Nursery and Flower Grower

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Figure 1. Organic amendments in water produce negatively charged surfaces and acidic conditions.
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Soil Mixes Part 8: Container Soil Chemical Properties

March 27th, 2019
By Steven A Tjosvold
Since a plant has a limited volume of soil to find and absorb nutrients, special attention has to be taken to make sure container soils have adequate nutrient concentrations through the entire crop cycle.
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Fig 2 Leaching fraction need for given salinity in irrigation water applied (EC A) and the water leached (EC L)
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Soil Mixes Part 7: How much to Irrigate

March 20th, 2019
By Steven A Tjosvold
In the last post, I showed that irrigation should occur when half of the available water in the container is used. That amount of water is what evaporated from the soil surface and the plant extracted (transpiration), collectively called evapotranspiration (ET).
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Fig 5 A scale can measure loss of water from transpiration and evaporation from the pot surface.
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Soil Mixes Part 6: When to irrigate

March 13th, 2019
By Steven A Tjosvold
When should container plants be irrigated? How much water should be applied? In this post, I describe the first step of irrigation scheduling, when, and the next post covers how much. First some background describing soil tension, available water, and the moisture release curve.
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Fig 4. Arctostaphylos uva-ursi with Phytophthora root rot on feeder roots in the lower profile of the soil. Healthy, white roots above.
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Soil Mixes Part 4: Effect on Root Disease

February 27th, 2019
By Steven A Tjosvold
Parameters for air- porosity and water- holding capacity have been established for container soils. These parameters were developed based on the needs of the plant. But the occurrence of root diseases can be affected by the amount of air and water in the soil too.
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