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Soils & Climate
Tobacco is very sensitive to the physical and chemical properties of the soil. The best soils are those which are open, well drained and properly aerated. The plant is highly susceptible to injury from flooding or inundation of the soil. The desirable soil pH is 5.0 to 6.0 . But, in many parts cultivation is successful where the pH is 8 or more.
In India, cigar, hookah, chewing and bidi tobaccos are grown on sandy loam to clay loams. The crop is raised either on irrigation as in Tamil Nadu and U.P. or as semi-irrigated crop as in Bihar, Bengal and Mysore or as a dry crop in Andhra.
A notable exception to the general rule regarding soil requirements is found in the case of cigarette tobacco. This tobacco is grown in India as a dry crop on heavy black soils which normally have poor drainage. In spite of unfavourable soil conditions it has been possible to raise cigarette tobacco fairly successfully. The reasons for this seem to be, first, that the crop is raised as a dry crop and as such the soils are not liable to get water-logged during the growing period, secondly, that because of very high clay contents, these soils are able to hold enough moisture to sustain a fair crop and, thirdly, that the humidity during the curing period is quite high and this makes the handling of crop easy.
FCV TOBACCO (A.P.)
FCV tobacco is grown on different types of soils ranging from sands to sandy loams of East Godavari, West Godavari and Khammam districts, the red loams of Prakasam and Nellore districts, the heavy black cotton soils of Guntur, Krishna, Prakasam and West and East Godavari districts and the silty loams of River side lanka lands in Krishna and Godavari districts in Andhra Pradesh producing a wide spectrum of leaf styles catering to the varying needs of importing countries in the world. These soils differ widely in type (texture) and in natural productivity (soil fertility plus management) because the properties of the soil are the potent factors in determining the type of leaf produced. Further, soils play an outstanding role in deciding the quality and commercial value of tobacco. The type, grade and quality of tobacco produced are, to a large extent influenced by the soil characteristics particularly the texture and colour of surface and subsoil. In an open, light textured soil, tobacco roots have been found at a depth of 120 cm utilising moisture and plant nutrients from such deep layers of soil. Three major soil conditions contributing to maximum leaf expansion are adequate supplies of oxygen, water and plant nutrients. Typical characteristics of soils best suited to the production of high quality Flue-cured tobacco are (1) a sandy surface soil up to 15 to 25 cm depth (2) a yellowish or a reddish sandy clay subsoil extending up to a depth of 150 cm. (3) an acidic soil reaction of pH 5.5 to 6.5 (4) a low reserve of essential plant nutrients (5) a low organic matter content and (6) very low chloride content (less than 100 ppm). Cultivation of tobacco on inundated lands and low-lying basins are to be avoided as the leaf produced on these soils has been found to exhibit very poor burning properties, due to absorption of moisture and deteriorates in colour during storage. Similarly, saline soils whose soil chloride content is greater than 100 ppm should be excluded from virginia tobacco cultivation.
Flue cured virginia tobacco is grown in India in four agroclimatic zones namely Traditional black soils (TBS), Northern light soils (NLS) and Southern light soils (SLS) in Andhra Pradesh and Karnataka light soils (KLS) in Karnataka. The soil characteristics, the cultivation practices and the quality of the tobacco grown are entirely different from one region to the other. The different styles of tobacco produced in different zones meet the demands of the customers of different countries.
The Traditional black soils are clay loams, silty clay loams and clays, highly clayey (50-80% clay) throughout the profile, slightly alkaline in reaction (pH 7.5 to 8.8), calcareous, rich in fertility, high in available soil moisture with very poor drainage. Tobacco is grown on conserved soil moisture as a post monsoon crop during winter. Based on the agroclimatic zones the Traditional black soils are divided into Northern black soils (East and West Godavari districts), Central black soils (Khammam, Krishna and Guntur districts) and Southern black soils (Prakasam and Nellore districts).
Northern light soils (East Godavari, West Godavari and Khammam districts of A.P.) are sandy loams to loamy sands, slightly acidic, very low exchangeable cations, low water holding capacity, poor fertility status with very good drainage. Tobacco is grown in these soils under irrigated conditions during winter.
Southern light soils (Prakasam and Nellore districts of A.P.) are red loamy soils, neutral in reaction, low to medium fertility status, moderately well drained, moderately low permeability, with moderate water holding capacity and low to medium cation exchange capacity with more than 75% base saturation. Tobacco is grown during winter on conserved soil moisture from North East monsoon rains.
