Journal of Shenyang Agricultural University

The Effect of Different Irrigation Methods on the Stability of Soil Aggregates and Organic Carbon Content in Greenhouse Soil

[Objective]Irrigation is the primary way to obtain water for greenhouse crops. Different irrigation methods affect the formation and stability of aggregates. In addition, the formation of aggregates is not only affected by environmental factors, but also by the types and forms of cementing materials. This study aims to explore the effects of different irrigation methods on the stability of soil aggregates and organic carbon in facilities, and provide theoretical basis for water regulation in facilities agriculture and improvement of soil structure in facilities. [Methods]The soil cultivated under different irrigation methods(drip irrigation, infiltration irrigation and trench irrigation) for 12 consecutive years was used as the research object, and the test crop was tomato(Huafang 5). The stability of aggregates and the content and distribution characteristics of organic carbon in 0-40 cm soil were analyzed. [Results]Through the analysis of the composition and stability of aggregates by wet screening method, it was found that drip irrigation significantly increased the content of large aggregates in 20-40 cm soil layer, increased the average weight diameter and geometric average diameter, and reduced the average weight specific surface area and fractal dimension. Drip irrigation significantly increased the organic carbon content of large aggregates in 20-40 cm soil layer. The contents of granular organic carbon, mineral-bound organic carbon and easily oxidized organic carbon in macroaggregates were also increased. The redundancy analysis on aggregate related organic carbon is82.09%, among which large aggregate organic carbon and microaggregate mineral bonded organic carbon are the main contributions to aggregate stability index. [Conclusion]Under long-term facility cultivation conditions, drip irrigation is more conducive to improving soil aggregate stability and organic carbon content.

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,quantitatively assessed the relative contributions of soil properties,biochar characteristics,and agronomic practices to the observed effects.[Results]The results indicate that biochar incorporation increased rice yields by an average of 9.70% and enhanced NUE by 12.00% in China.The material,C/N ratio,p H,and pyrolysis temperature are key factors affecting its performance,with straw and husk-derived biochar demonstrating the most significant efficacy.Biochar is most effective in alkaline (p H>7.5) and acidic (p H<6.5) soils with fine to medium textures.The dose and time effects were significant after returning biochar to the field.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 can also affect the effect of biochar.It is most significant under alternating wet and dry conditions and high nitrogen fertilization rate (>250 kg·hm^-2).Regional analysis highlighted greater benefits in southern rice-growing areas.Machine learning revealed that the significance of the factors on biochar efficacy is soil properties>biochar characteristics>agronomic practices.[Conclusion]The application of biochar in rice production in China can effectively increase rice yield and nitrogen fertilizer use efficiency.The rice yield and NUE can be increased by scientifically coordinating the material and application dose of biochar,the management practices and soil properties can simultaneously increase yields and NUE,to provide theoretical and technological support for promoting low-carbon,green and environmentally sustainable rice production in China.

Effect of Brassinolide Spraying on Soybean Yield under Straw Returning Conditions

[Objective]Soybean is an important food and oil crop, and its demand is constantly increasing both domestically and internationally. As an environmentally friendly agricultural technology, straw returning is widely used in soybean planting in China.Brassinolide(BR) is a non-toxic plant growth regulator, which is of great significance for regulating crop growth. Therefore,experiments were carried out to study the effects of different concentrations of brassinolide on dry matter accumulation, yield and yield components of soybean at the initial flowering stage under the condition of straw returning, and to find the best application concentration. [Methods]Two soybean varieties of Heinong 84 and Kenfeng 16 with sub-limited podding habits were selected as experimental materials, and water was sprayed as the control group. Five concentrations(5, 6.67, 10, 20, 40 mg·L^-1) of brassinolide were sprayed at the initial flowering stage of soybean. The dry matter accumulation of leaves, stems and petioles was measured at three stages of R2, R3 and R6. The plant height, bottom pod height, main stem node number, effective pod number, ineffective pod number,100-grain weight and yield were measured after harvest.[Results]After spraying 10 mg·L^-1 brassinolide, the bottom pod height of Heinong 84 reached the lowest value of 15.76 cm, and that of Kenfeng 16 reached the lowest value of 16.03 cm. The effect of brassinolide on both varieties are significant. The number of invalid pods of Heinong 84 reached the minimum but the difference was not significant. The number of effective pods, total pods, theoretical 100-grain weight, actual 100-grain weight, theoretical yield,actual yield and kernel weight per plant reached the highest value and the difference was significant, increasing by 11.31%, 43.66%,11.88%, 13.58%, 12.38%, 15.95% and 14.27%, respectively. The plant height, theoretical 100-grain weight, actual 100-grain weight,theoretical yield, actual yield and kernel weight per plant of Kenfeng 16 reached the maximum, which increased by 11.41%, 8.68%,8.84%, 13.67%, 12.48% and 15.77%, respectively. The dry matter accumulation of each part of the two varieties of soybean reached the highest value under 10 mg · L^-1 brassinolide treatment. [Conclusion]The application of brassinolide can reduce the height of soybean bottom pods, increase soybean plant height, effective pods, total pods, dry matter accumulation in various parts above the ground, 100-grain weight and yield, and 10 mg·L^-1 is the best application concentration of brassinolide.

