The word Agronomy has been derived from the two Greek words, agros and nomos having the meaning of field and to manage, respectively. 

 Agronomy is defined as “a branch of agricultural science which deals with principles and practices of field crop production and management of soil for higher productivity.”

 Importance :

Among all the branches of agriculture, agronomy occupies a pivotal position and is regarded as the mother branch or primary branch. Like agriculture, agronomy is an integrated and applied aspect of different disciplines of pure sciences.

 Agronomy has three clear branches namely,

(i) Crop Science

(ii) Soil Science, and

(iii) Environmental Science that deals only with applied aspects. (i.e.,) Soil-Crop-Environmental relationship.

Agronomy is a synthesis of several disciplines like crop science, which includes plant breeding, crop physiology and biochemistry etc., and soil science, which includes soil fertilizers, manures etc., and environmental science which includes meteorology and crop ecology.

Basic Principles

  • Planning, programming and executing measures for maximum utilization of land, labourer, capital and other factors of production.
  • Choice of crop varieties adaptable to the particular agro-climate, land situation, soil fertility, season and method of cultivation and befitting to the cropping system;
  • Proper field management by tillage, preparing field channels and bunds for irrigation and drainage, checking soil erosion, leveling and adopting other suitable land improvement practices;
  • Adoption of multiple cropping and also mixed or intercropping to ensure harvest even under adverse environmental conditions;
  • Timely application of proper and balanced nutrients to the crop and improvement of soil fertility and productivity.

Correction of ill-effects of soil reactions and conditions and increasing soilorganic matter through the application of green manure, farm yard manure, organic wastes, bio fertilizers and profitable recycling of organic wastes;

  • Choice of quality seed or seed material and maintenance of requisite plant density per unit area with healthy and uniform seedlings

; • Proper water management with respect to crop, soil and environment through conservation and utilization of soil moisture as well as by utilizing water that is available in excess, and scheduling irrigation at critical stages of crop growth.

  • Adoption of adequate, need-based, timely and exacting plant protection measures against weeds, insect-pests, pathogens, as well as climatic hazards and correction of deficiencies and disorders

; • Adoption of suitable and appropriate management practices including intercultural operations to get maximum benefit from inputs dearer and difficult to get, low-monetary and non-monetary inputs;

  • Adoption of suitable method and time of harvesting of crop to reduce field loss and to release land for succeeding crop(s) and efficient utilization of residual moisture, plant nutrients and other management practices;
  • Adoption of suitable post-harvest technologies.
  • Agronomy was recognized as a distinct branch of agricultural science only since about since about 1900. The American Society of Agronomy was organized in 1908.

Agronomist “Scientist who studies the principles and practices of crop production and soil management for production of food for human beings and feed for his animals”.

Role of Agronomist

  • Generally agronomist studies the problems of crop production and develops better ways of producing food, feed and fibre.
  • Agronomist aims at obtaining maximum production at minimum cost e.g., developing efficient and economic field preparation method (i.e.) energy should be minimized (i.e.) what type of crop, in what season, etc.
  • Agronomist shoulder the responsibilities of all social, economic, cultural problems in addition to field problems for the effective functioning of the farm in general.
  • Agronomist exploits the knowledge developed by basic and allied, applied sciences for higher crop production.
  • Agronomist carries out research on scientific cultivation of crops taking into account the effect of factors like soil, climate, crop varieties and adjust production techniques suitably depending on the situation.
  • Since, the agronomist co-operates and co-ordinate with all the disciplines of agriculture, it is essential that an agronomist should have training in other disciplines of agriculture also

. • To develop efficient method of cultivation (whether broadcasting, nursery and transplantation or dibbling, etc.) The method may vary according to the germination period and depending upon the crop establishment and what should be the optimum plant population.

  • He has to identify various types of nutrients required by crops, e.g., for long duration rice (150-100–50 kg), for pulses N2, P and K. If the method of cultivation varies the nutrient content also varies. The time and method of applying nutrients must also be taken into account. Method refers to broadcast or to apply close to the root or through leaves (i.e.) foliage.


Potential Yield – It is the maximum possible economic yield for a crop from a unit land area, when all the factors affecting the crop growth and yield are available without any constraints (or) this is the maximum possible yield that could be obtained under controlled condition. Here, all the environmental factors are provided to the crop to express the full potential.

Research yield – The yield obtained in the research station under correct management and supervision by the scientist. Hence, all the technologies are being used by scientists to get maximum yield.

Potential farmers yield – The yield obtained by the progressive farmers under the guidance of scientists using new techniques.

Average farmers yield – Actual yield obtained by the farmer.

Gap I – The latest technologies developed by the scientists are not completely transformed to the extension agency. The extension agency should fill up the gap by advocating the farmers by acquiring themselves with these improved methods of cultivation.

 Gap II – Here, there is no input constraints and only environmental constraints exist.

 Gap III – Variation in management of field and crop.

 Only few farmers get higher yield. Gap can be filled up by improving the socio-economic condition of the farmers

  1. Potential yield
  2. Research yield
  3. Potential farmers yield
  4. Average farmers yield