Geography and Climate
This zone covers the hilly regions, namely,
- The Nilgiris,
- Elagiri - Javadhu hills,
- Pulneys and
- Podhigai malai.
The Hilly and Tribal agro - climatic zone shows considerable diversity in physiography, climate, soils, irrigation , rainfall, cropping pattern, etc., This necessitates the delineation of the agro -climatic zone into a number of agro -ecological situations each as homogenous as possible. Since the diversity in soils,rainfall and physiography is large, these factors are considered as basis for delineation of the zone into agro - ecological situations.
The major soil types occurring in this zone are:
- Laterite in Pulney Hills, Anamalais
- Laterite in (Deep to very deep no calcareous Loam to clay loam in texture ) in Kolli hills,
- Laterite soil with loam to clay loam in texture in Pachamalai
- Dark Reddish Brown in Shevroys,
- Reddish Brown Soil - non calcareous fine, loamy in texture in Kalrayan hills.
- Red loam clay and sandy soil in Javadhu Hills.
- Red loam - sandy loam to loam in texture in Pothigai Hills.
- Reddish Brown with Loamy in texture in Megamalai
The rainfall varies from 850 mm in Kalrayan Hills to 4500 mm in Anamalai Hills.
The zone consists of eight hill sub zones as indicated earlier with different topographical features, Variations occur in soil, altitude and rainfall and with different farming practices.
Districts and Blocks Covered
|1.||Nilgiris district||Nilgiris Hills|
|3.||Dindigul||Lower Pulney Hills|
|4.||Dindigul||Upper Pulney Hills|
|9.||Vellore||Yelagiri and Javadhu Hills|
|11.||Tirunelveli and Kanyakumari||Pothigai hills|
The Nilgiris district known as "The Queen of Hill Stations" is situated at an elevation of 900 to 2636 meters above MSL. Approximately 65% of the geographical area of this district lies at an altitude of above 1800-2500 meters above MSL and the remaining 35% at lower altitude. The climate is temperate to sub-tropical. The average annual rainfall ranges from 950 to 1550 mm. The total geographical area is 2,54,381 ha.
Ooty subdivision is located at an elevation ranging from 950 m (Masanagudi) to 2200 m Ooty from MSL. The maximum temperature ranges from 16.6 to 28°C and the minimum temperature ranges from 9 to 0°C during the winter months of November to February. The source of irrigation mainly depends on the summer showers, South West and North East monsoons.
The average annual rainfall ranges from 900 mm to 2000 mm of which about 30% is received during the South West monsoon period. The incessant rains throughout the seasons leads to the formation of rivers like Bavani, Moyar, Kundha, Pykara and various other streams supplement water for drinking and irrigation. Pykara, Mayar and Kundha rivers contribute for the hydro-electric projects enhancing the socio-economic status of the state.
There are three distinct agroclimatic regions.
- The Thuneri firka which is a rain shadow area.
- The Kundha firka which receives moderate rainfall.
- Ooty urban area which receives heavy rainfall.
The predominant soils of this taluk are lateritic loam of kaolonite origin. The fertility status of the soil is medium to high with limitation of nutrition retention capacity due to its loose and friable structure and topography. The soil reaction is acidic and the pH ranges from 3.8 to 6.2. Due to this acidic condition most of the applied phosphorus is fixed in the soil and not readily available to the crops.
Coonoor sub division is situated in Eastern part of the Nilgiris District with elevation ranging from 4000 feet to 6000 feet above mean sea level. The average rainfall ranges from 1200 mm to 1500 mm. It receives rain mostly in the North Eastern Monsoon. The temperature ranges from 20°C to 28°C in Summer from 0°C to 15° during Winter. Slight ground frost is noticed during December and January. The relative humidity ranges from 85% to 100%. Wells continue to be the major source of irrigation.
Plantation crops like tea and coffee, hill vegetables like potato, cabbage and carrot and Temperature Fruits like plum, pear, peach and mandarin orange are being grown in the sub division.
