1. Increasing Crop Production Noadswood Science, 2012

2. Increasing Crop Production • To understand how crop production can be increased

3. Numbers • Plants compete for: - • Light • Water • Space • Minerals (within the soil) • The number of predators or prey affect the number of organisms • Disease also affects the number of organisms in a habitat

4. Plants • If a plant sheds its seeds and they land nearby the parent plant will be in direct competition to its seedlings – why is a parent plant likely to win this competition? • The parent plant is already established – it probably has a good root structure for nutrients and water, and will have a wide spread of leave for photosynthesis (so very little light will be reaching directly underneath the parent plant)

5. Plants

6. Experiment • Plan an experiment to investigate how plant growth is affected if their environmental conditions are changed – specifically due to competition… • What environmental change could you introduce to change competition within the plant and how would you measure this? • Possible competition changes: - • Amount of light • Number of seeds in a given area (space) • Supply of nutrients • Supply of water

7. Experiment • Setup 3 experiments with different densities of plant seeds – in the first box sow 10 seeds, in the second box sow 20 seeds and in the third box sow 50 seeds • Keep all other factors (amount of light / nutrient / water) the same • Predict what will happen to the number of seeds which germinate and survive the first six weeks between the different boxes and why…

8. Pests • What are pests and how can farmers remove them? • Pests are animals that eat and damage crops, being a problem for farmers as they reduce crop yield and compete with humans for food • What pests can you think of? • Caterpillars, snails, slugs, aphids, insects, fungi, birds, and mice can all be classified as pests (often eating the crop planted for man…)

9. Pest Control • How can farmers control pests? • Farmers can use organic farming techniques and introduce a natural biological predator to eat the pest (such as ladybirds eating aphids)

10. Pest Control • Farmers can also use chemical known as pesticides to control pests – they contain poisonous chemicals (toxins) but they’re cheaper than biological control methods = more money!

11. Pesticides • There are some major problems with pesticides • Pesticides can kill useful animals as well as the pests that they were meant to kill • Pests are also part of the food web - the toxins in pesticides can affect other organisms in a food chain or food web if they eat an infected pest…

12. Safety • DDT was considered as a safe pesticide when it was first used to kill insect pests • The problem was that DDT does not break down in the environment, and the levels of this toxin that built up in top carnivores proved to be a major hazard • DDT is now banned in many countries in order to protect the environment – alternative chemicals which break down quickly in the environment are now used as pesticides

13. Fungicides • Fungicides are a specific branch of pesticide – specifically targeting fungi which may be competing with the crop…

14. Weeds • How can farmers remove unwanted plants they may be competing with the crop (for light, space, nutrients, water etc…)? • Any plant that is unwanted is known as a weed – these can be removed by hand (organic farming) or farmers can use herbicides (intensive farming)

15. Herbicides • Herbicides can be sprayed which target specific plants (i.e. the weeds farmers do not want)

16. Growing Crops • Farmers wish to maximise the amount of crops they can grow – the more crops and the fewer control measures (such as pesticides / herbicides / fungicides / biological control) the more money they will make • These are strictly controlled to ensure maximum yield is produced which makes growing the crop more economical… • Fertilisers are also extensively used (natural, such as horse poo and chemical, such as miracle grow) – these increase the growth and quantity of crops…

17. Minerals • Plants need essential minerals for growth (nitrates, phosphates and potassium amongst others) • They absorb these from the soil through the roots – however the minerals are soon depleted if not replaced • Fertilisers contain these minerals – so spraying the fields with natural or chemical fertilisers allows more crops to grow / the crops there to grow bigger (year after year)

18. Fertilisers • Fertilisers are essential to modern farming, as they allow crops to grow well, increasing their biomass (producing lots of food for us) • Fertilisers are needed because plants remove minerals from the soil which need to be replaced

19. Fertiliser Problems • Fertiliser problems arise when the fertiliser finds its way out of the soil and into rivers and streams • This can happen easily if too much fertiliser is applied or it rains immediately after it has been applied • The result is called eutrophication (as shown in the Caspian Sea with rapid algae growth)

20. Eutrophication • Excess nitrates make their way into rivers and lakes causing rapid growth of some plants and algae • Some plants and algae then start dying due increased competition for light • Micro-organisms feed on the dead plant (which respire using up lots of oxygen) • A lack of oxygen in the water can be very bad news for larger organisms such as fish

21. Anagrams