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Drift and deposition of ultra-low altitude and low volume application in paddy field

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International Journal of Agricultural and Biological Engineering 2014年第4期7卷 23-28页

作者： Xue Xinyu Tu Kang Qin Weicai Yubin Lan Huihui Zhang Nanjing Agricultural University Nanjing 210014China Nanjing Research Institute for Agricultural Mechanization Ministry of AgricultureNanjing 210014China South China Agricultural University Guangzhou 510642China USDA-ARS Fort CollinsCA 80526USA

field trials were performed to evaluate various techniques for measuring spray deposition and aerial drift during spray application to paddy field.The application of a spraying agent containing the fluorescent dye Rhodamine-B was applied by an unmanned aerial vehicle(UAV)which flew at a height of 5 m,a speed of 3 m/s,and the wind speed of 3 m/s.The results showed that because the downdraft produced by a helicopter rotor increased the penetrability of crops,there is a higher deposition on the upper layer and the under layer than the traditional spraying.The average deposition on the upper layer accounts for 28% of the total spraying,the deposition on the under layer accounts for 26% of the total spraying.The deposition on the under layer takes up 92.8% of the deposition on the upper layer.Droplets drift data showed that the drift of non-target area took up 12.9% of the total liquid spray.The 90% drifting droplets were located within a range of 8 m of the target area;the drift quantity was almost zero at a distance of 50 m away from the treated area.

关键词： paddy field ultra-low altitude low volume UAV droplet drift deposition

Modeling the fate of paddy field pesticide in surface water and environmental risk assessment

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Journal of Environmental Sciences 2000年第3期12卷 337-343页

作者： LI Shi\|yu 1, Tohru Morioka 2 (1. Institute of Environmental Science, Zhongshan University, Guangzhou 510275, China. E-mail: eeslsy@*** 2.Department of Environmental Engineering, Osaka University, Yamada oka 2 1, Suita, Osaka 565, Japan. E- 中山大学广东广州 51 0 2 75 Osaka University 日本 Osaka 56 5

The risk of drinking water is greatly concerned because of the large amount of pesticide applied to paddy field and the contamination of drinking water sources due to the runoff. A mathematical model is developed, based on the mass balance, to predict the fate of paddy field pesticides from application, runoff and mixing in a river, taking account of the physical chemical properties and processes of volatilization, degradation, adsorption and desorption. The model is applied to a river basin in Japan to estimate the contaminant level of several popularly used pesticides at the water intakes. The health risk in drinking water induced by each pesticide concerned is estimated and evaluated by comparing with the acceptable daily intake values(ADI) and with that induced by trihalomethanes. An index to evaluate the total risk of all pesticides appearing in water is proposed. The methods for risk management are also discussed.

关键词： modeling pesticide paddy field environmental risk assessment drinking water

Water-efficient sensing method for soil profiling in the paddy field

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International Journal of Agricultural and Biological Engineering 2018年第4期11卷 207-216页

作者： Zhenran Gao Jun Ni Yan Zhu Qi Jiang Weixing Cao National Engineering and Technology Center for Information Agriculture Jiangsu Key Laboratory for Information AgricultureJiangsu Collaborative Innovation Center for Modern Crop ProductionJiangsu Collaborative Innovation Center for the Technology and Application of Internet of ThingsNanjing Agricultural UniversityNanjing 210095China

The comprehensive and reliable perception of moisture in a soil profile is essential to irrigation.To establish an efficient method for sensing soil moisture,field trials were conducted to analyze the spatial and temporal variations of moisture in a paddy soil profile by using coefficients of variation.The results showed that soil layers at shallow depths undergo more extensive changes in the coefficients of variation.Moisture perception is most sensitive within a depth range of 0-60 cm in the vertical soil profile of a paddy field.By using the clustering algorithm of Euclidean distance,the paddy soil profile was divided into three categories based on soil depth.The first category includes depths ranging from 10-20 cm,the second is from 30-40 cm,and the third is from 50-100 cm.Path analysis indicated that the most sensitive depths for moisture sensing in a paddy soil profile were 20 cm,30 cm,and 50 cm,whereas the most sensitive depths for moisture sensing by time stability analysis were 20 cm,40 cm,and 60 cm.Based on the multiple regression of sensitive depths,the results of quantitative inversion indicated that the time stability analysis results were 0.962 when the(y,y)Coryy of path analysis was 0.980,and the time stability analysis was 0.61 when the root mean square error(RMSE)of path analysis was 0.40.The relative error range between the measured and predicted values of path analysis was less than that of time stability analysis.These findings suggest that it is feasible to effectively sense the moisture of the entire vertical soil profile based on the sensitive depth.The present study has also determined that path analysis is superior to time stability analysis.

