Agricultural Engineering(Protected agriculture)
Taking ‘Shanghaiqing’ as the object, the effects of 4 different types of bio-organic fertilizer on the yield, quality and soil properties of greenhouse vegetable were studied to determine the best bio-organic fertilizer type suitable for promotion in Yuhang district, Hangzhou. The results showed that the application of bio-organic fertilizer could promote the growth of green vegetable, increase chlorophyll concentration, improve agronomic traits and increase biological yield. Compared with the control group, the application of Original bio-organic fertilizer had the best effect on promoting growth and increasing yield, with plant height, leaf number, root length and biological yield increased by 19.1%, 11.7%, 27.7% and 9.2%. Senjing bio-organic fertilizer had the second effect, which increased plant height, leaf number, root length and biological yield by 16.0%, 14.5%, 17.5% and 6.6%. In addition, the application of bio-organic fertilizer could enhance soil organic matter and nutrient content. The contents of organic matter, alkali-hydrolyzed nitrogen, available potassium and available phosphorus were increased by 6.7%, 18.4%, 4.9% and 2.2%, respectively. Among them, the application of Tanggu bio-organic fertilizer had the largest increase in soil alkaline hydrolyzed nitrogen and available potassium, and the application of Zhinong bio-organic fertilizer and Original bio-organic fertilizer had the largest increase in soil organic matter content. Based on the above results, the Original bio-organic fertilizer and the Senjing bio-organic fertilizer could be used as the advantageous fertilizers for demonstration and popularization in the greenhouse vegetable in this region.
‘Jingying F1’ was used as scion and ‘Jingxin rootstock No.9’, ‘Yuyi rootstock No.1’, ‘Luqing Sturdy’ and local pumpkin seed were used as rootstocks, the most suitable rootstock-scion combination was screened. At the same time, an experiment was carried out by directly transplanting self-rooted seedlings and applying biological bacterial fertilizer to explore the effects of different rootstocks and the application of biological bacterial fertilizer on soil-borne diseases and quality of small-scale watermelons in early spring greenhouses in Dongming County. The survival rate, plant growth, fruit quality, resistance to anthracnose, wilt and other soil-borne diseases of watermelon were investigated after grafting and transplanting. The results showed that the four rootstocks could almost control the watermelon soil-borne diseases and the quality of watermelon plants was improved effectively. ‘Jingxin rootstock No.9’ and ‘Jingying F1’ were the best combination, the graft survival rate was 94%, the incidence of watermelon anthracnose and the root-knot nematodiasis were reduced 23 and 57 percent respectively and the yield reached 19350 kg/hm2 and the soluble sugar content reached 10.56 Brix and no soil-borne diseases occurred after grafting compared with the self-rooted seedlings. The incidence of root-knot nematodiasis decreased significantly and the yield reached 19500-19800 kg/hm2 with the soluble sugar content reaching 12.5 Brix on average after grafting with biological bacterial fertilizer. Rootstock grafting has significant effect on increasing yield and disease resistance, but will reduce watermelon sweetness. Applying bio-fertilizer is beneficial for disease resistance, growth, and flavor improvement.
