The application of electronic computer in agriculture

Application of electronic computer in agriculture

Application of computer in agriculture

An important means to promote the scientific management of agricultural production, the automation of agricultural production process control and the modernization of agricultural scientific research and agricultural education. Electronic computers are divided into electronic digital computers and electronic analog computers, generally referred to as electronic digital computers, which are mainly composed of hardware and software. Users input information to the computer through software, and the computer automatically processes the input information under the control of the software, and finally outputs the processing result. The application of computer in agriculture was reported as early as 1946, the first computer in the world came out soon, and it has developed rapidly in the past 20 years. Contemporary computers are characterized by fast operation speed, high precision, strong storage capacity and artificial intelligence such as memory, judgment and reasoning, and are often called "computers". Therefore, it has played a great role in agricultural planning and decision-making, resource survey and monitoring, pest and yield prediction, agricultural information and intelligence data management, agricultural scientific research and teaching. The application of electronic computers in China's agriculture began in the early 1970s, but it was not until the 1980s that better development conditions were obtained. At present, the application field has been gradually extended from planting and animal husbandry to fishery and forestry, from teaching and scientific research to production management, and the application approach has been gradually deepened from scientific calculation to information processing, simulation test and real-time control, and preliminary results have been achieved.

So far, the application of electronic computers in agriculture mainly includes the following aspects.

Numerical operation mainly includes scientific calculation and numerical experiment.

Scientific computing At present, the computing speed of computers is generally several hundred thousand to one trillion times per second, and supercomputers can reach more than 100 million times per second. More and more digits are calculated, and the commonly used 32-bit computer can be accurate to more than a dozen significant digits. Therefore, it is of great benefit to use computers for complex and time-sensitive calculations in agriculture. In the calculation and agricultural engineering design with complex problems, large amount of calculation and high precision, in algebra and matrix operations, differential and integral operations, or in complex statistical analysis (such as regression analysis, cluster analysis, variable analysis and time series analysis) and optimal selection, computers can greatly save time. Time-sensitive calculations, such as weather forecast and pest forecast, often need to collect a large number of observation data and use mathematical models to calculate. In the past, it took 60,000 people to make the calculation results catch up with the three-hour weather change in a place. Today, it takes only tens of minutes to make a four-day weather forecast with a small computer. In order to carry out these calculations, modern computers are often equipped with powerful scientific and engineering computing applications, which are widely used in agricultural research, including GENSTAT, NAG library and SAS. In addition, application units can also write special computer programs according to their own needs, and only need to input the necessary parameters when using them, and the calculation results will be given.

Numerical experiment is to design, analyze and compare the schemes through computer calculation, and select the best scheme from many designs, so as to obtain lower cost and greater benefits. It has been widely used in agricultural engineering, enterprise management and scientific research. A prominent example is the formulation of livestock and poultry feed formula under the guidance of computer: according to the feed stock, the demand of livestock and poultry for various nutrients, the change of market price and other conditions, the relevant data are input into the computer, and then some constraints are put forward, such as specifying the dosage range of a certain feed or additive, controlling the dosage of high-priced or out-of-stock feed and so on. And the computer can give a variety of mixed feed formulas and choose the best formula. In addition, the computer is also used to select the best fertilization scheme, crop planting scheme and production management scheme. Because numerical experiments need to adopt linear programming, integer programming, dynamic programming and other methods, powerful computers are equipped with these calculation programs, which is very convenient to use.

Information processing The information processed by a computer includes numbers, characters, image patterns and sound signals. Sound processing is still under study, and the processing of digital text data and image patterns has been widely used.

Data processing refers to digital and digital-text data processing, also known as data comprehensive analysis. All kinds of statistical data and experimental data obtained in production practice, scientific research and economic activities generally do not need complex mathematical operations, but need to be processed.

Large, fast, in line with the storage, retrieval, editing and other purposes. The data processed by computer in agriculture mainly include: ① environmental and resource information, including water and soil resources information, meteorological resources information, animal and plant resources information, etc. Most of them are relatively stable basic data, which is an important source of information for formulating agricultural zoning planning and production planning. Some countries have established computer databases or data processing systems, which can store and manage hundreds of thousands of crop variety resource information. Relying on the online retrieval network, breeders can transmit the information of new varieties to the database at any time through computer terminals all over the country, find the crop varieties they need, and distribute the variety resource information to all parts of the world. In addition, computer digital land information system and land resource management or geographic information system also play an important role in providing data and information about agricultural natural resources. ② Information on production and economic activities. It is active and dynamic information, and computer database can help to grasp this information accurately and timely and serve agricultural decision-making. Starting from 1983, China began to establish a national database of county statistics and rural survey data. ③ Scientific and technological information. According to FAO 198 1 statistics, as many as 250,000 kinds of new agricultural materials are produced every year in the world. In order to improve the utilization rate of these materials, some countries use large computers or information networks composed of multiple computers for data management, and have established many independent scientific and technological information centers. Some of these networks are within a country or between countries, and they provide agricultural science and technology information to all parts of the country or relevant countries through the network. The Agricultural Science and Technology Information Network (AGRIS) of FAO has 107 member countries, and its computer processing center is located in Vienna. In addition, it has four sub-centers in Southeast Asia and Europe. The computer management of agricultural science and technology information in China is also under experimental study.

