Grow Your Own, Nevada! Spring 2013: Gardening in Nevada's Soils- A Hero's JourneyPresentation Transcript
Gardening in Nevada’s SoilsGardening in Nevada’s Soils
Gardening in Nevada’s SoilsGardening in Nevada’s SoilsWhat is healthy soil?How does soil form?Soil has many components:– Textural or structural– Biological– ChemicalHow can you improve your soil?
OSU Extension ServiceHealthy soil has:Healthy soil has:Good porosityGood drainageGood water-holding capacityGood tilth, meaning they’reeasy to workLots of organic matterLots of organismsA pH of about 7Low salinity and sodium levels
How are soils formed?How are soils formed?A. Miller
It’s not your fault!It’s not your fault!You didn’t do anything wrong!We have very young soils geologicallyTheir youth makes them:– Highly variable both vertically andhorizontally– Low in organic matter– Still a work in progress
Compare horizonsCompare horizonsOSU Extension Service
What are soils made of?What are soils made of?MineralsAirWaterOrganic matter(humus)www.statlab.iastate.eduUSDA NRCS
Water = 20 to 30%Air = 20 to 30%MineralFraction(sand, silt,clay) = 45 to 50%Organic Matter = 0 to 5%““Ideal” composition of a soilIdeal” composition of a soil
Texture by feel: SandTexture by feel: SandAdapted from NRCS, Bozeman Mont. by A. Miller
Texture by feel: Loamy sandTexture by feel: Loamy sandAdapted from NRCS, Bozeman Mont. by A. Miller
Texture by feel: Loams and claysTexture by feel: Loams and claysAdapted from NRCS, Bozeman Mont. by A. Miller
Why determine soil texture?Why determine soil texture?Soil texture influences:Ease of tillageAmount of pore space or porosityWater infiltration ratesWater-holding capacitySoil fertility or nutrient-holding capacity
WaterWaterspreadsspreadsdifferentlydifferentlyinindifferentdifferentsoilsoiltexturestexturesDeepestpenetrationModeratespread andinfiltrationWide, but moreshallow, infiltration CLAYSILTSAND
Note the amount ofwater that drainedfrom the sandy loamsoil.NRCS, Bozeman, Mont.Soil texture affects infiltrationSoil texture affects infiltration
Less water hasdrained from the siltyclay loam soil.Soil texture affects infiltrationSoil texture affects infiltrationNRCS, Bozeman, Mont.
The loam soildrained almost asmuch as the sandyloam.Soil texture affects infiltrationSoil texture affects infiltrationNRCS, Bozeman, Mont.
Soil texture and infiltrationSoil texture and infiltrationSoil textureInfiltration rate,inches per hourSand 2 - 4Sandy loam 1 - 3Silt loam, loams 0.25 – 1.5Silty clay loams, clay 0.1 – 0.3A. Miller
Sand versus ClaySand versus ClayClay - “Heavy” soil- High water-holding capacity- Slow infiltration- High nutrient-holding capacitySand - “Light” soil- Low water-holding capacity- Fast infiltration- Low nutrient-holding capacity
Water InfiltrationWater Infiltration
Where do plants get their waterWhere do plants get their waterfrom in the root zone?from in the root zone?Adapted from PNW 475 by A. Miller
Soil textureSoil textureSandy soil watering tipsSandy soil watering tips Emitters close to theplant Higher volume perhour emitters Low duration Increased frequencyClay soil watering tipsClay soil watering tips Emitters further fromthe plant Lower volume perhour emitters Higher duration Lower frequency
Can you change soil texture?Can you change soil texture?No, not really!Add sand to clay – mess!Add clay to sand – mess!Texture may limit yourplant choicesHow can you improveyour soil texture? – addorganic matter!
Benefits of soil organic matterBenefits of soil organic matterImproved water infiltrationIncreased water- and nutrient-holding capacityFormation of soil into stableaggregatesReduced soil compaction
NutrientsNutrientsheld in theheld in thesoil aresoil areavailableavailablefor plantfor plantgrowthgrowthlesco.com
Soil StructureSoil Structure
PlatystructureGranularstructurewww.statlab.iastate.edu/soils/Soil structure:Soil structure:How particles are grouped together intostable collections by organic matter “glue,”also called “peds” or soil aggregates
Composition of a compacted soilComposition of a compacted soilNote the reduced air space in acompacted soil.Before After70%50%
Soil CompactionSoil Compaction
Soil compactionSoil compaction
Avoid walking or driving on wet soilAvoid working wet soilOSU Extension Service
Adding organic matter:Adding organic matter:Improves water infiltrationIncreases water- and nutrient-holdingcapacityForms soil into stable aggregatesReduces soil compaction Also – feeds soil biota!
USDA NRCSThe living soilThe living soil
Add organic matter to your soilAdd organic matter to your soilOSU Extension ServiceWhat kind of organic matter?Composted or well-aged OM
What about manure?OSU Extension ServiceUncomposted manure can be high in salts(burns plants and seeds) and can contain weedseeds, diseases, and insect eggs and larva.
