NCERT Solutions for Class 12 Geography Chapter 5 Land Resources And Agriculture

Ans : (i) (b) Marginal land
(ii) (c) Increase in notified area allocated for forest growth
(iii) (c) Salinisation of soils
(iv) (d) Sugarcane
(v) (c) Mexico and Philippines 

Ans : (i)
Barren and Wastelands : The land which may be classified as a wasteland such as barren hilly terrains, desert lands, ravines, etc. normally cannot be brought under cultivation with the available technology.
Culturable Waste-Land : The land which is left uncultivated for more than five years is included in this category. It can be brought under cultivation after improving it through reclamation practices.


(ii) 
Net sown area: The physical extent of land on which crops are sown and harvested is known as net sown area.
Gross cropped area: The area which includes net sown area plus area sown and harvested twice or thrice in a year.


(iii) The strategy of increasing cropping intensity is important in a country like India because:
To increase the production of foodgrains for the increasing population and to meet out
the demand of raw materials for the agro-based industries.
A higher cropping intensity is desirable not only fuller utilisation of land resources but also for reducing unemployment in the rural areas.


(iv) Total cultivable land can be measured by adding up net sown area, all fallow lands and
cultivable wasteland.


(v) Dryland Farming
The dryland farming is largely confined to the regions having annual rainfall less than 75 cm.
These regions grow hardy and drought resistant crops such as ragi, bajra, moong, gram and guar (fodder crops) and practise various measures of soil moisture conservation and rain
water harvesting. Wetland Farming
The rainfall is in excess of soil moisture requirement of plants during rainy season. Such regions may face flood and soil erosion hazards.
These areas grow various water intensive crops such as rice, jute and sugarcane and practise aquaculture in the freshwater bodies.
 

Ans : (i) The different types of environmental problems of land resources in India are:
Alkalisation of soils: The bad irrigation practices made the soil less productive such as irrigation through hard water with a high lime content degrade the fertility of soil.
Salinisation of soils: The accumulation of salts in soil leads to degradation of soils and
vegetation. It occurs due to less precipitation, prolonged wetness and poor drainage system.
Waterlogging: Waterlogging is the lowering in land productivity through the rise in groundwater close to the soil surface. It is caused due to poor irrigation system.
Use of Chemicals: Excessive use of chemicals such as insecticides and pesticides has led to their concentration in toxic amounts in the soil profile.
Soil erosion: Soil erosion removes topsoil which is fertile layer of soil. Rainfed areas in humid and semi-arid tropics also experience degradation of several types like soil erosion by water and wind erosion which are often induced by human activities.


(ii) Before Independence, Indian agricultural economy was largely subsistence in nature. During partition about one-third of the irrigated land in undivided India went to Pakistan.
After Independence, the immediate goal of the Government was to increase foodgrains production by
(a) switching over from cash crops to food crops
(b) intensification of cropping over already cultivated land
(c) increasing cultivated area by bringing cultivable and fallow land under plough.
Initially, this strategy helped in increasing foodgrains production. But agricultural production stagnated during late 1950s.
New seed varieties of wheat (Mexico) and rice (Philippines) known as high yielding varieties (HYVs) were available for cultivation by mid-1960s. India introduced package technology comprising HYVs, along with chemical fertilizers in irrigated areas of Punjab, Haryana, Western Uttar Pradesh, Andhra Pradesh and Gujarat.
This strategy of agricultural development paid dividends instantly and increased the foodgrains production at very fast rate. This spurt of agricultural growth came to be known as Green Revolution'.