31/01/2016 Plants for Food How do fertilisers affect plant growth? Lesson Aims To review key ideas about plants for food and study how fertilisers affect plant growth.

31/01/2016 Learning outcomes By the end of the lesson you should know / be able to link ideas about feeding relationships and photosynthesis that plants require a range of minerals for healthy growth that fertilisers supply these minerals to crop plants

31/01/2016 We need plants ! Write down 3 reasons to support this statement

Remember: The three main types of nutrient are: 1.Nitrogen in the form Nitrates – used to make proteins 2.Phosphorus in the form of Phosphates – used to provide phosphorus to help photosynthesis and respiration 3.Potassium – helps the enzymes that are needed for photosynthesis and respiration

Remember: Lack of the three minerals would lead to a “Deficiency Symptom”: Lack of nitrates: Small plant, yellow leaves Lack of phosphates: Small roots and purple leaves Lack of potassium: Yellow leaves with dead bits

Page 143 On your own : a)What is a fertiliser? b)Answer questions 1- 3 In groups of 3 or 4 : Answer questions on newsprint 31/01/2016

1.What is a weed? 2.What is a weedkiller? 3. Why are they used ? Answer question1-4 page 145 Extension questions 5-11 p\age 146 Remember your pondweed report is due in next lesson ! 31/01/2016

Advantages Helping plants to grow Farmers can use a number of chemicals to help plants to grow: 1) Fertilisers 2) Herbicides 3) Pesticides Disadvantages Disrupt food chains Provide nutrients NPK Too much of it can kill pond life Kill weeds Kill pests Disrupt food chains

31/01/2016 Another disadvantage of pesticides Insecticides can wash into a stream or lake where they are taken up by microscopic water plants. Consider the food chain: Although the level of insecticides in the plants is small, it will build up through the food chain due to the number of organisms in each stage. Small plantsKingfisherMarine insectsFish