Hort 1001 Lecture 19

Front 1

Two key properties of soil

Back 1

1. Texture

2. Structure

Front 2

Texture

Back 2

Relative proportion of sand, silt and clay particles in soil.

Front 3

Mineral particles in order from largest size to smallest size.

Back 3

Largest: Sand

Medium: Silt

Smallest: Clay

Front 4

How does high amounts of sand make soil feel?

Back 4

Gritty

Front 5

How does a high amount of silt make soil feel?

Back 5

Floury

Front 6

How does a high amount of clay make soil feel?

Back 6

Velvet when dry, sticky when wet

Front 7

In a soil sample (like from the assignment), what particle will be suspended to the bottom? How about the top?

Back 7

Sand on the bottom, clay on the top

Front 8

What tool is used to identify the type of soil based on percent composition of particles?

Back 8

Texture Triangle

Front 9

Lester soil was proposed in 1939 in what county?

Back 9

McLeod (near Lester Prairie, MN)

Front 10

When was the soil established (Lester reading)

Back 10

1945 in Dakota County

Front 11

Lester soils are ___ ___ and formed in loamy glacial till on ground moraines.

Back 11

Lester soils are well drained and formed in loamy glacial till on ground moraines.

Front 12

Lester soils have properties developed from grassland and forest environments and are primarily used for ____, ____ and ____ production.

Back 12

Lester soils have properties developed from both grassland and forest environments and are primarily used for forage, corn and soybean production.

Front 13

What is the state soil?

Back 13

Lester (passed in 1987, official on April 28, 2012)

Front 14

Soils high in sand have great ___ and aeration so roots are exposed to air in the soil and don't rot.

Back 14

Soils high in sand have great drainage and aeration so roots are exposed to air in the soil and don't rot.

Front 15

True or False: Sandy soils are good at holding moisture during dry spells and hold nutrients well.

Back 15

FALSE: Sand soils don't hold moisture well when it is dry outside and they do not hold moisture well.

Front 16

True or False: Nutrients and moisture hang on to a soil best when the soil particles have lots of surface area, and sand has the least surface area (relative to particle volume) of the three types of particle.

Back 16

True

Front 17

True or False: Roots penetrate easily in a dry clay soil.

Back 17

False

Front 18

Clay soils tend to be what?

Back 18

Fertile

Front 19

Clay holds water so much that what occurs?

Back 19

It can be hard for the plant to water itself

Front 20

Silt has ___ properties between sand and clay.

Back 20

Silt has intermediate properties between sand and clay.

Front 21

True or False: All soil textures have good and bad points.

Back 21

True

Front 22

Potatoes and peanuts are grown in what type of soil to make harvesting easier?

Back 22

Sandy soil

Front 23

Loam soils are used for what types of crops?

Back 23

Corn, wheat and soybeans

Front 24

True or False: It is tough to modify soil so you just have to make do (you can't really add clay for instance...)

Back 24

True

Front 25

Structure

Back 25

The way in which the soil particles and other materials like organic matter in the soil bind together in clumps.

Front 26

Aggregates

Back 26

Clumps of soil

Front 27

True or False: Pure sand does not clump together into aggregates.

Back 27

True

Front 28

Granular

Back 28

When sand, silt, clay and organic matter interact to form small aggregates

Front 29

Large holes in aggregates allow for what?

Back 29

Spaces for water and gases to pass

Front 30

Aeration-Porosity

Back 30

Holes available for gas exchange. They are important because if soil becomes water-clogged, they can die.

Front 31

Organic matter is like glue in what way?

Back 31

It builds aggregates by stickle soil particles together.

Front 32

Good Tilth

Back 32

Soil with granular aggregation that favors plant growth by holding water and nutrients while still allowing for drainage and gas exchange - does not form clumps and breaks apart into crumbly moist chunks

Front 33

2 ways to improve soil structure

Back 33

1. Increase organic matter

2. Reduce compaction

Front 34

Increasing organic matter improves and stabilizes what?

Back 34

Soil aggregation

Front 35

Reducing compaction does what?

Back 35

Maintains macro- and micro-pores in soil to promote drainage, moisture retention and gas exchange

Front 36

Tillage exposes ___ ___ to oxygen, which breaks down organic matter through oxidation. As organic matter is lost, so is the glue that causes aggregation.

