2. Nitrogen
-Nitrogen is found in the chlorophyll molecule which is
important for photosynthesis (also found in proteins)
-gives plants dark green colour
Deficiency:
-plants have yellow leaves and stunted growth
3. Phosphorus
-P is found in many molecules (DNA, RNA, ATP,
membrane)
-important in protein synthesis during plant growth
Deficiency:
-plants grow slower -young leaves are grey in colour
-older leaves are red in colour
4. Potassium
-helps with protein synthesis
-important in plant growth and disease resistance
-improves quality of plant seeds
Deficiency:
-plants don’t grow -older leaves turn brown and die
8. Nomadic Hunter Gatherers
1. Knowledge: knew which plants were edible,
what parts were edible, where they grew and
what time of year the plants could be
harvested.
2. Tools: for digging edible roots, harvesting
seeds and grinding seeds in an edible form.
9. Monoculture
• One crop is planted
• Maximizes the amount of food
Problems (soil nutrients are depleted)
-if the land is used year after year for the same
crop, the same minerals will be depleted that the
plant needs.
-eventually the soil becomes unusable
10. Possible solution
• Crop Rotation – alternating different plants year
after year that require different nutrients to
sustain the crop.
Solutions:
• Planting legumes one year.
• Farm manure
• Green manure
•
11. Farm Manure – rich in N, P, K
Advantages
-manure is natural and easily obtained
-manure needs to be disposed of
-decomposes and forms humus (increases the
soil’s ability to absorb and retain water.
-rich in N, P, K
12. Potential Problems
- Difficult to distribute nutrients evenly
- Large volume of manure is required (strong
smell)
- High levels of E.Coli (compromise water safety)
- Need to be stored to avoid nutrient loss from
rain
- Cost of labour
