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Impacts of agrochemicals on soils in Lango sub-region

(Last Updated On: 16 February 2023)

By Nancy Atim

Just like in many countries in Sub-saharan Africa, agriculture remains the major source of livelihood in Uganda. According to the Uganda National Household Survey (UNHS) 2016/17, the majority of the working population was engaged in agriculture, forestry and fishing (65%). 

Among the female population, 70% are engaged in agriculture compared to 58% of the males. Furthermore, the main source of earnings for the majority of households (43%) was subsistence farming while for one in every four households (25%) it was wage employment. 

The summary of sector performance for 2014/15- 2019/20 shows that agriculture remains the main thrust of Uganda’s economic growth. The sector contributes 23% of the national GDP and employs over 70% of Uganda’s population directly or indirectly. 

Soil

A schematic illustration depicting the response and effects of pesticides on soil microbial communities and biodiversity.


Plant insects, pests and human activities such as bush burning coupled with the arrival of climate change have pushed farmers into using agrochemicals to help minimize this loss by protecting crops, increasing productivity and maintaining the quality and maintain the quality of the produce. This was witnessed a lot during the repeated lockdowns Uganda had pushing people into agriculture. 

However, only 23 per cent of farmers in Uganda have received training in pesticide use such as proper application techniques, storage, and safety measures, according to studies made by the pesticide use, Health and Environment Project and Uganda National Association of Community and Occupational Health and whose results were released in 2019.

The impact of pesticides on agronomic yield and profit margin makes them a significant component of modern agricultural practices.

However, the indiscriminate use of pesticides leads to the degradation of soil and its microbial ecosystems. Weeds and insects are the major reducing biotic factors in agriculture and hamper crop yield, productivity, and resource use efficiency. 

Therefore, herbicides (type of the pesticide that kills specifically targeted herbs) and insecticides (the type of pesticide that kills specifically targeted insects) are being used indiscriminately for ensuring higher production by eliminating or suppressing the pest population.

Soil

These chemical compounds are either applied directly to the soil strata or as a spray. Using pesticides chemicals to weed. File photo.


The Lango sub-region is situated within the annual cropping and cattle-farming systems that are primarily found in Northern Uganda (2.8780° N, 32.7181° E). 

The region is dry compared to the rest of the country and experiences one long rainy season also called the unimodal type of rainfall, yet farmers can still grow crops at least twice a year.

Although still recovering from war and related effects, such as ecosystem degradation, the region is recognized for its potential of being the country’s grain basket and contributing to the Gross Domestic Product (GDP).

 Farmers grow cereal, oil crops, pulses, and root tubers, in addition to rearing cattle and small ruminants such as goats. The main cereal crops grown there are maize, finger millet, sorghum, and rice; other crops grown are cotton, sweet potatoes, and cassava. 

The sub-region is also notable for growing oil crops such as sesame, sunflower, ground nuts, and other legumes, such as pigeon peas, soybeans, and beans. These provide staple food for people beyond the region and play a role in income generation for rural households, with a substantial contribution to the national economy. 

Soil types in Lango are ferralsoils (old soils, or soils that are developed in strongly weathered parent materials), alisols (highly acidic, poorly drained soils prone to aluminium toxicity and water erosion) and plinthosols  (iron-rich soils characterized by the presence of plinthitepetroplinthite or pisoliths).

Over the years, farmers in the Lango sub-region have applied agrochemicals to control weeds, pests and diseases that ravage crops in the region following the demand for food from the ever-growing population of about 1.5 million people as per the 2022 National census.

As of July 2018, its population was estimated at 2.3 million, about 5.75% of the estimated 40 million Ugandans at the time.

Soil

Map showing districts within the Lango sub-region in Northern Uganda.


Such spraying was also witnessed in 2020 when desert locusts invaded the districts of Otuke and Alebtong. Earlier, farmers in Lira, Kole and Oyam had sprayed crops to control fall armyworms.

Soil

Uganda People’s Defence Forces (UPDF) soldiers spray trees where the locust swarms were with insecticides in Otuke on February 17, 2020.


Joshua Oloma, a farmer growing rice, vegetables, tomatoes and fruit trees based in Te-Duka ward, Aduku sub-county in Kwania district says for the past years, he has used agrochemicals such as weed killers, and fertilizers to boost soil fertility.

“The amount of chemical one applies also affects the soil fertility and soil PH and once the guidelines are not followed, this results in poor yields,” Oloma added. Watch her explain more here

Mrs Betty Ouni, another farmer in Lira District says she uses agrochemicals she purchases from fully licensed and registered dealers who provide her with all the necessary guidelines before use to avoid soil damage during the farming process. Take a listen to her here.

Unlike others, Bazilo Okello a farmer from Amolatar district who has been in the farming business for the last 15 years shares his bad ordeal of using agrochemicals before switching to using organic matter like leaves, and grass among others that have greatly paid off.

Click here to listen to Bazilo share his experience as a farmer.