Kotagiri sub division comes under two taluks in the Nilgiris. It comprises 14 revenue villages in Kotagiri Taluk and Kukul Revenue Village in Ooty Taluk. It is surrounded by Erode District in the North and East, Coonoor and Ooty Taluks in the West and Coimbatore District in the South.
The average rainfall of this sub division is 1210.5 mm in 75 rainy days. The maximum temperature ranges from 10°C to 30°C and the minimum temperature ranges from 2°C to 14°C. The main soil type is lateritic red loam, the pH ranges from 3.9 to 7.5. Due to the receipt of adequate rainfall both during South West and North East monsoons and congenial agro-climatic conditions, foreign exchange earning crops like Tea and Coffee are grown on a large scale. The main crops cultivated in this tract are Tea, Coffee and Fruits like Pear, Mandarin Orange and Hill vegetables like Potato, Cabbage, Carrot, Beans and Minor vegetables like Beetroot, Turnips and Knol khol. Thengumarahada village forms part of Kotagiri Taluk. Due to the tropical climate that prevails here crops like paddy, groundnut, soya bean and marigold are cultivated. Spices crops like pepper is being introduced in this sub division.
Gudalur sub division forms a part of Nilgiris District meeting on the Western ghate at a distance of 50 km from Ooty on the way to Mysore and Kozhikode. It is mainly a hilly region with flat lands enjoying a salubrious climate of sub tropic during most part of the year. The elevation is from 950 to 1500 m. The total geographical area of Gudalur Taluk is 72,171 hectares of which 53.0% in forest and uncultivable land and 56.0% is cultivable area. Out of the total cultivated area 65.7% is under perennial and 14.3% is under annuals. The normal rainfall is 2300 mm per annum. While 75% of the rain is received during the South west monsoon, contribution of North east monsoon is only 15% to the total of rainfall and 8% of the rains are received during the hot weather and 2% during the winter.
Lower Pulney Hills
The Pulney hills (of Western Ghats) is situated in Kodaikanal Taluk of Dindigul District. The hills lie between 10°-5’ and 10°-25’ North and 77°–15’ and 77°-50’ East. The Pulney hills are an eastward off shoot of 65 km length and a width of 40 km (mean width of 24 km), and an area of 2068 sq.miles. The hills are divided into two district geographical zones viz., The Upper and Lower Pulneys. The Lower Pulneys include the revenue villages of Kamanur, K.C. Patti, Pannaikadu, Pachalur, Poolathur, Periyur, Thandigudi, Vada kavunchi and Vellagavi.
The Lower Pulneys consist of a confused jungle of peaks from 1000 to 1500 M height separated from one another by steep wooded vallyes. These hills are some times designated as Thandigudi and Virupatchi hills. The Lower Pulney hills enjoy a subtropical climate, with a maximum temperature of 20 oC to 30 oC, and a minimum of 15 oC to 20 oC. The rainfall is around 1455 mm. Nearly, 43 to 46% of the rainfall is received during the North East monsoon. The South West monsoon, summer showers and winter season rains account for 25%, 22% and 5% respectively.
Upper Pulney Hills
Soil of Palani Hills falls under the brood soil group "LATERITE" Soil are very deep and the surface texture ranges from loam to clay loam. The color of the soils ranges from brown (7.5 YR 4/4) to black (2.5 YR 2/0) depending from the organic matter contend of the soil. The strawelure of the surface soil is in general splroidal in nature. The soil are friable under moist condition and offers no resistance for root perpetration. The colour of the B horizon soil ranges from dark yellowish brown (10 YR 3/4) to yellowish red (5 YR 5/6) with texture ranging from sandy clay loam to clay loam. The structure in generally blocky in the 'B' horizon. The soils are generally well drained with moderate to very rapid permeability. Morphological examination of soils reveals no visual soil physical problems such as surface hardening crusting sub surface hard panel. The morphological descriptions of soils examined in different transacts of pulney hills are given in.
