CHAPTER 3 AGRICULTURAL METEOROLOGICAL DATA, THEIR PRESENTATION AND STATISTICAL ANALYSIS 3.1 INTRODUCTION 3.2 DATA FOR AGRICULTURAL METEOROLOGY Agricultural meteorology is the science that applies knowledge in weather and climate to qualitative Agrometeorological data are usually provided to and quantitative improvement in agricultural users in a transformed format; for example, rainfall production. Agricultural meteorology involves data are presented in pentads or in monthly meteorology, hydrology, agrology and biology, amounts. and it requires a diverse, multidisciplinary array of data for operational applications and research. 3.2.1 Nature of the data Basic agricultural meteorological data are largely the same as those used in general meteorology. Basic agricultural meteorological data may be These data need to be supplemented with more divided into the following six categories, which specific data relating to the biosphere, the envi- include data observed by instruments on the ground ronment of all living organisms, and biological and by remote-sensing. data relating to the growth and development of (a) Data relating to the state of the atmospheric these organisms. Agronomic, phenological and environment. These include observations physiological data are necessary for dynamic of rainfall, sunshine, solar radiation, air modelling, operational evaluation and statistical temperature, humidity, and wind speed and analyses. Most data need to be processed for gener- direction; ating various products that affect agricultural (b) Data relating to the state of the soil envi- management decisions in matters such as crop- ronment. These include observations of soil ping, the scheduling of irrigation, and so forth. moisture, that is, the soil water reservoir for Additional support from other technologies, such plant growth and development. The amount as geographical information and remote-sensing, of water available depends on the effective- as well as statistics, is necessary for data process- ness of precipitation or irrigation, and on the ing. Geographical information and remote-sensing soil’s physical properties and depth. The rate data, such as images of the status of vegetation of water loss from the soil depends on the and crops damaged by disasters, soil moisture, and climate, the soil’s physical properties, and the the like, should also be included as supplementary root system of the plant community. Erosion data. Derived agrometeorological parameters, such by wind and water depends on weather factors as photosynthetically active radiation and poten- and vegetative cover; tial evapotranspiration, are often used in (c) Data relating to organism response to vary- agricultural meteorology for both research and ing environments. These involve agricultural operational purposes. On the other hand, many crops and livestock, their variety, and the state agrometeorological indices, such as the drought and stages of their growth and development, index, the critical point threshold of temperature as well as the pathogenic elements affect- and soil water for crop development, are also ing them. Biological data are associated with important for agricultural operations. Weather phenological growth stages and physiological and climate data play a crucial role in many agri- growth functions of living organisms; cultural decisions. (d) Information concerned with the agricultural practices employed. Planning brings the best Agrometeorological information includes not only available resources and applicable production every stage of growth and development of crops, technologies together into an operational farm floriculture, agroforestry and livestock, but also the unit. Each farm is a unique entity with combi- technological factors that affect agriculture, such as nations of climate, soils, crops, livestock and irrigation, plant protection, fumigation and dust equipment to manage and operate within the spraying. Moreover, agricultural meteorological farming system. The most efficient utilization information plays a crucial role in the decision- of weather and climate data for the unique making process for sustainable agriculture and soils on a farm unit will help conserve natural natural disaster reduction, with a view to preserving resources, while at the same time promoting natural resources and improving the quality of life. economic benefit to the farmer; 3–2 GUIDE TO AGRICULTURAL METEOROLOGICAL PRACTICES (e) Information relating to weather disasters and carrying out similar research work. At the their influence on agriculture; same time, the existence of these data should (f) Information relating to the distribution of be publicized at the national level and possi- weather and agricultural crops, and geograph- bly at the international level, if appropriate, ical information, including digital maps; especially in the case of longer series of special (g) Metadata that describe the observation tech- observations; niques and procedures used. (d) All the usual data storage media are recom- mended: (i) The original data records, or agromete- 3.2.2 Data collection orological summaries, are often the most The collection of data is very important as it lays convenient format for the observing the foundation for agricultural weather and climate stations; data systems that are necessary to expedite the (ii) The format of data summaries intended generation of products, analyses and forecasts for for forwarding to regional or national agricultural cropping decisions, irrigation manage- centres, or for dissemination to the user ment, fire weather management, and ecosystem community, should be designed so that conservation. The impact on crops, livestock, water the data may be easily transferred to a vari- and soil resources, and forestry must be evaluated ety of media for processing. The format from the best available spatial and temporal array should also facilitate either the manual of parameters. Agrometeorology is an interdiscipli- preparation or automated processing nary branch of science requiring the combination of statistical summaries (computation of general meteorological data observations and of means, frequencies, and the like). At specific biological parameters. Meteorological data the same time, access to and retrieval of can be viewed as typically physical elements that data files should be simple, flexible and may be measured with relatively high accuracy, reproducible for assessment, modelling or while other types of observations (namely, biologi- research purposes; cal or phenological) may be more subjective. In (iii) Rapid advances in electronic technology collecting, managing and analysing the data for facilitate effective exchange of data files, agrometeorological purposes, the source of data summaries and charts of recording instru- and the methods of observation define their char- ments, particularly at the national and acter and management criteria. Some useful international levels; suggestions with regard to the storage and process- (iv) Agrometeorological data should be trans- ing of data can be offered, however: ferred to electronic media in the same way (a) Original data files, which may be used for as conventional climatological data, with reference purposes (the daily register of obser- an emphasis on automatic processing. vations, and so on), should be stored at the observation site; this applies equally to atmos- The availability of proper agricultural meteorological pheric, biological, crop and soil data; databases is a major prerequisite for studying and (b) The most frequently used data should be managing the processes of agricultural and forest collected at national or regional agrometeoro- production. The agricultural meteorology logical centres and reside in host servers for community has great interest in incorporating new network accessibility. This may not always be information technologies into a systematic design practical, however, since stations or laborato- for agrometeorological management to ensure ries under the control of different authorities timely and reliable data from national reporting (meteorological services, agricultural services, networks for the benefit of the local farming universities, research institutes) often collect community. While much more information has unique agrometeorological data. Steps should become available to the agricultural user, it is therefore be taken to ensure that possible users essential that appropriate standards be maintained are aware of the existence of such data, either for basic instrumentation, collection and through some form of data library or compu- observations, quality control, and archiving and terized documentation, and that appropriate dissemination. After they have been recorded, data exchange mechanisms are available to collected and transferred to the data centres, all access and share these data; agricultural meteorological data need to be (c) Data resulting from special studies should be standardized or technically treated so that they can stored at the place where the research work is be used for various purposes. The data centres need undertaken, but it would be advantageous to to maintain special databases. These databases arrange for exchanges of data among centres should include meteorological, phenological, CHAPTER 3. AGRICULTURAL METEOROLOGICAL DATA, THEIR PRESENTATION AND STATISTICAL ANALYSIS 3–3 edaphic and agronomic information. Database ways, including by mail, telephone, telegraph, management and processing and the quality fax