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Soil acidity spells doom for future of Kenya agriculture


A study commissioned by the Nation Media Group recently, which covered more than 11 counties, paints a dire picture of the status of soil in the country. FILE PHOTO | NMG

In 2014, President Uhuru Kenyatta launched the national soil report on fertility to inform a policy that would correct deterioration.

However, five years later, much has not been done to correct the situation even as production dwindles, posing a major food security challenge for the growing population.

A study commissioned by the Nation Media Group recently, which covered more than 11 counties, paints a dire picture of the status of soil in the country with the little support from both levels of government worsening the situation.

The falling fertility is blamed on continuous use of acidic fertiliser and the government is right at the centre of the blame.

“The continuous use of non-organic fertiliser is to blame for the deteriorating state of soil in the country and the government is contributing to this by importing and issuing the wrong type of the supplement to farmers,” says Rodney Kili, a farmer in Uasin Gishu County.

Mr Kili, who is also a graduate student of agronomy, says that the government should give the fertiliser type that matches a given soil pH to fix missing nutrients in the soil and neutralise acidity.

The 2014 analysis of soils showed that acidity levels in most farms was higher as a result of continuous use of artificial fertiliser.

Such soils cannot support the growth of plants sustainably and give desired yields.

The report was based on suitability of maize growth in different sub-counties and gave recommendations on fertiliser to use.

The survey by the Kenya Agricultural and Livestock Research Organisation (Kalro) carried out in 164 locations recommended fertilisers to be used in each sub-county, depending on soil status.

Under the government supported subsidy programme, the State through National Cereals and Produce Board farmers get fertiliser without regard for soil type and status.

Continuous use of Diammonium Phosphate (DAP) has been blamed for damaging soil but farmers have shown less interest in other types of the supplement, arguing it gives better yields.


Andrew Tuimur, the Chief Administrative Secretary in the Ministry of Agriculture, says the government is importing blended fertiliser to address the challenges of declining soil fertility.

Dr Tuimur said that the Toyota Tsusho fertiliser blending plant has also helped farmers to get the supplement that is specific to their soil and growers were preferring them to DAP.

“We are at the preliminary stages of setting up a fertiliser board that will address challenges ranging from declining soil fertility to other issues that affect productivity,” said Dr Tuimur.

To correct the situation, farmers need to lime their soils to neutralise acidity and create better conditions for crops to perform well.

However, most farmers have been hampered by lack of money to acquire the supplement.

A tonne of lime goes for Sh3,000, which is way beyond the reach of small-scale farmers who are the majority.

The CAS said the national government will work with the counties the possibility of extending subsidy programmes to cover lime as well. However, he pointed out that this scheme cannot be sustained for long.

A majority of farmers said they would be willing to lime their farms if they got support from the government, but they cannot do that on their own since they do not have financial ability.

“We have been told that lime can help us to increase our yields but the problem is that as much as we would like to use it, our pockets do not permit it,” said John Bosire, a farmer in Nyamira, whose soil was found to be acidic in the tests conducted by NMG.

The problem of deteriorating soil fertility is gross because most farmers do not know the status of their soil since they don’t test due to costs.

A sample of soil tests at the national laboratory goes for Sh1,500 but a farmer requires about three sample tests from different points of the farm.

Agriculture officers encourage conduct soil tests to know the status of farms, however, this might not be practical because of costs, adding to the cost of production.

Patrick Gacheru, a director at Kalro says testing help in determining the pH and also knowing the elements that are missing to fix them.

“Soils in Kenya used to be okay, however, continuous mining of the nutrients without replenishing has deteriorated its quality, hence the need for testing in order to fix the problem,” said Dr Gacheru.

Dr Gacheru says that some of the elements that never missed in soils such as potassium, is now a big issue.

“Micro-nutrients that were not missing in the soils in previous years now are inadequate and this is one of the reasons there has been a decline in productivity,” he said.


Dr Gacheru says a research conducted in 1960 indicated that potassium was adequate.

But in 1987, it was found that this element was missing, especially in the maize-growing belt where there has been a continuous use of DAP.

He says a continuous use of DAP only added phosphorous in the soil while ignoring other elements such as potassium.

Farmers who have moved a mile to conduct tests and lime their soils have registered a tremendous increase in yield.

For instance, when Mr Kili started farming at his Komol farm in Uasin Gishu, he could hardly get 12 bags of maize from an acre. At the time, the pH was way below the optimum of six.

When he first limed in 2002, the pH started improving and so were the yields from his 800 acres in Uasin Gishu.

Maize production shot up from 12 bags in 2002 to 25 while wheat grew from eight bags to an average of 15 today with the pH improving from four to almost five.

In Nyamira County, a pilot done jointly by the county and Amiran saws yields improved significantly on use of right fertiliser.

Nyamira County executive for Agriculture Peris Mong’are said farmers who use blended fertiliser designed for their soils got better yields.

“The farmers who were issued with this fertiliser had their maize production increase between 10 and 15 bags from a low of five bags initially,” said Ms Mong’are.


She said the soils have become so acidic that they are asking farmers to use lime as they seek to extend the pilot to other regions.

Ms Mong’are said some regions of Nyamira have recorded a pH of as low as three, which makes it non-conducive for crops to perform well.

The government drafted a programme last year that would have restricted fertiliser purchase to what suits soil types to curb deteriorating soil health.

The maize growing counties, which have been using excessive DAP recorded poor state of soil in the report.

The study indicated that the soil pH in Trans-Nzoia County ranged from strongly acidic (4.53) to slightly acidic (7.12).

It recommended the use of alternative fertilisers such as Single Super Phosphate (SSP), Calcium Ammonium Nitrogen (CAN) and Nitrogen Phosphorous Potassium (NPK) and Mavuno.

Agriculture Principal Secretary Hamadi Boga said they had planned a supply model to provide zones with fertilisers that match their soil profile.

“We are currently working on a scheme that will see the government issue e-voucher to farmers in the next planting season to ensure they only get the fertiliser that suits their soils at their local agro-vets,” said Prof Boga.

The fertiliser vouchers would be bought from county Agriculture offices to redeem them at agro shops at subsidised rates.

Anthony Barasa, a farmer in Trans-Nzoia says he once changed from using DAP to NPK but the yields went down significantly that he had to revert.

Mr Barasa who grows 300 acres of seed maize in Kitale, says his production went down from 1,500 kilos per acre to 1,000 on the switch.

It was becoming costly for farmers in zones not close to the NCPB depots to access the subsidised fertilisers retailing at Sh1,800 a bag, a 34 percent discount on the market price of Sh3,000.

The government spends about Sh4 billion annually to subsidise fertiliser.

Some farmers have also been missing out on fertiliser because of the unscrupulous officials who connive with traders to deny genuine producers access, a move that has seen them plant without the supplement, hence compromising on production.

The e-voucher could also curb graft linked to the selling of subsidised fertiliser to non-farmers by the NCPB officials.

The NCPB managers for western, North Rift and South Rift regions were suspended amid revelations that they sold State-funded fertiliser to traders who repackaged at market rate.


Then Auditor General Edward Ouko said in October last year the NCPB could not provide verifiable documents for the audit to confirm the actual quantity, the quality sold to farmers and prices under the Sh2.1 billion disbursed to the agency by Ministry of Agriculture.

A technical hand book on soil fertility by Regional Land Management Unit notes that eastern Africa faces worsening problems of food security, decreasing per capita food production and massive poverty.

“Yield levels on these farms are generally very low for a variety of reasons. One important reason is the declining soil fertility,” says the book.

The report says that to adequately address soil fertility and land productivity national level action was necessary.