Over
95 percent of smallholder farms in Kenya show severe depletion of essential
soil nutrients – nitrogen, phosphorous and potassium. Moreover, Kenya’s
agricultural soils have dangerously low soil organic matter and exhibit
worrying trends of acidification. This is according to a report by the National
Accelerated Agricultural Input Access Programme (NAAIAP) released February 18,
2014.
The
report reveals that all the farms surveyed require an average of 8 tons of
manure per hectare, in addition to about 200 kilograms per hectare of different
compound inorganic fertilizer. The NAAIP soil testing report is based on traditional
labor-intensive soil survey methods and conventional soil laboratory
techniques. 9600 soil samples were collected from 4800 farms spread over 42 out
of 47 counties.
The soil
testing report serves the purpose of directing public and policy focus to the
magnitude of Kenya’s soil fertility crisis. However, the 464-page NAAIAP
report, dense with text and tables is an unequal response to Kenya’s soil
fertility and agricultural productivity crisis. The report is gravely limited
in its capacity to provide a robust and reliable basis for fertilizer use
recommendation at the farm level. Moreover, 9600 samples are too few as a basis
for extrapolation over 42 counties, given the high spatial variability of soil
properties. Relying on this report to fix our soils and boost land productivity
is like using horses and bayonets to wage war in the 21st century.
Invariably,
the soil sampling and analytical methods would yield unhelpful blanket
recommendations. For example, it is curious that farms in the humid Trans Nzoia
East sub-county and farms in the semi-arid Ijara sub-county in Wajir have the
same fertilizer recommendations – 7-8 tons of manure per hectare; 250 kg per
hectare of NPK (23:23:0) at planting; 125-150 kg per hectare of CAN.
We
need techniques, which can be deployed at a national scale for rapid
assessment, testing, generation of spatially explicit soil management
recommendations and routine monitoring of soil quality. Management recommendations
must be buttressed by farm level agronomic trials, over multiple seasons, to
ascertain fertilizer response. The NAAIAP report does not mention any farm
level trials.
Advances
in infrared spectroscopy, GIS and Remote Sensing now permit rapid diagnostic
assessment of soils at higher sampling intensities. These methods were
developed and tested 10 years ago at the World Agroforestry Centre here in
Nairobi by a team of landscape ecologists, systems agronomists, including
myself.
Ethiopia’s
Agricultural Transformation Agency is using these techniques to establish the
Ethiopian Soil Information System (EthioSIS). The final product will be
interactive high resolution (0.1 - 1 ha) grid maps of key soil properties such
as pH, texture, mineralogy, organic matter, nutrient content, erosion and other
soil degradation prevalence estimates across all of Ethiopia. This system will
enable Ethiopia to provide spatially explicit, evidence-based and targeted
recommendations for: fertilizer applications, and water management practices.
The
hundreds of thousands of archived topsoil held by Kenya Agricultural Research
Institute, including the 9600 samples analyzed for NAAIP as well as samples
held by universities could be a great starting point for building reflectance
spectral libraries for rapid characterization of soil quality at the farm
level. Working with farmers and using the Land Degradation Assessment Framework
(LDSF), I would recommend additional soil samples from 75 percent of all farms.
A
large national spectral library of soils can be used to set up distributed soil
testing and farm advisory centres at the sub-county or ward level. All it would
take is an infrared spectrometer, an electric socket and a technician. With
such as set up one can establish a farm level soil report card, where farmers,
with basic training in sample collection and pre-processing, could turn in
soils from their field for testing. The report would contain critical soil
quality parameters such as organic carbon, nitrogen, soil acidity, soil bulk
density, phosphorous, potassium and other essential elements.
Moreover,
the farm level soil report card could also be used to monitor landscape level
processes, facilitating identification of areas at risk of soil degradation and
designing locally appropriate recommendation domains for integrated management
of land health, beyond fertilizer application.
Civilizations
have fallen because they failed to manage their soils. We have an opportunity
to harness the capability of infrared spectroscopy, remote sensing, spatial statistics,
the cellphone and Ushahidi’s crowd sourcing applications to change the way soil
information is collected analyzed and used to guide soil management decisions
at the farm and landscape level.
Very well put Alex, in-fact we are in the processes of doing the same in Tz like EthioSIS, I think we need more farmer centered innovations in Kenya
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