Agriculture grade 10-11, topic: Environmental influences on agricultural practices.

 1. Name the environmental factors that effects on agriculture.

• Temperature.
• Humidity.
• Wind.
• Rainfall.

2. Explain the effects of the following environmental factors on agriculture: Temperature, humidity, wind and rainfall.

• Minimum temperature - This is the lowest temperature at which plants may still not grow and produce. Germination is poor. Low temperature slows down the movement(translocation) of food in plants. This cause poor growth since the substances are not provided in sufficient. Enzymes controlling physiological reactions are inactive physiology reactive e.g photosynthesis, diffusion, and osmosis. Water in the soil freeze and plant cannot absorb enough water. High temperature- Plants begin to drop, wilt, and die due to too much evaporation and transpiration. The enzymes are denatured (destroyed) when the temperature is high.
• Humidity-High humidity leads to low evaporation because there is too much moisture in the atmosphere. This result in plants growing well because there is enough water in the soil for plant roots to absorb. It also leads to low transpiration rate. Low humidity may discourage the development and spread of fungal infection to take place.
• Wind-The effects of high amount of wind (unfavourable): Strong wind spreads disease causing organisms. Strong wind breaks plant stem, branches and shade of flowers and uprooting plants. It causes soil erosion, removing fertile topsoil. It lowers the rate of pollution. Strong wind increases transpiration and evaporation. Favourable effects of wind-Moderate wind promotes cross pollination. It promotes good transpiration steam. It helps in seed dispersal. It dries excessive moisture on leaves to prevent spread of fungal diseases.
• Rainfall-Effects of high amount of rainfall  It causes leaching (meaning that nutrients are washed down in the soil where plant roots cannot be able to use them). 
•  Leads to soil erosion, removing fertile topsoil.  Breaks plant stems, branches, leaves, and remove flowers. Leads to waterlogged soil, plant do not respire well in waterlogged condition. Lack of rainfall  No plant growth to take place.  Inadequate soil moisture will cause plants to wilt and die