Ch. 4: Soil Water, Plant Nutrition, Soil Symbioses

Soil Supplies H2O & nutrients 1) What influences soil water? 2) What nutrients plants need, & what influences nutrient supply?

Plant nutrition 17 essential elements Deficiency: < needed Toxicity: > needed Molybdenum (Mo) deficiency in citrus Aluminum (Al) toxicity

Plant nutrition 17 essential elements Macronutrients (9): > 0.1% of plant C, H, O, P, K, N, S, Ca, Mg “C Hopkin’s car is an MG” “C HOPKiNS Car is an Mg” >1% plant dry weight is C,H,O,N,K (Chonk!) Chuck Hopkins and his car

Plant nutrition 17 essential elements Micronutrients (8): < 0.02% plant Fe, Mo, B, Cu, Mn, Zn, Cl, Ni “A festive mob comes in clapping nicely” “A Festive MoB CuMnZn Clapping Nicely”

Plant nutrition Ex, Mo deficiency Australia Mo used N-fixing bacteria 140 g/ha (13 oz/acre!) Mo every 5-10 yr Increased growth 6-7 times! Another Moe

Soil Fertility: Recall….. CEC (organic matter and clay): “potential fertility” pH determines BS & influences “actual fertility” Overall, hi CEC & hi BS means pH high & soil fertile

Recall…… pH influences nutrient availability

Nutrient sources 1) Soil 2) Some nutrients mobile: recycled old to new leaves Removal nutrients: resorption –Important N, P, K, Mg (mobile nutrients)

Ch. 4: Soils, Nutrition etc.

Soil Taxonomy Soils classified Tony Danza?

Soil Taxonomy Smallest unit: series. Basic unit classification. = species (biology) Largest: order (ends in -sol). = domain (biology) What official AL state soil??

Soil Taxonomy Bama series!

Soil Taxonomy Tour 7 orders (AL) Major profile characteristics, vegetation

1: Entisols Named for RECENT Little profile (young): A/C or A/R Steep rocky places, new sediments, etc. A/C A/R

1: Entisols Scattered AL

2: Inceptisols Little profile (inceptus=beginning): > Entisols –A & weak B Steep slopes, young soils Appalachian forest soil on sandstone

2: Inceptisols Widespread AL

3: Histosols Histos=tissue: High organic matter (20-30%) –Thick O Drainage restricted: little decomposition—flooded, anaerobic

3: Histosols Shrink when dry (subsidence) Everglades swamp histosol 1924: post surface 1975: photo taken (4 ft drop)

3: Histosols Burns when dry! Peat = fuel When farmed: can burn/blow away N. Carolina histosol

3: Histosols AL: pitcher plant bogs & swamps (lower coastal plain)

4: Vertisols High clay (shrink-swell type) Cracks when dry –Self-turning (verto=to turn)

4: Vertisols Self-turning: little profile development Peds have slickensides (smooth shiny surfaces) Engineering problems

4: Vertisols AL: common Black Belt

5: Mollisols From mollis=soft Grassland (prairie) soils

5: Mollisols From mollis=soft Grassland (prairie) soils Thick, dark A. Hi OM Hi CEC & BS. (Fertility?)

5: Mollisols Good ag soils. Little prairie left

5: Mollisols Few N AL

6: Alfisols Hi Al & Fe (AlFe) –Well developed (A, E, B) –B claypan (Bt layer) BS high (>35%)

6: Alfisols Fertile ag soils Most midwest/north US

7: Ultisols Well developed, acidic. Humid climate B: claypan (Bt), red/yellow Fe oxides

7: Ultisols Low BS (<35%) Good ag soil if fertilized & limed.

7: Ultisols #1 AL (SE US)