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Science

Farming methods

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Most of the food we eat is produced by intensive farming, but an increasing proportion is produced by organic farming. If farmers in the UK want to claim that their products are organic, they have to follow UK national standards.

Fertilisers

Picture showing a field with oil seed rape crops

Crop field

As crops grow they remove nutrients, such as compoundscompounds: Substances formed by the chemical union (involving bond formation) of two or more elements. of nitrogen, potassium and phosphorus, from the soil. These crops are harvested and taken away from the fields where they were grown. If this process is repeated for a number of years the supply of nutrients in the soil is exhausted. The land becomes less fertile, so plants grow poorly and produce only a small yield.

Farmers use fertilisersfertilisers: nutrients applied to crops to speed up growth to put back into the soil the nutrients that have been removed by growing crops.

Different methods of farming

Farmers using intensive methods of agriculture use synthetic fertilisers. These contain nutrients that have been made in factories.

Farmers using organic methods use manure, which is the waste material from animals such as cows. Both synthetic fertilisers and manure contain the essential nutrients needed for crops to grow well.

Farmers using organic methods may also use crop rotation. In a field they grow a plant that puts nutrients into the soil, for example the leguminous plant, clover, then the next year they grow a crop that uses these nutrients. This cycle is repeated to ensure that the nutrients in the soil are not exhausted.

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