The managing director of Lira farmers supply house, Lira City, Mr Isaac Otim says his clients are always given proper guidelines on how to handle, apply and store agrochemicals, recommending them to spray these chemicals in the wee hours or the evening. 

Here he explains during an interview.

Otim further says he supplies farmers with Agrochemicals such as pesticides, herbicides among others used in clearing gardens, killing weeds, controlling pests as well as boosting crop growth but, poor measurement of these agrichemicals during application equally affects the soil negatively as well as killing soil insects such as termites that are good in soil composition. 

Soil

Different agrochemicals are displayed in an agrochemical shop. 


The District Agriculture Officer, Oyam district, Tommy Opio defined agrochemicals as ‘non-organic synthetic products made for use in farm’.

Chemicals like DDT2 were banned by the government. They are known for killing terminates yet they are very paramount to soil health.

According to Opio, the rate of using agrochemicals in Lango sub-region by farmers is gradually increasing.

In a recent research conducted in 2019 by the agricultural department of Oyam district on the control of fall armyworm on maize crop, agrochemicals practices stood at (43%), agronomic (16%), botanic (11%), and cultural practices (10%). Additional statistics are found here

With the above trend in the use of agrochemicals, Opio is worried about the negative impact on the soil and its components like killing soil microbes which play a great role in soil decomposition of organic matter to produce soil nutrients necessary for the plants, leads to soil compaction, death of soil insects like termites hence crop yields will be impaired.

According to data from the National Agricultural Research Organisation – Ngetta ZARDI, farmers across Lango use agrochemicals to among others; clear their farm gardens, boost plant growth, control pests, and kill the weed without prior knowledge and guidance on chemical application thus causing severe damage on soil and other soil components.

Lawrence Ogwal, a research technician (soils) at NARO-Ngetta ZARDI in Lira city says agrochemicals are synthetic chemicals. They are composed of fertilizers and pesticides. Insecticides herbicides are used by farmers to boost crop growth, kill weeds, and pests and well as regulating plant growth (rooting hormones).

They are either in granular or liquid form and applied at different levels which also affect soil and soil organisms. Agrochemicals is a common name given to chemicals which are used in agriculture, to aid plants and crops’ growth and safety. 

Ogwal explains the different types of agrochemicals being used.

According to Mr Ogwal, the increase in demand for food by the ever-increasing population has led to the drastic use of agrochemicals in all farming processes in the region, simply to boost production and supply leading to environmental degradation as well as killing soil properties, soil, nutrients, and also shifting soil PH fertility.

Agrochemicals were manufactured to protect crops from pests and for augmenting crop yields. It is a costly input for agriculture however, they affect the soil by killing beneficial bacteria, increasing nitrate levels in soils, altering the PH of the soil, residual effect, killing soil organisms and also leading to toxicity and reduction in soil quality.

Judicious and discriminatory use of pesticides is critical because most harmful effects are caused by application doses that exceed the recommended rates.

The education of farmers, distributors, industry, policymakers, and other stakeholders in the discriminate use of pesticides is critical to reducing the adverse effects on soil and the environment.

Well-designed experiments are needed on the long-term effect of pesticides on microbial communities and their long-term eco-toxicological effects in the soil environment.

“With the statistics at hand, farmers should buy agrochemicals from fully licensed and registered to fully get proper guidelines on how to use, handle, store and apply the agrochemicals. This can eventually be coupled with broad farmer training to avoid the damaging effects of the agrochemicals on the soil environment,” Ogwal added.

On what he can recommend, listen to him here.

Meanwhile, Molly Bellah Akello, the executive director of Fountain of Life Uganda who also doubles as an environmental activist, said the continuous use of agrochemicals has adverse effects both on humans and the soil.

She advised farmers to rather use traditional ways of controlling pests, boosting plants’ growth among others, such as mulching, which only requires the use of grass leaves and plant stems. 

Soil

Dry grass is used to mulch maize crops in the garden.


Furthermore, Akello encourages farmers to utilize cow dung and red pepper solutions to spray against pests and diseases, citing that organic components do not affect the soil crops and humans. Watch her here.

An Act to control and regulate the manufacture, storage, distribution and trade in, use, importation and exportation of, agricultural chemicals and for other purposes is into force.

The mandate for agriculture development is to feed and provide adequate nutrition and surplus to the mounting human population without compromising on the ecology and environment of the biosphere. Pesticides and their use are considered magic bullets in developing nations.

Pesticides cause serious hazards to the soil environment and human health because a lot of pesticides and their derivatives remain in the soil system for a considerable period.

Most pesticides negatively affect the biological functionaries of microbes, their diversity, composition, and biochemical processes. Pesticides cause an imbalance of soil fertility which directly affects crop yield.

This story was fully funded by Ultimate Multimedia Consult (U) Ltd.

2 thoughts on “Impacts of agrochemicals on soils in Lango sub-region

  1. The write up is misleading and devoid of scientific facts. the data presented for chemical use has got no connections to Soil damages they are alleged to cause.

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