关键词： paddy field profile soil moisture perception clustering algorithm path analysis

Design and test of laser-controlled paddy field levelling-beater

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International Journal of Agricultural and Biological Engineering 2020年第1期13卷 57-65,F0002页

作者： Hao Zhou Lian Hu Xiwen Luo Lingmao Tang Pan Du Ting Mao Runmao Zhao Jing He Key Laboratory of Key Technology on Agricultural Machine and Equipment Ministry of EducationSouth China Agricultural UniversityGuangzhou 510642China

The technology for implementing a precise soil beating after precise soil levelling was proposed to improve the flatness of the paddy field and shorten the cycle time between the soil beating and levelling;in addition,a laser-controlled paddy field levelling-beater was designed according to the working principle.And the grade and tilt of the levelling scraper and beating mechanism are automatically controlled according to the levelling-beater vertical height and the tractor roll angle,respectively.The designed levelling-beater is capable of precise levelling and beating paddy fields at the same time with an adjustable beating depth.A paddy field test of the levelling-beater was conducted to compare the performance under both manual and automatic control modes,with the roll angles of the tractor and the levelling-beater measured using two attitude and heading reference systems(AHRSs),and the change in grade of the levelling-beater was measured using a global navigation satellite system(GNSS).The test results demonstrate that the operational quality of the levelling-beater is more stable when operating in automatic control mode than when operating in manual control mode.More specifically,the elevation of the levelling-beater varied±4 cm around the mean elevation and roll angle varied within the range of±0.5°when operating in automatic control mode.However,when operating in manual control mode,the elevation and roll angle were greater than±11 cm and±2.5°,respectively.The test results also demonstrate that the laser-controlled paddy field levelling-beater significantly improves the paddy field flatness,and enables it to operate at a stable depth to realise an even levelling and beating layer.More specifically,the maximum variation of elevation was reduced from 26.4 cm before the levelling and beating operation to 11.5 cm after the operation.In addition,the standard deviation of the elevation was reduced from 4.13 cm to 2.18 cm after the operation.The total number of flatness sampling points with the absolute differen

关键词： laser control levelling beating paddy field flatness

Determination of crop and soil evaporation coefficients for estimating evapotranspiration in a paddy field

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International Journal of Agricultural and Biological Engineering 2017年第4期10卷 130-139页

作者： Yan Haofang Zhang Chuan Hiroki Oue Peng Guangjie Ransford Opoku Darko Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang 212013China Institute of Agricultural Engineering Jiangsu UniversityZhenjiang 212013China United Graduate School of Agricultural Sciences Ehime University3-5-7 TarumiMatsuyama790-8566Japan Department of Water Management Delft University of TechnologyDelft2600GAthe Netherlands

Accurate estimation of evapotranspiration is important in efficient water management for improving water use efficiency.In order to obtain evapotranspiration and evaporation beneath the canopy using the Food and Agriculture Organization(FAO)method,pan evaporation was used instead of reference evapotranspiration calculated by the Penman-Monteith equation with detailed meteorological data.The total crop coefficient and soil evaporation coefficient were determined using actual measured daytime evapotranspiration and evaporation by the Bowen ratio energy balance and lysimeter,respectively,in a rice paddy field in Japan.The average evapotranspiration was 5.3 mm/d,4.4 mm/d,7.4 mm/d and 6.3 mm/d and crop coefficient was 0.79,1.18,1.01 and 0.86 for the initial stage,development stage,middle-season stage and late-season stage,respectively.The evaporation was low and almost constant with an average value around 0.77 mm/d when the leaf area index(LAI)reached 3.The proposed average crop coefficients for different growing stages were applied to estimate daytime evapotranspiration and found suitable.A simple soil water evaporation coefficient model was developed using leaf area index for practical use and it was found that it could accurately estimate evaporation.

关键词： evapotranspiration evaporation paddy field lysimeter leaf area index(LAI) Bowen ratio energy balance

Optimization of working parameters for puddling and flatting machine in paddy field

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International Journal of Agricultural and Biological Engineering 2016年第3期9卷 88-96页

作者： Xu Chunlin Zhang Chengliang Li Lianhao Li Mingjin College of Engineering Northeast Agricultural UniversityHarbin 150030China College of Mechanical and Electrical Engineering Henan Agricultural UniversityZhengzhou 450002China Harbin Agricultural Mechanization Research Institute Harbin 150070China

In order to improve the soil preparation quality,a wide puddling and flatting machine for paddy field was designed with the functionality of tillage,soil crushing,puddling,burying stubble and flatting in one-time operation,which can be equipped on tractors with high power.This study focused on the design and analysis of key components of the machine including puddling equipment,flat shovel and balance structure.Optimal results with field trials and response surface analysis showed that the machine can operate optimally when the working speed,puddling depth and angle of flat shovel were 1.05 km/h,16 cm and 31.30°,respectively.The surface flatness standard deviation was 3.7 cm,and slurry degree was 1.03 g/cm3.field validation test results were consistent with the optimal parameters,which was able to meet agronomic requirements of mechanical planting in China.

