Syed Sheraz Mahdi

Measurement of Sunshine Duration

Sunshine duration is the length of time that the ground surface is irradiated by direct solar radiation (i.e., sunlight reaching the earth’s surface directly from the sun). The instruments and accessories are required for measurement of sunshine duration have been explained. The installation of these instruments as well as the procedure for taking the observations has been discussed.

Measurement of Precipitation

Precipitation denotes all forms of water (liquid or solid) that reach the earth from atmosphere. Precipitation includes rain, snow, hail, dew, fog, drizzle etc. Of all these only rain and snow contribute significant amount of water on the earth. The chapter explains different forms of precipitation and the instruments and techniques associated with their measurement. Different methods used for analysis, presentation and trend analysis of rainfall data are discussed.

Measurement of Wind

Wind plays an important role in crop evapotranspiration and thus determines crop water use. The measurement of wind is thus necessary for studying the crop growth. The chapter deals with the measurement of wind speed and direction and the instruments used for the same. The units used for expression of wind speed and their correlation have been given. The chapter also introduces wind rose and Beaufort Scale.

Measurement of Soil Moisture

The water present in the interstices of the soil matrix constitutes the soil moisture. It is one of the most important constituents of the soil. The water stored in the root zone is used by the plants for photosynthesis, evapotranspiration and building of its tissues. Soil properties such as soil moisture content, texture, structure density, fertility, salinity aeration, drainage and temperature have a pronounced effect on growth and yield responses of a crop. The chapter describes the methods and techniques for determination of soil moisture content and expression of soil moisture content.

Measurement of Atmospheric Pressure

The atmospheric pressure on a given surface is the force exerted per unit area by the weight of the Earth’s atmosphere above. Atmospheric pressure is an important parameter for studying weather of a location and its interaction with the crops. The chapter includes various types of barometers used for the measurement of atmospheric pressure. The relation between atmospheric pressure and weather has been discussed in brief.

Agro Meteorological Advisory Service

The Agro-meteorological Advisory Service (AAS) rendered by India Meteorological Department (IMD), Ministry of Earth Sciences (MoES) is a mechanism to apply relevant meteorological information to help the farmer make the most efficient use of natural resources, with the aim of improving agricultural production; both in quantity and quality. A brief introduction to Agro meteorological Advisory Service, Information Support Systems under AAS and Database provided by AAS is given.

Measurement of Temperature

Temperature symbolizes the thermodynamic condition of a body. The direction of the net flow of heat between two bodies determines the value of temperature. For meteorological purposes, temperatures are measured for a number of media. The most common variable measured is air temperature (at various heights), ground, soil, grass minimum and seawater temperature. The chapter describes measurement of temperature of air and soil required for agro-meteorology. Various instruments used for measurement of air and soil temperature have been discussed.

Growing Degree Days to Forecast Crop Stages

Plant development depends on temperature. Plants require a specific amount of heat to develop from one point in their life-cycle to another. The ability to predict a specific crop stage, relative to insect and weed cycles, permits better management. This is especially important when three or more crops are being grown on the same farm, each with a different management schedule for pesticide application, fertility management and harvest. The chapter introduces the concept of growing degree days, and other thermal indices used to study and monitor plant growth.

Agro-climatic and Agro-ecological Zones of India

India exhibits a variety of land scopes and climatic conditions those are reflected in the evolution of different soils and vegetation. These also exists a significant relationship among the soils, land form climate and vegetation. Regions are delineated such that each one is as uniform as possible with respect to physiographic, climate, length of growing period (LGP) and soils for macro level and land use planning and effective transfer of agro-technology. Various Agro Climatic Zones of India according to the planning commission of India have been explained along with the classification by Indian Council of Agricultural Research. A section on Agro-ecological Zones of India has been included. The chapter also introduces the Agro-Climatic zones of Jammu and Kashmir and the Micro Agro-Climatic zones of the state. The State of Jammu and Kashmir is located almost in the middle of three climatic regimes of Asia. The chapter introduces the Agro-Climatic zones of Jammu and Kashmir based on physiography. Each province of the state of Jammu and Kashmir has been further delineated into micro agro-climatic zones which have been discussed.

Crop Yield Forecast Models

In agro-meteorological research, the crop models basically help in testing scientific hypothesis, highlight where information is missing, organizing data and integrating across disciplines. The crop growth models can be used to predict crop performance in regions where the crop has not been grown before or not grown under optimal conditions. The chapter introduces Crop Simulation Models and their applications.