To provide a feasible technical scheme for the overwintering Leiocassis longirostris culture in the Yangtze River Delta, the feeding and growth of the Leiocassis longirostris under the overwintering culture mode were studied. The overwintering rearing technology and the growth characteristics of 0+ age young fish and 1+ age fish Leiocassis longirostris under greenhouse pond condition in 2021—2022 and 2022—2023 were explored and investigated in this study. The initial body length and mass of 0+ age young fish Leiocassis longirostris were 14.78 cm and 40.83 g, with the stocking density of 83340 tails/hm2 (3402.60 kg/hm2). The initial body length and mass of 1+ age fish Leiocassis longirostris were 21.99 cm and 156.86 g, with the stocking density of 42525 tails/hm2 (6670.20 kg/hm2). The results showed that the water temperature could be kept above 11℃ and 10℃ under the greenhouse pond condition. During the pre-winter breeding period (December to the end of February), the feeding of Leiocassis longirostris was relatively stable. Since March, with the increase of water temperature, the daily feeding amount rapidly increased. The cumulative feeding amount during the overwintering period was 4009.00 kg/hm2 and 4715.00 kg/hm2, respectively. After 150-152 d of rearing, the growth rate of 0+ age young fish and 1+ age fish Leiocassis longirostris were 23.7% and 10.2%, weight gain rates were 131.8% and 51.7%, specific growth rates for body length were 0.140%/d and 0.065%/d, specific growth rates for body mass were 0.553%/d and 0.278%/d, daily growth rates were 0.023 cm/d and 0.015 cm/d, and daily mass gain rates were 0.354 g/d and 0.541 g/d, respectively. The condition factors of 0+ age young fish and 1+ age fish Leiocassis longirostris at harvest time were 1.52 and 1.62, the survival rates were 92.8% and 99.7%, the yield per unit area was 7317.00 kg/hm2 and 10093.65 kg/hm2, and feed coefficients were 1.02 and 1.38, respectively. In conclusion, the water temperature can be kept above 10℃ under greenhouse pond condition, Leiocassis longirostris may maintain continuous feeding and exhibit good growth performance. This study provides technical support and theoretical basis for the facility culture of Leiocassis longirostris in the Yangtze River Delta region.
Intelligent identification technology is a technology to recognize, judge and simulate images and videos by simulating the visual performance and thinking model of mankind. This paper listed the latest research of computer vision and intelligent identification technology in automatic grading of flue-cured tobacco from image and near infrared spectrum acquisition, feature extraction and intelligent identification model, summarized the advantages and disadvantages of different intelligent identification model. At last, we put forward the robustness and accuracy of defect in identification model, and the application of intelligent recognition and multi-dimensional characteristic data fusion in tobacco grade determination would be the future research direction.
As a new protection method for agricultural disaster, new varieties of protective nets have been developed and promoted in recent years, which provide new idea for human to improve agriculture protection conditions and reduce agriculture disaster. This paper introduced the present application status of various agricultural protective nets, expounded the influence of specification parameters of protective nets on crop growth, analyzed the defects in the application of the protective nets at present, and prospected the development direction of protective nets in the future.
In recent years, facility agriculture in China has developed rapidly as one of the important forms of agricultural modernization. In facility agriculture, facility ventilation is a key means of regulating the facility environment, which is used to regulate environmental factors such as temperature, relative humidity, and wind speed inside the facility. It directly affects the growth, development, yield, and quality of crops inside the facility. This study provides an overview of the current development status of facility ventilation control technology and equipment, analyzes the problems and shortcomings in technical equipment and intelligent systems, and explores future development trends.
To investigate the effects of sheltered rain-avoiding cultivation on the growth, hormones, and yield of chili pepper ‘Sichuan 20’ in the Sichuan basin, and clarify the influencing mechanism, we set up sheltered rain-avoiding cultivation treatment and field control treatment, measured the height of chili pepper plants and the content of endogenous hormones in the apical tissues of chili pepper plants in the two treatments, and conducted transcriptome sequencing and qRT-PCR validation of related genes. The results showed that there was no significant difference in chili pepper plant height in the early period of sheltered rain-avoiding cultivation, and the plant height in the middle and late periods of sheltered rain-avoiding cultivation was 1.13 and 1.5 times that of the field control treatment, respectively. The yield per plant in the sheltered rain-avoiding cultivation treatment was 74.9% of that in the field control treatment. After sheltered rain-avoiding cultivation, the content of gibberellin was 1.29 times that of the field control treatment, and the content of jasmonic acid was 63.3% of that of the field control treatment. GO analysis showed that the two treatments were significantly enriched in biological functions related to stress response and defense response and were significantly enriched in molecular functions related to adenosine nucleotide binding, adenosine diphosphate binding, and guanosine diphosphate binding. KEGG pathway analysis showed that compared with the sheltered rain-avoiding cultivation treatment, the field control treatment of chili pepper in the sesquiterpene biosynthesis metabolic pathway had four genes related to gibberellin degradation, CaGA2ox1.1(Gibberellin 2-beta-dioxygenase 1, T459_20483), CaGA2ox1.2 (Gibberellin 2-beta-dioxygenase 1, T459_24753), CaGA2ox8(Gibberellin 2-beta-dioxygenase 8, T459_05864), CaGRP3(Gibberellin-regulated protein 3, T459_06266). After the installation of facilities for rain protection cultivation in the Sichuan basin, the expression level of the gene for degradation of gibberellin at the top of the chili pepper decreased, while the content of gibberellin increased, causing the excessive growth of chili pepper, ultimately leading to a lower yield of chili pepper in the facilities for rain protection cultivation than in the field cultivation.
