Teaching Organic Farming and Gardening

Soil Tests and Amendments

Unit 1.11 | 39
Demonstration 4

Demonstration 4: Field visit to A Working

Agricultural Operation — Relating Crop growth

Observations to Fertility Programs

for the instructor

Overview

Visit a local garden or farm for

which a soil analysis report has

been prepared and reviewed by the

class. Request from the grower an

overview of the current soil fertility

and pest and disease management

plans and practices used in the

operation. The overview should

include the following components:

soil textural classification; hydrology

of fields; history of cultivation;

history of soil testing and amending;

the use of cover crops, compost,

and crop rotation; the use of supple-

mental fertilization; primary tillage

practices used; any persistent pest,

disease, plant growth response and/

or crop quality concerns occurring in

the production of the crop(s).

Following the presentation, tour the fields/gardens look-

ing for any nutrient deficiency symptoms that may be

correlated with known physical or chemical properties of

the soil (refer to soil analysis), and that may be associated

with specific cultural practices. With the permission of the

grower, samples of crop vegetation can also be taken for

later comparison with photographs of crops with known

nutrient deficiencies.

PreParatiOn and MateriaLs

•    Sample lab analyses    report

•    Crop   deficiency  and toxicity    reference   charts  (see    below)

resOUrces and references

•   Agronomy Handbook: Soil and Plant Analysis. A & L

Western Agricultural Laboratories, Inc. 1311 Woodland

Ave., #1. Modesto, California 95351. (209) 529-4736. (For

crop deficiency symptoms see pp. 87-92.)

•    Unit   2.2 of  this    manual, Introduction    to  Soil    Chemistry   

and Fertility. (For crop deficiency symptoms see Detailed

Lecture Outline; for web sites containing photographs

of specific crops with specific nutrient deficiencies see

Resources section.)