Paul Wanjahi is a small-scale farmer who grows maize, peas and potatoes in Mawingu area of Nyandarua County.
To secure the government-subsidised fertiliser in March last year, he had to be registered and vetted by a ward official from the Agriculture Ministry.
His credentials as a farmer established, he paid Sh1,500 for a 50-kilo bag of the fertiliser which he was to collect from a National Cereals and Produce Board (NCPB) depot in Cereal area - some 30 kilometres away.
Several visits without success - the fertiliser was not available - did not deter him. And when his turn came he spent Sh500 on transport to get the farm input to his home.
"Although the fertiliser was quite cheap, it took me weeks to get it. The official took long before informing us when to go collect the fertiliser," Mr Wanjahi said.
More disappointment followed when there was no noticeable improvement in his crop. "The bags indicated that it was from Tanzania. I do not think it was suitable for the soils here," he said.
Mr Wanjahi's not-so-fulfilling experience with the subsidised fertiliser programme is not unique.
Despite being driven by the desire to attain food security, pumping billions to subsidise farmers has not helped boost productivity. Instead it has declined.
Poor planning, corruption, hoarding, profiteering and poor targeting of beneficiaries are blamed for the programme's failure to achieve the desired end.
For instance, the Auditor-General reported in October that the NCPB could not account for more than Sh2 billion allocated for the purchase of subsidised fertiliser in 2017.
This was part of the Sh3.7 billion that could not be accounted for at the Department of Agriculture between 2016 and 2017.
"Apart from an invoice and a schedule raised by the NCPB, no other verifiable document was produced for audit to confirm the actual quantity of fertiliser bought, the quantity sold to farmers and the purchase and selling price.
"Consequently, the expenditure of Sh2.13 billion on subsidised fertiliser could not be ascertained," Auditor-General Edward Ouko said.
In one case, a contractor was paid Sh456 million to deliver 182,000 bags of fertiliser but only supplied 165,000 bags. NCPB had in May 2016 interdicted 22 regional managers over collusion with traders to steal, repackage and re-sell the subsidised fertiliser to unsuspecting farmers.
The inputs subsidy programme was started in 2009 with the goal of stabilising fertiliser prices for smallholder farmers and boosting food production.
Last year NCPB procured 2.3 million bags of fertiliser.
Revival of traditional crops like cassava, sorghum and millet, affordable credit, tax concessions, debt relief and waivers to organisations serving smallholder farmers like Chemelil and Muhoroni sugar companies, Meru Dairy Union and the Agricultural Finance Corporation (AFC) were other measures the government hoped would boost farm output.
Also targeted through sectoral reforms were cash crops like tea and coffee.
These raft of measures have failed to reverse the steady decline in production of most crops, with agriculture growth averaging slightly above four percent between 2010 and last year.
Data from Tegemeo institute had shown in 2009 a general decline in productivity in the decade between 1997 and 2007, prompting the intervention.
In the maize sub-sector, peak production has stagnated at 39 million bags since 2013 despite the value of fertiliser used doubling from Sh8.9 billion in 2013 to Sh17.6 billion in 2017.
For rice, an acre of land yields up to 15 bags in Kenya against a maximum of 35 bags per acre when conditions are suitable.
As a result, Kenya has to import at least five million bags of maize annually and more than three quarters of its rice needs -- 400,000 tonnes -- to feed its people.
Coffee production has also declined to less than a third from 130,000 tonnes in 1989 to 38,000 tonnes in 2017.
A coffee bush now produces two kilograms per year which is far below the five to 10 kilograms expected from a well-tended farm.
This has been followed by a notable drop in quality and area under the crop.
In contrast, coffee production in Africa rose by 12.6 percent between 2014 and 2017 with Uganda, Ethiopia and Rwanda raising their production by 36 percent, 16.3 percent and 17.6 percent respectively over the same period.
From interviews with experts and farmers, the subsidy scheme cannot achieve desired ends because it does not address key factors causing low productivity.
"All we've been doing is to add artificial fertilisers to seriously sick soils. We are not trying to improve agro-ecological practices like organic farming, economical use of pesticides, crop rotation and less use of other chemicals," Wanjiru Kamau, an official at the Kenya Organic Agriculture Network (KOAN), said.
Other factors discouraging farmers include poor infrastructure and lack of markets, especially for fresh produce.
It is also not clear how the type of fertiliser to subsidise was arrived at since Kenya is yet to exhaustively establish map soil nutrient deficiencies in different agro-ecological regions.
By implication, farmers have no idea of the corrective measures they ought to adopt.
In a presentation to governors last year, J.N. Mburu, a soil chemist at the Coffee Research Institute, said all coffee growing areas suffer greatly from what he calls "continuous mining of nutrients without balance replacement".
Other experts say for the fertiliser subsidy to work, other components of the agriculture vale chain such as processing and marketing have to be in place.
"Fertiliser is just but one of the factors that influence production. If you just improve on one you will not get the results you are looking for. Even if farmers raise production, where is the market?" Dr Patrick Mbataru, a Public Policy Analyst based at the Kenyatta University, said.
Most small-scale farmers growing tomato, potato, carrots and other crops, he said, do not have knowledge on where to market their produce and the prevailing prices which often leads to losses after harvesting.
NCPB officials have occasionally complained that they are not able to determine genuine farmers from fake ones because the vetting is done by local administrators, agriculture officials and community members.
This has led to infiltration by cartels which buy the subsidised fertiliser for resale at commercial prices.
"There is a deliberate scheme to work with bigger farmers by targeting the subsidies to them and eventually weed out smallholders," Mrs Kamau said.
Agriculture Cabinet Secretary Mwangi Kiunjuri is on record saying unscrupulous people take advantage of the gaps in farmers' vetting processes to access the subsidies.