Which of the following is a key principle of sustainable agriculture? Using chemical pesticides without crop rotation b Relying on monoculture farming for higher crop yields C Expanding farmland by clearing forests d Conserving soil and water while maintaining long-term farm productivity

## Step 1<br />The question is asking us to identify the key principle of sustainable agriculture among the given options. Sustainable agriculture is a method of farming that focuses on producing long-term crops and livestock while ensuring the health of the environment. This involves practices that are environmentally friendly and economically viable.<br /><br />## Step 2<br />Let's analyze each option:<br /><br />a) Using chemical pesticides without crop rotation: This practice is not sustainable because it can lead to the development of pesticide-resistant pests and can harm the environment.<br /><br />b) Relying on monoculture farming for higher crop yields: This practice is not sustainable because it can lead to soil degradation and can harm the environment.<br /><br />c) Expanding farmland by clearing forests: This practice is not sustainable because it can lead to deforestation and can harm the environment.<br /><br />d) Conserving soil and water while maintaining long-term farm productivity: This practice is sustainable because it focuses on maintaining the health of the environment while ensuring the productivity of the farm.