In order to improve the mechanical performance of the greenhouse skeleton, prove the feasibility of the assembled skeleton in the solar greenhouse structure, and then optimize the assembly design of the solar greenhouse skeleton, this study took a solar greenhouse in Yangling District of Shaanxi Province as the research object, and selected the oval single tube skeleton structure. The joint design and finite element analysis were carried out under two different connection modes of internal and external assembly. Three common specifications of 8 cm, 9 cm and 10 cm were selected to assemble the elliptical steel pipe respectively. ANSYS software was used to calculate the force and deformation of the joints at the connection parts of the assembled oval pipe span under the concentrated force of 5 kN, 7 kN and 10 kN, and then the untruncated elliptical steel pipe was set as the control group for comparison. The results showed that the structural deformation of the assembled solar greenhouse was minimal when the 10cm long connector was placed in the oval tube. In addition, when the main section angle was 10°, the stress was the least. In this study, the elliptical assembled skeleton and the assembly node for it were developed. The mechanical performance of the assembled skeleton was studied by static test. Finally, the reliability of the static test and the feasibility of the assembly design of the solar greenhouse skeleton were verified by finite element numerical simulation. This study can provide a basis for the assembly development of elliptical skeleton and the optimization of assembly joints in solar greenhouse.
Based on the daily meteorological data of 95 meteorological stations in Henan Province from 1961 to 2020, the spatiotemporal variation characteristics of the climate resources and major agrometeorological disasters of facility agriculture were analyzed by using the methods of climate tendency rate and the Matlab and ArcGIS software. The results showed that the average temperature and the average minimum temperature in the growing season of facility agriculture in Henan Province showed a significant increasing trend, while the sunshine hours showed a significant decreasing trend. The spatial distribution showed a zonal distribution. The average temperature and the average minimum temperature increased from north to south, while the sunshine hours decreased from north to south. The number of low temperature stations with the daily average temperature < - 8℃ had a significant decreasing trend, and the number of sunshine days had a significant increasing trend, with the number of snowstorm stations no obvious trend of change. The days of low temperature decreased from north to south, while the days of sparse sunlight increased from north to south, with the spatial distribution of snowstorm days implicit. Arrangements on planning of facility agriculture should be done in Henan Province, because of the diversity of agricultural meteorological disasters.
This study provides a theoretical basis for the design of efficient rainwater collection and utilization systems in facility agriculture, and it also serves as a reference for evaluating and selecting other efficient water-saving agricultural practices. By considering economic costs, technical performance, operational management, and environmental impacts, an evaluation index system for rainwater collection and utilization in facility agriculture was constructed. An improved rank correlation analysis and Analytic Hierarchy Process (Reelies-AHP-FSE) model were employed to analyze the influencing factors of efficient rainwater collection and utilization in facility agriculture. Expert ratings and sequential relationship methods were incorporated in the analysis. Fuzzy comprehensive evaluation was used to score different design options for rainwater transmission and storage systems, and the optimal solution for rainwater collection and utilization in the research area was selected. The results showed that the fuzzy comprehensive index value for the rectangular concrete channel with slope treatment was 3.922, indicating it as the preferred option for rainwater transmission. The fuzzy comprehensive evaluation value for the pipeline storage structure was 4.003, making it the optimal choice for rainwater storage. This evaluation method optimized the material and form selection based on factors such as terrain adaptability, water storage efficiency, and water quality maintenance, providing valuable insights for promoting the utilization of rainwater collection in facility agriculture.