Comparative Study on Production Performance and Nutritional Value of 21Alfalfa Varieties

[Objective]This study aims to evaluate the production performance and nutritional value of 21 alfalfa (Medicago sativa)cultivars in the Aohan Region of Chifeng,Inner Mongolia,to identify high-yield and high-quality cultivars suitable for local cultivation,to provide a scientific basis for the development of the regional forage industry.[Methods]A three-year field trial was conducted to assess the production performance indicators of 21 alfalfa cultivars,including overwintering survival rate,plant height,fresh forage yield,hay yield,and fresh-to-dry ratio.The nutritional indicators such as crude protein content,crude protein yield,crude fat content,ash content,acid detergent fiber content,neutral detergent fiber content,and relative feed value were also measured and compared.The comprehensive performance of different cultivars was analyzed,and classification was conducted accordingly.[Results]In terms of production performance,Longmu 803 exhibited the highest average annual overwintering survival rate (98.83%),while WL440 had the lowest (74.00%).WL363HQ had the tallest average annual plant height (189.99 cm),whereas WL319HQ was the shortest (163.43 cm).4020MF produced the highest average annual fresh forage yield (52.17 t·hm^-2),while AC Caribou had the lowest(34.14 t·hm^-2).Xinmu No.4 and 4020MF had the highest average annual hay yield (14.34 t·hm^-2 and 14.32 t·hm^-2,respectively),while AC Caribou had the lowest (9.96 t·hm^-2).WL326 exhibited the highest fresh-to-dry ratio (3.57),whereas WL354HQ had the lowest(3.22).Regarding nutritional value,Longmu 803 had the highest crude protein content (23.03%),while WL363HQ had the lowest(20.78%).Xinmu No.4 had the highest crude protein yield (3.27 t·hm^-2),while AC Caribou had the lowest (2.25 t·hm^-2).Longmu 806,WL326,and MagnumⅡexhibited the highest crude fat content (1.72%),whereas WL440 had the lowest (1.55%).WL298 had the highest ash content (10.59%),while Gongnong No.1 (9.59%) and AC Caribou (9.54%) had the lowest.The annual variations significantly affected multiple traits,and the performance trends of different cultivars varied across years.Based on an analysis of 12phenotypic traits,the 21 cultivars were classified into three categories:high-yield and high-quality,medium-yield and low-quality,and low-yield and medium-quality varieties.[Conclusion]Considering both production performance and nutritional value,Xinmu No.4and 4020MF demonstrated the best overall performance,exhibiting both high yield and high quality.These cultivars are recommended for promotion in the Aohan Region to enhance local forage production efficiency and feed supply capacity.

Study on the Spatial-temporal Differentiation and Driving Mechanism of Non-grain Cultivation in the Black Soil Region of Northeast China

[Objective]Examination of the spatial and temporal distinguishing features along with the influential elements affecting the non-grain conversion of arable land in the Northeast black soil area, with the aim of providing a basis for the rational utilization of cultivated land and the guarantee of food security in the Northeast black soil region. [Method]Based on the data of cultivated land sown area from 2010 to 2020 and the driving force data of policies, economy, society and technology, by the non-grainization rate of cultivated land, spatial autocorrelation analysis, quantification of policy documents, and geographically weighted regression model. The characteristics of spatial-temporal differentiation and the driving factors behind the non-grain of cultivated land in the Northeast black soil region were investigated. [Results]From the perspective of temporal evolution, the non-grain rate of cultivated land in the northeast black soil region has decreased significantly overall from 2010 to 2020, which can be mainly divided into the fluctuating decline stage from 2010 to 2016, the rapid decline stage from 2016 to 2018, and the slight rebound stage from 2018 to 2020. From the perspective of spatial characteristics, non-food cropland in the north-eastern black soil region shows obvious spatial variability,and the overall layout is characterised by 'high in the west and low in the east'. The distribution has significant spatial agglomeration characteristics, presenting a high-high agglomeration area in the northern part of Inner Mongolia and a low-low agglomeration area in the central part of Heilongjiang. From the perspective of driving mechanisms, the proportion of the primary industry has the most significant impact, and mainly has a negative effect. Secondly, the two policies of land transfer and grain subsidie have significant effects. The land transfer policy has different effects in different regions, exerting an inhibitory effect in the north and a promoting effect in the south. The grain subsidy policy has an inhibitory effect overall. Based on this, the following suggestions are proposed.[Conclusion]According to the geographically weighted regression(GWR) model, the factors with relatively strong driving forces for the non-grain production of cultivated land in the black soil area of Northeast China are the proportion of the primary industry, land transfer policies, and grain subsidy policies. The impacts of other factors are relatively small. While ensuring that the primary function of arable land is dedicated to grain production, efforts should be strengthened to provide policy support for grain cultivation.Additionally, regional layouts should be adjusted based on the supply and demand of agricultural products and development advantages.

