One of the easiest ways of increasing crop yields in Rwanda, as it is in many  other parts of sub-Saharan Africa, is through increased use of fertilizers and planting high yielding varieties that respond positively to fertilizer application.

In an article titled, "Fertilizer has key role in Africa’s future – and the NEPAD vision”, Suruwa B. Wawa Jaiteh, of Gambia News ascertains that the increased correct use of fertilizer could trigger an African Green Revolution, give new hope to millions of poor farmers and free Africa from the shackles of food insecurity and hunger.

Africa has some of the lowest fertilizer application rates per hectare of cropped land in the world. Contrary to popular belief, every season and every year, farmers crop the same land, grow crops that use the same nutrients and as a result cause soil mining.

This means that every year crops remove nutrients from the soil to concentrate it the harvested parts which are taken away to be eaten or sold in the markets, without replacement of the soil nutrients from the fields where they are taken from.

In a year where crop rotation or fallowing is almost impossible due to the heavy land pressure exerted by high population growth, the only way of using soil sustainably is to ensure that soils are constantly replenished to ensure optimal crop yields.

It is no surprise that the current economic thinking as regards agricultural development holds timely and correct application of fertilizers a crucial component.

In developing countries like Rwanda, up to 90 percent of the population depends on subsistence agriculture that is basically for provision of food to homesteads leaving little for sell. 

"Without adequate and timely fertilizer usage, farmers often cannot meet the food needs of their own families, much less those of a rapidly growing population.

" Suruwa wrote. "To feed themselves and their countries, farmers will need to shift from low-yielding, extensive land practices to more intensive, high-yielding practices, with increased and sustained use of fertilizers.”

According to Rwanda Agricultural Development Authority, the extraordinarily depleted but fertilizer responsive soils of Rwanda offer opportunity for achieving an annual agricultural growth of 5.3 percent.

Fertilizer use is estimated to contribute 4 percent, area expansion and improved genetic material would contribute 0.8% and 0.5 percent respectively.

As part of a holistic initiative towards agricultural development, such initiatives as the Catalyst Project by the International Center for Soil Fertility and Agricultural development, the Koffi Annan led Alliance for Green Revolution have placed the increased use of fertilizer, both inorganic and organic as the center piece of their programme to optimize fertilizer use and increase yields. 

As far as integrated plant nutrient management which inculcates both inorganic and organic sources into farming is concerned, and as much as organic fertilizers remain a much more sustainable source on nutrient supplementation to crops, the basic truth is that organic fertilizer is just too expensive to be adapted for large scale profitable agriculture that would make economic sense.

For Rwanda’s case, the issue of recommended fertilizer formulations and application rates is a thorny one. The government, through the Ministry of Agriculture and the Clinton Foundation, has made a very brave initiative to ensure that farmers can maintain timely and adequate application of fertilizers in the major cash and food crops farming.

In this programme, the government has let it known that one of the surest ways of increasing per capita yield per hectare of crop grown is by more intensive use of fertilizers. In the case of the green revolution in Asian countries, a marked increase in fertilizer usage and improved crop varieties in mainly the grain crops of rice and grain led to increased yields of food available although not to desired levels as seen in other grain growing countries.

According to Suruwa, in the early 1960s an average application of plant nutrients of 7 kg per hectare of cultivated land was recorded for India compared with 180 kg for Britain, 250 kg for Taiwan, and 250 kg for the Netherlands.

For the same period the wheat yield in India was 800 kg per hectare against Britain’s 4,000 kg/ha. India’s average rice yield was then about 1,400 kg/ha while Taiwan’s was 3,200 kg/ha. These differences accounted for the varying levels of development indicators for the four countries. 

According to a BBC report, in 1968 the green revolution saw annual wheat production rise from 10 million tonnes to 17 million and in 2006 stood at 73 million tonnes.

Recently science has come up with a new product called foliar fertilizers, which can supplement basal fertilizer by being applied as a liquid spray onto the leaves and hence gaining immediate entry to the plant, minimizing wastage of nutrients, encouraging absorption of water by the plant in dry seasons.

Foliar feeding is an effective method for correcting soil deficiencies and overcoming the soil’s inability to transfer nutrients to the plant. Such fertilizers are now currently available in Rwanda from Balton, an agro-input supplier.

The writer is an agronomist

Contact: kelviod@yahoo.com