Montana Soil ResourcesMontana Soil Resources

Montana Small Grain GuideMontana Small Grain Guide

Soil PotentialSoil Potential

All Montana Soils have potential for All Montana Soils have potential for cereal grainscereal grains

Irrigated soils cover 3% Irrigated soils cover 3% • doubles production per acredoubles production per acre

Characteristics of Montana SoilsCharacteristics of Montana Soils

Soil characteristics that influence efficiency:Soil characteristics that influence efficiency:

Soil TextureSoil Texture

Organic Matter ContentOrganic Matter Content

Amount of ClayAmount of Clay

pHpH

Salt LevelSalt Level

Arrangements of HorizonsArrangements of Horizons

Soil TextureSoil Texture

measure of relative proportions of sand, measure of relative proportions of sand, silt and claysilt and clay

texture determines:texture determines:

water-holding capacitywater-holding capacity

infiltration rateinfiltration rate

tendency to become compactedtendency to become compacted

Organic MatterOrganic Matter

1-5% OM in soils1-5% OM in soils helps bind soil particles into aggregatehelps bind soil particles into aggregate improves infiltrationimproves infiltration holds more water, nutrients, airholds more water, nutrients, air Soils farmed for 30 years have 1/2 the Soils farmed for 30 years have 1/2 the

O.M.O.M.• thus need for more fertilizerthus need for more fertilizer

Soil pHSoil pH

measure of Acidity or Alkalinitymeasure of Acidity or Alkalinity ideal pH for nutrient availability = 6.5ideal pH for nutrient availability = 6.5• many soils 7.5 to 8.3many soils 7.5 to 8.3

SaltsSalts

arid climates salts do not leach out of arid climates salts do not leach out of soil, thus accumulate in the soilsoil, thus accumulate in the soil

Saline Seep is one exampleSaline Seep is one example

Climate and Cereal Grain Climate and Cereal Grain ProductionProduction

Late spring moisture = reduced growing Late spring moisture = reduced growing season = lower yieldsseason = lower yields

Harvest rain = lodging, bleachingHarvest rain = lodging, bleaching Temperature: Barley & Wheat like coolTemperature: Barley & Wheat like cool Temps over 90 deg F damagesTemps over 90 deg F damages Winterkill: low winter temps kill winter Winterkill: low winter temps kill winter

wheatwheat• min temp -17 deg Fmin temp -17 deg F• protective snow coverprotective snow cover

ChinooksChinooks

rise in temp. of 29 degrees F in 24 hour rise in temp. of 29 degrees F in 24 hour periodperiod

more water enters the soil in areas of more water enters the soil in areas of few chinooksfew chinooks

Figure I-7 page 11Figure I-7 page 11

DroughtDrought

Lack of precipitation, high temps., high Lack of precipitation, high temps., high windswinds

Dry April suggests that rest of growing Dry April suggests that rest of growing season will be dryseason will be dry• help decision makinghelp decision making