Karnataka light soils (Transitional belt of Karnataka) are red soils which are yellow to deep red in colour, loamy sands and sandy clay in texture (clay content varies from 10 to 25%), low in inherent fertility, slightly acidic in reaction with fairly good water holding capacity. The soils are well drained and highly leached. The clay complex of red soils consist of a mixture of Illite and Kaolinite with traces of Montmorillonite.
Tobacco is grown as a monsoon crop during south west monsoon period.
HDBRG tobacco is grown in Central black soils of Andhra Pradesh where the FCV tobacco is also grown.
The burley tobacco is grown during monsoon season in Agency area of East and West Godavari districts of Andhra Pradesh and the soils are generally sandy loams on the surface and loams at the sub-soil level and the pH is neutral to acidic (5.5 to 6.5 pH) in reaction. The soils are very low in soluble salts, chlorides and light in texture. The organic matter content, available nitrogen and available phosphorus status is low.
The crop is raised on medium to heavy black soils with a pH range of 7.0 to 8.5. These soils are poor in available nitrogen, organic carbon, medium to high in phosphorus and high in available potash. It is also grown on sandy to sandy loams with low organic carbon, low in available N, P and K as an irrigated crop.
Lanka tobacco is exclusively grown on the banks and deltaic islands of Krishna and Godavari rivers in Andhra Pradesh. The soils are derived from the recent alluvium deposited annually by the rivers Krishna & Godavari during floods and range from sandy to loam in texture. Some of these soils, which are submerged during floods every year are silty in nature and therefore highly fertile. These soils also conserve lot of moisture and tobacco is cultivated year after year on such low lying lankas. Lanka tobacco raised on high level lands on the other hand, requires two or three irrigations.
In Gujarat, bidi tobacco is grown in Charotar area comprising of Anand, Petlad and Nadiad taluks of Kheda District and in some parts of Vadodara District. The soils in this tract are mostly sandy to sandy loam called "Goradu". The Bhatha lands of the rivers Mahi and Sabarmathi are considered to be the best soils for bidi tobacco. It is mostly grown under irrigated conditions. In Karnataka, bidi tobacco is mainly grown in Nipani area of Belgaum District on the banks of river Krishna and its tributaries. Hence the crop is grown on black silt loams which have good moisture retentive capacity. In Maharashtra, cultivation of bidi tobacco is concentrated in the fertile, medium to deep and black soils in upper Krishna basin in Kolhapur and Sangli Districts. In Karnataka and Maharashtra bidi tobacco is a rainfed crop though in Nipani area it is grown under irrigation from wells. Bidi tobacco is also grown to some extent in Koraput District of Orissa and in Kurnool District of Andhra Pradesh.
CHEWING AND HOOKAH TYPES OF TOBACCO
Chewing and hookah types of tobacco are grown on different types of soils ranging from sandy loam upland soils of Vaishali, Samastipur, Muzaffarpur to medium and heavy paddy growing soils of Purnea, Katihar and Saharsa. But the main tobacco growing area in north Bihar consists of non-saline calcareous sandy loam soils of alluvial type with soil pH ranging from 7.5 to 8.5. The content of calcium carbonate in these soils is as high as 45%. The presence of sufficient fluffy calcium carbonate particles in these soils provides obstruction to moisture evaporation from the soil surface. As a result soil moisture holding capacity of these soils is quite good, because of which good tobacco crop is grown in certain pockets even without supplementary irrigation.
Most of the tobacco growing soils are low in organic matter, available N and P, medium in K content and mostly alkaline in reaction (pH 8.2 to 8.4). The illite and muscovite are the dominant minerals responsible for the enrichment of such soils. Available phosphorus content in these soils is low. Well drained, neutral to slightly alkaline soil with good nutrient supplying capacity is considered ideal for chewing and hookah tobacco cultivation.
The chewing tobacco cultivation in Tamil Nadu is concentrated in the districts of Coimbatore, Salem, Thanjavur, Madurai, Tirunelveli and South Arcot. Chewing tobacco in Tamil Nadu is grown in a wide range of soils. But in any location, soils of comparatively alkaline in nature and irrigated with waters having high salt content are assigned to chewing tobacco.
In Gujarat also chewing tobacco is grown in an area of 6000 ha mainly in Kaira district. The chewing tobacco of this tract is known as Lal Chopadia.