The soils are acidic to near neutral in reaction (pH 4.25 - 6.6) and are non saline (Electrical conductivity 0.04 to 0.39 mbs/cm). The available nitrogen status ranges from 408 to 2038 kg /ha with very high proportion falling under high status. Available phosphorus is low to medium and available potassium is low to high. As regards to micronutrients, iron is present in sufficient level and the contents ranges from H to 200 ppm and copper content ranges from 0.8 to 80.0 ppm. Very low percentage of the area was found to be deficient in copper (<1.2ppm) and manganese (<2 ppm). Zinc content ranges from 0.3 to 3.15ppm with high percentage of area deficient in zinc (< 1.2ppm)
The Anamalai Hill Region is situated in the Western Ghat, and belongs to Coimbatore District of Tamilnadu. This hill zone lies between the latitude 10° 10 - 30 North and longitude 76°30 and 77°0 East. This Hill is situated in Pollachi Taluk of Coimbatore District and is surrounded by Kerala state in the west and south and Udumalpet Taluk in the East.
The total geographical area of this hill zone is 97280 acres, and the altitude ranges from 800 to 1200m. above MSL. Valparai is the only revenue village in this hill zone and there are about 60 estates in this region. Valparai is situated about 110km. from Coimbatroe and 70km from Pollachi.
Top Slip is the highest point in Anamalai Hills. The Hills is abounded with dense forests, which is responsible for the highest amount of rainfall. The annual mean maximum temperature of this Hills zone is 28°C and the annual mean minimum temperature is 13*C, The relative humidity ranges from 50-90%. High and evenly distributed rainfall is observed in the Anamalai Hills. This zone is benefitted by both the monsoons. Southwest and Northeast monsoon, An average rainfall of 400m I received annually with a range of 3000mm to 4500mm. South west monsoon is most effective accounting 77% of the total rainfall.
The Soil type in Anamalai hills is mostly acidic (ph ranges from 4.5 to 5.5 in tea plantations and 5.5 to 7.0 in other plantations.)
The soils are lateritic, Kaolinite clay predominates. The soil is rich in iron and aluminium. Because of the porous nature of the soil and continued heavy rainfall, The nutrient “K” is leached out and there is no fixation of “K” in this Kaolinite type clay. There is zinc deficiency in the soils which needs to be supplemented through foliar sprays.
Kolli hills is one of the developing blocks situated in Namakkal and Rasipuram taluks. The total population of this block is 28,499 of which Scheduled Tribes constitute 27,202 i.e., 95.45% of total population. The total area of the block is 22,793ha. of which forest constitutes about 4688 ha. It lies at a longitude of 78.20’ to 78o.30’E and a latitude of 11o-10’ to 11o-30’ N. There are 14 villages and 247 hamlets in this block. Agriculture is the principal occupation of the people. The temperature prevailing here is conductive for pine - apple, coffee, banana citrus etc., Among the food crops, paddy, ragi and samai are the major crops.
Kolli hills, which is located on the south eastern side of the Salem District contains peaks over 1,300m. The dense forest reserves of this hills. yield good fuel and timber yielding trees. The general slope of the hill is grading towards west and southwest.
A tropical monsoon climate prevails in this area, with mild to pleasant temperature, which is conducive, for raising horticultural crops like pine - apple, coffee, etc..,
The Mean annual temperature ranges from 14oc to 28oC. The average annual rainfall of the hill is around 1600mm of which a major portion is obtained during the months of September. October and November. The soils are deep to very deep to very deep, non- calcareous and developed from weathered gneiss. Colour of surface soil ranges from reddish brown to dark yellowish brown and texture, Loam to clay loam. They are excessively drained externally with moderate permeability. Reaction is strongly medium acid. the foot hills, and soil is very deep, clayey and saline alkaline in nature. These soils are poor in drainage.
The entire Kalrayan hills are divided into two by a valley running Eastward to pappanaickanpatti. The Chinnkalrayan forms a similar pattern which is cut into two by a lofty ridge. The northwest portion is called Melnadu. and Southwest portion is called Kilnadu. The elevation of the hills ranges between 760m - 1370m above mean sea level. Of the total geographical area, forest land accounts for about 42.02% while the net cultivated area comes to about 21.42%. It enjoys a mild tropical climate with a mean annual rainfall of about 860mm. The Major share of rainfall is obtained during north east monsoon period especially in the months of October and November.