In order to understand the requirements of meteorological conditions in different growth stages of tobacco seedling bed, microclimate stations were set up in three sunlight greenhouses with different altitudes. Leaf age and physiological indexes of tobacco leaf were observed in combination with the sunshine and total radiation exposure data of tobacco leaf automatic weather stations outside the shed, and the requirements of temperature, humidity and light on seedlings at different altitudes were analyzed. The results showed that the ecological factors affecting the growth of seedlings in sunlight greenhouse were temperature > water > light. It takes 14-19 days from seeding to emergence, and about 4 days for each true leaf. The average temperature of the whole seedling period is 12.0-15.5℃, the relative humidity is controlled at 72.4%, the average temperature of nutrient solution is 11.0-15.1℃, and the accumulated temperature required for the seedling period is 555.1-640.8℃. The sunshine duration is 247.0 -293.0 hours, and the total radiation exposure is 550.5-686.7MJ/m2. In this paper, temperature, humidity and light requirements of tobacco seedlings at different altitudes are studied and summarized, which provide theoretical support for meteorological services during the whole growth period of tobacco planting.
In order to optimize the digital production management measures of hydroponic lettuce in facility plastic greenhouse in southern China, the hydroponic planting experiments on ‘Italian lettuce’ were conducted in facility plastic greenhouse of Guangdong Agro-meteorological Experimental Station from November 2021 to February 2022. Models for predicting hydroponic lettuce growth index based on two agro-meteorological indicators of effective accumulated temperature (EAT) and product of thermal effectiveness and PAR (TEP) were used to determine greenhouse environmental elements and lettuce growth data, and the models were validated by independent experimental sampling data. The results showed that, (1) the determination coefficients (R2) of the predicted and measured values of leaf number, leaf area, leaf fresh and dry weight based on the EAT model were as follows: 0.911, 0.963, 0.948 and 0.934, the root mean square errors were 3.194 pieces, 398.298 cm2, 26.488 g and 1.934 g. (2) The R2 of the predicted and measured values of the model based on the TEP indicator were 0.940, 0.972, 0.965 and 0.956, the root mean square errors were 1.260 pieces, 170.672 cm2, 9.261 g and 0.464 g, respectively. This study suggests that the TEP model is superior to EAT model in general, and the fitting accuracy of TEP model between the predicted value and the measured value is better than EAT model in facility plastic greenhouse of southern China.
In this study, lettuce was used as experimental material, the effects of different phosphorus application rates on yield, quality, soil available phosphorus content and agronomic efficiency of vegetable fields with high, middle and low phosphorus levels were studied by using the method of plot experiment. The results showed that the yield of lettuce of high phosphorus vegetable fields was the highest when the phosphorus application rate (P2O5) was 36.54 kg/hm2. When 54.91 kg/hm2 phosphorus (P2O5) was applied on medium phosphorus vegetable field, the yield of lettuce was the highest, the content of nitrate was lower, the content of vitamin C increased, and the content of soil available P was significantly increased. When 91.35 kg/hm2 phosphorus (P2O5) was applied on low phosphorus vegetable field, the yield of lettuce was the highest and the content of nitrate was decreased. The agronomic efficiency of phosphorus fertilizer decreased with the increase of soil phosphorus content and phosphorus application amount. Therefore, applying no phosphate fertilizer or little phosphate fertilizer on high phosphorus vegetable fields, combining medium phosphorus vegetable fields with medium phosphate fertilizer, and low phosphorus vegetable fields with high phosphate fertilizer were effective measures to improve the yield, quality and agronomic efficiency of nodular lettuce.