Household vegetable debris andgrass clippings can also be usedto make compostUNCE Reno, Nev.
Types of compostingTypes of compostingSlow composting– Less labor intensive– Slower product production– Good for folks that produce low volumesFast composting– More labor intensive– Quicker production– Good for folks that produce higher volumes
Types of compostersTypes of compostersCompost piles– Can be messy– Easy access for animals– Harder to turn?
Types of compostersTypes of compostersCompost tumblersBin composters– Neater, cleaner
Steps to creating a compost pileSteps to creating a compost pilePick a site– Level, well-drained– Build on bare soil forbacteria– Shade– Near water and sourceof raw materials– Esthetically pleasing?
Steps to creating a compost pileSteps to creating a compost pilePile size– Cool or slow composting– Hot or active composting• At least a cubic yard (3’ x 3’ x 3’)• Not more than 5’ cube
Steps to creating a compost pileSteps to creating a compost pileIngredients– Ratio of 1:2 (1:1) green to brown material– Finer the size, quicker to compost– Too fine and it will compact 1-1.5” is best– Sprinkle some soil or finished compostevery 8 to 12 inches as you build the pile
What to CompostWhat to CompostGreen Materials– Grass clippings– Animal manure (from herbivores only)– Non-animal-based kitchen wastes– Garden trimmingsDry or Woody (“Brown”) Materials– Fall leaves, dry cornstalks– Wood chips or sawdust (caution)– Hay or straw (soiled or clean)
WhatWhat notnot to compostto compost Yard trimmings or grass clippings treated withpesticides. They may kill the beneficial organisms in thecompost pile or later in your garden. Weeds, if the pile will not be hot enough to kill theseeds. Diseased or insect-infested plant parts. The diseases orinsects may be transferred to the soil with the compost. Parts of any plant known to contain poisons or toxins,such as black walnut. Fats, grease, lard or oils. These do not break downquickly and may attract pests, vermin, dogs or largecarnivores. Meat or fish bones or scraps. Dairy products.
Oh dear!Oh dear!
WhatWhat notnot to compostto compost Too much of any plant that contains tannins or resinsthat inhibit decomposition, such as junipers, pine,spruce, arborvitae, oak or cottonwood. Charcoal ash, as this may contain substances harmfulto plants. Fireplace ashes, since they have a very high pH, as doour native soils. High pH levels can result in nutrientdeficiencies and other plant problems. Pet wastes, such as dog or cat feces or soiled cat litter.They may contain parasites, bacteria or viruses harmfulto humans. Swine or other omnivore wastes. They also may containparasites, bacteria or viruses harmful to humans.
Steps to creating a compost pileSteps to creating a compost pileAddWater
Steps to creating a compost pileSteps to creating a compost pileMix the pile– Weekly for hot or active composting– Whatever for slow or cool composting– Should reach 120 to 160 degrees– After 6-8 weeks of cooking, pile needs tocure for another 4-8 weeks– Turn pile while it is curing also
Preventing problemsPreventing problemsNuisance insects andanimalsFood wastes can attractthemMay need to vermicultureor worm compost orcompost tumble highvolumes of food wastes
Compost troubleshootingCompost troubleshooting
Composting Pros and ConsComposting Pros and ConsPROS Recycle nutrients backinto your soil Reduces waste to yourgarbage can and landfill It is a cost-effectivemethod of improvingyour soil Get good at producingit, you will have manyfriends wanting someCONS Can be messy and/orsmelly Can be labor intensive Can attract vermin,predators, stray dogs, etc. Can be weather dependent Do you have space? Do you have time tomanage?
What if I don’t want toWhat if I don’t want tocompost?compost?How about buying organic matter to addto my soil?– Steer manure– Compost– Worm castings– “Triple mix”– Neighbor’s horse manure– “fill dirt”
Use caution adding soilUse caution adding soilamendments!amendments!