关键词： paddy field puddling and flatting machine rice production design field test optimization

field experimental study on pullout forces of rice seedlings and barnyard grasses for mechanical weed control in paddy field

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International Journal of Agricultural and Biological Engineering 2014年第6期7卷 1-7页

作者： Wang Jinwu Tao Guixiang Liu Yongjun Pan Zhenwei Zhang Chunfeng Engineering College Northeast Agricultural UniversityHarbin 150030China

Pullout forces of rice seedling and barnyard grass were tested by universal testing machine controlled by WDW-5 type microcomputer to obtain the pullout forces of rice seedling and barnyard grass.The measured pullout force was used to improve the weeding rate and reduce the rice seedling damage rate caused by mechanical weeding device.According to the measured continuous curve of pullout forces of rice seeding and barnyard grasses in weeding period,the best range of force required to pull out barnyard grasses from soil with no injury and damage to rice seedlings was discussed.Reasons for the difference in the pulling force were analyzed.Results show that,with the increment of the number of single cell rice seedlings the pullout force increases.The pullout forces of single cell rice seedlings and barnyard grasses at first increased slowly reaching the maximum value followed by rapid drop and finally it remained steady.The minimum pullout forces recorded during rice seedlings at the first and the second weeding periods were 2.57 N and 9.70 N,respectively,while the minimum forces during the first and second weeding periods were recorded as 1.24 N and 7.51 N,respectively,for barnyard grasses.The results show that the pullout forces of weeding to rice seedlings and barnyard grasses should be within 1.24 N to 2.57 N and 7.51 N to 9.70 N respectively in the first and second weeding periods.

关键词： paddy field mechanical weed control pullout force rice seedlings barnyard grasses field test

Nitrogen and Phosphorus Loss Law and Emission Reduction Effects Under Water and Fertilizer Management Integrated Mode in Dike paddy field

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Journal of Northeast Agricultural University(English Edition) 2009年第4期16卷 31-37页

作者： GUO Longsheng ZHOU Guangtao GUO Zhongyuan Hydraulic and Electricity Survey and Designing Institute of Heilongjiang Harbin 150080 China Rice Irrigation Experiment Centre of Heilongjiang Province Qing＇an 152400 Heilongjiang China

To achieve the purpose of reducing farm non-point source pollution, we integrated site specific nitrogen management precise irrigation, controlled drainage, and wetland eco-repair system in dike area of Taihu basin. During investigation, it had given prominence for the water and fertilizer coupling effects of precise irrigation and site specific nutrient management, the characteristics of integration on controlled irrigation, controlled drainage and wetland ecosystem non-point source pollution control. Then the water and fertilizer integrated management mode of paddy field was put forward in Taihu basin where the water production efficiency increased to 1.64 kg. m-3, water saved 37.8%, fertilizer use efficiency raised 15,4%, yield raised 10%, and N, P load decreased 26%-72%. The modern agricultural and farmland ecosystems that control and cut down the farm non-point source pollution came into being, which can be a reference by Taihu basin to control its agricultural non-point source pollution and eutrophicated water body.

关键词： paddy field the integrated mode of water and fertilizer management non-point source pollution nitrogen and phosphorus loss

Co-transformation of HMs-PAHs in rhizosphere soils and adaptive responses of rhizobacteria during whole growth period of rice(Oryza sativa L.)

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Journal of Environmental Sciences 2023年第10期132卷 71-82页

作者： Shengwei Yi Feng Li ChenWu Fei Ge Chuang Feng Ming Zhang Yun Liu Hainan Lu College of Environment Science and Resources Xiangtan UniversityXiangtan 411105China Hunan Engineering Laboratory for High-Efficiency Purification Technology and its Application in Complex Heavy Metal Wastewater Treatment Xiangtan 411105China Scientific Research Innovation Platform of Environmental Behavior and Control Principle about New Pollutants in Hunan Provincial Universities Xiangtan 411105China Department of Environmental Engineering China Jiliang UniversityHangzhou 310018China Shanghai Academy of Environmental Sciences Shanghai 200233China

This study investigated the transformations of heavy metals(HMs) and polycyclic aromatic hydrocarbons(PAHs) in rhizosphere soils and adaptive responses of rhizobacterial community under the real field conditions during four growth stages(e.g., greening, tillering, heading, and maturity) of early rice(Zhongjiazao 17) and late rice(Zhongyou 9918) in Jiangshe village(JSV) and Yangji village(YJV). Results showed that rhizosphere soils of YJV were mildly polluted by Cd and PAHs compared to that of JSV. The relative abundance of bioavailable Cd(bio-Cd) and bioavailable As(bio-As) in rhizosphere soil increased before the heading stage but decreased at the subsequent growth stage, but the content of ΣPAHs in rhizosphere soil decreased gradually during whole growth period. The dominant rhizobacteria genera at YJV(e.g., Bacillus, Massilia, Sphingomonas, and Geobacter) increased at an abundance level from the tillering to heading stage. Rhizobacteria interacted with the above co-pollutant more intensely at the tillering and heading stage, where genes involved in HM-resistance and PAH-degradation appeared to have a significant enhancement. The contents of bioCd and bio-As in rhizosphere soil of early rice were higher than that of late rice at each growth stage, especially at the heading stage. Bio-Cd, ΣPAHs, and organic matter were key factors influencing the community structure of rhizobacteria. Results of this study provide valuable insights about the interactions between HM-PAH co-pollutant and rhizobacterial community under real field conditions and thus develop in-situ rhizosphere remediation techniques for contaminated paddy fields.

关键词： Heavy metals(HMs) PAHs Co-pollutants Rhizobacterial community paddy field