Based on the water surface evaporation of a 20 cm evaporating dish and the water demand law of watermelon at different growth stages, the effects of irrigation amount and irrigation frequency on the growth, yield and quality of small-fruit watermelon were studied. The results showed that the stem diameter, leaf chlorophyll content, fruit yield, quality and irrigation water use efficiency of watermelon were closely related to irrigation amount and irrigation frequency. Among them, W2F2 (irrigation volume 75%Ep, irrigation frequency 6 d) had the best comprehensive performance. The quality indexes of watermelon fruit such as soluble solids, glucose, sucrose, fructose and lycopene content in this treatment were the highest, and the nitrate content was low; the yield reached 41247 kg/hm2, which had no significant difference from W3F1 (irrigation volume 90%Ep, irrigation frequency 3 d) with the highest yield; the irrigation water use efficiency was 53.4 kg/m3, and there was no significant difference from the highest W1F1 (irrigation volume 60%Ep, irrigation frequency 3 d); other indexes were at the middle level, indicating that W2F2 was the best irrigation technology scheme. This study can provide theoretical and technical support for green and high-quality production of small-fruit watermelon in greenhouse.
The vertical slit fishway has the characteristics of good flow conditions of water, clear location of the reflux zone, and strong adaptability to changes in upstream and downstream water levels. It is currently a high efficient and widely used fish passing engineering facility. In order to increase the effectiveness of fish migration in the research area, according to regulatory requirements, three types of fishway tank compartments were preliminarily designed, and numerical simulation methods were used to explore the impact of changes in baffle types on the flow structure of water of the tank compartments at a constant depth of 2 meters both upstream and downstream. The baffle type was optimized by analyzing the water flow pattern inside the pool, the velocity distribution at the vertical joints, and the energy dissipation effect. By changing the size of the second type of baffle, the width of the vertical joint was reduced from 0.6 m to 0.5 m. Under the premise of flow pattern of good water in the tank and flow velocity at the vertical joint, the maximum flow velocity near the vertical joint was reduced to less than the design flow velocity of 1.2 m/s; and the flow capacity of the optimized body under different conditions of equal water depth was calculated. When the water depth changed between 0.5 m and 2.0 m, the flow capacity of the fishway was between 0.236 m3/s and 0.951 m3/s. The flow pattern of good water inside the pool and the rationality of the velocity distribution at the vertical joints provided a good channel for the trace back of most fish in the study area, and the flow capacity at different water depths provided a reference for the operation and scheduling of the fishway.
Adjustment of agricultural planting structure is the main content of agricultural supply-side reform, and is also an important measure to promote farmers’ income. In order to study the impact of agricultural planting structure adjustment on agricultural mechanization, based on the panel data of 14 prefecture-level cities in Guangxi, we empirically analyzed the impact of agricultural planting structure adjustment on the development level of regional agricultural mechanization in Guangxi by the fixed-effect model. The results show that: the adjustment of agricultural planting structure has no direct impact on agricultural mechanization. Rural road facilities and agricultural operation scale have significant positive impact on the development level of regional agricultural mechanization. The increase of farmers’ income has a mediating effect on the development level of agricultural mechanization in Guangxi. According to the research results, the level of agricultural mechanization can be comprehensively improved by improving the rural infrastructure, promoting the moderate scale of agricultural operation, adjusting the agricultural planting structure and increasing farmers’ income.
