soil test results - sodic, clay, ph 8
I had a soil test done in March. My soil is sodic, clay, has a ph of 8, and very little OM (2%). Nitrogen is low too, but that seems easy enough to fix. Everything else was high/adequate.
I'm confused by the results though. Under "Sodium Absorption Ratio" it says that the soil can be reclaimed by leaching the site with "good quality water" and that gypsum/sulfur may be added. Yet under gypsum, it says gypsum is NOT needed.
What exactly is good quality water? Is it about sodium content? Ph? I only have access to tap & ditch water (from the San Juan River). Ditch water is going to be tricky though - haven't managed to figure out how to use the pump yet, or set up a way to get it to the garden site.
Our plans were for a 40' x 40' garden area (although, about half of that will be cover crops until next Spring to improve for next year).
I don't have access to large quantities of leaves, grass clippings, etc. I have maybe 2-3 yards of compost (never saw it really heat up, but its been sitting around since last summer - mainly horse manure, chicken manure, kitchen scraps, shredded newspaper & sawdust). And about 10-11 yards of horse manure (not a "ball" in sight, not much smell at all, very fluffy). I've called around and can't find bulk compost anywhere. Buying it bagged is so expensive, but I might consider it.
Here's the report. What would you do with this info?
pH is high, but native and introduced plant species that are adapted to this pH should not be negatively affected.
Electrical Conductivity or Salts: 8.1
Salts are very high with may cause poor plant growth. Salts may be reduced by leaching the site with 6-12 inches of
water to help push salts deeper into the soil profile to dilute their effect. Leaching depends on the availability of good
quality water and good drainage.
High: Lime is 2%-5% in the soil. Plants can still grow quite well in soil with this lime content.
Texture Estimate: Clay
This soil may drain at a very low rate. Watering schedules may have to be increased to allow for better water
infiltration into the soil profile.
Sodium Absorption Ratio: 23.1
High: This soil has high sodium and is considered to be sodic. Sodic soils can be reclaimed by leaching the site with
good quality water. Gypsum or sulfur can be added to the soil along with water to help remove sodium from the root
Organic Material: 2.0
Organic Matter is Low. Gradually increase the OM content to about 5% over a period of years. For 2-3 years in the
spring or fall, apply 2-3 inches depth of plant-based compost, or 1 inch depth of animal-based compost, and
incorporate into the top 6-8 inches of the soil in flower beds. When planting trees and shrubs mix the backfill soil
with low salt OM such as peat moss at a rate of 15-20%. For established trees and shrubs add OM to the soil surface
at a depth of 0.5 inch.
N is low: Apply 0.3 lb N/100 sq ft to the soil. For each 0.1 lb of N needed, apply about 1/4 lb urea, or 1/2 lb
mmhos/cm ppm ammonium sulfate, or 3/4 lb bloodmeal, or 1 lb corn gluten meal, or 5 lb alfalfa meal pellets per 100 sq.ft. Other
fertilizers can be used as well. Check with your local garden center or home improvement store to determine what
fertilizers are available in your area. When calculating fertilizer rates take the amount of N needed and divide by the
% N in the fertilizer. For example, if your fertilizer contains 30% N, take 0.30 lbs (N needed) divided by 0.30 (N in the
fertilizer) to get 1 lb of the 30% N fertilizer that is needed to apply per 100 sq.ft. For rates per 1000 sq. ft multiply the
quantities by 10.
Phosphorus is High; No additional Phosphorus is needed.
Potassium is High; No additional K20 is needed.
Zinc is Adequate; No additional Zn is needed.
Iron is Adequate; No additional Iron (Fe) is needed
Manganese is Adequate; No additional Mn is needed.
Copper is Adequate; No additional Cu is needed.
Boron is High. No additional boron is needed.
Gypsum is NOT Needed.