Little water and salty soil
The Po Valley is one of the most important agricultural areas in Italy. But the Po currently lacks water. The fields have dried up. The region must expect regular water shortages in the future. In addition, the soil is becoming more and more salty. A glimmer of hope comes from Southeast Asia, where salt-resistant rice varieties are braving the saline soils.
Thursday, July 28, 2022
The cultivated fields of the Po Valley currently resemble deserts. The plants, which should actually glow lush green in summer, are yellow or brown. There has been no precipitation here since the beginning of last winter. The soil has completely dried up. The “10vor10” program on “Swiss Radio and Television” reports on the precarious situation of Italian farmers in the region. Less water is currently flowing through the Po than ever before in the past 70 years. In ordinary times, the river guarantees the region's water supply and allows corn, rice and grain to be cultivated. Harvest losses of 50 percent are now expected. 25,000 hectares of land can no longer be irrigated. The water level of the river is currently so low that seawater flows inland from the Po Delta and salts the fertile soil.
Seawater is salting the soil
The seawater reaches up to 30 kilometers inland. The irrigation canals, although filled with water, are unusable. The water has a salt content of 4 grams per liter. That is far too high to be used to irrigate the fields. The water should contain a maximum of one gram of salt per liter to be used for agricultural production. With the lack of rainfall and fresh water that usually flows down the Po, the salt coming from the sea is moving further and further inland in the soil. As a result, more and more farmland is increasingly saline and unusable for agricultural.
Salt disrupts plant growth
Not only in the Po Valley, but all over the world, farmers are struggling with salty soil. For example, southern India, Bangladesh and the Mekong Delta in Vietnam are regularly flooded with seawater. This causes major problems when growing rice, as the soil contains too much salt. Excessive salt content causes stress in plants. The uptake of nutrients and water is disturbed, which has a negative effect on growth. Large areas of the coastal regions of Bangladesh are affected by saline soil. One major problem is that the types of rice that are usually grown there are very sensitive to salt.
Searching for salt-tolerant plants
However, in 2006, the Bangladesh Rice Research Institute, in collaboration with the International Rice Research Institute, managed to breed a successful salt-resistant rice variety. Compared to conventional varieties, it can withstand significantly higher salt levels. In the meantime, many more varieties have been developed that make rice cultivation possible again in the south of the country. The example demonstrates the great benefit of research with regard to the breeding of plants with stress-resistant properties. This applies to traditional breeding as well as classic genetic engineering and new breeding technologies such as CRISPR/Cas. It is hoped that farmers in the Po Valley will also be able to benefit from new salt-resistant varieties in the future.
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