Some solutions to treat salt poisoning in rice plants

Prevention of salt poisoning is carried out right from the beginning of the crop, because the rice seedling stage is very sensitive to salinity.

Current salt-tolerant rice varieties can usually withstand a salinity of about 3 - 4‰, some varieties can withstand a higher salinity such as: Mot Bui Do can withstand a salinity of 6‰, which is considered the salinity in the soil. Therefore, if fresh soil is infiltrated by salt water, it will not significantly affect the rice plants if the rice fields are not allowed to dry out. Therefore, it is necessary to keep the fresh water level at 3 - 5cm above the field surface. If the field dries out, the water evaporates, causing salt water to rise through the capillaries, gradually increasing the salinity of the soil, leading to salt poisoning of the rice plants.

Rice is affected by salinity.

When seeing that the water is at risk of drying up in the rice fields on the shrimp farming land, if there is no rain or no fresh water, it is possible to bring water with a salinity of 5 - 6 ‰ into the fields to prevent salinity from penetrating into the soil when the fields dry up, but note that when bringing in saline water, it must be continuously brought in for 2 - 3 days and then pumped out and brought in another water, because if left for a long time, the water will evaporate and the salinity will continue to increase, causing harm to the rice plants.

* Symptoms of salt poisoning

There are 2 symptoms of salt poisoning on rice plants:

- Direct manifestation: Na+ toxins will burn the leaf tips, because when the rice plant absorbs salty water and releases it at the leaf tips, Na+ toxins (salt) will accumulate, and under the influence of sunlight, the rice leaves will burn from the leaf tips.

- Indirect manifestation: Na+ in soil and water will make rice roots unable to absorb water, leading to not being able to absorb nitrogen and potassium, so when salt poisoning occurs, rice plants will lack nitrogen and potassium.

During the flowering stage, observing 2 white husks without grains due to lack of pollination is a sign that the rice plant is salt poisoned.

* Prevention of salt poisoning

- Regularly visit the fields and strengthen the dikes to prevent saltwater intrusion. When the tide from the sea is very strong, if the dike is not well maintained, saltwater will intrude, so the dike must be strengthened well. If the fields are left to dry and crack, saltwater will infiltrate through those cracks into the rice fields.

- For shrimp-rice rotation areas, after harvesting rice, prepare to raise shrimp without letting the soil dry and crack too much because then salt water will gradually seep through the cracks and penetrate the topsoil layer.

- Experienced farmers are advised to check the salinity in the soil: dig one or several holes in the rice field before planting. After draining all the water in the field, scoop all the water out of the hole, let the water in the soil seep into the hole and use a salinity meter to determine the salinity. If the salinity is 1 - 2‰, it is not advisable to plant because when the seeds are germinating, the rice sprouts will curl up when exposed to salinity.

- If the soil is saline but not acidic, apply Ca(SO4)2. In the Mekong Delta, salinity is usually accompanied by acidity, so it is best to apply quick lime at a dosage of 30 - 50 kg/1,000 m2. When preparing the soil and applying lime, add water to the field to dissolve the lime and push the salt away, then drain the water, then measure the salinity. If the salinity is below 1‰, it is safe to prepare for sowing.

- Prevention of salt poisoning is carried out right from the beginning of the crop, because the rice seedlings are very sensitive to salinity. During the stage of rice panicle formation and flowering, if the rice is poisoned, it will greatly affect the yield and quality of the rice grain, severe salt poisoning will lead to crop failure. The measure to detoxify salt for rice plants at this stage is to monitor the high tide to bring in fresh water to save the rice plants.

* Experience in monitoring high tides to bring fresh water to detoxify salt for rice plants

In the Mekong Delta, the water in the fields is fresh water. When the tide is low, the water from the fields flows out to the sea as fresh water. When the tide rises, the water from the sea flows into the fields as salt water. Therefore, farmers need to monitor until the tide is low, then scoop up water to measure the salinity. If the salinity is below 1 - 2‰, then pump water into the fields. When the tide rises, measure the salinity again. If the salinity is higher, then stop pumping water into the fields.

Note: Salt water is heavy and located at the lower layer, fresh water is located at the upper layer, so when you scoop water from the upper layer to measure the salinity, and then put the pump deep down to get water, it will pump water that is saltier than the water at the upper layer.

According to Khuyennongvn.gov.vn