The soil in the hill is reddish brown to dark red, shallow to moderately deep, fine loamy, non - calcareous, excessively drained and subjected the severe erosion and run off. In the bottom of the valley, the soils are red to dark reddish brown, very deep, fine loamy to fine non - calcareous moderately well drained and subjected to soil deposition. In general, the soils have a low nutrient status and are badly affected by erosion.
Generally the elevation of Pachamalai ranges from 1000 metres above MSL to 1200 metres. This has wooded Jungle with dense forests.
A Sub - tropical climate prevails with a maximum temperature ranging between 23 to 31oC, And a minimum temperature range of 12oC to 18oC. The annual rainfall varies with years. A maximum of 1250 mm. had been recorded so far in the past ten years. Generally Maximum amount of rainfall is received only during Northeast monsoon (i.e.,) in the months of September, October and November. Southwest monsoon rains are received during the months of June, and August. The northeast monsoon rains are however more dependable
The soils are classified as hill soils. The surface soil is reddish brown to dark yellowish brown in colour with a texture ranging from loam to clay loam; soil depth is about a meter and the soil reaction is near neutral (6.5).
Yelagiri and Javadhu Hills
Yelagiri and Javadhu hills are within the district boundaries of Vellore District. the Yelagiri hills is situated in the Jolarpet Panchayat Union of Thirupattur taluk, surrounded in the north, west and south by Vaniambadi taluk, This hill is situated 92 km. east of vellore and 30 km. West of Tirupattur. It has only one revenue village namely Athanavoor with thirteen hamlets. It has an area of 51 square km.
Javadhu hills are spread over five taluks namely Thirupattur, Vaniambai, Vellore, Polur and Chengam. It is surrounded in the North by Thirupattur and vellore taluk and in the Southwest and west by part of Thirupattur taluk. This hill lies between 78.35o and 79.35o East longitude and 12.24o and 12.55o North Latitude with an area of 2405 square km. It has fifty revenue villages. The Government of Tamil nadu (in G.O.Ms.No.598, Rural Development dt.29.07.85) has constituted a new Panchayat Union by name Jamunamarathur Panchayat Union comprising of all the hill and tribal villages of Javadhu Hills with head quarters at Jamunamarathur Mainly for the welfare of the Hill tribes of Javadhu hills. It is 54km. west of Tirupattur via. Alanagayam.
The Yelagiri hills situated in Jolarpet Panchayat Union of Tirupattur taluk, have a district geographical unit and have an elevation of about 1411m. It has an area of 51 square km. of which 3297.68 ha. are under reserve forest. The hill villages are situated mostly at an elevation of 1889 meters.
The Javadhu hills have an elevation of 762 meters. The highest points in this hills are pattimals Vellanda Ponmalai and Pudur Nadu which have an elevation of 1094 meters. The hill has an area of 2405 square km. of which forests constitute 14 percent. The Javadhu hills contain sandalwood trees which grow widely due to the favourable topographic situation. In the Plateau Region of Kavaloor, an astronautical observatory has been established which is the biggest in southeast Asia.
The temperature of Yelagiri hills during summer (April) reaches 27oc and the minimum temperature goes down in winter (December - January) to 11oC. It is comparative dry climate with low humidity of 45-50. The mean annual rainfall for Elagiri hills is 1026.16mm. with maximum of 131.8 mm during South West monsoon and 333.7 mm during Northeast monsoon. Javadhu hills enjoys an equable climate . During the cold season there is a substantial amount of dewfall which generally benefits the vegetation. The mean maximum temperature is 36.6oC Minimum temperature ranges from 20.7oC to 26.0oC, The mean annual rainfall for javadhu wills is 1100.85 mm with 480mm in south west monsoon (June - September) and 429mm in North east monsoon (October - December).
