Bangladesh has approximately 2.5 million hectares of coastal low-lying land, which is submerged between 0.9 to 2.1 meters below sea level. About 1.51 million hectares (53%) of this coastal area is affected by salinity intrusion, and it continues to increase. The coastal areas constitute around 20% of Bangladesh’s total land area. These areas have very limited agricultural use, unlike the average agricultural land use of 50% in the country. The livelihood of the people in the southwestern region heavily depends on natural resources. These densely populated areas largely practice intensive farming on small plots of land, resulting in decreased fertility and productivity of the soil. During the wet season, from June to October, when the soil and river salinity are low, rice cultivation is possible in this region. However, from November to May (Rabi and Kharif 1 seasons), during the dry season, the salinity of the soil increases annually, limiting agricultural production. Agriculture production in Bangladesh is severely challenged during the dry season due to salinity and soil degradation. Various salt-tolerant crops such as akh, tal, date palm, and betel leaf are cultivated in these saline-prone areas. By promoting the cultivation of these salt-tolerant crops in the salt-affected regions, socio-economic conditions can improve for the general population and increase sugar and in detail.
The sugarcane crop is considered to be tolerant to salinity. It can withstand a salt concentration of up to 14 dS/m (decisiemens per meter). The Bangladesh Sugarcane Research Institute has developed salt-tolerant sugarcane varieties suitable for cultivation in saline areas. Some of these varieties include Ishwardi 39, Ishwardi 40, BSRISugarcane 43, BSRISugarcane 44, BSRISugarcane 45, BSRISugarcane 46, and BSRISugarcane 48. Even in areas prone to flooding and excessive moisture, when all other crops fail due to waterlogging or water inundation, sugarcane stands tall. Especially during periods of scarcity of food, such as during natural disasters, the juice of sugarcane can serve as an immediate source of beverage. One glass of sugarcane juice provides around 27 kilocalories of energy. The juice contains about 15% sugar. The remaining portion of the juice consists of water, which contains abundant vitamins and minerals. Sugarcane juice is a good source of calcium, thiamin, magnesium, manganese, phosphorus, potassium, zinc, iron, and various vitamins such as A, C, B1, B2, B3, B5, and B6. It also contains a high concentration of phytonutrients, antioxidants, proteins, soluble fiber, and other health-enhancing compounds. Through its active functioning, these nutrients play a significant role in promoting overall health. Research has shown that these nutritional components have extensive benefits in preventing cancer, regulating blood sugar levels in diabetes, weight loss, reducing fever, kidney cleansing, preventing tooth decay, and other health benefits.
Date Palm Tree: The date palm tree can survive in dry, arid, salty, and waterlogged conditions. Apart from cultivating it in the fields of crops, it is also planted by following agricultural construction methods on fallow land, dykes, pond banks, sloping land, around houses and gardens, and on both sides of dirt roads. Each tree produces an average of 5 liters of date juice per day. Date juice contains 15-20% sucrose, and for every 10 liters of juice, one kilogram of jaggery is obtained. Approximately 20-25 kilograms of jaggery can be obtained from one date palm tree per year. Date juice can be extracted from November to February. The date palm tree is environment-friendly and adaptable. It plays a role in preventing natural disasters. In addition, the date palm tree maintains the water table in the soil..
Palmyra Palm Tree: The palmyra palm tree is an important sugar crop in Bangladesh. It can survive in dry, arid, salty, and waterlogged conditions. Due to the flexibility of palmyra leaves, it is an effective lightning protector. The palmyra tree is widely cultivated as a result. The adverse effects of excessive rainfall and lightning strikes can be observed in Bangladesh due to climate change. In recent years, due to an increase in lightning strikes, many people and other animals have died prematurely. Due to the absence of palms, especially in coastal and haor areas, the death rate from lightning strikes is significantly higher. In order to mitigate this situation, the spread of palmyra trees throughout the country is of utmost importance.
Golpata Tree: The Golpata tree is a potential mangrove species in Bangladesh. It is found in the coastal areas of Sundarbans as well as the riverside areas of the hilly regions. Golpata trees can be seen in the coastal areas of Patuakhali, Barguna, Bagerhat, Bhola, and Khulna districts. The sap is harvested from the trunk of the gol tree. This sap contains approximately 18% sucrose, which is used to make jaggery and tonic. Additionally, vinegar is made from the sap. The use of gol leaves is increasingly popular worldwide.
Soil salinity is a major environmental challenge that negatively affects crop growth and productivity. Sodium chloride (NaCl) is a primary salt pollutant in soil. When it dissolves in water, it forms sodium (Na+) and chloride (Cl-) ions. These toxic ions accumulate in the plant’s cellular level, creating ion toxicity and osmotic stress.
There are several effective methods for mitigating salt-affected soil and promoting soil development. These include leaching, chemical amendments, and phytoremediation. Chemical amendments can be used to counteract salt-affected soil, such as gypsum (CaSO4.2H2O), calcite (CaCO3), and calcium chloride (CaCl2.2H2O). Additionally, the use of organic materials such as farmyard manure, compost, and bio-fertilizers can be beneficial.
Among these methods, gypsum application alone or in combination with organic amendments has shown significant improvement in crop yield and soil recommended to apply chemical fertilizers and organic fertilizers (per hectare: urea-58 kg, TSP-30 kg, MOP-32 kg, gypsum-23 kg, potash-2 kg, boron-2 kg, cow dung/compost-1500 kg) for sugarcane cultivation. By covering the field with dried leaves or sugarcane trash, the salt accumulation in the soil can be reduced, leading to better yield.
Considering the growing population of the country, meeting the current and future demand for sugar, including other sugar crops such as date palm, palmyra palm, and sugar palm, requires substantial efforts. According to Van Die (1974), with proper care and improved management, it is possible to achieve a sugar production rate of 20 tons per hectare per year from palm species (date palm, palmyra palm, and sugar palm), where sugar production from sugarcane ranges from 5 to 15 tons per hectare per year. Date palms and palmyra palms are for their cultivation. Additionally, they are more resilient against natural disasters compared to other crops. Palmyra palms also have a higher carbon sequestration capacity. Therefore, they can contribute significantly to environmental conservation.
Golpata (Nypa fruticans) is mainly found in areas with high soil salinity, near rivers and canals where tidal water intrusion occurs. Most of the time, the land remains submerged. As a result, golpata cultivation is suitable for saline-affected land. However, this crop also has significant economic potential, as golpata leaves are highly valued for their uniqueness and quality.
Now, considering the above discussion, it is clear that soil salinity is a major challenge for crop production. However, effective management strategies such as gypsum application, organic amendments, and cultivating salt-tolerant crops like date palms, palmyra palms, and golpata can lead to successful outcomes. These methods are widely recognized and implemented worldwide, and they are efficient, cost-effective.
