Yahan tsai（China Productivity Center Agricultural Innovation Department）
Agricultural survey started in Taiwan as early as in 1947, mainly covering the planting areas and yields of major crops and the areas of specific crop production. With the changes in science and technology and the agricultural environment, there are three surveys now implemented annually on planting areas of crops (for crops growing all year round, those in the first crop season, those in the second crop season, and those intermittent crops between the second and the first crop seasons), crop yield, and production forecasts of important agricultural products (on economically sensitive crops or crops that are prone to unbalanced production and sales). The collection of survey data is mainly through field surveys by surveyors locally hired by respective township, city or district halls, who use cadastral maps, farming maps, or mobile devices, etc., to conduct the surveys in three designated periods (between the second and the first crop seasons, in the first crop season, and in the second crop season.) There is an average of one field surveyor in every 300 hectares. Where the arable land is scarce and there is no field surveyor assigned, the local agricultural status reporter is responsible for on-site survey.
The surveyors’ visual and subjective judgments may lead to observation errors of the crop area size. The Agricultural and Food Agency (AFA) of the COA has made use of IC technologies as the cadastral survey basis so that with mobile devices, crop information like the crop types, area ratio, growth stage, and photographs can all be obtained. However, field surveys based on cadastral data require more manpower and time than regular surveyors can contribute. Other part-time surveyors are recruited for the job on a case-by-case basis, such as local farmers, members of the agricultural production and marketing groups (APMGs), young farmers groups, and local residents with the related knowledge and willingness. The involvement of these human resources would require appropriate management mechanisms and effective instruments, without which the labor cost, the quality and the efficiency of the survey cannot be well controlled. These three factors, the management cost, the quality, and the efficiency of the survey are closely related. This article will summarize and explain the improvement of the survey efficiency and the applications of the survey data.
II. Improved Efficiency of Agricultural surveys
The key to the efficiency of agricultural surveys lies in the talent development and the enhancement of the instrument used. Talent development involves the training courses (use of survey tools, knowledge of survey content, crop identification ability), field operation, SOP, survey Q&A item bank, and survey personnel databank, and their learning history, etc. Systematic training and experience transfer are essential for the improvement of the quality of surveyors, who may turn into dedicated professional surveyors. The enhancement of survey instrument may involve both the operation interface optimization and the use of technical aids.
1. Survey APP Operation Interface Optimization
The user-friendliness of the survey instrument is the key to the survey efficiency. Graphic interface, for example, is helpful even to first-time users. With the large variety of crops, inexperienced planters may have trouble identifying plants similar in characteristics (e.g. citrus, leguminous or cruciferous crops), immature vegetable seedlings or trees that have not yet grown fruit. Vegetable farmers and fruit farmers do not easily identify the crops of their counterparts. The crop imaging system can assist the identification. When in doubt, the system can immediately provide timely and accurate assistance. The fool-proof mechanism is also important, such as automatic checking of crop area ratio (reasonable ratio to land area), standardization of data input (specific code or format) and the keyword search function (land number or crop), etc. These can reduce the chance of errors during on-site survey and shorten the time of on-site work for better efficiency.
2. Use of Technical Aids
The sophisticated global positioning system (GPS) technology, with data stored in APP, such as the parcels selected (land numbers), the shooting angles and directions (depression angle, azimuth angle), etc., has made possible real-time display of the distance and relative position of the parcels to assist the surveyor to locate the correct parcels. In case of a long distance, the shooting mode is automatically locked and must be unlocked to enter the shooting mode. This can ensure high accuracy and efficiency when used in dangerous terrains, where there are fierce dogs, or where the GPS positioning is inaccurate. On the data management platform, the survey data can be linked in real time to the survey APP, where the surveyors can maintain the progress in real time with higher survey efficiency. The data manager, on the other hand, can monitor the survey in progress, keep reminding the surveyors to make constant rolling adjustment, thereby enhancing the overall quality of the investigation.
In addition to talent cultivation and enhancement of survey tools, appropriate management mechanisms are needed to regularly track the progress of the surveyors for task planning and assignment. Periodical data sampling inspections are performed to optimize the survey efficiency.
III. Applications of Agricultural survey Data
The use of mobile devices on individual cases based on cadastral records can greatly improve the applicability and accuracy. The data managers confirm the locations of each piece of land, control the data of land area, cadastral information, and land use status, etc. The use of the GIS in conjunction with the spatial information can quickly calculate the survey results by nesting analysis, to accurately measure the locations and crop areas, to use on services that require location confirmation (such as on-site surveys for natural disaster rescues), and even to assist in remote image interpretation; descriptions of which are provided below:
1. Current Crop Planting Status and Yield Forecast
With information of crop area surveys, agricultural administration agencies have a comprehensive understanding of the annual land use situation, crops planted, as well as the distribution and the main planting areas. With the accumulated data and the real-time nature of the survey, they can also monitor economically sensitivity crops and make precautionary measures, or integrate the climate data with the crop growth stages to provide farmers with advanced suggestions. In addition, with the government’s information open policy, the results of agricultural surveys are available for general public inquiries (such as on the information platform of the COA and the agricultural information network of the AFA). Agricultural enterprises and farmers can also use information obtained on the planting areas and distribution of crops, as reference in making decisions on planting or investment in related product development.
2. The Demand and Applications of Agriculture Related Surveys
As information of the geographic space is incorporated in the survey, it can be used on the surveys that require land identification. For instance, survey maps can be drawn for surveys on natural disaster sites, on conversion and fallows, agricultural land inventory, and economically sensitive crop tracking, etc. For cabbage planting distribution positioning, planting area tracking can be performed on a rolling basis for imbalanced production warning. For natural disasters causing paddy field lodging, inventory and survey can be carried out through the rice planting distribution information, which minimizes false declarations and increases convenience and accuracy.
3. Interpretation based on Remote Image Sensing
The remote image sensing technology is widely used now including the satellite telemetric images adopted to analyze crop area surveys. Remote image sensing is particularly powerful in large-area surveys and rapid scanning. Crops in Taiwan, however, are cultivated on complicated terrains mostly on small parcels, and there are a big variety of crops grown in close proximity. Remote image sensing technology has reached a certain degree of recognition accuracy (for example, the recognition rate of the rice field lodging area can be over 90%). Unfortunately, the satellite or aerial imagery cannot yet identify all the crops, particularly where a variety of crops are mixed (for instance, in certain areas crops planted under betel nut trees are hard to identify). On-site data based on the cadastral survey, through spatial overlapping performed through the GIS and the image interpretation results, are used to interpret and adjust the data from two sources to ensure the accuracy. The differences between the field survey personnel and the satellite telemetry images are inevitable because of the different time points of shooting and all the climatic factors. Therefore, a collaboration mechanism is most valuable for the integration of data from both sources.
The agricultural survey can manifest information of crop planting areas and yields. Based on the cadastral survey data combined with the application of mobile devices, more efficient survey methods are adopted to provide accurate information to the crop space database. The information facilitates the advanced management of production and marketing of agricultural products to reach a balance between the supply and the demand.