In order to prove role of mechanization in
Path planning is crucial for autonomous reaping process and in particular reaping path should be as identical as possible to seeding trajectory so that autonomous vehicles can reap precisely.In the case of autonomous seeding, planned seeding path can be applied directly to reaping process, yet in the case of non-autonomous seeding in which there is no planned path, it is crucial to generate reaping path close to seeding trajectory.The most common applied path planning is the AB line which is generated by setting terminals of a path.However, in some specific cases, paths may be limited to curved and irregular shapes, hence AB line is no longer applicable.Through research, a lot of Chinese farmers prefer path planning similar to AB line when it comes to cases mentioned above.In order to meet needs presented by farmers, a solution for generating parameterized reaping paths wass proposed.Firstly, coordinates and attitudes of main antenna on a seeding vehicle were sampled and used for calculating coordinates of rear axis midpoint.Next, aggregated points and outlier points were eliminated and path nodes were picked which showed general shape of seeding trajectories.Finally, parameterized paths were generated using piece-wise interpolation based on cubic Bezier curves.LOVOL M1004 tractor was used as experiment platform and data was sampled in experimental station in Xiaowangzhuang, Changping District, Beijing City.Experiment results showed that maximum lateral errors between parameterized curves and raw trajectories were 0.52 and 0.40 m in two experimental groups under condition that average operation speed being 5 km/h, compression threshold for aggregated points being 1 cm, curvature threshold for outlier points being 1 m−1 and compression threshold for path nodes being 30 cm.This solution proposed was confirmed to be effective in precisely restoring seeding trajectories restoration and generating reaping paths.
A laboratory study was conducted to evaluate influence of soluble nitrogen addition on N2O emissions from three soils of different tea planting age: high age(more than 50 years), middle age(20 to 25 years)and low age(less than 8 years).Four treatments were designed as follows: control(CK), low nitrogen(LN), medium nitrogen(MN), high nitrogen(HN).Results showed that N2O emissions from high age tea planting garden were higher than middle age and low age tea planting garden due to higher pH and organic C content.Compared with the control, single nitrogen addition enhanced N2O emissions from both soils, and N2O emissions from middle age planting garden and low age planting garden soil had significant positively correlation with N fertilizer rate, while the maximum N2O emissions were observed from MN treatment in high age tea planting garden soil.Application of exogenous ammonium nitrogen promoted decrease of soil pH, change quantity of pH from high age and middle age tea planting garden solis were in the order HN>MN>LN>CK , while from low age planting garden soil was in the order MN>HN>LN>CK.Application of exogenous ammonium nitrogen had a significant effect on soil acidification of tea plantations.Exogenous ammonium nitrogen significantly reduced soil pH and increased soil N2O emissions.
Rice and wheat are main grain crops in Jiangsu Province.Losses caused by humid climate and lack of time to dry after harvest exceed relevant standards.Therefore, it is necessary to vigorously promote and support grain drying and storage industry.Advantages and problems of drying loss reduction technology in grain producing areas were analyzed.Green drying loss reduction technology system for grain producing areas was structured.Grain drying technology integration, drying equipment supporting mode and drying operation mode were explored.It provided drying production guidance for business entities.This system divided grain drying and storage process into four modules: pre-drying before drying, fast green drying at place of origin, low-consumption temporary storage and long-term low-loss storage.Different business entities could choose combination of different modules according to their own production conditions to meet differentiated needs of different planting scales and operation modes for grain drying and storage.
