Page 45 - Agriculture_Form_3

Agriculture for Secondary Schools

Activity 3.5
Visit a sorghum field at your school/home farm and perform the following tasks:

1. Divide the farm into two plots. In the fist plot apply well-decomposed manure
before planting. In the second plot, do not apply manure. Keep on observing
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how the plants in both plots grow and compare the results.

2. Subdivide the plot which you have applied a well decomposed manure into
two sub-plots. Then, apply mulches in one of the sub-plot, and do not apply
to the second sub-plot. Compare the growth of the plants, the soil moisture
content, and the population/number of weeds in the two sub-plots.
3. Using suitable techniques, determine the adequacy of the soil water and
nutrients in the sorghum farm. If not adequate, suggest measures that can be
applied to improve it.

4. Record all your work activities and lessons learnt in your portfolio.

Management of weeds in sorghum fields
Weeds are unwanted plants that compete with sorghum for essential resources like
soil water, nutrients, and sunlight, thus potentially reducing yields if not properly
managed. To control weeds, adopt one or more effective methods. The common
weed control methods can be grouped under mechanical or physical, cultural,
biological, chemical and integrated methods. Regular weeding helps keep the
field clean and supports healthy sorghum growth. Appropriate land preparation
reduces the intensity of weeds. In addition, the use of cover crops such as beans,
cowpeas, and pumpkins can suppress weed growth while enhancing soil fertility.
Applying mulches, such as dried grass or crop residue, where applicable, helps
suppress weeds while conserving soil moisture, particularly in dry regions. In
some cases, herbicides or weed killers can be used; however, they must be applied
carefully to prevent soil and environmental contamination. By implementing
these strategies, the management of weeds can be done effectively to ensure
better sorghum yields.

Activity 3.6

1. Visit a school/home sorghum field to carry out the following tasks:
(a) Identify different types of weeds and explain how they affect the crop

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