Brick kilns destroy fertile topsoil in port city

Dozens of illegal brick kilns, set up in arable land near schools and colleges, have formed a powerful clique who are removing the fertile topsoil for making bricks, rendering the fields unusable for agriculture. Fields that used to be covered by crops are now dotted with brick kilns operating right under the nose of the local administration.

Locals said they had filed complaints with the administration but there has been no change. They said nobody dares speak against the practice of cutting topsoil as the brick kiln owners are working in collusion with a local syndicate and the administration.

"No-one dares protest against the removal of topsoil," a local man said, declining to be named. Bangladesh, the fourth largest brick producer in the world, has a voracious appetite for the construction material. In a 2017 report, the Department of Environment said there are more than 7,000 brick kilns in Bangladesh that produce about 23 billion bricks annually.

The $2.53 billion industry accounts for approximately 1 percent of the GDP and generates employment for more than a million people. It consumes 3.350 billion cubic feet of clay and uses 5.68 million tonnes of coal every year. The sector is responsible for emitting 15.67 million tons of CO2.

industry is growing about 10 percent every year. more than a hundred brick kilns were established in the upazila which has 16,180 hectares of arable land. dozens of trucks being loaded with topsoil from arable lands and taken to brick kilns.

land grabbers are only thinking about making profits. "The most helpful ingredients are contained in 4-6 inches below the surface area. It takes lands 15 to 20 years to get back their lost nutrition if they lose topsoil. Farmers are producing brinjal, chili, potato, and other crops in the fertile land of the upazila,  adding that illegal soil cutting is threatening crop production. they do not find land grabbers during their drives.

Around 7,000 soil-burning brick kilns use over 1.27 billion cubic feet of topsoil every year Unplanned urbanization and growing number of brick kilns are rapidly depleting Chitta-gong's topsoil, wreaking havoc on farmland fertility. According to the Bangladesh Brick Manu-facturing Owners' Association, around 7,000 soil-burning brick kilns produce approximately 25 billion bricks every year, using over 1.27 billion cubic feet of topsoil.

According to the Department of Agricultural Extension (DAE), as many as 806 brick kilns are now operating in five districts in Chittagong division, with 410 in Chittagong city, 83 in Cox's Bazar, 113 in Noakhali, 107 in Feni, and 93 in Lakshmipur.

Topsoil depletion has reached such an alarming rate that it made the agenda at the Chittagong Divisional Development Coordination Committee meeting on January 23, held at Chittagong Circuit House.

In line with the meeting's decision, the Divisional Commissioner's office wrote a letter to the DAE to submit a report citing ways and means to prevent further topsoil depletion. Apart from coming up with a set of recommendations, the DAE explained the reasons for topsoil loss in the Chittagong and Comilla regions. According to the report, fertile top layers of farmland are ruined by the removal of topsoil used to manufacture bricks.    

Oblivious to the long-term detrimental impact, farmers sell topsoil to brick kilns to rapidly turn a profit. The report suggested that agricultural land loss is due to unplanned human settlements, road construction, mill and factory construction, excavation of ponds and tanks, and brick kilns and poultry farms.

Furthermore, topsoil on agricultural lands are degraded during sand extraction by dredgers.   

The top layer of soil is losing fertility due to its depletion in organic matter, while farmers apply chemical fertilizers and pesticides for high yields. ndiscriminate felling of trees and water washing down the hills are also causing the topsoil to erode and become infertile.

The DAE report recommends designating zones for procuring soil for brick kilns, and using soil dredged from ponds, rivers, and canals for this purpose.  Additionally, the report suggests allowing brick kilns to be to be set up on two-crop farmlands.

"High and medium-high farmland should not be used for any other purpose," the report adds.  Expressing grave concern regarding rapid depletion of topsoil, soil scientists and environmentalists said that non-agricultural use of agricultural land is increasing alarmingly in Bangladesh.

Dr Md Golam Kibria, professor of Soil Science Department at Chittagong University, explained: "A piece of cultivable land should have at least 3% organic matter. Unfortunately, the soil of Bangladesh contains less than 1% organic matter.

"The topsoil, or plough layer, has the highest concentration of organic matter and micro-organisms. Land fertility will be under serious threat if this topsoil depletes further." Kibria added. Topsoil loss adversely impacts soil aggregate stability.

Good aggregate stability is dependent on organic matter and biological activity in the soil, which helps root development in plants. Poorly-aggregated soil disintegrates easily.

"Topsoil is the most fertile portion of the soil. Plants require 17 essential elements for growth and those elements are found in abundance in the top layer," said Dr Md Al-Amin, professor of Institute of Forestry and Environmental Sciences at Chittagong University. 

Farmers are lured into selling the topsoil, which will take 10 to 15 years to regain fertility. A farmer will have to use huge amounts of fertilizer over the years to make up for the loss of topsoil.

"Meanwhile, the sustained growth of cropland will decrease. Eventually the loss would far outweigh the instant monetary gain from selling topsoil," said Prof Amin, adding that sometimes farmers voluntarily sell farmlands adjacent to brick kiln.

This is because the fly-ash produced from a brick kiln spreads up to one kilometre. "The fly-ash deposited on plants reduces the rate of transpiration in a plant. Transpiration is the primary basis by which a plant sustains its life," added Dr Amin.

Dr Md Jahangir Alam, professor of Civil Engineering Department at CUET said that the Housing and Building Research Institute  has developed concrete blocks that could substitute clay-rich topsoil bricks."We should shift to concrete blocks from burnt clay bricks. The structures made from concrete blocks will be strong, sustainable and cost-effective," said Alam. Soil scientists also recommend farmers growing legumes along with their main crops, or between harvests.

A leguminous crop refers to those, which have symbiotic nitrogen fixing bacteria called root nodules. These bacteria fix atmosphere nitrogen into soil there by increasing the soil nitrogen content naturally.  They are important for crop rotation in order to avoid soil deterioration.