About 50 percent of the land area is red loam clay and sandy soil, roughly constituting 13 and 12 percent respectively, This type of soil is derived basically from felspar and hormablend. In this plateau regions near Kavaloor and Nellivasal in Javadhu hills, the soil is derived basically from felspar and hormblend and the soil is fairly loamy. In the valleys near Paramanadal and Channasamudram, the soil is clayey. It has been observed that mineral resources such as Sulphides, Quartz,Haryte, apatite and vermiculite occur in areas adjoining Tirupattur units of these hills.
The sub-zone of Megamalai region consists of Megamalai Hills, Highways estate, Manalar Estate and Venniar Estates of the Tea Estates of India, Megamalai Villages and Highways Township. This sub-zone lies in two taluks of Uthamapalayam and Periyakulam of Theni District. The elevation of the Hill range from 290 to 1980 MSL.
Stretching between the Surliar river on the west and Vaigai river on the East in Periyakulam taluk, bordering Kerala on the South near Thekkadi and Periyar wild life sanctuary, this zone extends up to Surli Forest and Gandamanaickanur Reserve Forest on the North and Northeast. The two main rivers in this zone are surliar river on the west and Vaigai river on the East. Legend says that ‘Kannagi’ the heroine of the great epic Silappathigaram, travelled to Kerala above Gudalur from Madurai through the river banks of Vaigai. On the west, the Surliar river is joined by Veeravan river from Thekkadi and passes through Megamalai. There is a storage dam at Surliar Lower camp.
The elevation of the Hilly region in this zone varies from 1000m to 1800mt. Megamalai lies in Kadamalaigundu Mayiladumbarai, Panchayat Union of Periyakulam Taluk. The tea estates of India has an assigned area of 4297.5 ha. in Narayanathevanpatty village of Cumbum panchayat union in Uthamapalayam taluk.
This zone is sub tropical with cool climate during winter months, the temperature going down to 6oc during December - January. The maximum temperature goes upto 32oC during April. The average humidity is from 40 to 100%. Wind is normal throughout the year but high velocity is experienced during July - August. This high velocity has been considered as one of the constraints by the tea planters. The mean annual rainfall in Megamalai hills is 745.91mm of which 64.00 percent is received during Northeast monsoon.
The soil texture in Megamalai hill region is loamy with 20 to 120 cm. depth. In the hilly region, the top soil appears to be black because of the high humus content. Below the depth of 15cm. the soil is red load. Depth of the soil varies from 60cm to 120cm. The slope ranges from 20 to 50 percent which encourages soil erosion.
The Pothigai hills are situated in Tirunelveli District and traditionally called as “Agasthiya Malai” . This hill zone lies between 8.25o and 9.10 of the Northern Latitude and 77.89 and 78.25 of the Eastern longitude. It is flanked by the Kanyakumari District in the south. by the ranges of Eastern ghast with the Kerala state on the west.
The prominent hills are part of the Western Ghat and form the boundary between Kerala state and this district of Tirunelveli on the western side. The Altitude of Pothigai hills is 6132 ft.
The Climate in this hill sub - zone is equitable. Thousands of people from all over Tamil nadu and even from other states visit the popular Courtallam falls during June -August to enjoy in the showers of the waterfalls (Saaral). Minimum temperature is 14oC during January and the maximum is 34o c during May. The humidity is 65-80% during October November and below 60% during January - March. This hill receives rains during both the monsoons. The average rainfall in the hills at Shenkottai and at Ambasamudram is around 1400 - 2000 mm. Around 65% of the rainfall is received during North East ,monsoon.
The hill areas comprises two major groups of rocks viz. the knondalities and the charnockites with pyrozeno granulites and the associated migmatistic rocks. Bands of quart zites and crystalline limestones occur with the geneiss and are found around Ambasamudram.
In Shengottai, deep red soils, in patches on hill slopes and mountains are formed. In Ambasamudram Sandy loam to loam in texture due to alluvium deposits are found which are acidic in reaction.
