As the harmattan season comes with dry and dusty weather, experts have advised Nigerians, especially farmers to take precautionary measures against man-made disasters during the period.
The experts gave the advice in separate interviews with Newsmen in Abuja, on the effect of the harmattan season on agriculture.
A soil scientist, Prof. Victor Chude said that farmers should avoid indiscriminate bush burning after they have harvested their crops.
Chude said that farmers should gather trashes at various spots before burning bushes as a way of clearing the land before the next cropping season.
He said that bush burning during harmattan could be very disastrous as it could affect the neighbouring farms with economic trees and destroy important micro nutrients in the soil.
We will not advise farmers to just set the whole farm ablaze as a way of clearing his land because it will be difficult to control.
If it is a forest area where the undergrowth is very thick, the duration of burning will be longer and this is very destructive to some essential soil micro-organisms in the soil that perform the job of mineralisation of nutrients in their organic form and make them soluble.
When those micro-organisms are destroyed, the nutrient will remain in the organic form and in terms of availability to crops during cropping, it will be a problem.
What we advise them is to first slash and then do spot burning; if there are trees, they should do selective cutting of trees so that the whole place is not exposed to erosion,'' he said.
Chude observed that most of the wild fire particularly in the savanna regions of the country was caused by herdsmen who were looking for fresh sprouts.
He said that they set the bush ablaze because after the burning, with residual moisture dews, new sprouts would come up to be used to feed their cattle and to chase rats and other small ruminants.
He said in developed economies, fodders were harvested during the wet season and stored to be given out to animals during the dry season, adding that the method could that be explored.
Another soil scientist, Dr Olaseinde Adeshida, told reporters that bush burning, whether the result of a wildfire or a controlled burn, affects not only the appearance of the landscape, but the quality of the soil.
The landscape may quickly recover after a fire, with fresh new growth and emerging seedlings.
However, bush burning has a negative effect on soil conditions, and soil may take much longer to recover, according to the National Resources Conservation Service.
Bush burning can cause the soil to lose its ability to absorb and retain water.
After a fire, the top layer of soil may become water repellent. This causes rain to drain off the soil without absorbing into the ground. Once fire consumes bushes, their roots no longer pull moisture into the soil.
Additionally, the loss of shade that the bushes once provided means soil moisture is more likely to evaporate,'' he said.
Adeshida said that bush burning during the harmattan season might cause the soil to be less stable and erosion is a major concern after a fire''.
Shallow-rooted plants are affected by unstable soil, as they depend on vegetation, such as shrubs and bushes, to hold the soil in place,'' he said.
Adeshida, however, said that bush burning exposes the soil to the sun adding that the lack of shade raised the temperature of the soil.
If the fire also caused the soil to become water repellent, the soil will be even warmer due to the lack of moisture.
Depending on the ecosystem, this warmer soil may hinder or encourage seed germination. Microbes present in the soil, if not killed by the burning, may not survive in the warmer soil.
Many plants depend on soil microbes and although they may grow, will not thrive if microbes are absent from the soil,'' he said.
He, however, suggested the way out by targeted extension advocacy, enforcing legislation against bush burning, strategic bush burning and cleaning.
Prof. Sani Mashi, the Director-General of Nigerian Meteorological Agency (NiMet), had recently announced that the severity of harmattan period would be higher and longer over the northern states.
He said that this was due to the proximity of the northern states to the Sahara desert compared to the South, in NiMet in 2018/2019 dry season forecast.
During the harmattan season, sunny and hazy conditions are expected over the northern states and central cities down to the inland cities of the southern parts with thick dust haze conditions which can impair horizontal visibility to less than 1,000m (1km).
The harmattan season is characterised by the prevalence of dry and dusty wind consisting of fine particulate matters emanating from the Sahara desert blowing southward into the country.''
Mashi warned that the expected reduction in visibility in the coming weeks might disrupt flight operations through cancellation and delay of flights at some airports across the country.
He advised road users to be careful and avoid speeding, especially during early morning period when horizontal visibility would be impaired by fog, mist or dust haze.
According to him, these weather conditions can increase traffic congestion or even cause accidents.
Mashi also warned that bush burning should be avoided as the dryness and strong wind could increase fire incidences and cause severe crop damage at harvesting period.
The public is advised to take adequate water during the harmattan period to avoid dehydration and heatstroke, he said.
Source: Voice of Nigeria