AGRON 101 Agroclimatic zones of India and agro ecological zones

Agro climatic zone

1. B.Sc (Ag.) Course FUNDAMENTALS OF AGRONOMY (3+1) Topic: AGRO-CLIMATIC ZONES OF INDIA Faculty : Dr Sourav Ghosh, Scientist, ICAR-CRIJAF

2. Agro climatic zones in India ‘ Agro -climatic zone ’ refers to a land unit in terms of its major climate , superimposed on the length of growing period ( moisture availability period); The Planning Commission of India, divided the country into 15 broad agro -climatic zones based on physiography and climate. These are further divided into more homogeneous 72 sub-zones. The main objective was to integrate plans of the agro -climatic regions with the state and national plans to enable policy development based on techno- agro -climatic considerations. 

3. Agro -climatic and agro -ecological regions The Planning Commission of India, divided the country into 15 broad agro -climatic zones based on physiography and climate. National Agricultural Research Project (NARP) was launched by ICAR for initiating agricultural research in the agro -climatic zones of the country . The objective was to set up or upgrade a zonal research station in each agro -climatic zone for generating location specific, need based research targeted for specific agro -ecological situations. In NARP, the country was divided into 127 agro -climatic zones .

4. Agro -ecological regions The National Bureau of Soil Survey & Land Use Planning (NBSS&LUP) came up with 20 agro -ecological zones which were sub- divided into 60 sub-zones . Based on the four parameters, a) Physiographic features, b) Soil characteristics, c) Bio-climatic features, d) the Length of Growing Period.

5. Methodology for delineation of Agro -ecological zone Four basic maps i.e. soil , physiography , length of growing period (LGP) and bioclimate are required to delineate agro -ecological regions (AER) (Sehgal et al. 1992) Criteria used for agro -ecological delineation Soil Physiography Bioclimate LGP Agro -ecological Regions (AER) of India (20 AER) For resource planning at national level Great group association (1:7 m scale) Broad 15 divisions Arid, Semi-arid, Subhumid, Humid, Per humid (Thornthwaite and Mather, 1955 and Penman PE) <90 days 90-150 days 150-210 days > 210 days Agro -ecological sub-regions (AESR) of India (60 AESR) For resource planning at regional level Sub-group association (1:1 m scale) Sub division Arid, Typic arid, hyper arid, dry semi arid, moist semi arid, sub-humid, dry humid, moist humid, per humid. <60 days (with 30 days interval) to > 330 days