Agro-Climatic Zones and Land Use of India: Exam Notes

Agriculture in India is not one activity but many, because rainfall, temperature, soil and water differ sharply from the Punjab plain to the Kerala coast. To plan for those differences the country is divided into agro-climatic zones, and the way its surface is actually used is recorded under the nine-fold land use classification. Both are standing favourites in geography and economy papers because the facts are fixed: the number of zones, the states in a zone, the meaning of each land use head and the formula for cropping intensity.

What an agro-climatic zone is

An agro-climatic zone is an area that is uniform enough in rainfall, temperature, soil type, water resources and existing cropping pattern to be planned for as one unit. The purpose is practical: a package of crops, seeds, irrigation and credit that suits the zone as a whole. The best known division is the one the Planning Commission adopted in 1988 for agro-climatic regional planning, which split the country into fifteen zones. Earlier the Indian Council of Agricultural Research had grouped the country into eight agro-climatic zones on broader climatic lines, and the National Bureau of Soil Survey and Land Use Planning later delineated twenty agro-ecological regions, divided further into sixty sub-regions, by adding soil and length of growing period to climate. Remember all three numbers with the body that gave them: fifteen for the Planning Commission, eight for the ICAR and twenty for the agro-ecological regions.

The fifteen agro-climatic zones

Zones inside the states

States zone themselves again for their own agriculture departments, and state examinations ask these sub-zones. Rajasthan is divided into ten agro-climatic zones, numbered as the arid western plain, the irrigated north western plain, the hyper arid partially irrigated zone, the transitional plain of inland drainage, the transitional plain of the Luni basin, the semi arid eastern plain, the flood prone eastern plain, the sub humid southern plain, the humid southern plain and the humid south eastern plain; the flood prone eastern plain, written as zone three B, covers Alwar, Bharatpur, Dholpur, Karauli and Sawai Madhopur. Uttar Pradesh is divided into nine agro-climatic zones, from the Bhabar and Tarai belt to the Bundelkhand and Vindhyan zones.

The nine-fold land use classification

Village land records, collected by the states and published as land use statistics, put every parcel of the reporting area into one of nine heads.

Net sown area, gross cropped area and cropping intensity

The geographical area of India is about 328.7 million hectares, but land use records cover a smaller reporting area because some areas are not surveyed. Net sown area is about 140 million hectares, close to 46 per cent of the reporting area, the largest of the nine heads. Gross cropped area counts a field as many times as it is sown in the year, so it is larger than the net sown area, and the relation between the two gives the standard formula: cropping intensity equals gross cropped area divided by net sown area, multiplied by one hundred. For India it works out to roughly 140 per cent, which means a good part of the sown land carries a second crop. Barren and unculturable waste, permanent pastures and culturable waste land have all shrunk over the decades, while land put to non-agricultural uses has grown steadily with towns, roads and industry. The National Forest Policy of 1952 set the target of keeping one third, that is 33 per cent, of the geographical area under forest, with 60 per cent in the hills and 20 per cent in the plains; the area recorded as forest in land records has stayed well below that target.

Crop seasons

• Kharif, sown with the onset of the south west monsoon in June and July and harvested in September and October: rice, jowar, bajra, maize, cotton, groundnut, soyabean, tur.
• Rabi, sown in October and November on residual and irrigated moisture and harvested in March and April: wheat, barley, gram, mustard, peas.
• Zaid, the short summer season between rabi and kharif on irrigated land: watermelon, muskmelon, cucumber, fodder and vegetables.

Why the zoning matters

Agro-climatic planning is the reason a dry zone gets millets, watershed work and drought resistant seed while a canal irrigated zone gets rice and wheat, and it is also the basis of the warning against growing a water hungry crop in a low rainfall zone, as with paddy in parts of the Trans-Gangetic plain. For an aspirant the examinable core is small and fixed: the number of zones under each body, which states fall in which zone, the nine land use heads with the five year rule that separates culturable waste from fallow, and the cropping intensity formula.