Exploring variation laws and characteristics of soil water and heat helps to efficiently utilize water and heat resources in artificial grasslands.Based on mathematical statistics and multifractal theory, response and distribution characteristics of soil water and heat variations to rainfall were compared and analyzed in Wulan County, Qinghai Province.Results showed that influence of rainfall on soil moisture content had obvious delayed effect.Variation of soil moisture content was of moderate intensity with a "thin-tailed" distribution, and mainly caused by distribution of high values with a short-distance variation.Compared with pattern of mixed sowing oats and arrows, soil moisture content was higher and effect by rainfall was stronger in pattern of mixed sowing peas and quinoa.Effect of rainfall on soil temperature of deep depth had a certain delay.Soil temperature belonged to moderate intensity variation showing a "thick tail" distribution, among which soil temperature in 0~10 cm soil layer had the highest variation intensity.The deep soil temperature was mainly short-distance variation, and variation of soil temperature was mainly caused by high value distribution.Compared with pattern of mixed sowing oats and arrows, soil temperature was higher and effect by rainfall was less in pattern of mixed sowing peas and quinoa.In conclusion, there were differences in effects of mixed sowing patterns on soil water and heat.Pattern of mixed sowing peas and quinoa had more advantages in soil water and heat utilization than pattern of mixed sowing oats and arrows.The results could provide a theoretical basis for full utilization of soil water and heat resources in artificial grasslands in alpine desert regions.
Anji White Tea is one of important productions of specialty agriculture in Anji County of Zhejiang Province.Understanding spatiotemporal dynamic of these tea plantations will promote local tea industry and regional sustainable development.Based on relevant land use data of Anji County in 2012, 2016 and 2020, dynamic change process and differential characteristics of tea garden pattern in Anji County, Zhejiang Province from 2012 to 2020 were studied and analyzed by using methods of land use dynamic degree index, comprehensive index of land use expansion degree and land use transfer matrix.Results showed that there were obvious temporal and spatial differences in pattern of tea plantations from 2012 to 2020.From perspective of transfer quantity and spatial distribution, number of tea garden land transfer from 2012 to 2016 was very small, area of tea garden was basically stable, and spatial distribution was relatively scattered.Area of tea gardens increased significantly from 2016 to 2020, and distribution of new tea gardens was relatively concentrated.From perspective of transfer process, 2016−2020 was more intense than 2012−2016, with a significant increase in number of transfers.Transfer process led to a more concentrated spatial distribution of tea gardens.From perspective of transfer type, from 2012 to 2016, tea gardens were mainly converted into cultivated land, with almost no transfer, and transfer type was relatively single.From 2016 to 2020, tea garden would be mainly converted into forest land, garden land and construction land, mainly forest land, farmland and garden land, with various types of transfer.The above results clarified spatiotemporal dynamic change characteristics of tea garden pattern in Anji County, Zhejiang Province from 2012 to 2020, and provided data basis and scientific guidance for study of spatiotemporal dynamic change of regional tea garden and future sustainable development planning.
In order to change existing seed metering technology of
Facing requirements of professional degree postgraduates' practical ability and engineering accreditation, reform practice of China Agricultural University in cultivating application postgraduates by connecting closely with reality was introduced.Comprehensive practice platform of "Six Party integration" took professor workstation in Qixian County, Henan Province as the core, which included "workstation, enterprise, engineering technology research center, postgraduate off-campus joint training base, comprehensive test station for modern agricultural-industrial technology system, and moral education base".Based on concept of "setting a goal, going through three stages of training, implementing secondary management, realizing three connections, and highlighting four characteristics", the "13234" model for training qualified higher personnel were explored and practiced, and training practice with strong innovation and practical ability for compound qualified personnel with high level were carried out.These all promoted scientific research innovation of agriculture-related fields and transformation and upgrading of its industries and effectively formed a stable long-term output mechanism for talent training.
Combining existing practical experience of five national rural industrial integration demonstration parks in Shaanxi Province, three types of rural industrial integration development models were summarized.Based on status quo of Shaanxi Province rural industrial integration demonstration parks, follow-up development countermeasures and suggestions were put forward, that was, clarify development direction of demonstration park, constantly strengthen government's guidance, improve financial support policy, expand source of funds for demonstration park, upgrade talent and public service system, and attract people to participate in park construction.