Study on Genetic Rule of Resistance of Tussah Silkworm to Nuclear Polyhedrosis Virus

[Objective]The genetic rule of resistance of tussah to ApNPV was studied to provide theoretical basis for breeding of ApNPV resistant varieties. [Methods]Five tussah silkworm varieties(strains) were used as parents and crossbred according to complete double-cross Griffing II method. The silkworm was fed with ApNPV polyhedrosis venom at a concentration of 2.5×10⁵units·mL^-1 for 24 h, and the genetic effects, heterosis and combining ability of parents and hybrids were calculated using the incidence rate as the measure of resistance of tussah. [Results]The resistance of Tussah silkworm to ApNPV was consistent with "additive-dominant" genetic model, and was controlled by both dominant and additive genes. The dominant effect was dominant, and the additive effect was complementary. The narrow heritability was 11.1%, and the broad heritability was 34.1%, which reached a very significant level. The hybrid generation showed heterosis. [Conclusion]Among them, the F1and F2generations of "Liaocan H816" × He had the weakest heterosis, the lowest incidence, the strongest resistance and the lowest combining ability, which can be used as important materials in the breeding of resistant varieties and make full use of its heterosis.

Design and Test of Eccentric Shaftless Spiral Metering Mechanism for Rice Precision Hill Fertilization

[Objective]In view of the difficulty of existing fertilizer application machinery to realize rice fixed-point precision fertilizer application, this study innovatively designs an eccentric shaftless screw precision fertilizer application device to meet the needs of rice basal fertilizer precision spreading. [Methods]According to the agronomic requirements of rice fertilizer application, the key factors affecting the fertilizer application effect and the range of values of the main structural parameters of the screw fertilizer metering mechanism, the key component of the device, were determined through theoretical analysis. The screw radius, eccentricity, and pitch were taken as the key experimental factors, and multi-factor experimental analyses were carried out using discrete meta-simulation,with the coefficient of variation of the metering stability of the fertilizer applicator and the qualification rate of the fertilizer metering range taken as the evaluation indexes in the experiments to identify the optimal parameter combination for the design and testing of the hill fertilization device. [Results]The obtained optimal parameters combination is screw radius of 6 mm, eccentricity of 3.4 mm,and pitch of 58 mm. finally, the test rig of the hill fertilizer application device was constructed, and the hill fertilizer application control system based on STM32 microcontroller was developed, and the bench test was carried out according to the optimal parameters combination. In the bench test, the hill fertilization device achieved an average fertilizer application rate of 2.54 g, with an average coefficient of variation of fertilizer discharge stability of 8.355% and an average qualification rate of the discharge range of 95.174%.In the field test, the average fertilizer application rate was 2.63 g, the average coefficient of variation of discharge stability was 8.18%,and the average qualification rate of the discharge range was 93.1%. [Conclusion]The fertilizer application amounts are all within the required range of rice hole fertilization, and the test results are basically consistent with the simulation test, which verifies the reliability of the bench test and field test. The fertilizer application effect meets the agronomic requirements of rice cultivation in the south, and it can also provide reference for the research on the fixed-point and quantitative application of fertilizers in other crops.

