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Soil and Climate of Bihar

Soil is one of the most important resources of a nation. It is the gift of nature of immense value. The most common use of the word soil is in the sense of a medium in which plants grow, although it has a different connotation at different time and place, and for persons engaged in different professions. Almost all the economic activities are directly or indirectly dependent on soil. Thus soil is the backbone of agricultural and industrial development.

Soil

Soil has a number of characteristics, which may be regarded as the aggregate of the physical, chemical and biological properties. The Bihar plane consists of a thick alluvial mantle of drift origin overlying in most part. The siwalik and older tertiary rocks. The soil is mainly young loam rejuvenated every year by constant deposition of silt, clay and sand brought by different streams. This soil is deficient in phosphoric acid, nitrogen and humus, but potash and lime are usually present in sufficient quantity.

There are three major types of soil in Bihar:

Piedmont Swamp Soil - found in northwestern part of west Champaran district.
Terai Soil – found in northern part of the state along the border of Nepal.
The Gangetic Alluvium – the plain of Bihar is covered by gangetic alluvium (both new as well as old).

Climate

The climate of Bihar is a part of the climatic pattern of the Indian subcontinent. It enjoys a continental monsoon type of climate owing to its great distance from the sea.

The factors affecting the climate of Bihar are:

It extends from 22-degree north to 27-degree latitude. Hence its
location is tropical to sub tropical.
The Himalayan Mountains in the north have a significant bearing
on the distribution of monsoon rainfall in Bihar.
Bihar joins the Ganga delta and Assam.

Seasons and their duration:

Cold weather season - December to February.
Hot weather season – March to May.
Southwest monsoon – June to September.
Retreating southwest monsoon – October to November.

Climate
Classification	Cwa
Avg. temperature	27 °C (81 °F)
• Summer	34 °C (93 °F)
• Winter	10 °C (50 °F)
Precipitation	975.86 mm (Source:IMD)

Seasons

Winter

The cold weather commences early in November and comes to an end in the middle of March. The climate in the October and November is pleasant. The days are bright and warm and the sun is not too hot. As soon as the sun sets the temperature falls and the heat of the day yields place to a sharp bracing cold. The temperature in Winter all over Bihar varies from 0–10 °C. On 7 January 2013, in early morning, mercury dipped to a record low to 0 °C in Gopalganj, 0.2 °C in Jehanabad, 0.7 °C in Vaishali, 1 °C in Patna, Muzaffarpur and other cities. December and January are the coldest months in Bihar.Forbesganj Bihar Also recorded -2° Celsius.

Summer

The hot weather sets in March and lasts until the middle of June. The highest temperature is often registered in May which is the hottest month in the state. Like the rest of the northern India, Bihar also experiences dust-storms, thunder-storms and dust-raising winds during the hot season. Dust storms having a velocity of 48–64 km/hour are most frequent in May and with second maximum in April and June. The hot winds (loo) of Bihar plains blow during April and May with an average velocity of 8–16 km/hour. This hot winds greatly affects human comfort during this season.

Monsoon

Soon after Mid June this the rainy season commences and continues till the end of September, the beginning of this season occurs when a storm from the Bay of Bengal passes over Bihar. The commencement of monsoon may be as early as the last week of May or as the first or second week of July. The rainy season begins in June. The rainiest months are July and August. The rains are the gifts of the south west monsoon. The south-west monsoon normally withdraws from Bihar in the first week of October.

Post Monsoon

An important feature of the retreating monsoon season in Bihar is the invasion of tropical cyclones originating in the Bay of Bengal at about 12° N latitude. Bihar is also influenced by the typhoons originating in the south China sea. The maximum frequency of the tropical cyclones in Bihar is during September–November especially during the asterism called hathiya. These cyclones are essential for the maturing of paddy, and are required for the moistening of the soil for the cultivation of rabi crops.