পৃষ্ঠাসমূহ

EFFECT OF PRECIPITATION ON CROP PRODUCTION

EFFECT OF PRECIPITATION ON CROP PRODUCTION

Role of water on Crop Production

Water is the most important climatic factor that is very vital for the existence of plants. The significance of water is described below:

1.Water is the basic raw material for photosynthesis

C02+H20 Light C6H1206 + 02

ChlorophyII

So, without water there is no photosynthesis and no existence of plants

2.Water acts as a universal solvent. All the essential elements being dissolved are transported to different parts of the plants.

3.It is a major constituent of protoplasm, which is the basis of life. It regulates the functioning of protoplasm.

4.The most important function of water is the transpirating cooling of the leaf surface, which protects the leaves from heat and coagulation of proteins.

5.It regulates the opening and closing of stomata by regulating the turgidity of the guard calls of the stomata.

6.Respiration, nutrient uptake and other metabolic activities are regulated by water.

7.Germination, growth, flowering, fertilization are influenced by water.

* Effect of precipitation on distribution of vegetation :

Precipitation is one of the most important factors influencing the vegetation of a place. Most of the crop receive their water supply from rain water. The amount of rainfall in different localities largely determines the nature of vegetation therein.

Based on rainfall the world vegetation can be classified as follows:-

Annual rainfall (cm) Vegetation

1. O to 13.24 Desert

2. 13.25 to 35.1 Semi arid grass-land

3. 35.2 to 63.5 Dry subtropical grassland

sarana and open wood land

4. 63.6 to 114.3 Humid subtropical forest

5. 114.4 to 203.2 Tropical rain forest

Water requirements of different plant species different considerably. On the basis of water requirement of plants, the plants are grouped into following ecological groups:

I. Hydrophytes : Plants adapted to aquatic environment. e.g. Floating rice.

II. Xerophytes: Plants adapted to grow in dry lands where water content is low. e.g. cactus, Thaja etc.

III. Mesophytes: Plants living in the habitat that usually shows neither an excess or nor a deficiency of water. e.g. Wheat, maize, mustard etc.

Time, amount, frequency , form and extent of precipitation influences crop production. As for example-

- Onset of monsoon rainfall determines the transplanting time of T-amam rice in Bangladesh.

- Heavy rainfall causes flood that result in havoc loss of crops.

-Grain yield in aman season (reainfed aman)

-Hail causes shattering loss of grains and decimates foliage.