CHAPTER 3 : Agro - Ecological System

AGRO-ECOLOGICAL SYSTEM

Defines itself as a network of partners aiming to gather, format and disseminate useful and operational information in order to meet the needs for information of practitioners in natural resources management and agricultural development.

      CLIMATE

      Tropics

• Can be further sub-divided into super humid, humid and dry zones.
• Super humid zones are very high average daily ambient temperature and heavy rainfall.
• Many agricultural activities are possible with readily.
• Example:rubber, oil palm, cocoa, coconuts and sugar cane.

       Temperate

•  Neither too warm nor too cold and neither too wet nor too dry.
•   Four season can be identified a warm summer, cool winter, mild spring and autumn.
• Crops are usually planted in spring and harvested in summer like maize, and wheat.
• Advancement of science and technology in agriculture – Vegetable and flowers are grown continuously even during the cold winter season under controlled environment such as under shelter (glass-house).
• Livestock farming, the temperate climate appears the most suitable for nearly all farm animals.

      Tundra

•   Very low temperature and short growing season.
•  Three  types of tundra are Arctic,  Antartic and Alpine.
•  Dominant vegetation like grasses, mosses and lichens.
• Farming of crops and livestock are possible but in restricted enclosures adequate water supply.

      Deserts

• Very little precipitation of less than 250 mm annually.
• Usually have extreme diurnal temperature range, very high in the day, and extremely low at night.
•  Agriculture is made possible with sufficient irrigation for the supply of water.

        WATER

• Agricultural activity needs for seed germination, root development and subsequent growth.
• Started along the river banks like the Nile Valley in Egypt and Tigris – Euphrates in Mesopotamia.
• Southern peninsular Malaysia has an average annual rainfall in excess of 3000mm, most suitable for oil palm cultivation.
• Kedah-Perlis region received <2000mm, more suitable for rubber and mangoes.
• Rain-fed or irrigation –cultivation of paddy.
• Good water irrigation system – Krian (Perak), Tanjung Karang and Sekinchan (Selangor), and area belonging to MADA(Kedah) and KADA(Kelantan).

        SOIL

        Nutrient Cycle

• Water move from the root to throughout the plant based on process of evaporation.

      HUMAN RESOURCE

      Agriculture needs many:

• Scientists - who conduct research from production level to processing and marketing.
• Teaching institutions of agriculture - produce graduates in numerous agricultural fields.
•  Supporting specialists - extension specialist to pass the knowledge to the operators in the fields, marketing specialists and the economists.
• Skilled operators - land preparation, managing machine and tools, planting and harvesting.

      ENVIRONMENT

      Global Agro-Ecological Zones

• Tundra (simple vegetation of mosses and grasses)

• Grasslands (mild climate, African Savannah, Russian Steppes)

• Deserts (barren land, xerophytes)

• Tropics (rainforest, rain and sunshine all year round)

      Impact of Climatic Changes

• Global Warming - releases greenhouse gases

• Desertification - expansion of desert areas

      Impact of Pollution

                i.            Acid Rain

• Has adverse impact on forest, fresh water and soil, killing off life forms, and effecting crops and animal production.

               ii.            Heavy Metals

• Continuous use of fertilizer that contain heavy metals such as cadmium contained in phosphate rocks will pollute the soil and render the crops toxic.

              iii.            Pesticides

• Excessive use of chemical pesticides which exceed permissible limit cause undesirable health effects and reduces biodiversity.

               iv.            Nitrates

• This cause an excessive enrichment of the water (eutrophication) leading to rapid algal growth which in turn creates an oxygen deficit aquatic ecosystem and killing off aquatic life.