Barren soils threaten future of farming in the Great Lakes region

Bananas growing near a homestead. The crop's yields in Eastern Africa are low due to poor soils and low fertilizer - organic or inorganic-application by small-holder farmers.

Most of the soils in the Great Lakes region of Eastern Africa are poor with very little fertility left in them. This is one of the main reasons behind the low yields in the area, which has one of the lowest rates of fertilizer use in the world and a rapidly increasing population to feed, according to a recent study.

The barren soils are a result of years of mining and insufficient replacement of nutrients by small-holder farmers mostly practicing low-input agriculture. They  remain a threat to the future of small-holder farming and the food and income of millions of people in the region if appropriate action is not taken.

The study, which sought to identify and rank the constraints faced by small-holder banana growers in the region, also measured the actual nutrient content left in the soils―in both the organic and mineral part―across different agroecoregions in Rwanda and Uganda.

This was after establishing that poor soil fertility was one of the main causes of the current low banana yield of 5-30 tons/year against a potential yield of over 70 tons/year. It accounted for up to 50% of the yield gap.

The study found that there was little fertility left in most soils and what was there was mostly due to the organic matter in the topsoil. Furthermore, while banana is a very important crop for the region, providing food and income for over 85% of the population, the use of external inputs such as fertilizers was virtually nonexistent and soil fertility was mostly managed by recycling local organic residues.

The study was conducted from 2007 to 2011 in four agroecological regions in Rwanda (Butare, Kibungo, and Ruhengeri) and South-West Uganda (Ntungamo) and looked at the banana plants, various crop management practices, pests and diseases, and the chemical properties of soils.

It was undertaken by Séverine Delstanche as a PhD student of the University of Louvain in Belgium and formed part of the Belgium (DGD)-funded project titled 'Sustainable and profitable banana-based systems for the African Great Lakes Region' led by the International Institute of Tropical Agriculture (IITA). It was also part of the Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA) project.

The study further established that soil fertility and banana productivity varied not only between the regions but also within regions, villages, and at the farm level. The regional differences were due to differences in soils and their parental material whereas at the farm level, they were often the result of differential management practices. The soils close to the homestead were more fertile due to kitchen wastes of ashes and organic residues.

Delstanche says that despite the acknowledgment by farmers and researchers of the importance of soil fertility in agricultural production, little research has been carried out to understand the current state of soils and the impact of past and present farming practices.

Therefore, she says, farmers are unaware of the nutritional status of their soil and how best to make use of the little resources available to them to increase production and productivity.

Dr Piet van Asten, IITA systems agronomist, says the findings of this research are very significant. "We knew that our soils were poor but we did not know just how poor. But now, we've calculated the nutrient stocks and have learned that very little nutrients are left. Moreover, the soil fertility almost entirely depends on the organic matter in the soil."

"The study therefore stresses the importance of recycling crop residues to improve soil fertility. Over 80% of the nutrients in the soil comes from the organic matter and not from the clay or sand itself."

A related study by Van Asten and his team estimated that the over 100 trucks of banana bunches that reach Kampala everyday deplete the soils in the rural areas annually of 1.5 million kg of potassium (K) and 0.5 million kg of magnesium (Mg).

The study supports the Africa Union's Abuja declaration on fertilizers for an African Green Revolution which has stated that efforts to reduce hunger on the continent must begin by addressing its severely depleted soils and recommends countries to increase fertilizer use from the current 8 tons/ha to at least 50 tons/ha by 2015 to boost agricultural production.

IITA DG calls for a “Brown Revolution” for a “Green Revolution” in Africa

The push for a “Green Revolution” in Africa to increase agricultural production for food and economic development will not bear much fruit if adequate attention is not paid to managing soil fertility in the continent.  

Dr Sanginga making a presentation on Brown Revolution at the
 Global Cassava Partnership conference in Kampala, Uganda.

According to Dr Nteranya Sanginga, IITA Director General, Africa cannot achieve a “Green Revolution” without first having a “Brown Revolution”. He noted that the current application of 8 kg/ha of soil nutrients, whether organic or inorganic fertilizers, was very low and was a major setback to the continent’s vision of adequately feeding itself.

Dr Sanginga spoke at the Global Cassava Partnership meeting currently taking place this week in Kampala, Uganda, that brought together over 400 international scientists from all over the world to strategize on how cassava can play a bigger role in economic development by exploiting the diverse uses of this hardy crop. Cassava performs well under harsh conditions, such as poor soils and drought.

The conference was launched by the Honourble Minister of Agriculture, Animal Industry and Fisheries, Hon Tress Bucyanayandi who noted that frequent droughts and floods as a result of climate change were one of the leading causes of food insecurity in the world today with millions of USD going into emergency food aid.

The Guest of honour Hon Tess Bucyanayandi makes
the opening remarks. 

He noted that cassava was a crop that performs well in drought conditions and is becoming an important food security crop. He therefore urged the researchers gathered at the conference to develop solutions to some of the challenges facing the production of the crop in the region such as Cassava Mosaic Disease (CMD) and Cassava Brown Streak Disease (CBSD), the two diseases wreaking havoc on the crop’s production. 

