Agro-Ecological zoning and niches form the horticultural perspective

1. Agro-ecological zones
Prepared by
Umesh Timilsina
Assistant Professor
CNRM, Bardibas

2. Agroecological zones:
• Agroecological zones are geographical areas exhibiting
similar climatic conditions that determine their ability to
support agriculture.
• A land resource mapping unit, defined in terms of climate,
landform and soils, and/or land cover, and having a specific
range of potentials and constraints for land use.
• Agro-ecological zoning (AEZ). The division of an area of
land into smaller units, which have similar characteristics
related to land suitability, potential production and
environmental impact.
Ecological Niche:
• Ecological niche is a term for the position of a species
within an ecosystem, describing both the range of
conditions necessary for persistence of the species, and its
ecological role in the ecosystem.

3. • Ecological niche is an inclusive term that involves
not only the physical space occupied by an
organism but also its role in the community.

4. Agro-Ecological Zoning of Nepal and It’s
Significances
• Mainly Nepal can be divided into 4 zones on the basis of
crop’s production.

6. 1. Tropical zone
 The tropical zone below 1,000 meters (3,300 ft)
experiences frost less than once per decade.
 It can be subdivided into lower tropical (below 300 -1,000
m) with 18% of the nation's land area) and upper (18% of
land area) tropical zones.
 The best mangoes and well as papaya and banana are
largely confined to the lower zone.
 Other fruit such as Litchi, Jackfruit, Citrus and Mangoes
of lower quality grow in the upper tropical zone as well.
 Winter crops include grains and vegetables typically grown
in temperate climates.
 Average annual temperature ranges >24ºC.

7. 2. Subtropical zone
• The subtropical climate zone from 1,000 to
1,500meters (3,300 to 5000ft) occupies 22% of Nepal's
land area and is the most prevalent climate of the
Middle Hills above river valleys.
• It experiences frost up to 53 days per year.
• Crops include rice, maize, millet, wheat, Potato, Stone
fruits and Citrus.
• Average annual temperature ranges 15 to 24ºC.
• In the Middle Hills, upper-caste Hindus are
concentrated in tropical valleys which are well suited
for rice cultivation while Janajati ethnic groups mostly
live above in the subtropical zone and grow other grains
more than rice.

8. 3. Mild Temperate Zone
The Mild Temperate Zone ranges from altitude 1500
to 2000 metres.
 In this zone, there is moderate climate throughout
the year and winter is not very severe.
The higher altitude may get snow during winters.
High hills, mid-hills, base of high hills, lower
mahabharat lekh fall in this zone.
 The mild decidious fruits such as Peach, Plum,
Pear, Almond, Apricot, etc and hardy and semi-
hardy vegetables can be grown here.
Average annual temperature ranges 10-15ºC.

9. 4. Temperate zone
• The Temperate zone from 2,000 to 3,000 meters
(6,600 to 9,800 ft) occupies 12% of Nepal's land
area and has up to 153 annual days of frost.
• It is encountered in higher parts of the Middle Hills
and throughout much of the Mountain region.
• Crops include cold-tolerant rice, maize, wheat,
barley, Potato, Apple, Walnut, Peach, various
Cole crops, Amaranthus and Buckwheat.
• Average annual temperature ranges<10ºC.

10. 5. Subalpine zone
• The Sub-alpine zone from 3,000 to 4,000 meters
(9,800 to 13,100 ft) occupies 9% of Nepal's land
area, mainly in the Mountain and Himalayan
regions.
• It has permanent settlements in the Himalaya, but
further south it is only seasonally occupied as
pasture for sheep, goats, yak and hybrids in warmer
months.
• There are up to 229 annual days of frost here.
• Crops include barley, Potato, Cabbage,
Cauliflower, Amaranthus, Buckwheat and Apple.
• Medicinal plants are gathered.

11. 6. Alpine zone
• The Alpine zone from 4,000 to 5,000 meters (13,100
to 16,400 ft) occupies 8% of the country's land area.
• There are a few permanent settlements above 4,000
meters.
• There is virtually no plant cultivation although
medicinal herbs are gathered. Sheep, goats, yaks and
hybrids are pastured in warmer months.
• Above 5,000 meters the climate becomes Nival and
there is no human habitation or even seasonal use

12. Economic significance of Agro ecological
Zones
• There are various significances of agro ecological zones. Economically they are
listed below:
• The highly variable agroecological zones in the region make it a suitable production
area for a wide variety of crops.
• A number of food crops are cultivated by smallholder farmers with the economic,
social, and nutritional importance varying from one agroecological zone to another.
• After separating the areas zones, specific programmes can be formulated in each
zones to provide the most effective support in the path of development.
• Those zones help to improve the existing land use situation either by limiting land
degradation or by increasing production.
• The information obtained from the zones provides the basis for advanced
application such as land degradation assessment, livestock productivity,
modelling, population support capacity assessment and land use optimizing
modelling.
• It also creates the harmonization between the national institutes which deals with
elements of land characterization, evaluation and rural physical planning.

13. • Those zones identify the areas where particular users
may be encouraged through development programmes,
services, financial incentives.
• It also provides a basis for infrastructural development.
• Ecological zones help to flourish the agronomical and
horticultural crops which lead towards development.
• By the study of ecological zones, it helps in the
protection and conservation of needy areas which has
been facing various problems related to fertilizers,
irrigation and soil etc.
• This technology and zoning embraces all elements of a
natural resource system with maximum concern for on
and off site environmental effects.
• Every people of every ecological zone will be
convinced for their investment and business in
agriculture.

14. Practical no: 1
Mapping of Nepal in terms of agroclimatic zones and depict regions for growing
major fruit crops