Montana Soil Resources

1. Montana Soil Resources Montana Small Grain Guide

2. Soil Potential • All Montana Soils have potential for cereal grains • Irrigated soils cover 3% • doubles production per acre

3. Characteristics of Montana Soils • Soil characteristics that influence efficiency: Soil Texture Organic Matter Content Amount of Clay pH Salt Level Arrangements of Horizons

4. Soil Texture • measure of relative proportions of sand, silt and clay • texture determines: water-holding capacity infiltration rate tendency to become compacted

5. Organic Matter • 1-5% OM in soils • helps bind soil particles into aggregate • improves infiltration • holds more water, nutrients, air • Soils farmed for 30 years have 1/2 the O.M. • thus need for more fertilizer

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

7. Salts • arid climates salts do not leach out of soil, thus accumulate in the soil • Saline Seep is one example

8. Climate and Cereal Grain Production • Late spring moisture = reduced growing season = lower yields • Harvest rain = lodging, bleaching • Temperature: Barley & Wheat like cool • Temps over 90 deg F damages • Winterkill: low winter temps kill winter wheat • min temp -17 deg F • protective snow cover

9. Chinooks • rise in temp. of 29 degrees F in 24 hour period • more water enters the soil in areas of few chinooks • Figure I-7 page 11

10. Drought • Lack of precipitation, high temps., high winds • Dry April suggests that rest of growing season will be dry • help decision making