Participants following workshop proceedings

Dr Eugene Terry from Transfarm Africa noted that a number of efforts to transform cassava were already underway in the region starting with the development and deployment of improved better yielding varieties by IITA. He noted that over 80% of the new varieties released by national programs in Africa had incorporated these varieties released in the 1970’s and dubbed TMS series.

He said there were many challenges facing the transformation of the crop that needed to be tackled through research including control of pests and diseases and the need for early maturing and drought tolerant varieties. On marketing issues, he said there was need to research on better organization of value chains, better infrastructure support and how to reduce transaction costs.

Dr Sanginga on his part told the conference participants that while much investment had gone into developing high-yielding cassava varieties that were resistant to some of the major pests and diseases, the gains achieved cannot be realized if these varieties are grown in poor soils.

He said it was unfortunate that cassava had been tagged for many years as a poor man’s crop that does not require much input such as fertilizers. He argued that the crop harvested as much nutrients from the soil as other crops and that these nutrients needed to be replenished. It also requires nitrogen, phosphorous, and potassium similar to other crops.

“Nutrient use in cassava has been very minimal as it is considered a poor man’s crop. However, if we are talking about cassava transformation, about increasing cassava production not only for food but also for commercial use, we must change these wrong perceptions. If we think of growing cassava in soils that are too poor for other crops such as maize,” he said, “then, we are missing the other half of the equation.”

The African Union has recommended for the countries in the continent to increase application of soil nutrients to 50 kg/ha of nutrients combining both organic and inorganic fertilizers.

The Global Cassava Partnership for the 21st Century (GCP21) conference is taking place on 18–22 June 2012 in Kampala, Uganda. GCP21 consists of 45 member institutions working on research and development of cassava, a staple crop relied on by more than 700 million people worldwide. The ultimate goal of the partnership is to improve cassava productivity through scientific research and development. 

Group photo of participants

The conference participants include representatives from NARS, international agricultural research centers, advanced laboratories and universities from developed and developing countries, United Nations’ agencies, governmental and non-governmental organizations, donor and development organizations, businesses in the ag-biotechnology and food processing industries.

Project to save farmers from bogus agricultural commercial products launched

Most small holder farmers in sub-Saharan Africa are struggling to make ends meet and are always on the lookout for ways to boost their production. And they are even more desperate now in the face of unpredictable weather due to climate change.

Unfortunately, they sometimes fall prey and loose huge sums of their hard earned money to unscrupulous companies selling them ‘miraculous’ products that promise to increase their yields but which turn out to be fake or sub-standard and do  not live up to their claims.  

Moreover, the regulatory bodies established to control these products and safeguard farmers’ investments are often poorly funded, poorly equipped and the regulations are not up to date to include some of these new innovative products coming into the market such as bio-fertilizers and bio-pesticides.

To address this, the International Institute of Tropical Agriculture (IITA) recently launched the second phase of the Commercial Products (COMPRO-II) project that aims to benefit two million smallholder farmers in East and West Africa by providing information on which agricultural products are genuinely effective to boost their production among the myriad currently available in the market.

IITA's Director General Dr Sanginga speaking during the project launch. 

 “We have all these products in the market which, like the witchdoctors’ potions, promise to solve all the farmers’ problems. Our concern therefore is that our poor small-scale farmers are using their little hard earned money to pay for products that do not produce results. So we first set out to understand the problem then see how to help them,’ said Dr. Nteranya Sanginga, Director General for the International Institute of Tropical Agriculture (IITA) during the launch that was held in Dar es Salaam, Tanzania on 16 May 2012.  

‘Under phase I of the project, with a grant from the Bill &Melinda Gates Foundation, we screened over 100 such products in the market to see which ones are useful. And out of these only three were found to be really effective,” he said.

The three were Rhizobium inoculants for legumes, mycorrhizal inoculants for tissue-culture banana, and fertilizer seed coating of for maize.

Rhizobium and mycorrhizal are bio-fertilizers that make use of useful micro-organisms that are naturally found in the soils. Rhizobium is a bacterium that converts the free nitrogen in the air into a form that plants can absorb from the soil. Mycorrhizal fungus assists plants to absorb nutrients from the soil and strengthen their resistance to soil-borne pests such as nematodes.

Fertilizer seed coating for maize on the other hand, avails essential nutrient to the crop on germination making it grow better, have better root development and become better established.

Participants drawn from the six project countries at the its launch.

The second phase will primarily focus on creating awareness and disseminating to farmers these tried and tested quality products to increase their production and building the capacity of national systems to continuing screening such products coming into the market.


“The project will engage with and support national institutions to put in place systems to continue screening these products to check their quality. This will ensure farmers are not wasting money on fake products that do not work,” said Dr Prem Warrior, a Senior Program Officer at the Bill & Melinda Gates Foundation.

At the end of the project, more farmers are expected to confidently use these products because their safety, efficacy, and quality will be ensured through institutionalized regulatory and quality assurance mechanisms.

“We want to make farmers’ life better. Using some of these productions that we have checked and ascertained their quality together with other good farming practices such as use of fertilizers and improved varieties, they can get better yields of maize, soybean and banana and improve their lives,” said Bernard Vanlauwe, IITA Director for Central Africa and the project team leader.