Crops in Nilgiris
The topography of this district is rolling and steep. About 60% of the cultivable land falls under the slope ranging from 10 to 33%. Nilgiris, being basically a Horticultural District, the entire economy depends on the success and failure of horticulture crops like
- Spices and
Crops in Shervroys
Coffee is the major crop grown in Shervroys besides
- mandarin orange,
- pine apple,
- spices like pepper, cinnamon, clove, nutmeg and cardamom,
- flowers like anthurium, gerbera, orchids, dahlia,
- vegetable like beans, chow chow, cauliflower, tomato, tapioca, carrot, beetroot etc.
The low lying areas of the Shervroys are being cultivated with
- mustard etc.
Crops in Anaimalais
Perennial Plantation crops like
- Tea and Coffee occupy major areas in this zone.
- Cardamom, spices cinchona are the other crops. Cinchona Plantation are owned by Government and no private grower grows cinchona.
- Spices crops like nutmeg and fruit crops like oranges, banana and citrus are grown in limited area,
- Cereals, Millets and vegetables are cultivated in some pockets by the tribals of this zone.
Crops grown in lower Pulney hills
Lower Pulneys: a) Single crop:
- Pine apple
b) Multitier cropping system:
- Coffee + banana + orange
- Coffee + orange + silver oak (or) jack (with pepper)
- Coffee + orange + silver oak
- Coffee + chow chow
- Coffee + orange + chow chow
- Coffee + lime + jack (or) silver oak
- Pine apple + banana
- Pine apple + orange
Crops grown in Upper Pulney hills
- Pine Apple,
- Garlic and
- Cocoa are the important crops grown in Kodaikanal or Upper Pulney hills.
Crops in Kolli hills
- Pine - apple and banana are the major horticultural crops grown.
- acid lime,
- orange, and
- guava are also cultivated on a large scale.
- pepper and mustard are grown in certain pockets only.
- Chillies is the major vegetable crop grown on a commercial basis.
In levelled areas and in some valleys,
- paddy, is grown
It is the only irrigated crop, grown in this hill tract. Besides paddy,
- small millets and
- pulses are also grown
Irrigation is only through the natural streams and flooding is the irrigating method followed. Coffee is slowly getting importance and the area under this crop is gradually increasing. In the multiter system, coffee or pine - apple is the base crop. Jack, oranges, lime, mango, guava and banana are grown as intercrop without having a regular sequence. These trees are seen within the plantation, either in a scattered manner or in groups. In coffee plantation, silver oak, and jack are the common shade trees over which are trained pepper vines. Banana is also grown in coffee plantation to a limited extent. Along the sides of natural streams, cardamom is grown, The area under cardamon is very meagre (i.e.. less than 1 %).
Crops in Kalrayan hills
Tapioca is the major horticultural crop which is cultivated over an area of 1542.16% ha. The other crops are
- turmeric and
- coriander which are grown only in some pockets.
The major food crop grown are
- cereals and millets (paddy,
- Cholam, Samai, Thenai and Varagu) which are cultivated in larger area.
Crops in Pachaimalai hills Dry Paddy is the major crop. Only local variety is grown is this hill. Among the fruit trees. Seedlings of guava, Cashew, mango, Jack, lime, oranges, and coconut have been tried.
Crops in Yelagiri and Javadu hills
In the Javadhu hills, farming is mainly done under rainfed conditions. The Major dry crops are
Few other crops like
- Vegetable, and are cultivated by well irrigation.
In Yelagiri hills, major rainfed crops are
- samai thinai, mango, citrus and vegetables are grown.
- Minor Forest produces like
- wood apple,
- surul bark etc, and obtained.
Crops in Pothigai hills
Perennial plantation crops like
- cardamom and
- tea occupy major areas in this zone.
- fruit crops are also grown in the hill slopes and near the plains.
- Tea is the major crop in Jamin Singampatty and Vikramasingapuram areas.
Crops in Megamalai
The major crops grown in this region are perennial in nature. They are
- banana and
- Medicinal and aromatic plants are also grown in smaller area in Megamalai village.