LAND JUDGING

Land Classification The Soil Conservation Service uses a classification system to describe the capability of the soils to produce crops.

SCS CAPABILITY CLASSES There are 8 SCS land capability classes. Each class is based on what the land may be used for and what is required to maintain the classification

LAND CAPABILITY CLASSES Class I-Cultivated crops Class II-Cultivated crops Class III-Cultivated crops Class IV-Cultivated crops Class V-Pasture Class VI-Pasture Class VII-Forestry Class VIII-Wildlife & Recreation

FACTORS AFFECTING LAND CLASS Slope Topsoil thickness Erosion Topsoil texture Permeability of subsoil Drainage Effective depth

SLOPE CATEGORIES for South Georgia RangeLand Class Nearly level0-2%I Very gentle2-5%II Gentle5-8%III Sloping8-12%IV Strongly Sloping12-17%VI Steep>17%VII Very SteepNANA

TOPSOIL THICKNESS CategoryRangeLand Class Extremely Thick>40”III Very Thick20-40”I Thick10-20”I Moderate5-10”I Thin<5”II Topsoil thickness is measured from the soil surface to the 1 st texture change.

EROSION The percentage of original topsoil which has eroded. Determined by subtracting the actual topsoil from the original and dividing the eroded by the original and multiplying by 100.

EROSION CATEGORIES CategoryRangeLand Class None to slight<25%I Moderate25-75%II Severe>75%III

SOIL TEXTURE Soil is made up of 3 particles: sand, silt & clay There are 3 categories of texture: Fine-smooth, sticky with no grit, will form a 2 inch or longer ribbon Medium-between fine & coarse, will form a ball and show some finger marks, will form a short ribbon Coarse-sandy, will not form a ribbon

PERMEABILITY OF SUBSOIL The ability of air & water to move through the subsoil. Based on subsoil texture. Rapid-coarse texture >20” Moderate-medium texture subsoil Slow-fine texture subsoil

DRAINAGE Refers to surface & internal drainage As a general rule, the quicker the soil can be tilled following a good rainfall the better the drainage. Color is the best indicator of drainage Bright colors (reds & yellows) indicate good drainage Dull colors (grays & browns) indicate poor drainage

DRAINAGE CATEGORIES CategoryLooks Excessively drainedCoarse texture for over 40” Well-drainedNo gray mottles in top 30” Moderately well-drainedNo gray mottles in top 20” Somewhat poorly drainedNo gray mottles in top 10” Poorly drainedGray matrix or gray mottles in top 10” Very wetSurface water

DRAINAGE LAND CLASS CategoryLand Class Excessively drainedIII Well-drainedI Moderately well-drainedII Somewhat poorly drainedIII Poorly drainedIV Very WetV

EFFECTIVE DEPTH The depth to which plant roots can easily penetrate. Usually the combined thickness of the topsoil and subsoil. Hard pans and plow pan layers may affect root depth. The presence of roots is a good indication of effective depth.

EFFECTIVE DEPTH RANGE CategoryRangeLand Class DeepRoots over 40”I ModerateRoots from 20-40”II ShallowRoots from 10-20”III Very ShallowRoots <10”IV

LAND TREATMENT PRACTICES Vegetative 1.Use conserving & improving crops occasionally-Always on class I 2.Use conserving & improving crops 1/2 of time-Always on class II 3.Use conserving & improving crops 2/3 of time-Always on class III 4. Use conserving & improving crops 3/4 of time-Always on class IV

5. Prevent residue burning-Always on classes I, II, III, & IV 6.Provide mulching with crop residue- Always on classes I, II, III, & IV 7.Use strip crops-On II, III & IV if terraces are not used & D slopes if terraces are used 8.Use crop rotation-Always on classes I, II, III, & IV

9. Control weeds, bushes & trees- Always on classes I, II, III, IV, & VI 10. Establish recommended grass and/or legumes-On pasture if < 50% of the plot is covered by a desirable species 11. Improve present stand of pasture- Always on class VI when practice #10 is not used 12. Control grazing-Always on class VI 13. Fence the pasture-Always on class VI

14.Use artificial reforestation-On class VII with no trees or if stand is poor & seed trees are absent 15.Use natural reforestation-Always on class VII; applies to current & future growth 16.Use prescribed burn occasionally-Always on class VII 17.Protect trees from wildfires-Always on class VII 18.Control forest insects & diseases-Always on class VII 19.Protect trees from animal damage-Always on class VII

20.Control undesirable species-Always on class VII 21.Harvest trees by clear cutting-On VII with a mature stand or if it has merchantable trees of an undesirable species & no merchantable trees of a desirable species 22.Harvest trees by selective cutting- Always on class VII; applies to current or future growth

LAND TREATMENT PRACTICES Mechanical 23.Terrace the field-On II, III & IV when slope > 2% & topsoil < 20 inches 24.Maintain field terraces-Always when #23 is used 25.Establish vegetative waterways- Always when #23 is used

26.Construct diversion terraces-On I, II, III, IV & VI if an up-slope water problem exists 27.Plow & cultivate on the contour- Always on cropland & pasture 28.Control existing gullies by special methods-Always on cropland and on pasture when present

LAND TREATMENT PRACTICES Plant Nutrients 29.Apply lime-On I, II, III, IV if pH < 6.0 & on pasture if pH < Apply manure-On I, II, III, IV & pasture when available 31.Apply nitrogen-Always on classes I, II, III, IV & pasture 32.Apply phosphorus-On I, II, III, IV & VI if phosphorus is less than very high 33.Apply potash-On I, II, III, IV & VI when potash is less than very high