California Assembly Bill 1881 – effective January 1, 2010
California Landscape Ordinance
For Water Conservation and Water-use Efficiency
Soil Management Report
Plant water-use efficiency is enhanced with friable, fertile, and suitable soil free of restrictive constituents. Well rooted plants are able to effectively capture and utilize soil moisture including deep soil moisture. Suitable soils have near neutral pH values, have low sodium, have proper amount of effective organic matter, and other beneficial properties.Since non-friable soils do not allow water to infiltrate, water is wasted as it runs off the surface. Soils with excess undesirable salinity need to be leached. However, water is conserved if leaching is not needed. High sodium disperses soil and precludes water use efficiency. Where required, sodium can be removed from soil by leaching after applying gypsum. Soil analyses indicate how soils need to be prepared for sustainable and successful plant establishment as well as how they need to be irrigated.
Desirable soils have near neutral acidity, moderate salinity, moderate concentration of true soil organic matter to make soils friable, optimum concentrations of 14 essential nutrients for optimal water use efficiency, freedom from non-desirable minerals such as high sodium and high concentrations of heavy metals. Properly amended soils have higher infiltration rates and better capture rainwater with less runoff and less erosion. Note that erosion is caused by runoff water.
Irrigation water needs to be applied at a lower rate than the rate of water infiltration. Irrigation needs to be cycled on and off with soils that have low rates of water infiltration. The rate of water infiltration is estimated based on the soil texture, amount of gravel, percent soil organic matter, salinity and bulk density.
- pH (acidity/alkalinity determination)
- Salinity and determination of the concentration of soluble salts
- Fertility for all 14 essential mineral nutrients
- Evaluation of the toxicity – determine the concentrations of 14 non-essential minerals including arsenic, lead, and cadmium
- Determination of soil texture (sand, silt, clay and gravel)
- Determination of soil organic matter and quality of the organic matter
- Estimate the rate of water percolation
- Provide recommendations for soil acceptance and soil amending requirements