🌱 Energy and Food Production


Introduction

Net productivity

gross productivity respiratory lossΒ 

chemical pesticides and biological agents

Intensive rearing of animals

Prioritising land

Controlling the effects of chemicals

Drawing ethical boundaries


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Introduction

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As seen in the previous topic on energy transfer, plants produce a great deal of energy which is used up increasingly at every trophic level. This is the basis on which decisions are made in agriculture and rearing of domestic livestock.

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In the wild, both plants and animals are subject to a lot of energy loss due to pests, physical activity or insufficient nutrients. This results in a relatively inefficient flow of energy between trophic levels. We think of this in terms of net productivity.

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Net productivity is equal to gross productivity minus respiratory loss.

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In both terms, productivity refers to the amount of leftover useful tissue such as cereals or animal flesh.

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As opposed to the wild, in human-made growth environments this respiratory loss is kept as low as possible. Extreme measures are taken to achieve this, which Include:

Chemical pesticides and biological agents

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The use of chemical pesticides and biological agents to kill all or certain organisms which may infect or feed on plants e.g. insects, fungi, small animals.

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Intensive rearing of animals

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Intensive rearing of animals which includes keeping them indoors and in confined spaces to prevent their energy being lost on movement; and administering antibiotics to prevent mass spread of infection

To enhance plant growth fertilisers are used, whether natural (manure) or artificial.

A strategy to maximise net productivity is an…..