Effect of poor drainage

1) Saturation condition stops air circulation in the soil and prevent bacterial activity.

2) Evaporation, which takes heat from the soil lowers soil temperature. Wet soil requires more heat to warm up than does dry soil. Thus, the growing season is shortened.

3) The ground water table is raised and root penetration is limited.

4) Salt and alkali if present in the soil or ground water tends to be concentrated in the root zone or at the soil surface.

5) Wet spots in the field, delay farm operations.

6) Certain plant diseases and parasites are encouraged. The change in balance between O2 and CO2 affect the growth and longevity of the disease organisms and plants weakened by this soil condition are more susceptible to infection eg. Cereal root rot and fusarium root rot of sugarbeet.

7) Soil structure is adversely affected.

8) Poor aeration causes decomposition of organic matter producing hydrogen sulphide gas that is toxic to the roots.

9) Poor aeration may accumulate sufficiently high concentration of reduced iron and manganese causing toxicity to the roots.

10) Denitrification occurs rapidly in saturated soil and reduction in number of nitrifying organisms.

11) High moisture level reduced the uptake of plant nutrient. Restricted root growth limits the volume of soil from which the plant may draw nutrients.