2Recycling elementsNitrogen is very important for all plant life! Animals eat plants.When plants and animals die,they decompose (rot) and thenitrogen returns to the soil.Microbes also break downanimal waste so that it can beused by plants again (manure).
5Harvesting crops When crops are harvested (taken for food), the elements(e.g. nitrogen) are taken away instead of being returned to the soil by dying and rotting.If the elements are not replaced (put back), the next crops will not growwell.
6Intensive Farming - chemicals Many different chemicals are used to make plants and animals grow fasterIntensive farmers use artificial fertilizers to put elements nitrogen, phosphorus, potassium back into the soil.It is easier to use than manure and smaller quantities are needed, because it contains more of the elements.Artificial fertilizers are spread on theground or sprayed on the crops.
7Intensive Farming - chemicals Problems:They do not just disappear but stay in the plants that we eat, so our food is contaminated with chemicals.Soil used to grow the plants will also be contaminated and have chemicals in it for a very long time.Animals eat the grass , which has hadchemicals sprayed on to it, so the chemicalsget into their blood and therefore the meatthat we eat.Chemicals run off the land into riversand kill plants and fish.
8ORGANIC farming Artificial fertilizers are banned in Organic farming. Organic farmers use animal manure, compost and human sewage, (which has been heated to destroy any harmful microbes) to make their crops grow.‘Green manure’ is grown – plants are grown,then ploughed in and left to rot.Worms, insects and bacteria underground arealways working on making the soil good.By using a process called CROP ROTATION(changing the crop grown each year), the farmercan keep a good soil for many years.
9Organic farmingIt is illegal to sell produce as organic if it hasn’t been produced that way.Farmers must keep to National Standards.Artificial chemicals are banned.Artificial fertilizers and pesticides in the soil have to be below a certain level.Animals must be allowed to move freely, given organic feed but no artificial hormones.
10Pest and disease control Pests e.g. aphids, are insects that eat crops.Diseases e.g. potato blight, can kill crops.Pests and diseases can mean that the yield from the crop is small – but pests and diseases can usually be controlled.aphidsPotato blight
11Intensive farms – Pests and Diseases The crops are sprayed with man-made chemicals to get rid of pests (pesticides or insecticides) and diseases (fungicides)– this means bigger yields and plants that look good.Other chemicals (herbicides) are used to kill weeds (plants not wanted).But the chemicals stay on theplants and could be eaten byhumans as well as the pests.
12Organic farms-pests and diseases Organic farmers are not allowed to use man-made chemicals for this.Farmers introduce natural predators e.g. ladybirds to eat aphids (biological control).Hedges and grass are left around fields toencourage other natural predators e.g. birds.Crop rotation prevents diseases of aparticular crop building up.Natural pesticides may be used.Pest and disease-resistant (stronger) varieties of plants are planted.
14Advantages Intensive farming Organic farming Bigger yields from land availableFewer workers neededAnimals lead happier livesSoil structure is betterFewer blemishes on cropsUse of hormones increases meat productionIntensive farmingOrganic farmingProduce is cheaperLarge numbers of animals kept in ideal conditionsMore birds and insectsLess harmful to environmentAntibiotics use keeps animals healthyNo harmful chemicals – healthier?
15Disadvantages More expensive More blemishes on crops Chemicals stay in soilMan-made chemicals usedIntensive farmingOrganic farmingAnimals live in crowded conditionsSmaller yieldsNatural predators destroyedChemicals wash into riversMore farm workers neededHedgerow habitats destroyed