Design and Experiment of Subsoiling Shovel with Offset Column and Curved Surface Based on Discrete Element Method

[Objective]Aiming at the problems such as high working resistance of agricultural machinery and poor subsoiling effect caused by a large amount of straw covering the soil surface when the subsoiling technology at the seedling stage of conservation tillage is applied to corn fields in the agricultural areas of Liaoning Province, an offset column and curved surface subsoiling shovel that can reduce the operating resistance was designed.[Method]The discrete element simulation software is used to establish the models of soil particles, straws and soil bin, and a comparative simulation of the operation performance between the offset column and curved surface subsoiling shovel and the straight shank chisel-shaped subsoiling shovel is carried out. [Results]On the premise of ensuring the subsoiling effect, the straight shank chisel-shaped subsoiling shovel is likely to damage the original soil plough layer structure. While the curved surface subsoiling shovel only loosens the soil without turning it over when disturbing the soil of the tillage layer and the plow sole layer, maintaining the original soil plough layer structure. Compared with the straight shank chisel-shaped subsoiling shovel,the soil porosity of the curved surface subsoiling shovel is increased by 0.78%, and the soil disturbance coefficient is increased by4.07%. The field test shows that the soil disturbance cross-section contours obtained from the simulation and the field test are basically fitted. The maximum error between the measured values and the simulated values of the soil porosity and the soil disturbance coefficient of the two types of subsoiling shovel is 4.74%, and the minimum error is 0.69%, and the range of relative errors meets the requirements, verifying the accuracy of the simulation. [Conclusion]While reducing the soil disturbance area, the curved surface subsoiling shovel makes the soil porosity and the soil disturbance coefficient superior to that of the straight shank chisel-shaped subsoiling shovel, and has a good resistance reduction effect, so that it can better adapt to the agronomic requirements and operation environment of conservation tillage with a large amount of straw covering.

Genome-wide Identification and Comprehensive Analysis of LEA Gene Family in Rice

[Objective]A large number of studies have shown that LEA proteins can help plants cope with environmental stress through various mechanisms. However, the functions of many LEA family members in rice have not been fully verified. Therefore, this study aimed to identify new LEA members involved in rice responses to abiotic stress through bioinformatics analysis of the OsLEA gene family and by combining their gene expression changes under different stresses. [Method]The OsLEA gene family was identified and analysed using a genome-wide bioinformatics approach. [Result]The results reveal that the rice genome contains 83 OsLEA family members, which are unevenly distributed across 12 chromosomes and can be classified into eight subfamilies based on structural domain features. Physicochemical property analysis shows that LEA proteins are highly hydrophilic and stable. Subcellular localization predictions indicate that most LEA proteins are localized in cellular compartments such as the cytoplasm, cell membrane, and mitochondria. Promoter cis-acting element analysis highlights that the OsLEA gene promoters are enriched with elements associated with abiotic stress response, phytohormone regulation, and growth and development. Tissue expression pattern and hormone response analyses reveal significant expression specificity across different tissues and under various phytohormone treatments. Additionally,certain OsLEA genes exhibit notable responses to abiotic stresses such as low and high temperatures, salt, and heavy metal(cadmium)treatments. These findings provide valuable insights into the role of OsLEA genes in coping with environmental stress. [Conclusion]This study integrated bioinformatics analysis with expression profiling data under multiple hormone treatments and abiotic stress conditions, preliminarily revealing the molecular regulatory mechanisms through which the OsLEA gene family participates in stress responses. Building on these findings, we successfully screened core member genes—including Os04g0589800, Os05g0362600,Os06g0324400, and Os08g0163600—which exhibited significant upregulation under high-salinity, high-temperature, and lowtemperature stresses. This confirms their critical biological functions in abiotic stress responses and establishes them as highly promising molecular targets for breeding stress-resistant rice cultivars.

Effect of Continuous Enterprise Paring Assistance on County-level Economic Inequality

[Objective]Exploring the effect of regularized help from enterprises to underdeveloped counties on narrowing regional,urban-rural, and income gaps is a integral part of precise help in China, and is crucial for solidly promoting comprehensive rural revitalization. [Methods]Based on county-level panel data from 2014 to 2022, By organizing the information of listed enterprises paring assistance applying NLP technology, the research used the two-way fixed effect model to explore the impact of Continuous Enterprises Paring Assistance(CEPA) on the economic gap of counties. [Results]CEPA can help reduce the economic gap between counties, which verifies the positive effect of“develop the big picture from individual points”.The more state-owned enterprises there are, the more enterprises there are in the same province, and the more award-winning enterprises there are with greater industry diversity, the more obvious the poverty alleviation effect in alleviating economic inequality. At the macro level, the CEPA reduces the economic gap between the recipient counties and other regions by promoting the entry of new enterprises in primary and secondary industries; at the micro level, the CEPA reduces the economic gap between the recipient counties and other regions by promoting the employment of the local population. [Conclusion]Through the combination of an active government and an effective market, we should continue to deepen the“Ten Thousand Enterprises Help Ten Thousand Villages(TEHTV)”, and accelerate the promotion of common prosperity in formerly impoverished counties.

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.