I decided to write this article because of the general misconception in Nigeria that contain plants don’t do well in certain parts of the country. I have heard people make the claim that Plantain wouldn’t grow in Kwara state or Peppers wouldn’t do very well in Lagos, etc. These types of misconception are not helping us optimized agriculture in Nigeria, because they are plainly wrong. The only soil you cannot grow food are contaminated or waterlogged soil.

In fact, I can tell you unequivocally that you can grow any type of crops anywhere in Nigeria and be very successful. However, there are few things you need to control and they are:

1. Sunlight. Make sure your plants have enough sunlight between 6-8 hours daily. All leaves of the plants must be exposed to sunlight. You do this by using the right crop spacing and sticking your crops especially, tomatoes. If your tomatoes crawl the ground, they get less sunlight.
2. Temperature. The ideal temperature of your tropical plants is between 20 to 32 degrees Celsius depending on the stage of growth. Anything higher or lower will start giving problem and must be controlled.
3. Sufficient Water. Make sure plants get enough water all the time, especially during the dry season. The root system must stay moist all the time.
4. Soil Air. Ensure there is enough drainage in your soil to allow air and water to flow through.
5. Nutrition. Make sure plants have sufficient nutrition all the time.
6. Competition. Control the competition, such as weeds, insects, animals, etc.
These are the basic things. If you can control these, you can control the growth of your crops anywhere in the world.

The most important thing to know about the soil.
Apart from the application of fertilizer, whether it's organic or inorganic, the most important thing that affect the productivity of your land is the SOIL pH. pH stands for Power of Hydrogen. The soil pH is a measure of the concentration of hydrogen ions in the soil. If the soil has very low pH the soil is said to be acidic. And a very high soil pH means the soil is Alkaline. pH is measured on a scale from 1 to 14, with 7 being neutral. A soil with a pH of 4 has 10 times more acid than a soil with a pH of 5 and 100 times more acid than a soil with a pH of 6.
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Basically, as you can see from the image, the optimal pH level of the soil to grow most crops is between 6 to 8. For example, the recommended soil pH for growing plantain is between 5.5 to 7. Whereas Okra needs 6.0 to 8.0 and peanuts is 5.0 to 6.0.
Most beneficial soil microbes and earthworms also prefer this optimal pH level to strive. The correct pH increases the microbial activities of the soil.

Here is where the problem starts.

The soil pH controls the availability of soil nutrients to the plants. In a very acidic soil most nutrients will not be available to the soil. This means you can add all the manure on earth to your farm, the plant will not be able to use it because the acidity of the soil will prevent it from being absorbed by the plant. When they fail, people will generally conclude that the type of crops doesn’t grow in that area. But this is not true.
Take for example the yellowing of young plant leaves between the veins. It indicates an iron deficiency, however, it may not be because the soil doesn’t have iron, but the soil pH might be too high to make iron available in the form that a plant can absorb.

On the other spectrum, if the soil pH is too low it can result to soil poisoning of your plants. If your pH level is too low, it can result in too much release of Manganese into your crops. Too much Manganese is poisonous to your plant. Also, too low pH will release aluminium from the soil. Aluminium is a poisonous metal. When you have too many poisonous elements affecting your plants, coupled with the fact that other beneficial nutrients cannot be released to the plant due to low or too high pH then your crops will start dying or not produce well.

Below you will see a chart of 11 plants essential nutrients and the optimal pH range they are available to the plant. Notice for example, Nitrogen is highly available to the plant between soil pH of 5.5 to 8.0. but Iron ard Zinc will not be available from soil pH of 8.0. However, all nutrients are readily available between 5.5 to 7.5 pH. This is your optimal soil pH level.


Factors Affecting Soil pH.
There are four major factors that influence the soil pH level.
The pH of the soil is already determined by the materials from which the soil was formed. Soils which were formed from basic rocks generally have higher pH more than soil formed from acid rocks.

Rainfall is a very major factor that influence the soil pH. In the southern part of Nigeria, where you have higher rainfall, the soil pH tends to be lower due to the erosion factor of heavy rainfall. With excess rain, the calcium and magnesium from the soil is washed off. These are then replaced with acidic elements such as aluminium and iron.

The application of ammonium based fertilizers such as ammonium and urea accelerates the acidity of the soil or lower pH.

Finally, when organic Matter decomposes, it has the tendency to lower your soil pH. The more decomposing organic matter you have, the more acidic your soil will be in the long run. This is the problem even organic farmers have. Your land will become less fertile over the years if you just keep adding chicken or cow manure without checking and amending the soil pH.

So, the next time you see your plantain or vegetable are not growing well or looking sick, you will do well to check the soil pH level before spending lots of money in applying NPK.

How to Adjust the Soil pH.
The first thing you need to do before you start land preparation is to test the soil pH. There are very cheap soil pH testers that will give you an accurate pH level test. You need to sample various areas of your farm to get an accurate reading of your soil pH.
After you know the soil pH determine the soil’s texture, find out if it is clay, sand or something else. This is important because more soil neutralizing material is needed to change the pH level of a clay soil than for a sandy soil because the charged surfaces of clays make them more resistant to pH changes than the uncharged surfaces of sand particles.

Raise soil pH.
Limestone is used to raise the soil pH. In Nigeria lime is in abundance and cheap we don’t need to import it. There are different types of lime. Calcium bicarbonate and Dolomite are very easy to find in Nigeria. Dolomite has added advantage of adding Magnesium, a very important soil nutrient to your soil.

Lower Soil pH
Anything containing Sulfur can be used to lower soil pH, but they are a bit hard to find in Nigeria because of government restrictions.


I hope this has been helpful to you.

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