Amendment Pros and ConsAmendment Pros and ConsPROS Good quality organicmatter amendments willimprove your soil No down time Less labor involvedCONS Good quality organicmatter amendmentscost $ May be introducing anew problem– Weed seeds– Insect eggs or larva– Diseases
Add “pantryAdd “pantryshelves” -shelves” -nutrientsnutrientsare held inare held inthe soil onthe soil onorganicorganicmattermatterparticlesparticleslesco.com
Chemical Properties of SoilChemical Properties of SoilpH – potential of HydrogenEC – Electrical ConductivityNutrient content (plant nutrients)
pHpHIndicates relative acidity or alkalinitypH 7 = neutral; less than pH 7 = acid;more than pH 7 = alkaline or basicAdapted from library.thinkquest.org by A. Miller
pH – Potential of HydrogenpH – Potential of HydrogenMeasure of the amount of hydrogenNegative logarithm of hydrogen ionactivity - 1 pH point is a ten-fold changepH of 7 = 1.0 x 10-7hydrogen ions equalH+and OH-ionspH of 3 = 1.0 x 10-3Hydrogen ionsmore H+ than OH- acidicpH of 10 = 1.0 x 10-10Hydrogen ions moreOH-than H+alkaline or basic
Soil pHSoil pHandandnutrientsnutrientsAdapted from www.soil.ncsu.edu by A. MillerWidest part of the bar indicates maximum availability
Can I change my soil pH?Can I change my soil pH?Not really – our soils are alkalineLimestone (calcium carbonate) buffersour soilsCaCO3 + 2HCl = 2Cl-+ Ca+2+ H2O + CO2 (gas)Can add sulfur, but takes time to lowerpH and change is not always notpermanent
EC or Electrical ConductivityEC or Electrical ConductivityMeasures how well soil conducts anelectric currentSalts that dissolve in water conductelectricityPlants need some “salts” – these arenutrientsVery high EC = high salt contentIf salt contents are high, it can interferewith plant growth
Classifying salt-affected soilsClassifying salt-affected soilsElectrical conductivity measurements (EC)Exchangeable sodium percentage (ESP)Salt-affected soils are commonly classifiedfor management purposes into threegroups: saline, sodic, and saline-sodicbased on EC and ESP
What to do aboutWhat to do aboutsalt-affected soil?salt-affected soil?If you have tested and find you have salt-affected soil:– Flush the soil with water to wash the saltdown below the growing zoneProblem:– High water tables, poorly drained soil andhigh salt content irrigation water are oftenthe cause of or contribute to high salinity
Managing salt-affected soilsManaging salt-affected soilsSelect plants that can tolerate salinityAvoid excess or salty forms offertilizersIncorporate organic matterIf appropriate, add sulfur to lower thepHIf a serious problem, go to raised bedswith good drainage
A word about gypsumA word about gypsumGypsum is CaSO4.H2OGood source of Calcium and SulfurGood for Sodium-Affected SoilsNOT a panacea for clay soils!Too much Ca can interfere withchemical balance in soil and cancontribute to a magnesium deficiencyand interfere with other micronutrientavailability
Sulfur:Sulfur:• Essential plant food for production ofprotein• Promotes activity and development ofenzymes and vitamins• Helps in chlorophyll formation• Improves root growth and seed production• Helps with vigorous plant growth andresistance to cold
Plant nutrientsPlant nutrientsSubstances necessary for plant growthPlants make their own food – these arethe vitamins and minerals plants need tomake their food and to growExcess or improper use of fertilizersmay result in plant damage and waterpollutionSplit into two groups, based on theamount of the nutrients the plants needto survive and thrive
How do we add nutrients?How do we add nutrients?Minor amounts in compostMinor amounts in soil “amendments”Generally added as fertilizer
Types of fertilizersTypes of fertilizersChemical fertilizersOrganic fertilizers or amendments(bone meal, compost, manure, etc.)www.farmphoto.com
Complete vs incomplete fertilizerComplete vs incomplete fertilizer“Complete” fertilizers contains the top 3nutrients, like 16-16-16 general fertilizer:– Nitrogen (N)– Phosphorus (P)– Potassium (K)– 4thnumber, if present, is Sulfur (S)“Incomplete” fertilizers do not contain thetop 3 nutrients, like Ammonium Sulfate21-0-0
How doHow doI knowI knowwhat towhat toadd toadd tomymysoil???soil???A. MillerTestTestyouryoursoil!soil!
What should I test for?What should I test for?Soil textural analysispH and saltsSoil nutrient contentFertilizer recommendationsCall your local extension office fora list of soil testing labsWhat information does a normalWhat information does a normalsoil test provide?soil test provide?
Call the Lab FIRST!Call the Lab FIRST!Find out what they test forFind out if they have package dealsFind out how much sample they wantyou to takeFind out how they want the sampledelivered to themCall UNCE 784-4848 for list of labs
How to take a sampleHow to take a sampleFirst, select thesite. Your soilsample shouldrepresent onlyone soil type orsoil condition.OSU Extension Service
Each sampleshould consist ofsub-samples takenfrom about 5-15locations withinthe same soil typeor sampling area.OSU Extension ServiceHow to take a sampleHow to take a sample
Use the “slice”method for arepresentativesample.UNCE, Reno, Nev.How to take a sampleHow to take a sample
Erosion ControlErosion ControlAnother method to manage soilSoil takes time to form – you don’twant to lose it!Keep a cover on the soil – plants,mulch, etc.Provide for drainage paths and armorthem to reduce the potential forerosion
Protect slopesProtect slopes
Redirect the rainRedirect the rain
Check irrigation oftenCheck irrigation often
How can I manage my soils toHow can I manage my soils toimprove them?improve them?Increase the organic matter content• Increases water- and nutrient-holding capacityAvoid compaction by:• Reducing tillage of wet soils• Reducing traffic on wet soils• Establish pathsMaintain cover with vegetation or mulchto reduce potential for erosionFertilize when needed