Soil & Land Management Agriscience Applications

1. Soil & Land ManagementAgriscience Applications By: Johnny M. Jessup Agriculture Instructor/FFA Advisor

2. What is Soil? • Is the top layer of the Earth’s surface suitable for the growth of plant life.

3. The Soil Profile • Soil Horizon • They are the layers of the different types of soil found at different depths in soil profile. • Soil Profile • A vertical section through the soil extending into the unweathered parent materials and exposing all the horizons.

4. Master Horizons • What are the Master Horizons? • The are A, B and C horizons are known as the master horizons. They are a part of a system for naming soil horizons in which each layer is identified by a code O, A, E, B, C and R.

5. Horizons • The O Horizon • The organic layer made of wholly or partially decayed plant material and animal debris. • Normally found in a forest with fallen leaves, branches and other debris.

6. Horizons • The A Horizon • Usually called the topsoil. • Surface layer of soil for judging purposes. • Usually contains more organic matter. • Somewhat darker in color. • Provides the best environment for the growth of plant roots, microorganisms and other life.

7. Horizons • The E Horizon • This is the zone of the greatest leaching of clay, chemicals and organic matter.

8. Horizons • The B Horizon • Subsurface layer of soil for judging purposes. • Called the subsoil. • Called the zone of accumulation where chemicals leached out of the A horizon. • Reason why most subsoil has an increase in clay content.

9. Horizons • The C Horizon • Called the parent material. • Lacks the properties of the A and B horizon. • Less touched by soil forming processes.

10. Horizons • The R Horizon- • Is the underlying bedrock such as the limestone, sandstone, and or granite.

14. Soil Characteristics

15. Soil Texture • Refers to the size of soil particles. • Which are: • Sand (Large) • Silt (Medium) • Clay (Small)

16. Relative Size of Soil Particles

17. Soil Texture - Sand • Is the largest of the soil particles. • Individual particles can be seen with the naked eye. • Sandy soils have problems holding enough water for good plant growth.

18. Soil Texture - Sand • Sand is also gritty to the touch. • Sand grains will not stick to each other. • Four types of sand grains are…. • Very coarse sand • Coarse sand • Medium sand • Fine Sand

19. Soil Texture - Sand

20. Soil Texture - Silt • Intermediate or medium sized soil particles. • But can’t be seen with the naked eye. • Is the best soil as it has the ability to hold large amounts of water in a form plants can use.

21. Soil Texture - Silt

22. Soil Texture - Clay • The smallest of soil particles. • Clayey hold lots of water, but they…. • May be airtight. • Infertile for root growth. • Associated with wet soils. • Clay will hold more plant nutrients than any other soil particle. • Clay particles stick to one another.

23. Soil Texture - Clay

24. Textural Classes • There are 12 textural classes. • Represented on the Soil Texture Triangle. • Textural class determined by the percentage of sand, silt, & clay.

26. Soil Structure • Refers to the way soil particles cluster together to form soil units or aggregates, while leaving pore space to…. • Store air. • Store water. • Store nutrients. • Allow root penetration.

27. Types of Soil Structures • There are five types of soil structures. • They are: • Single grain • Granular • Platy • Blocky • Prismatic

28. Soil Structure – Single Grain • Associated with sandy soils.

29. Soil Structure - Granular • Particles cling together to form rounded aggregates. • Very desirable for all soil uses. • It is commonly found in A horizons. • Peds are small usually between 1 to 10 millimeters

30. Soil Structure - Platy • Usually found in E horizons. • Large, thin peds. • Plate-like & arranged in overlapping horizontal layers.

31. Soil Structure - Blocky • Particles cling together in angular aggregates. • Typical of soils with high clay content. • Typical of B horizons. • Peds are large about 5 to 50 millimeters

32. Soil Structure - Massive • Soil has no visible structure. • Hard to break apart & appears in very large clods.

33. Land Classification

34. Land Capability Maps • Based on the physical, chemical, and topographical aspects of the land.

35. Land Capability Classes • Assigning a number to land. • Eight classes used. • I to VIII with I having the best arability. • Class I to IV can be cultivated. • V to VIII tend to have high slope or are low & wet.

36. Land Capability Classes • Class I - Very good land. • Very few limitations. • Deep soil and nearly level. • Can be cropped every year as long as land is taken care of. • Class II - Good land • Has deep soil. • May require moderate attention to conservation practices.

37. Land Capability Classes • Class III - moderately good land. • Crops must be more carefully selected. • Often gently sloping hills. • Terraces and stripcropping are more often used. • Class IV - fairly good land. • Lowest class cultivated. • On hills with more slope than class III. • Class V - Unsuited for cultivation. • Can be used for pasture crops and cattle grazing, hay crops or tree farming. • Often used for wildlife or recreation areas.

38. Land Capability Classes • Class VI - Not suited for row crops. • Too much slope. • Usually damaged by erosion with gullies. • Can be used for trees, wildlife habitat, and recreation. • Class VII - Highly unsuited for cultivation. • Has severe limitations. • Best used for planting trees. • Steeply sloping. • Large rock surfaces and boulders may be found. • Very little soil present.

39. Class VIII • Cannot be used for row crops or other crops. • Often lowland covered with water. • Soil maybe wet or high in clay. • Best suited for wildlife & recreation.

40. Soil Conservation & Enhancement

41. Soil Erosion • Can be stopped and/or reduced by good soil management. • Management practices that reduce soil erosion increase water absorption and retention.

42. Types of Erosion • Sheet erosion • Removal of layers of soil from the land into streams. • Gully erosion • Soil removal that leaves trenches.

43. Soil Conservation Methods • Reduce rain drop impact. • Reducing/slowing the speed of the wind or water movement across the land. • Securing soil with plant roots. • Increasing absorption of water. • Carrying run-off water safely away.

44. Cover crops Mulching Conservation tillage Contour practices Strip cropping Crop rotation Add organic matter Liming and fertilizer Grass waterways Terracing Avoid overgrazing Use a conservation plan Recommended Practices

45. Recommended Practices – No Till • Cropping technique used to reduce soil erosion. • Crops are planted directly into the residue of a previous crop without plowing or disking • Very effective erosion control.

46. Recommended Practices – Conventional Tillage • Uses tillage system that disturbs the soil surface by…. • Plowing • Disking • Harrowing

47. Recommended Practices – Conservation Tillage • Intermediate tillage system between conventional & no-till.

48. Soil Enhancement - Fertilizer • Fertilizer • To add nutrients to the soil.

49. Soil Enhancement - Lime • Using as an amendment to raise soil pH. • Increases availability of nutrients. • Example: • If soil pH is 5.5, lime may be added to raise soil pH to a more acceptable 7.0 level.

50. pH Scale