Climate and Soil for Rice Cultivation

Climate and soil

Rice can be cultivated under a variety of climatic and soil conditionsRice comes up well in different soil types. For normal growth, a pH range of 5.0-8.0 is suitable.

 Different Climatic Factors Affecting Rice Cultivation  There are many varieties of rice which are cultivated with differential response to climatic factors, such as :

Rainfall

Rainfall is the most important weather element for successful cultivation of rice. The distribution of rainfall in different regions is greatly influenced by the physical features of the terrain, the situation of the mountains and plateau..

Temperature

Temperature is another climatic factor which has a favorable and in some cases unfavorable influence on the development, growth and yield of rice. Rice being a tropical and sub-tropical plant, requires a fairly high temperature, ranging from 20° to 40°C. The optimum temperature of 30°C during day time and 20°C during night time seems to be more favorable for the development and growth of rice crop. . Rice cultivation is conditioned by temperature parameters at the different phases of growth. The critical mean temperature for flowering and fertilization ranges from 16 to 20⁰C, whereas, during ripening, the range is from 18 to 32⁰C. Temperature beyond 35⁰C affects grain filling.

Day length or Sunshine

Sunlight is very essential for the development and growth of the plants. In fact, sunlight is the source of energy for plant life. The yield of rice is influenced by the solar radiation particularly during the last 35 to 45 days of its ripening period. The effect of solar radiation is more profound where water, temperature and nitrogenous nutrients are not limiting factors. Bright sunshine with low temperature during ripening period of the crop helps in the development of carbohydrates in the grains.

 Therefore, the rice growing seasons vary in different parts, depending upon temperature, rainfall, soil types, water availability and other climatic conditions. If the mean temperature is found favourable for rice cultivation through out the year then, two or three crops of rice are grown in a year.Where rainfall is high and winter temperature is fairly low, only one crop of rice is grown.

Three Seasons for Rice Cultivation
There are three seasons for growing rice. These three seasons are named according to the season of harvest of the crop.

Autumn Rice/Pre-Kharif Rice

Summer Rice/Rabi Rice

Winter Rice/Kharif Rice

Rice Soils

Rice cultivation has been carried into all regions having the necessary warmth and abundant moisture favorable to its growth, mainly subtropical rather than hot or cold.

Experts point out that, rice is grown in such varied soil conditions that it is difficult to point out the soil on which it cannot be grown. However, soils having

·         Good water retention capacity.

      ·         Good amount of clay and organic matter are considered ideal for rice cultivation.

It grows well in soils having a pH range between 5.5 and 6.5. The classification of soils has been done depending upon the soil texture, colour of the soil etc.

Distribution of Rice Soils in India

India has been broadly classified into the following eight agro-climatic zones. The distribution of various kinds of rice soils in the country are as follows :

1.The Arid Western Plains 

The Arid Western plains include the following states :

Haryana

Rajasthan

Gujarat

Dadra and Nagar Haveli

The major soil groups are as follows:

Alluvial soils

Red-yellow soils

Medium to deep black soils

2.The Humid Bengal-Assam Basin    

The Humid Bengal-Assam basin includes

West Bengal

Assam

The major soil groups are as follows :

Riverine alluvium

Terai soils

Lateritic soils

Red-yellow loams

Red sandy soils

One of the most limiting factor in this region is the availability of water. The crop is grown in this region on flat lands to facilitate the water supply requirement. The alluvial soils deposited by the rivers mostly occupy the major part of the wetland rice soils in this region. These soils are formed from the silt deposition by the numerous tributaries of the Ganges and the Brahmaputra rivers. The water table is high and drainage is poor in the wetland rice soils.

Soils in the Assam valley are acidic and high in available phosphorus and potassium and moderate in organic matter and nitrogen. In the north-eastern mountainous upland areas of Assam, the soil is lateritic. In the upland areas drainage is good. The rice crop is better grown in acidic soils in the pH range of 5.5 to 6.5 . In the Gangetic delta, rice is successfully grown in saline soils of Sundarbans.

