On the night of 25th March, at approximately 10pm the heavens around Eldoret and the neighboring towns opened up and hammered the town silly. The rains were announcing their long awaited arrival, filling the air with petrichor- the sweet smell of the first rains after a dry spell.
It is that time of the year again, a time when farmers put aside their triumph or disappointments from the previous season and brace themselves for a new beginning. They throng the agrovet stores buying seed, fertilizer, pesticide and faith. Faith that their soils will be good enough for the seed and the rains will fall right, the pests and weeds will keep off and the sun will shine when it’s time for harvest.
But this year, lets do things a little different, let us reduce the number of things we leave to fate, let’s take back abit of control in our farming processes and bring in some science and precision. For once farmers, let us have facts and figures of what we are doing.
Below is a list of things I think every serious farmer should do to get improved yields this year.
The importance and significance of soil testing cannot be stressed enough. Many farmers who do soil testing for the very first time get shocked at just how much information the report holds. The best part for me is the recommendations that come with it.
I have attached an actual soil sample example from one of the fields being planted this year. Find it below
Below the table showing the nutrient levels, you find the recommendations based on the results, the crop and the yield you are targeting
So what next when you get your soil test results and you find your soils to be acidic? Lime it.
Liming is meant to reduce acidity(increase ph) of your soils in order to create a better growing environment for your crops. Acidity is one of the biggest challenges facing the Kenyan soils at the moment, caused by blanket use of synthetic fertilizers without considering the condition of the soils first.
Soil acidity has a number of effects among them;
When your soils are acidic, the availability of the nutrients already in the soil and that in the fertilizer applied is greatly reduced meaning no matter how much fertilizer you apply, the plant can only access very little to utilize for growth due to acidity. When you apply lime and correct this, more nutrients are available to the plant and with time, you as a farmer use up less and less fertilizer reducing the cost of production.
Lime can be applied in one of two ways. As crushed lime and granulated lime. Crushed lime is usually in powder form and is spread on the surface of the soil using a lime spreader similar to the one in the video below and then disked/harrowed into the soil. Now, this is best done just after harvest and should be one of the activities you should do in preparation for the next season. In the case of Kenyan farmers, liming should be done around November/December and the field harrowed in readiness for planting in March/April for maize.
Granulated lime on the other hand is a more convinient though short term solution to acidity. The lime granules are mixed with fertilizer in the planter forming a lime-fertilizer mixture and applied at planting just as you would fertilizer.
The second most serious problem facing kenyan farms is compaction. This is the formation of a hard layer of compacted soil below the soil surface which causes several problems among them:
Look at the images below of maize plants, affected by compaction vs some without compaction.
Other than compaction, disk ploughs, due to how they work by turning the soil over i.e taking the top soil to the bottom and sub soil to the top, negatively affects the soil organism eg earthworms and others.
These soil organisms thrive in an environment protected from the scorching sun, turning over the soil exposes them to the harsh sun killing them.
Fun fact: Most soil nutrients are found in the top 2-6 inches of the soil(top soil)
This part of the soil is formed when organic matter from previous crops are brocken down by earth worms and other soil organisms forming humus which provide the naturally occuring nutrients in the soil. The mark of a good farmer is how well his soil is structured and the quality of his/her top soil.
Now having this in mind, the use of a disk plough completely destroys the progress we as farmers are attemping to make. After harvest, crop residue remains on the surface(this btw is what feeds the soil organisms eg earthworms), they begin to break down forming the much needed nutrients, and then just before planting, we move in with our disk ploughs and disorient this entire process by turning the soil over.
Think of the forest top soil and why it is considered some of the most fertile and nutrient rich soils. Because, when the leaves from the trees fall off, they are left on the surface to slowly break down releasing nutrients to the soil. Now if forest soil is the “perfect soil” for crop growing, then we as farmers should strive to recreate these conditions on our farms and the disk plough has no part to play in this.
To replace the destructive disk plough, use a chisel plough which gets the job done without turning the soil.
There are different types of chissel ploughs for different applications. There are those that operate at a shallow depth and those that go deep also referred to as rippers or sub soilers. These are usually heavy duty and mostly used to break the compaction layer.
We acquired a disk ripper 2 seasons ago, last years maize harvest was one of the best we have had in recent years owing to the deep soil ripper/subsoiler. We had been using a chisel for many years but this was not reaching the compaction layer since chisel operate at a shallow depth.
Farmers are recommended to use the subsoiler once every 3 years/seasons. As you can imagine, the implement takes a toll on the tractor, it also consumes considerably more fuel in the operation. Each tine on the subsoiler requires 20hp, meaning if you have a 5 tine subsoiler, you have to use a tractor with more than 100hp.
I have also noticed that the tines wear out easily. Whether it is an issue with the brand we acquired i am yet to figure out.
Now, ripping should be done soon after harvest. This is to ensure the ground is soft enough for you to operate easily and still break the compaction layer. If you do ripping when the soil is extremely dry will produce huge moulds as the ripper will break the soil and lift the huge pieces to the surface where as after harvest, the soil will break down to small pieces and hence not come to the surface.
Below are some pictures of the subsoiler.
Another interesting implement i came across was a strip till chisel from Ndume implements. Now this is particularly useful for farmers who have challenges with soil erosion. As the name suggests this implement tills only where the planting will be done as opposed to tilling the entire field ending up with strips where the planter will sow directly above and still have residue from the previous crop in between the rows. Below are pictures and a video. I saw this during a farmers field day in Eldoret Kenya.
They also have another that has the tines positioned just like you would have the discs on the traditional ploug, This can be used on smaller tractors and surprisingly enough these implements are cheap ranging from 250k to 500k.
With these changes as a starting point to a more sustainable farming system, i am confident every farmer can be able to achieve profitability.
Below is a video of last years maize harvesting at the Farming Afrika farm. Enjoy