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Smart farming boosts harvests in arid regions

Juliana Kinya grows vegetables in sunken beds
Juliana Kinya grows vegetables in sunken beds that harvest and retain water for longer periods in Mwala. PHOTO | SARAH OOKO 

Mwala sub-county in Machakos is one of the arid and semi-arid areas (ASALs) in Kenya. Farmers there have to contend with long dry spells and short rainy seasons that as a result of climate change, have increasingly become erratic and insufficient.

This has adversely affected their agricultural yields, leading to minimal harvests and low incomes for many households that rely on farming as their livelihood source.

“There are times you harvest and the food gets over before the next harvesting season. So you have to struggle to buy food even though the money is not there,” says Juliana Kinya, a farmer in Katheka village in Mwala (Masii).

Such stories are common in most rural households, especially those in ASALs that occupy about 70 per cent of Kenya’s land mass.

As farmers like Ms Kinya bear the consequences of minimal rainfall at a personal level, the country also suffers.

This is because agriculture is a major source of employment and the country’s largest single economic sector, accounting for 31.5 per cent of the gross domestic product (GDP) and roughly 50 per cent of export revenue, according to government statistics.

The food shortages are also major contributors to the high child malnutrition rates in eastern Kenya where dryland agriculture in Kenya is practised.

The region has a stunting (severe malnutrition) rate of 26 per cent against the country’s total rate of 34 per cent. Yet, malnutrition is an underlying cause of about 30 per cent of deaths among children below five years. The condition lowers the immunity, making children vulnerable to death from common childhood diseases such as diarrhoea and malaria.

“It also interferes with the optimal brain development. This results in low intelligence which will adversely affect school performance of affected children,” says Gladys Mugambi, head of the dietetics and nutrition department at the Ministry of Health.

To address farming hurdles in dryland areas like Mwala, agricultural experts are urging farmers to pursue an innovative farming technique known as conservation agriculture.

The approach encompasses agricultural practices that minimise soil disturbance hence preventing erosion. Aside from reducing pest and diseases, they also enable the soil to retain moisture or water.

“These are problems that farmers deal with here all the time. That’s why we believe that conservation agriculture is the ideal farming technique for us,” said Sarah Kabiru, an agricultural officer with the Ministry of Agriculture in Mwala.

Barrack Okoba, an expert on conservation agriculture from the United Nations Food and Agriculture Organisation (FAO) in Kenya says the farming method is well suited for dry lands which receive minimal rainfall.

The organisation is working with the Agriculture ministry to enhance its uptake among farmers in the arid and semi-arid areas.

According to FAO statistics, uptake of conservation agriculture is still low and far away from the recommended 10 per cent adoption rate in Kenya.

“That is the threshold level that can spur widespread adoption of the agricultural technique in Kenya,” says Mr Okoba.

He says small-scale farmers, who are the majority in Kenya, stand to benefit a lot from conservation agriculture as they are the most vulnerable to challenges in the agricultural sector.

Currently, about 40,000 hectares of land is under conservation agriculture in Kenya. But 70 per cent of them is owned by large-scale farmers.

“Our aim is to have many small-scale farmers embracing this new technique so their lives can change,” says Mr Okoba.

Ms Kabiru says in conservation agriculture, they urge farmers to practise minimal tillage to avoid disturbing the soil unnecessarily.

As such, she says the use of hoes (jembes) and ploughs, which turn over the soil during land preparation is discouraged. This is because such equipment loosens up soils, predisposing them to wind or water erosion.

“They also cause moisture and organic matter stored beneath the soil inner layers to evaporate and dry up hence accelerating land degradation.”

Worse still, use of hoes and ploughs over long periods leads to the creation of hard pans — solid cement-like layers — beneath the soil, which reduce agricultural productivity.

Aside from restricting root growth, decreasing seed germination and reducing soil aeration (which can result in stunted plants), the pans also cause poor water drainage and flooding that may wash away crops.

Ms Kabiru says to get rid of hardpans that have been formed in the soil over the years, farmers transitioning from conventional farming to conservation agriculture should begin by hiring a sub-soiler machine, which helps to open up the soil by destroying the hard pans.

Thereafter, farmers replace the destructive farm equipment (hoes and ploughs) with soil friendly equipment used for land preparation in conservation agriculture such as rippers and scrapers.

As a result of adhering to the above management practices in conservation agriculture, Ms Kinya noted that her crops are now able to grow well. She gets a bumper harvest even with the long dry spells that the community has been experiencing.

“I used to get about two sacks of maize but that has increased to six. I am also able to get enough produce to sell and consume at home until the next harvest season. In the past, I would run out of food mid-way, forcing me to buy things even when I lacked enough money.”

According to Ms Kabiru, conservation agriculture also advocates permanent soil cover, which cushions the soil against adverse weather events such as excess heat that accelerates the loss of soil moisture.

The complete soil cover can be attained through the use of cover crops like peas, which may be inter-cropped with tall and slender leafed commercial crops such as maize. “The broad leaves of legumes like beans cover the soil hence helping it to retain moisture that the maize uses to grow well.”

In addition, Kabiru says, farmers can also cover their land through mulching, which uses dry crop residues such as maize stalks from the previous harvest.

“At no point is my land bare. That’s why I am still able to get something even when we have long dry seasons. Last year, people’s crops dried up but mine withstood the drought,” said Kinya.

Mulching also suppresses weed growth whilst boosting soil fertility by adding organic matter to the land.

According to Kabiru, conservation agriculture farmers should also embrace crop diversity to cushion them from complete losses or starvation in case one crop fails due to drought.

“It also gives the farmer nutritional diversity which is good for their health and that of their children whose bodies are still developing.”

Inter-cropping diverse crops in different land sections also help with soil fertility. For instance, growing legumes after harvesting maize help replenish nitrogen in the soil that had previously been consumed by maize plants.

Similarly, deep-rooted crops mine nutrients stored in bottom layers of the soil. They then bring them to upper layers where shallow-rooted plants can easily access them.

Crop diversity is also good for pest and disease control. This is because most pests usually identify their favourite plant through smell. So, when different crops are combined in an area, they produce a cocktail of aromas that confuse the parasites hence keeping them away (especially if potent smelling plants such as basil, rosemary, lavender, ginger, garlic and onions are there).

To sustain soil moisture, Mr Okoba says farmers practising conservation agriculture are usually encouraged to harvest rainwater. This can be achieved through the use of tanks that collect roof water as well as shallow dams with heavy polythene liners that harvest surface run-off water, especially on gently dipping terrains.

“We still have water from the previous rainy season which can help in irrigation until rain pours again. Sometimes, our farming group also sell to other farmers facing water shortage problem. So we make money from water harvesting too,” Kinya said.

Farmers can also grow water sensitive crops such as vegetables in sunken beds that harvest and hold water for longer periods.

Stephen Mwandai, a project officer at FAO in Machakos says for conservation agriculture to be successful, farmers need to grow crops with the market in mind.

“Grow something that you know is in demand so you can readily sell it after harvesting,” he says.

To attain volumes or quantities of produce required for export markets and by large-scale buyers, he says it is advisable for small-scale farmers to work in groups.

“A single farmer might not have enough. But when many people combine their produce, then market targets can be met.”

Ms Kinya said: “Sometimes we can decide to hold on to our produce a bit longer and only sell when prices are high and the market is not flooded.”