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Soil testing promises sustainability

‘WOULD a parent go into town, enter a shop and buy the same shoe size for his five children based on an average age? Of course not, and that is why farmers need to know what type of soil they have before they buy fertiliser,” so says American soil scientist Professor Ray Weil.
Professor Weil was amongst a group of soil scientists who were in the country to promote the use of SoilDoc, a mobile soil-testing kit.
It is currently under trial in Eastern Province following collaboration between Dupont Pioneer and researchers from two prestigious American universities.
Farmers, both commercial and small-scale, use fertilisers to improve their crop yield but fertiliser application is not always at par with the actual soil make-up in the field.
Those farmers that can afford it are able to get information on the nutrients their soil lacks following laboratory tests undertaken at distant facilities. It is expensive and time consuming.
SoilDoc was developed by American researchers from the University of Maryland and the University of Columbia’s Earth Institute to provide solutions to falling soil fertility across the developing world.
Dupont Pioneer managing director Munyaradzi Mutsvairo says his firm got involved in the soil-testing research because of its commitment to environmental stewardship.
He stated that in partnership with Pedro Sanchez, director of the Earth Institute’s Agriculture and Food Security Centre, the soil-testing kit was introduced across Africa in the hope of science-enabled sustainable solutions for their customers.
Mr Mutsvairo said his firm wanted to play a role in ensuring farmers’ yields were increased and wanted to share this knowledge with governments and other agricultural service organisations.
Dupont Pioneer planted maize trials in Eastern Province with three different treatments based on recommendations from a SoilDoc analysis. The small-scale farmers were selected from Cargill farmers in the key districts of Lundazi, Chipata, Katete and Petauke.
The field tests were able to demonstrate the performance of crops that received different levels of fertiliser application.
It has been noted that even with the use of hybrid seed, crop performance can be affected by misapplication of chemical fertiliser.
Apart from Pioneer Dupont and Cargill, the Zambia National Farmers Union, Conservation Farming Unit, Profitplus, Catholic Relief Services and Musika have participated in the exercise that aims to develop fertiliser specific to soil needs.
Dr Lydia Gatere from the University of Colombia says the testing kit is simple enough to be used by agricultural extension workers and even progressive farmers following training.
She said the data from the tests are then uploaded onto a palm-held tablet device, which can provide instant results to the farmers as to the health of their soil faster than sending samples to a laboratory service.
The kit has been tested in the Democratic Republic of Congo, Kenya, Malawi and Tanzania, and using the android system, these results are uploaded to the Africa Soil Information Service (AfSIS).
The ultimate beneficiaries of AfSIS data and services are small-holder farmers and pastoralists across sub-Saharan Africa, who can benefit from detailed soil information to make informed decisions about things like fertiliser use, crop types and farming practices to increase the productivity of their land and manage natural resources. This will help farmers overcome the vast gap between the potential productivity of their plots, and the amount of crops they are able to currently grow, whilst maintaining forests, waterways, grazing lands and other resources essential to their survival.
The portable laboratory consists of reagents, different nutrient elements measuring meters, pH meters as well as an Android tablet with a programme that gives recommendations on nutrients based on the soil nutrient test results.
The key elements that can be tested within 24 hours include nitrogen, phosphorus, potassium, carbon and sulphur as well as soil pH and water quality.
Work is under way to include ability to test for micronutrients with SoilDoc Lab. These micronutrients also play a part in promoting organisms in the soil that help produce nitrates and other minerals essential to the growth of healthy plants.
So far, 100 soil samples have been collected and tested in Eastern Province with plans to collect 10,000 samples countrywide to further validate soil mapping information and create a data base for fertiliser firms to formulate precision fertiliser.
It is hoped that more farmers will be able to increase their yields based on proper application of fertilisers, and in some instances where soil is found to be rich in certain minerals, it can further reduce the cost incurred by farmers and Government in the Fertiliser Input Support Programme (FISP).
It has been noted that despite years of Government support to small-scale farmers, crop yields have failed to help graduate them off FISP, leading to the same farmers year after year depending on hand-outs.
Zambia Agriculture Research Institute (ZARI) deputy director Samuel Phiri said the collaboration by Dupont Pioneer and the researchers would help ensure farmers obtain the right information for the application of fertilisers and even type of crops to plant in their specific locations.
He noted that many farmers were experiencing deteriorating soil fertility and that soil health had to be restored to ensure that Zambia maintains its status as the region’s bread basket.
According to the United Nations, the amount of fertile soil on earth’s surface is limited and not renewable in human time frames. In the last 150 years, half of earth’s topsoil has been lost, with more being continually degraded through deforestation, over-tillage, irrigation and soil salinisation, excessive use of nitrogen fertilisers, acid rain, pesticides and chemical fertilisers, over-grazing and compaction by heavy equipment.
The 68th United Nations General Assembly designated 2015 the International Year of Soils to raise global awareness about the importance of “healthy soils for a healthy life”.
The Earth Institute’s director of research Cheryl Palm says the past 10 years has seen a lot of growth in terms of understanding Africa’s soil.
She says that with continued mapping, it will be easier for farming groups and governments to ensure proper use of soil and farming resources.
It is hoped that the collaboration between scientists and commercial entities will provide a basis for sustainable land use and eradicating poverty.

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