Soil and Nutrients

What do you notice about the samples? Make 3 observations and 1 inference Order the samples

How is soil formed? Interaction of 5 factors: –Rocks –Sunlight –Water –Air –Living organisms RATEWhat determines the RATE of soil formation? –climate TYPEWhat determines the TYPE of soil formed? –material and precipitation

Weathering Agents Chemical and physical forces that break apart rocks or remove minerals –Temp changes –Water/ice –Tree/plant roots –Sand and rocks –Glaciers –Wind

Soil Layers in ground

Look at your sample… What percentage of clay, silt, sand do you estimate? How does that help you determine your soil type?

Particle Size = Soil Texture SAND, SILT, CLAY What type of soil do we have? What type of soil do we want?

Particle Size = Soil Texture SAND, SILT, CLAY

So what…

SAND, SILT, CLAY, HUMUS Why don’t plants grow well in soil high in clay or sand content? What’s the best use for land with muck soil… –Housing development or farm specializing in vegetables? Why? Soil TextureInfiltrationWater Holding Capacity Aeration SANDGoodPoorGood SILTMedium CLAYPoorGoodPoor LOAMMedium

Now What? Can you Solve a Problem ? How will you organize your samples/tests? How will you split up the work? How will you record results? How will we know what our results mean? How well do you think you addressed your first challenge? –As an individual? –As a class? How many of these questions did you answer? Now evaluate your class performance… How well do you think you addressed your first challenge? –As an individual? –As a class? How many of these questions did you answer? Now evaluate your class performance…

Soil and Nutrients 3 Primary nutrients –N, P, K –why do we need them? Limiting factor vs. poisoning –Not enough limits growth, too much hurts plant Proper pH Levels –Allow for chemical absorption of N, P, K

Nitrogen Growth of leaves & stems Green v yellow Fungus danger Potassium Strong stems Ripen fruit Disease danger Brown edges Potassium Strong stems Ripen fruit Disease danger Brown edges Phosphorus Good root growth Flower & seed formation Disease danger purple

The Nitrogen Cycle The air is 78% nitrogen, why can’t organisms use this? What role do bacteria play in the nitrogen cycle?

The Phosphorus Cycle Takes hundreds of millions of years to complete cycle Sources – Guano, erosion of rock, ocean sediment

Fertilizer Solutions AdvantagesDisadvantages SYNTHETIC ORGANIC

Fertilizer Solutions AdvantagesDisadvantages SYNTHETIC Less needed Known [nutrients] quick Harmful concentration Easily leached ORGANIC Not as harmful Stay longer Add humus More needed $$ Variable nutrient am’ts

Copy this into your notebook and add to the chart from the GMO article. General Info about genetic engineering Positives / Advantages Negatives / Disadvantages

What do your results mean and what will you do with them? Now What?