International Ministries

Nourishing the soil

March 30, 2011 Journal
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Our well-being as a human species depends on the health of the and on which we depend.  The biblical message of creation underlines humankind's responsibility to care for the land and make it fruitful.  A semi-subsistence farmer understands this.  Unfortunately in places like Vanga she is caught in the maelstrom of population growth and demand for land.  The tradition of leaving the land in fallow is increasingly ignored in the struggle to feed children and make ends meet.  But caring for the land doesn't necessarily mean sacrificing better lives, as ACDI Lusekele's experience of the last six years has shown.

The corn was finally harvested from the small experimental field in the ACDI demonstration garden in January.    Antoine set the husked ears in the sun for another week.  Then the research guys shelled the corn, cleaned  the seed and weighed it: 69 kilograms of gleaming white kernels filled two large basins. 

No Iowa corn master would be impressed; an indifferent Iowa farmer produces 3 times as much per unit of land . . . in his sleep.  Still the 69kg translates into 1,586 kg per hectare (2.5 acres).  That is on a plot of weathered, sandy soil, using no fertilizers, in the sixth year of continuous corn cultivation on the same plot.  To put the yield in perspective: a Congolese woman planting corn on a newly opened forest field would be delighted to produce 700 to 1,000 kg per hectare.  And even she would never consider planting a second crop of corn on the same land until several years later.

How do we do it?  The secret is the nitrogen-fixing capacity of the leguminous cover crop that follows the corn each year.  Mucuna pruriens is a vigorous bean plant that buries the field in 3 feet of lush vegetation during the second rainy season.  The leaves, vines and roots store up nitrogen.  When the rains start again we plant the next corn crop.  The nitrogen locked up in the decomposing organic matter is released, nourishing the young corn plant and favoring rapid growth.  When the corn is maturing the next Mucuna cover crop is already developing.  We harvest the corn and the cycle continues.

Agronomists have estimated that the Mucuna cover crop provides the equivalent of 17 to 35 bags of mixed chemical fertilizer for each 2.5 acres of land.  That's about $1800 worth of fertilizer at current Kinshasa prices.

The yield in the experimental field was down a bit this year.  But still the average over the last five years has been 1,733 kg/ha, about twice the yield in a traditional Congolese corn field - despite continuous cropping.  This looks like one productive alternative to traditional slash and burn agriculture.  Corn-Mucuna is one way to increase productivity and income and reduce the human footprint on increasingly scarce prime** agricultural land.  ACDI Lusekele is helping people to understand that becoming good stewards of the land can also be a pathway to improving our lives.

* "prime" agricultural land in much of Bandundu is misleading.  These are old soils.  They are highly weathered, stripped of most of their basic nutrients and chemically altered, impairing their capacity to hold on to nutrients.  Most agriculture here depends on fertility locked up in the organic matter that accumulates during extended natural bush fallow intervals between cropping cycles.