Back 36

Tillage exposes ORGANIC MATTER to oxygen, which breaks down organic matter through oxidation. As organic matter is lost, so is the glue that causes aggregation.

Front 37

True or False: Tractors compact soil and reduces porosity.

Back 37

True

Front 38

Soil Organic Matter

Back 38

Carbon-based material in the soil that was originally a living organism (plant, animal or microbe)

Front 39

Humus

Back 39

Sticky substance that helps bind soil particles together. Humus created from the decomposition of former living materials.

Front 40

Humus can absorb __ times its weight in water, so it is important in improving light (sandy) soils.

Back 40

Humus can absorb 6 times its weight in water, so it is important in improving light (sandy) soils.

Front 41

True or False: Organic matter is negatively charged so it holds positively charged cations like calcium.

Back 41

True

Front 42

True or False: Decomposing organic matter makes nutrients such as nitrogen available to plants.

Back 42

True

Front 43

4 types of organic matter

Back 43

Compost

Raw organic matter

Green manure

Incorporating crop residues

Front 44

Compost

Back 44

Leaves, weeds, manure, grasses and other organic materials. Builds soil structure and retains moisture and nutrients.

Front 45

Raw organic matter

Back 45

Uncomposted organic material that is tilled into the soil. Slow working, but arguably provides more nutrients because nutrients aren't released into the atmosphere like in compost.

Front 46

Green manure

Back 46

Growing a crop with the sole purpose of tilling the crop into the land to increase organic matter. Helps improve moisture holding capacity. Great benefits for legumes.

Front 47

Incorportating crop residues

Back 47

Incorporating plant material into soil after harvest.

Front 48

No-till

Back 48

Using bare minimum tillage or leaving residue at the top of the soil. This minimizes erosion.

Front 49

If you add too much organic matter that has too much carbon and not enough nitrogen, what happens?

Back 49

You can harm growth and deplete the soil of nitrogen. That's why using manure (chicken manure especially) is a safe bet.

Front 50

USDA standards for organic production in the USA

Back 50

1. Description of practices

2. List of each substance used in production

3. Identification of monitoring techniques used to verify that the organic plan is implemented

4. Describe management practices and physical barriers

Front 51

Organic crops can only be grown on what type of land?

Back 51

Certified organic land with defined boundaries and buffer zones.

Front 52

In organic farming tillage must minimize what while improving the soil?

Back 52

Erosion

Front 53

How are crop nutrients and soil fertility managed in organic farming?

Back 53

Rotations

Front 54

Plant and animal materials are used to improve what in organic farming?

Back 54

Soil organic matter.

Front 55

Raw animal manure can be applied to what in organic farming?

Back 55

Land used for crops not intended for consumption OR it must be in the soil not less than 120 days prior to harvest (90 for some crops that don't come in contact with soil)

Front 56

In organic farming, what must the compost carbon:nitrogen ration be between.

Back 56

25:1 and 40:1

Front 57

In organic farming, the pile of manure must be between what temperatures for 15 days while being turned 5 times?

Back 57

131 to 170 degrees F

Front 58

GMO crops are not allowed in what?

Back 58

Organics

Front 59

Container gardening is not desirable because why?

Back 59

The plants are too compact and there is poor drainage. Instead, use soil-less mix or an organic mix to increase aeration-porosity.

Front 60

What type of gardening is better than container gardening for the purposes of porosity?

Back 60

Raised bed

Front 61

Fertilizer Analysis

Back 61

The 3-number NPK series on fertilizer bags

Front 62

What does N-P-K represent?

Back 62

The % nitrogen, phosphorous and potassium in fertilizer

Front 63

10-15-10 fertilizer has what percent of each nutrient? What is the rest of the fertilizer made of?

Back 63

10% N

15% P

10% K

The rest is "filler" (sand or gravel usually)

Front 64

In MN, what nutrient is typically absent in fertilizer? Why?

Back 64

Phosphorous because legislation limits it to prevent algae after run off.

Front 65

In MN, what nutrient is typically valued the most? In other words, we try to get the best deal on which nutrient?

Back 65

Nitrogen