In-depth study of the patent layout of the robotic milking machines in China is of great significance for Chinese technology research and protection. Based on the Derwent Innovation (DI) patent database, using the bibliometric method and topic clustering, the layout characteristics of the robotic milking machine in China are analyzed and summarized from the aspects of annual change of patent application, technology exporting country, patentee, patent legal status, classification defined by experts, IPC classification, research focus, etc. The analysis results showed that China started slowly in this field and entered a period of technological development in 2011. The key patentees of this technology were concentrated, the overall invalid patents accounted for 41%, and the patent maintenance was not strong. Foreign institutions had more effective patent ratios and technical directions in China than domestic institutions. Patent applications by foreign institutions accounted for 22.6%, mainly from Sweden, Germany, Netherlands and the United States, and patentees mainly included DeLaval and GEA. Among domestic institutions, Anhui Yomo Machinery Group Co. and Shandong Chengcheng Iot Technology Co. had more authorized and effective patents. Foreign institutions had more patents than Chinese institutions in advanced technology directions such as automatic teatcup attacher, automatic cluster remover, automatic teat identification equipment, mechanical arm and powerplant of automatic teatcup attacher or remover, automatic attaching or detaching of clusters. It is recommended that Chinese institutions should establish effective cooperation mechanisms such as patent pools, strengthen cooperation between companies, universities, and research institutions, and strengthen the overall patent layout and cutting-edge technology patent layout.
The occurrence, damage and pathogen species of the watermelon root-knot nematode disease were investigated at facilities in the Huyi District, Shaanxi Province. Safe and efficient pesticide control technologies against this disease were screened to ensure the healthy development of the Shaanxi watermelon industry. In May 2022, the incidence and disease index of root-knot nematode disease were determined in the main watermelon planting bases of Huyi District. Root-knot nematodes were isolated from watermelon root samples, the species was identified by morphological and molecular identification methods, and the effects of different chemicals were evaluated. The results showed that the average diseased field rate, diseased plant rate, and disease index in the main watermelon production area of Huyi District were 92.9%, 88.7%, and 73.1 respectively. Based on the morphological characteristics of second-stage juveniles, the perineal patterns of female adults, and molecular identification, Meloidogyne incognita was identified as the infectious nematode in watermelons. The test showed that 98% dazomet had a significant inhibitory effect. The appropriate dosage was 150 kg/hm2 of soil, reached 100% inhibition in 30 days and 92.1% in 70 days. In addition, soil treatment with 41.7% fluopyram (2250 mL/hm2) before transplanting watermelons could effectively inhibit M. incognita infection. After 70 days, the relative inhibitory effect was 75.7%, which was better than root irrigation.
The study aims to use a cellular automata dynamic model with spatiotemporal features to simulate the calculation process of fruit and vegetable medium treated by a high voltage pulse electric field, and this simulation provides theoretical support for the application of high-voltage pulse electric field technology in fruits and vegetable preservation, drying, and sterilization. On the basis of considering the phenomenon and principle of cell breakdown in fruits and vegetables caused by high-voltage pulsed electric field treatment, a cellular automaton model for fruit and vegetable breakdown in the electric field was constructed by specifying the cellular space, state, and rules. The results showed that the simulation results of the experiment were in line with the breakdown characteristics of pulsed electric field treatment of fruit and vegetable media. The fitting degree was high compared with the actual situation, and the error was small. By using cellular automaton to simulate the model of pulsed electric field treatment of fruits and vegetable media, the breakdown process of fruits and vegetable media was reflected, which was beneficial to the application and promotion of pulsed electric field technology in the field of fruits and vegetables.
In order to avoid the overall structural damage caused by the failure of local components, a Venlo type greenhouse in Xianyang area was selected as the research object, and an improved sensitivity analysis method was applied based on the basic mechanism of continuous collapse resistance, and the key components of the continuous greenhouse structure and their distribution were obtained. The design and optimization of the greenhouse skeleton section was carried out by MIDAS-GEN software, and then the sensitivity coefficient of the column was determined by combining the demolition member method and the sensitivity analysis method in ANSYS software. The results showed that: (1) the sensitivity coefficient of the long side column was close to that of middle column and greater than that of the short side column, and the sensitivity coefficient of the short side column was greater than that of the corner column; (2) the sensitivity coefficient of the long side column near both ends increased significantly, and the column with truss hinged had a slightly higher sensitivity coefficient than that of other columns; (3) the sensitivity coefficient of the middle column showed a positive correlation with the direct stress, while the long and short column were opposites. The research results can provide a reference for the optimization of multi-span greenhouse and the study of continuous collapse resistance.
Agricultural Engineering(Protected agriculture)
