Soil

The underlying principle in the use of the term “soil health” is that soil is not just a growing medium; rather, it is a living, dynamic and subtly changing environment. We can use the human health analogy and categorize a healthy soil as one that is:
A- In a state of composite well-being in terms of biological, chemical and physical properties;
B- Not diseased or infirmed (i.e. not degraded, nor degrading), nor causing negative off-site impacts;
C- With each of its qualities cooperatively functioning such that the soil reaches its full potential and resists degradation.

Organic agriculture and biodynamic agriculture improve soil properties. For example, organically farmed soils have:
A- Higher fertility, stability, moisture retention capacity, and improved soil structure which reduces the risk of erosion and desertification.
B- Significantly higher biological activity and a higher total mass of micro-organisms.
C- More rapid nutrients recycling.

In addition, there is no decrease in organic yield since higher biological activity and higher microbial root colonization counteract nutrient deficiency. Further benefits of biodynamic soils are their higher water-holding capacity and water efficiency, higher ability to sequester carbon, which helps to mitigate climate change, and their reduced CO2 emissions.

 
           

 

Healthy Soil
These soil properties, the main components of a biodynamic agricultural system, were evaluated under Egyptian conditions. (Zakaria El Haddad, International conference on “Plant nutrient management under stress conditions”, National Research Center, Cairo, Egypt in November 2008). 

Soil Property

BD

CONV

Bulk Density (Mg/m3)

1.07

1.15*

Penetration resistance (0-20 cm) (MPa)

2.84

3.18*

Penetration resistance (20-40 cm) (MPa)

3.55*

3.52

Topsoil thickness (cm) (includes surface and subsurface horizons)

22.8*

20.6

C (%)

4.84*

4.27

Respiration (microL O2  h-1 g-1)

73.7*

55.4

Mineralizable nitrogen (mg/kg)

140.0*

105.9

Ratio of mineralizable N to C (mg min N/g C)

2.99*

2.59

Cation exchange capacity (cmol/kg)

21.5*

19.6

Total N (mg/kg)

4840*

4260

Total P (mg/kg)

1560

1640

Extractable P (mg/kg)

45.7

66.2*

Extractable S (mg/kg)

10.5

21.5*

Extractable Ca (cmol/kg)

12.8

13.5

Extractable Mg (cmol/kg)

1.71

1.68

Extractable K (cmol/kg)

0.97

1.00

pH

6.10

6.29*