3.The Humid Eastern Himalayan Region  

 The Humid Eastern Himalayan region and the Bay Islands include the following states:

Arunachal Pradesh

Nagaland

Manipur

Mizoram

Tripura

Meghalaya

The Andaman and Nicobar Islands

        The major soil groups are :

Red loamy soils

Lateritic soils

Red yellow soils

Alluvial soil

4.The Humid to Semi-Arid Western Ghats and Karnataka Plateau  

 The Humid to Semi-Arid Western Ghats and Karnataka Plateau

The states covering this region are :

Karnataka

Tamil Nadu

Kerala

Union Territory of Pondicherry and Lakshadweep Islands

The soils of this region are

Laterite Soil

Red sandy or gravelly soil

Red loamy Soil

Coastal Alluvium.

5.The Humid Western Himalayan Region 

The Humid Western Himalayan Region

The major soil groups in this region are:

Sub-montane Soil

Hill Soil

Terai soils

The Humid Western Himalaya region comprises the following regions :

1) Jammu and Kashmir : The rice soils which are found in Jammu and Kashmir have been formed from the alluvium deposited by the major rivers Chenab, Ravi, Tawi and their tributaries. Such soil is found mostly in Jammu and Kathua districts. The sub-montane soils are formed from the alluvium deposited in the valley floor by the Indus and the Jhelum rivers. They are silty loam to clay loam and are neutral to alkaline.

2) Himachal Pradesh :Parent rocks such as sandstones, gray micaceous sandstones and shales of Sub-Himalayan region form the soils occurring in Himachal Pradesh. These soils are loam to silty loam and medium to high in organic matter. Generally, these soils are poor in available nutrients.

3) Kumaon and the Garhwal division of Uttar Pradesh : The hill soils are found in the districts of Almora, Chamoli, Pithoragarh, Uttar Kashi and Dehradun of Uttranchal. These soils are shallow with fragments of rock occurring according to the elevations and have been categorized as red loam, brown forest soil, meadow soil and podzolic soil.

6.The Semi-Arid Lava Plateau and Central Highlands 

 The Semi-Arid Lava Plateau and Central Highlands

This region comprises the following states :

Maharashtra

Western and Central Madhya Pradesh

Goa, Daman and Diu Union Territories

The soil groups are

Alluvium coastal alluvium.

Mixed red and black soils.

The Ratnagiri district, parts of Kolhapur and south of Kolaba are having laterite soils. This is a high-rainfall zone and rice is cultivated in laterite soils. In Western Madhya Pradesh, alluvial soils are found which are formed due to the alluvium deposited by the Chambal river. These soils are neutral to slightly alkaline, nitrogen and phosphorus are low in these soils. However, potassium is medium to high.

7.The Sub-Humid Sutlej-Ganga Alluvial Plains 

The Sub-Humid Sutlej-Ganga Alluvial Plains

In this region a single crop of rice is grown during May-June to September-October. The temperature during winter remains low. The Sub-humid Sutlej-Ganga plains include :

Punjab

Uttar Pradesh

Bihar

Delhi

The major soil groups are

Calcareous alluvial soils

Riverine alluviums

Saline and alkaline soils

Red-yellow loams

Mixed red and black soils

Red sandy soils

 8.The Sub-Humid to Humid Eastern and South-Eastern Uplands 

 The Sub-Humid to Humid Eastern and South-Eastern Uplands

The Sub-Humid to Humid Eastern and South Eastern Uplands comprises

Orissa

Andhra Pradesh

Eastern Madhya Pradesh

       The major soil groups are as follows:

Lateritic soils

Red-yellow loams

Mixed red and black soils

Alluvium

Deep and medium deep black soils

Red loamy soils

Coastal Alluvium Soil.

9. The Sub-Humid to Humid Eastern and South-Eastern Uplands

The Sub-Humid to Humid Eastern and South Eastern Uplands comprises

Orissa

Andhra Pradesh

Eastern Madhya Pradesh

The major soil groups are as follows:

Lateritic soils

Red-yellow loams

Mixed red and black soils

Alluvium

Deep and medium deep black soils

Red loamy soils

Coastal Alluvium Soil.