade, the more serious the wrinkling of the seeds. Correlation analyses of seed wrinkling and source-sink relationships revealed negative correlations between leaf net photosynthetic rate, nutrient organ dry weight, leaf-to-pod ratio and seed starch content and wrinkling grade; Leaf area index and reproductive organ dry weight were positively correlated with wrinkling grade. [Conclusion]Fourteen source-sink relationship traits of soybean germplasm were combined into four principal component factors with a cumulative contribution of 78.836%; Multiple linear regression analyses showed that major source-sink relationship traits such as net photosynthetic rate of leaves, leaf area index, dry weight of nutrient organs, dry weight of reproductive organs, and starch content of grains were the main factors affecting the grade of seed wrinkling.

Soil-sickness Problem in the sustainable Development for the Protected Production of Vegetables

As the development of specialized production of vegetable crops, soil sickness has been a problem for the sustainable production of vegetable crops. Soil sickness is mainly caused by soil--borne pests, disorder of soil physical and chemical properties, and autotoxicity. The present paper discussed possible role of cropping system, biological control and grafting in the soil--borne pest control, role of organic fertilizer, desalting and reasonable fertilization in soil restoration, and the alleviation of autotoxicity by grafting, adsorption with charcoal and degradation by microbes.

Current Situation and Prospects of Green House Industry Development in China

This paper summarized comprehensively the history, current development of the green house industry and its researches. The historic significance, problems, and prospects were also analyzed. The summary was expected to provide references for determining the historic position and future developmental direction of green house industry.

Effect of Lodging Resistance on Yield and Its Relationship with Stalk Physical Characteristics

Stalk physical characteristics and tilt angle of matured plant of eighteen populations from six cultivars wereinvestigated under three conditions. The relationships between lodging resistance and yielding were also studied. TheresultS indicated that: the intensity of lodging of rice population could be grouped into three categories-lodging, slantand erect types according to the tilt angle of matured plant. Lodging resistance is significantly negatively correlatedwith the length of the first internode, and significantly positively correlated with the area of the basal stalk and withthe thickness of the hasal stalk. Difference among varieties and lodging resiStance was also found. Nitrogenapplication also had an obvious effect upon population lodging of rice. But if only yielding was considered, the highyield populations were given usually in the medium fertilization treatment. Therefore, rice resistance to the lodgingcould be improved by means of shortening length between the first and the second internode, strongtheningthe hardnes of the basal stalk, lowering the position of panicle, and elonging panicle or the neck-panicle internode.So the contradiction between lodging resiStance and plant height could be settled at a level of higher yielding.

Comparison of A New Model of Light Response of Photosynthesis with Traditional Models

Photosynthetic rates increase gradually with light intensity in the traditional models of light response curve of photosynthesis,i.e.rectangular hyperbolic model and nonrectangular hyperbolic model.So the maximum net photosynthetic rates calculated by nonrectangular hyperbolic model and rectangular hyperbolic model were far more than the measured data,and the saturation light point was not obtained.A new model of light-response of leaf net photosynthesis was proposed in this paper.Some properties of the new model of light-response of leaf net photosynthesis were discussed in detail.Results showed that the data of light-response of leaf photosynthesis of winter wheat under different environmental conditions were modeled by three models.The results fitted by nonrectangular hyperbolic model,rectangular hyperbolic model and the new model were compared.In addition,the measured data of light response of photosynthesis under different temperatures and CO2 concentrations could be dealt with,and the main parameters of photosynthesis,i.e.the maximum photosynthetic rates,saturation light point,light compensation point and the rate of dark expiration could be calculated without any hypotheses.The response data of leaf photosynthetic rate to irradiance under low irradiance and photo inhibition could be fitted by the new model.The measured data of light response of photosynthesis under different temperatures,CO2 concentrations and light intensity,including at low photon fluxes and photo inhibition could be dealt with.The fitted results were tallied with very well the measured data.So the new model has generality.

Current Situation of Remediating Techniques of Petroleum Contaminated Soil and Its Prospects

Current situations and damage of petroleum contaminated soils were summarized. Several main methods and techniques of remediating petroleum contaminated soil, application as well as advantages and disadvantages of the techniques were introduced in the paper. It points that traditional methods and techniques should combined with the bioremediation in the process cleaning the pollution, which will play the advantages of respective techniques. In the same time, the economic benefit, social benefit and environmental benefit should be considered together in treating petroleum contaminated soils.

A COMPARISON OF METHODS OF MEASUREMENT OF CHLOROPHYL IN PLANTS

Current Situation and Prospects of Green House Industry Development in China

This paper summarized comprehensively the history, current development of the green house industry and its researches. The historic significance, problems, and prospects were also analyzed. The summary was expected to provide references for determining the historic position and future developmental direction of green house industry.

Status and Developing Prospects of Biopesticide Research and Application

Biopesticides have many advantages over the traditional chemical pesticides,being safe to human,livestock and nontarget organisms,having wonderful environmental compatibility,stable controlling effects and benefit to protect the biodiversity,and having many resources etc.Status of research and application of biopesticides were reviewed in this paper.The authors pointed out the major problems in the research and application of biopesticides.The developing prospects of biopesticides were discussed and some advices were given for biopesticide development in future.

Determination of Blueberry Anthocyanins through pH Differential Method

For determinieg the contents of blueberry anthocyanins more exactly,the blueberry pigments were extracted by acidic alcohol and were identified anthocyanins by UV-VIS spectra and chemical methods.The blueberry anthocyanins were quantitatively analyzed through pH differential method.The results indicated that the content of blueberry anthocyanins was 313.24mg.100g-1 and the relative standard deviation was 1.39%.The influence on measuring results by impurity in the solution was eliminated by pH differential method.

Current Situation of Remediating Techniques of Petroleum Contaminated Soil and Its Prospects

Current situations and damage of petroleum contaminated soils were summarized. Several main methods and techniques of remediating petroleum contaminated soil, application as well as advantages and disadvantages of the techniques were introduced in the paper. It points that traditional methods and techniques should combined with the bioremediation in the process cleaning the pollution, which will play the advantages of respective techniques. In the same time, the economic benefit, social benefit and environmental benefit should be considered together in treating petroleum contaminated soils.