The project is targeting small-holder farmers in six African countries: Tanzania, Kenya, Nigeria, Ethiopia, Ghana, Uganda, and Tanzania.

Work smart not hard - Boosting productivity of small-holder farmers through smarter farming practices

A man and his wife who are small-holder farmers, display their harvest of cassava and banana, two important staples in Sub-Sahara Africa. 

They have small farms, big families and few animals. They grow different types of crops to spread their risks and lack resources to invest in inputs such as fertilizers and pesticides to boost their production. They are at the mercy of the weather; when it rains their harvest is abundant, when it fails, their granaries are empty and they sometimes require food aid.

These are the small-holder farmers in Rwanda, Burundi and Uganda that Dr. Piet Van Asten, a system's agronomist with the International Institute of Tropical Agriculture (IITA) is trying to work with to ensure they get the most out of what they have. However, they represent a majority of small-holder farmers in Africa.
He works for the Consortium for improving agriculture based livelihoods in Central Africa (CIALCA) which brings together many partners to improve the livelihoods of small-holder farmers. IITA is one of the founding partners.

Too many challenges, where does one start? According to Van Asten, the starting point to improve the productivity of their farming systems is to understand their constraints and to try and identify the one or two issues that if tackled can have great positive impact. He says using tools such as yield gap analysis which looks at the actual productivity of the small holders farmers against the maximum yield they can get in the same circumstances, they have been able to make some headway.

Poor old soils

Dr Piet Van Asten, IITA systems agronomist. 

Van Asten says, focusing primarily on banana, they have established that poor soils are one of the most important constraints to the crop's production by the small-holder farmers in the three countries. Most soils, he said, were old, from old parent rocks and had very little nutrients left.


It therefore follows logically that supporting the farmers to use inputs such as fertilizer was one of the best-bet technologies to increase their production. However, Van Asten cautions, this must be applied based on the actual soil deficiency and include factors such as distance from the farms to market and banana prices.

"Investing in fertilizer does not always lead to profits for the farmers. They can only get value for their money if they live near markets or infrastructure is good and they are able to fetch good prices for their banana. They must also know which nutrients their soils are lacking and which are important for the crops they are growing. They should not follow blanket recommendations as is always the case," he said.

For example he said, they established that potassium, which plays a big role in banana production, was lacking in most soils in the three countries. Yet, the addition of the mineral led to great gains in banana production. Furthermore, Van Asten said, the banana plants that received adequate potassium fared better in times of drought.

He says the impact of adding nutrients to the soils was visible even at the farm level where bananas growing near the homesteads were healthier than those further down.

"This is because the soil closer to the homestead benefited from kitchen wastes as women tend not to walk far to throw away the rubbish. For example, ashes from the fire add calcium to the soils, "he said. "Food wastes add organic matter."

Banana growing near a homestead where the soil is often more fertile from kitchen waste 

.

Which crops give the highest returns?

Most African farmers practice mixed farming. The question therefore arises, with the little limited resources at their disposal, which crop would give them the highest return from fertilizer application and how do they make these decisions?

Van Asten says according to a scooping study they carried out in the three countries, they were surprised to discover that farmers would get the highest return from coffee, cassava and banana and not maize and beans which they gave preference.

"Coffee, banana and even cassava in the long run proved to be better value for money invested in fertilizer in terms of replenishing nutrient extracted in the soils and returns per dollar invested. However, farmers only see the immediate gains in maize and beans.

"Farmers still have to make the decision carefully because for example, once they start fertilizing their coffee it would be best if they can continue. If they stop, the coffee can't maintain its canopy and yields and will show some die-back. This fuels farmers' belief that fertilizer is bad and spoils soils," he said.

Coffee and banana - super mix

Coffee and banana intercrop. 

Other practices that were found to increase yield include inter-cropping banana and coffee. Piet says the farmers got more out of their land by growing the two crops together than having either of them alone. These findings he said are slowing leading to a change of hearts among policy makers who have for a long time preached mono-cropping of coffee in Rwanda and Burundi. This is because coffee is an import foreign exchange earner and they did not want anything to affect its production.

He said their research was not inventing anything new. Rather it was based on finding out what the best farmers were doing to get their good yields and helping the others to adopt them.

"Some of the best banana farmers get as much as 40 tons per hectare. We try to understand what they are doing and why, and then promote it to wider farmers in the community and even further," he said.

However, he says they don't always agree with the farmers views. For example, most farmers judge the productivity of their banana by the size of the bunches.

"To us, this is not the best indicator. We instead look at productivity per hectare. A farmer may have smaller bunches but more plants therefore his overall productivity is higher than the one with huge bunches but fewer plants. We therefore have been working with them to plant as many bananas as their land can accommodate based on its soil fertility, rainfall, among others" he said.

Piet says under CIALCA they have mapped most of the soils in the three countries and developed fertilizer usage recommendations that are region specific. They have also developed and are disseminating the rich information gathered on various ways that small-holder farmers can increase banana production. The crop is among their most important food and cash crop in the three countries but its productivity is very low.