Image information processing is a complicated pattern recognition process. Graphics or photos are first enhanced and digitized by a two-dimensional space scanning device, converted into digital signals, and input into a computer; Then the digitized image is compressed by computer, and the feature metrics reflecting the image characteristics are extracted. Finally, after comprehensive analysis and comparison, the image category is determined or discriminated. In agriculture, this method can be used to process the photos taken by airplanes and satellites during the general survey of resources, and to identify land types, vegetation conditions, crop growth and occurrence of diseases and pests. In the past, it took thousands of people to conduct a land use survey of 240,000 square kilometers in Britain, and the working time was as long as six years. 1976, remote sensing and computer pattern recognition technology, only 4 people used it in 9 months. In addition, computer image processing technology can also be used to analyze chromosome photos and EEG to help diagnose livestock and poultry diseases.

Computer simulation technology of simulation test is a powerful means to study the system. The scale and complexity of the system are different. The whole agriculture can be regarded as a large system, and the farm can also be regarded as a production system. The computer simulation research of the system generally includes the following procedures: ① investigate and analyze the studied system, find out the relationship between the objects that make up the system, and establish a mathematical model representing the system through mathematical abstraction; (2) establishing a computer model and writing a computer program according to the mathematical model; ③ Input the data needed to run the system and execute the computer program; (4) Compare the data obtained from the system before or through necessary supplementary tests with the results of computer programs, and modify and confirm the established computer simulation model; ⑤ Study the relationship between the performance of the real system and the main factors in the system by using the determined model, and find out the methods to manage and improve the system.

Agriculture is a complex system involving many factors. The application of computer simulation technology in agriculture and scientific research mainly has the following functions: ① It can help to choose the experimental scheme of long-term and high-cost experiments. For example, in the study of the genetic behavior of the hybrid offspring of crops and livestock and poultry varieties, researchers can calculate the genetic behavior of the hybrid offspring, including the performance and genetic segregation of the offspring, thus greatly saving the time and materials of the experiment. ② It can be used to predict the results of experiments that cannot be carried out in the field due to conditions. If a computer model is established according to the relationship between crop yield and the main influencing factors of pests and diseases, and then the corresponding data is input according to the actual situation, the crop yield or the occurrence trend of pests and diseases can be predicted. Some countries have successfully predicted the diseases and insect pests of rice and citrus, described the migration behavior of pests in the field, and calculated the field concentrated application area (trapping area) and time corresponding to different kinds of pests. China has also started computer forecasting research, and the established models of the relationship between wheat yield and meteorological factors, the daily infection rate model of wheat stripe rust, and the damage model of rice blast and stem borer have been applied in a small scale. (3) For important, but risky, research that cannot be carried out rashly, preparatory experiments can be carried out by computer. For example, in agricultural economic research and production management, establishing a computer model to simulate the current agricultural policy can analyze the relationship between supply and demand of major agricultural products and their price and output balance, which is helpful to formulate long-term strategic planning. For example, America's "national-regional agricultural planning system" model, Indonesia's land consolidation model and Cuba's sugar industry model all belong to this category. China is also studying the establishment of an optimized model for farm or county production management and a nationwide "strategic model for developing grain and cash crops" to serve the formulation of agricultural development strategies. Various specialized simulation languages, such as GPSS, GASP, CSMP, etc. , which is produced to adapt to computer simulation technology, can make it more convenient to write simulation programs than to use general algorithm language.

Real-time control is also called process control. That is, in production and scientific experiments, the main parameters in the system are detected and collected in time by computer, and automatically adjusted according to a predetermined standard state or optimal value, so as to realize control automation. Real-time control plays a particularly important role in horticultural cultivation and livestock and poultry raising. Due to the intensive and industrialized production in this field, it is required to automatically control and comprehensively adjust environmental conditions such as temperature, humidity and light, as well as the supply of water and nutrients. Many production units often use single board computers or microcomputers to achieve this goal. The method is to continuously input various parameters measured in greenhouses and barns into the computer, and the computer will compare them with the ideal values determined by pre-programmed programs. If they are not consistent, it will send out an alarm or adjustment signal, control the adjustment parts, and automatically carry out operations such as ventilation, shading, water supply and feeding, so as to ensure that the system is in an ideal state. In addition, some agricultural machinery, such as grain dryers and tractors, can also be automatically controlled by a single board computer to improve their working performance. Large-scale precision instruments used in scientific research, such as various spectrometers and neutron activation devices, can automatically collect and process data after being equipped with special microcomputers, which also greatly improves the use efficiency.

CAD design graphics are essentially composed of coordinate systems and points. An electronic computer can store thousands of points of data. If you specify the position of a point in the coordinate system, the computer can draw extremely complicated graphics. According to this principle, computer-aided design is completed by a computer system, which is equipped with a display with a light pen and a plotter. It is often used in agricultural engineering to help design barns, agricultural machinery and water conservancy facilities.