Protect our agricultural land from growing infertility

Food is one of the basic needs in human life. Even if all other elements are compromised, survival without food is impossible. A large portion of the world's per capita calories come from a variety of crops grown on the ground. It has been calculated that about 95 percent of the per capita calories come directly or indirectly from the soil. For this reason, the relationship of man with the soil is very close. And the relationship between soil and water is essential for the production of food crops. No matter how many nutrients the soil needs for plants, without water it is of no use to plants. Many countries in the world have land, but no soil for growing crops. So, in many places there are no animals. Soil can be both dead and alive. Desert soils are considered dead because they are relatively low in water and organic matter. The role of soil and water is immense for the existence of life. Because of this, the relationship between soil and water is very close. The interaction of water with soil produces plant growth and food for organisms. But today soil and water resources are under threat due to various reasons.

Agricultural Bangladesh does not have much natural mineral resources. As a result, the livelihood of most people in this country is dependent on agriculture. And the main basis of agricultural work is soil resources. 70 percent of the total population of Bangladesh i.e., about 11 crore people are directly or indirectly involved in agriculture. But unfortunately, it is true that the soil environment and soil fertility are under threat due to various reasons. Food prices are expected to increase by 30 percent in the next 25 years due to soil degradation. 75 percent of Bangladesh's total agricultural land has lost its fertility. Food demand is increasing day by day due to increasing population. Population growth rate is 1.37% per annum (BBS-2019). On the other hand, our arable land is getting limited. One, two, three or even four crops a year are grown in mono-cropped land. As a result, the presence of 14 nutrients required for plants in the soil is decreasing at an alarming rate. It should be noted here that rice crop from one hectare of land (rice yield of 6 tons/hectare) consumes 108 kg of nitrogen, 18 kg of phosphorus, 102 kg of potassium and 11 kg of sulfur annually. This means that large amounts of nutrients are removed from the soil each year. But balanced amount of organic and chemical fertilizers is not used in the land at that rate. Thus, the soil fertility is decreasing day by day.

Most of the soil in the Barendra and Madhupur average areas including the hilly areas of greater Rangpur, Dinajpur, Sylhet, Chittagong are highly to highly acidic. About 278,000 hectares of soil is highly acidic (pH value below 4.5) and about 36,44,000 hectares of land is more acidic (pH value 4.5 to 5.5). As a result, the desired yield of cultivated crops is not being achieved in all these regions. Excessive and high acidity of such soil must be reduced by application of lime to obtain desired yield.

About 53% of the country's coastal areas are directly affected by salinity. Currently, the salinity affected area is increasing beyond the coastal zone. According to the Soil Resource Development Institute's 2009 salinity survey data, about 1.056 million hectares of arable land in Bangladesh are affected by varying degrees of salinity. Soil salinity interferes with normal crop production. As a result, the productivity of the soil decreases to a large extent.

One-tenth of the hilly areas of the country, especially the hilly soil of Bandarban, Rangamati and Khagrachari districts of the Chittagong Hill Tracts, are eroding day by day where the tribal people cultivate Jum. But due to lack of modern technology and awareness, Jum cultivation leads to soil degradation on a large scale. The soil coming down from the hills is filling up the drains and grooves around the Jum. Studies have shown that 40 tons or more of fertile soil is being lost per hectare of land annually. However, if you are a little aware, you can increase the fertility by preventing the erosion of the mountain soil.

Besides, the fertile soil of the country is getting polluted due to various toxic substances. Biodiversity will also be adversely affected when soil becomes contaminated. Agriculture and food production will suffer. Household waste, polythene, solid and liquid waste from factories are major sources of soil pollution. A lot of heavy metals such as iron, manganese, lead, nickel etc. from the factories get into the rivers and land and pollute the soil.

In this situation, balanced manure management programs need to be strengthened through regular soil testing to ensure soil health and ensure optimal land use. The program of providing balanced fertilizer recommendations for various crops through soil testing through mobile soil laboratories needs to be strengthened. Sufficient amount of organic matter should be added to the soil. 10-15 tons of organic fertilizers should be applied per hectare per year. According to the study, it is possible to save 120-150 dollars' worth of chemical fertilizers from one ton of organic fertilizers. Along with this, it is recommended to take possible measures to prevent soil erosion.

On the other hand, fresh water reserves are constantly decreasing. Life without water cannot be imagined. Access to clean water is now recognized as a human right worldwide. The United Nations has declared the right to water as a human right. But even though it is recognized as a right, still more than 76 crore people are deprived of this right. So, protecting the right to fresh water is important today. Otherwise, critical areas will be at greater risk. According to the United Nations, about 40 percent of the world's people do not get enough water. It is said that by the year 2050, 700 million of the 930 million people will have water problems. According to a study by the Water Resources Engineering Department of Bangladesh University of Engineering (BUET), the groundwater level is dropping by two to five meters every year. As a result, the availability of water for drinking and farming in Bangladesh is decreasing.

A study has revealed that due to climate change, the situation in Barendra region of Bangladesh is increasing day by day. Between 1985 and 1990, the average groundwater level in the Barendra region was below 26 feet. The average water level in 2010 was 50 feet due to additional groundwater extraction for various purposes like food water, irrigation, fish farming. In 2021, the average groundwater level dropped further to 60 feet.

Like every year, this year too, 'World Soil Day 2023' was observed on 5th December all over the world. The theme of this year's World Soil Day is "Soil and Water: a source of life". I think this year's theme has been quite significant and timely to realize the importance of soil and water.

Finally, ensuring food security by producing more crops by increasing and conserving soil fertility is imperative for the economic development of the country. We have no choice but to increase food production to ensure our own food security. In the context of climate change, water problems will continue to increase day by day. Therefore, it is our duty to keep our earth habitable through proper management of soil and water resources. Awareness should be raised on the use of surface water by storing underground water now.

The writer is principal scientific officer, Soil Resource Development Institute, Ministry of Agriculture, Regional Laboratory, Faridpur