Farmers are increasing their maize yields by 40 per cent by letting weeds grow and digging them back in giving their farms some free manure.
Albert Rotich, a maize farmer in Trans-Nzoia informed us that he has gone from getting 10 bags to 14 maize bags per acre since he started letting weeds freely sprout on his farm rather than slashing and burning them and ploughing them back into the soil weeks before planting his maize. He also saves thousands of shillings he spent buying herbicides and ensures that when the rains finally arrive his crops have an early start.
Referred to as ‘dry tillage’, research has shown that ploughing during dry seasons produced 3.4 tons per hectare of maize; 42 per cent more maize than the national average.
This is because it brings weed seeds to the surface, where they are exposed to high temperatures and sunlight which kills most of them, reducing the weed seed bank in your soil.
“For the past three years I’ve been scorching my weeds, every planting season I have fewer and fewer weed problems,” Rotich explained.
Related News: Weed-reading: Kilifi farmers improve yields by learning from invaders
Related News: Weeds tell farmers the kind of soils they have the and crop to grow on them
Dry tillage also cuts the life cycles of soil pests and diseases and prevents them from being carried into the next growing season.
By eliminating weeds before the rainy season, crops face less competition for moisture. This is particularly beneficial in semi-arid regions, where little water is available.
The retired teacher explained that for the farming method to be a success, timing is critical. “Begin ploughing during the dry spell—ideally in mid-February, when the soil is dry and its temperature is high. The combination of soil disturbance and sun exposure effectively scorches the weed seeds, he said.
You’ll also need an ox-plough or tractor with disks or rippers with a 20–30 cm ploughing depth to expose the weed roots and seed banks properly. When working in the field, ensure that as many weed seeds as possible are brought to the surface. “Exposed seeds and roots are more likely to become weak and die from the heat than matured weeds,” Albert added.
After ploughing, give the soil a few weeks to fully dry and let the intense sunlight work its magic. This resting period ensures that all the weed seeds are reached by the sun.
Dry-season ploughing works best when combined with minimal tillage once the rains begin.
Related News: How to control weeds in maize without use of pesticides
Related News: Farmers use weeds to tame crop destroying moles