WRAPPER, FILLER, JATI & MOTIHARI TOBACCO IN NORTH BENGAL
Motihari (N. rustica) and jati, wrapper and filler (N. tabacum) tobacco types are cultivated in an estimated total area of 14,000 ha concentrated in Cooch Bihar, Jalpaiguri, Mushidabad and Malda district of North Bengal region. The soils of the area are alluvial flood plains in origin formed from the material deposited by the Ganga Brahmaputra river waters. The soils are sandy loams and silt loams, light in texture, whitish grey to greyish in colour, well-drained and well-aerated. The water and nutrient holding capacity of the soils is poor because of their coarse texture. Soils of North Bengal are of recent origin, and are less weathered. The alluvial sandy loams of North Bengal are acidic in soil reaction (pH 5.1-6.4), high in available P status and low to medium in available K
Besides soil, the other important factor which affects tobacco growth is the climate. Rainfall, temperature, relative humidity, wind and sunlight exercise marked influence on growth, flowering and metabolism of tobacco plant. To maintain turgidity and expansion of its enormous leaf area, tobacco plant needs considerable amount of water. On the other hand, tobacco plants are very sensitive to flooded/water-logged condition of soil because of deprivation of oxygen in soil essential for the development of a fibrous root system.
Tobacco is tropical in origin, but it is grown successfully under tropical, sub-tropical and temperate climates. Normally it requires about 100 to 120 days, frost-free climate with an average temperature of 80oF, to mature. In India, tobacco is grown under a very wide range of conditions from the coast-line to an altitude of 3,000 feet. In the South, the crop is raised in winter from October to March when the temperatures are moderate, but in Punjab it is grown as an early summer crop. In the eastern and western parts of the country it is grown between September and January.
Tobacco plant is remarkably sensitive to the environment. Ideal conditions required for successful production of high quality leaf are 1) a liberal and well-distributed rainfall during active vegetative growth stage 2) long day lengths 3) a mean temperature of 80oF (26oC) during growing season and 4) a high relative humidity of 70-80%.
The annual rainfall through South-West monsoon is around 800- 1000 mm starting from June to October. The crop is exclusively grown on conserved soil moisture during rabi season extending from October-November to February-March. Occasionally, the North- East monsoon becomes active and unprecedented rain to this crop through cyclonic storms boost yields. The crop requires good sun light, low evaporation, high relative humidity, sustained soil moisture in black soils and free from wet footing and cyclonic storms.
The Lanka crop needs 80 to 90% relative humidity during plant growth period that is from mid October to November ending with a mean day temperature of about 26.7oC and the crop needs 30 to 32oC so that the leaves on the plant will come to maturity with raising temperatures.
Mysore district is under the influence of tropical monsoonic climate with an average annual rainfall varying from 650 mm to 1000 mm of which over 80% is received during the south-west monsoon period from May to October which coincides with the FCV tobacco crop season. February to April are the dry summer months. The mean minimum temperature in the cold winter month of January is around 15oC while the mean minimum temperature in the hot summer month of April is 34oC. Thus, the transitional zone of Mysore tract is endowed with ideal climatic conditions like lower diurnal temperatures, higher relative humidities and monsoonic rains during the crop growth period from May to September which are highly conducive for production of high quality flue cured tobacco.
Agro-climatologically, this zone is characterised by humid and damp weather throughout the year. The day temperature varies from as low as 5oC during December-January (winter) to as high as 35oC during April-May (summer). The rains of North Bengal are long and persistent and the average annual precipitation exceeds 3000 mm, major part of which is received during the month of June, July and August. Relative humidity of the atmosphere is about 85% during April and May facilitating easy handling and conditioning of cured leaf.
The climate that prevails in North Bihar is quite suitable for growth, development and quality leaf production of chewing and hookah types of tobacco as well as some other types. The warm and humid weather of 2nd fortnight of October is considered congenial for establishment of transplants with desirable initial growth. Low temperature, bright sunshine and low humidity during early growth stage of crop plants help, in build-up of thick and heavy bodied leaf, thus producing higher leaf yield with desirable physical and chemical quality parameters.
Intermittent winter rains from October to January are good for tobacco growth and development as well as expansion of leaves, but continuous rains and high humidity particularly after 15th December may result in severe incidence of leaf spot and black shank diseases. Prolonged rainfall and late onset of winter may result in more incidence of leaf curl disease.
The bidi tobacco in Charotar area of Gujarat is grown with few irrigations while in Nipani area of Karnataka it is not irrigated. A less irrigated bidi tobacco is more prized than a more irrigated crop. In Gujarat the crop comes to maturity during winter due to which the leaf thickens and becomes rugged. This is desirable feature for bidi tobacco.