How to protect your soils for bumper harvest every year

What you need to know:

  • Instead of ploughing and harrowing, the soil could be sub-soiled using a sub-soiler and then ripped using a ripper to make furrows for seed placement, writes Lominda Afedraru Lominda Afedraru.

Land degradation stemming from deforestation, burning of grasslands and organic residues as well as continuous cultivation with minimum soil fertility enhancement leads to soil erosion and organic matter and nutrient depletion.
Other unsustainable land-use practices such as overgrazing have produced compacted soil layers and often bare grounds in extreme cases.
Another underlying factor in the development of compacted soil layers is that hand-hoeing, which only disturbs the top layer when done consistently and regularly, can potentially produce restrictive layers.
Under these soil conditions, nutrient and water use efficiency is reportedly very low. These soil layers act as barriers to root and water movement and soil water holding capacity making land susceptible to the frequency and intensity of rainfall.
This affects agricultural land severely including inhibiting root and water movement hence limiting water infiltration and retention.
There has been concerted effort to address such challenges with Global Water Partnership Eastern Africa (GWPEA) being one of the stakeholder players.
Gerald Kairu from GWPEA explaining to Seeds of Gold about the concepts, principles and applications of efficient water usage notes that, in regard to land degradation and a total dependence on rain-fed agriculture, this has increased the vulnerability of farming systems and predisposed rural households to food insecurity and poverty.
He explains that water insecurity has led to significant adverse impacts on smallholder agro-ecosystems, including direct damage and loss of critical ecosystem services such as biodiversity.
There are efforts by ministry of agriculture in sensitising farmers to adopt new technologies to conserve water in the soil during the dry season in a bid to keep plants healthy. One such initiative is by Mukono Family Farmer’s Association located in Bugereka village who are practicing sustainable land management through adoption of minimum land tillage, permanent planning stations termed as basins and rip lines.
In an interview with Job Mpaata, the farmer leader of Mukono Farmers Association who has adopted these technologies on his farm and is in massive sensitization of his fellow farmers, he takes Seeds of Gold through it and below are excerpts.

Permanent planting basins
Seeds are planted not along the usual furrow but in small basins—these are small pits that can be dug with hand hoes without having to plough the whole field.
Planting basins are prepared across the slope of a field along the contour before rains.
They enable the farmer to plant the crop after the first effective rains when the basins have captured rainwater and drained naturally.
Seeds are placed in each basin at the appropriate seeding rate and covered with clod-free soil.
It helps to capture storage of rain water and allows management of limited nutrient resources.
Prior to the establishment of the basins, the fields have to be slashed and sprayed with herbicide or simply slash and remove weeds two weeks to digging the permanent basins.
Permanent planting basins are designated using planting lines and digging planting basins 35cm long by 15cm wide and 15cm deep.
The spacing between basin holes is 75cm between rows and 70cm within rows from center-to-center.
Farmers are expected to lay available crop residues between rows to create a mulch cover.
In case of groundnuts each basin is seeded with six seeds and farmers plant three maize seeds per basin and six bean seeds per basin.
During planting the seeds are dropped into the basins which are half filled with soil and covered.
When rains start, it penetrates in the basin and is absorbed. This can last for three months and it will continue feeding the plant during dry season. This is advantageous in that the plant will germinate very fast and it will develop a deep root system thereby leading to increased yield.
Farmers are expected to dig 760 basins in one acre land. It is important to dig contours to capture rain water which will infiltrate the soil to keep it moist. It will serve the plants during dry season.
During the next planting season, there will be less labour required because it will be a matter of reopening the basins for further planting. It is the reason it is referred to as permanent basin.
Example: Parents and teachers have embarked in teaching their children to go into conservation farming and one such child is 12 - year-old Gloria Naakazi from St Joan Bright Infant School.
Her mother gave her half an acre of land where she used permanent basin technology to grow groundnuts.
She planted half a kilogramme of groundnuts and ended up harvesting 25 kilogrammes and she sold each kilogramme at Shs1,000. She has been doing this over time and is able to raise part of her school fees from the proceeds.

Rip lines
This method is where farmers are expected to break the hard pan of soil using tines which can penetrate deep by digging the rip lines. It is efficient where machinery or ox plough is used.
After removing the compaction layer by deep ripping, plant roots grow faster and deeper, increasing the amount of water and nutrients they can access and as a result crop yield improves.
This method according to Mpaata is not yet adopted so much by farmers in Mukono but sensitisation work is ongoing.
Farmers can use ox ploughs for penetration of the rips which must be in lines.
Traditionally deep rippers rip the soil with tines all set to the same depth which has to penetrate and fracture the soil to full working depth.
Research has shown, however, that single shallow leading tines working in-line and ahead of the deep ripping tine reduce the draft force.
The ripping tines must be able to penetrate just below the compacted soil layer
Soil must be moist enough to allow penetration of the ripping tines but not so moist that the tines cause smearing without fracturing and shattering the soil. Both methods above reduce the risk of crop failure due to erratic rainfall and extended droughts. Farmers are advised to use these methods in combination with improved seed and crop residues to create a mulch cover that reduces evaporation losses.