Managing the Soil Section 4.2

Managing Soil Nutrients The nutrients plants require are found in the soil Potassium Nitrogen Phosphorous As plants grow they take in these nutrients As plants are harvested these nutrients are removed from the ecosystem

Fertilizers Natural: Synthetic: From plant/animal waste Compost Manure Manufactured by chemical processes Farmers started using them in 1960s and saw increased crop yields

Environmental Impacts of Fertilizers Synthetic fertilizers are very concentrated so they change the community of soil organisms Can leach out of the soil and enter the water system.

Algal Blooms Fertilizer in water systems causes an increase algae, which then dies and decomposes The bacteria involved in decomposition use up a lot of dissolved oxygen which kills fish and other organisms

Water in the Soil Farmers often use irrigation to add water to crops If there is too much water then drainage must be added

Soil Compaction If soil is compacted it has decreased oxygen levels and water will have difficulty passing through.

Today’s Task Pg. 128 #3, 4, 6, 8 Read Black Gold – page 129