Restoring Soil Fertility and Agricultural Practices
This page delves deeper into the methods used to restore soil fertility and various agricultural practices related to the nitrogen cycle. It is particularly relevant for students studying GCSE Biology Edexcel, GCSE AQA, or preparing for GCSE questions on this topic.
The page begins by discussing artificial fertilizers, which are a common method of adding nitrates to the soil. These fertilizers are produced through industrial processes and contain nitrates and other mineral nutrients. They are typically applied as granules, powder, or liquid, and are spread by tractors.
Vocabulary: Artificial fertilizers are man-made substances containing nitrogen and other nutrients, designed to enhance soil fertility and promote plant growth.
The advantages and disadvantages of artificial fertilizers are outlined:
Pros:
- Easy to use
- Known amount of nutrients added to crop
- Dissolves easily in soil water
Cons:
- Run-off can cause eutrophication of waterways
Highlight: The use of artificial fertilizers can lead to environmental issues such as water pollution if not managed properly.
The page then discusses natural fertilizers, which are nitrogen-rich substances derived from animals (e.g., manure) and plants (compost). The pros and cons of natural fertilizers are also presented:
Pros:
- Useful way of clearing animal waste
- Cheaper than artificial fertilizer
Cons:
- Must be spread before the new crop is planted
- Possibly unknown quantity of nutrients
Example: Manure is a common natural fertilizer that can improve soil fertility but requires careful management in terms of timing and quantity.
The concept of crop rotation is introduced as another method to maintain soil fertility. Crop rotation involves growing different crops in a field in different years. A table is provided showing examples of crop rotation patterns over three years.
Definition: Crop rotation is the practice of planting different crops sequentially on the same plot of land to improve soil health, optimize nutrients in the soil, and combat pest and weed pressure.
The page highlights the importance of legumes in crop rotation. Legumes, such as beans, peas, soybeans, and clover, have a special ability to fix nitrogen in the soil through their root nodules.
Vocabulary: Legumes are plants in the family Fabaceae (or Leguminosae) that have the ability to form symbiotic relationships with nitrogen-fixing bacteria in their root nodules.
Finally, the concepts of fallow land and green manure are explained:
- Fallow: Leaving the field with no crop for a year
- Green Manure: Growing a non-crop legume, such as clover, then ploughing it into the soil
These practices are important for students to understand when studying the nitrogen cycle GCSE OCR or nitrogen cycle GCSE WJEC syllabi, as they demonstrate practical applications of nitrogen cycle knowledge in agriculture.
