Quynh Luu: Applying technology to clean salt production

(Baonghean) - With the goal of planning and developing the salt industry, applying technical advances to the production process to improve product quality for salt farmers, in 2013, from the funding source of the National Agricultural Extension Center, Nghe An Agricultural Extension Center built a model of "Cooperative group and application of technical advances in clean salt production" in Quynh Thuan commune.

Before implementation, the Agricultural Extension Center organized many training sessions for salt farmers and established a cooperative with 25 participating households, building a clean salt production model with an area of ​​500m2 of salt crystallization yard; 50 filter trays; 50 settling tanks, 25 masonry cells covered with 500m2 of 0.5mm thick HDPE tarpaulin. The goal of the model is to support salt farmers in changing their production methods from individual to group and cooperative association; upgrading the infrastructure of the salt area according to modern methods, thereby helping to improve output and product quality.

According to the traditional salt production method, the old-style salt fields often arrange the filter cells far from the drying fields, so transporting sand from the filter position to the drying field is the most difficult step. Every time people dry sand, they often have to use wheelbarrows to push the sand. Because of the hardships and difficulties of salt making, salt farmers have come up with the saying: "From the grandfather's generation to the father's generation, there is a pile of sand being transported in and out". The agricultural extension model has redesigned the fields for people by placing the filter cells in the middle of the sand drying field combined with using plastic pipes to carry the concentrated brine from the filter position to the settling tank close to the crystallization cell to dry the salt. With this scientific and convenient design, it not only helps salt farmers reduce labor but also brings a lot of value in terms of output. Mr. Tran Ngoc Binh - Vice Chairman of Quynh Thuan Commune People's Committee excitedly said: "When guiding salt farmers to use salt fields designed according to the agricultural extension model, there are many benefits. People only need to stand in one place to throw sand and when collecting sand to filter, it also saves a lot of effort. In addition, not having to use wheelbarrows has overcome the phenomenon of hardening of the field surface, thanks to which the rate of salt crystallization is much higher than before."

This is the first time Quynh Thuan salt farmers have been acquainted with and used HDPE-covered crystallization cells. Initially, many salt farmers were quite cautious with this new technology. However, after being trained in the technique and especially when put into practical use, HDPE-covered crystallization cells have shown many advantages over traditional cement-based cells: shortening the production cycle due to rapid water evaporation, bright white salt grains without impurities, and receiving high support from salt farmers. Mr. Nguyen Dinh Nguyen - a salt worker who has been involved in the salt industry for 40 years in Hoa Thuan village shared: "According to the traditional production method, on a sunny day, only 2 buckets of water can be poured, the crystallization process usually lasts 12 hours, so when the salt is harvested, it will be around 5-6 pm, this is the time when there are often thunderstorms, so it is extremely difficult and arduous. Now, production on the tarpaulin-covered crystallization plot has been poured 3 buckets of water, the salt crystallization time has also been shortened by 2-3 hours. In particular, through our monitoring and evaluation, the salt grains produced on the tarpaulin-covered crystallization plot are large and white, without impurities, ensuring food hygiene and safety much better than before."

Salt farmers of Thang Loi Cooperative - An Hoa commune (Quynh Luu) improved the salt drying yard.

An Hoa is one of the two largest salt granaries in Quynh Luu district with an area of ​​over 140 hectares. The commune's annual salt output reaches 18,500-19,500 tons with a total value of over 20 billion VND. The whole commune has 14 villages, of which 7 have over 1,200 households specializing in salt production, and 3 salt production cooperatives have been formed: Tan Thinh, Tan An and Thang Loi. To continue promoting the strengths of local economic development, in 2013, An Hoa commune organized for salt farmers to visit the salt production model spread on canvas on the bottom of crystallization ponds in Dien Van commune (Dien Chau). After learning from this model, the commune conducted a trial on an area of ​​3,000m2 in 3 villages Tan An, Tan Thinh, Tan Thang with support of 50,000 VND/m2 of canvas and tape from the province and district. Immediately after applying this model, the efficiency was higher than the old production method. Mr. Hoang Van Man's household (Nam Tien village), Mr. Bui Xuan Dien (Tan Thang village), Mrs. Ho Thi Thung (Tan Thang village)... are exemplary households leading the way in applying the model. They said that the productivity of the new production model is 30% higher than the normal plot, the salt is cleaner and whiter, the price is 2-3 prices higher than before. Meanwhile, the production work is easier, even though there is little sunshine, there is still salt to harvest, so the salt farmers participating in the model are very excited.

Currently, along with focusing on promoting the rapid increase of salt production area according to the new process, An Hoa also invests in upgrading, expanding the area, building salt field infrastructure such as building water supply and drainage channels, improving drying cells... In addition, the locality also supports salt farmers in building improved filters, replacing sand in canals to increase productivity and reduce labor for salt farmers. According to Mr. Hoang Van Hai - Head of the Agricultural Extension Board of An Hoa commune: "The clean salt production model still ensures the same processes as traditional salt production, but when drying water instead of drying directly on the masonry cells as before, it will now be dried on canvas. This is a 0.5 mm thick HDPE canvas with high durability, resistant to hot weather, good solar heat absorption capacity to help the process of water evaporation quickly. HDPE canvas is spread on the leveled and well-compacted masonry cell floor. The canvas area is cut larger than the masonry cell to cover the edge so that the salt water does not flow down the cell.

Then use 10cm long bamboo nails to pin around the masonry cell, every 30 - 40cm pin 1 bamboo nail, around the cell build a border to separate the cells from each other, each crystallization cell uses PVC pipe with grooves on the body of the pipe about 15 - 20cm to let the air out. Use glue to stick the edge of the canvas (before sticking the edge, the canvas surface must be flattened, squeeze out all the air so that when spreading the canvas and drying the canvas will not swell)... With the method of drying on the canvas, these impurities will be limited, so the salt will be cleaner. The clean salt production model also uses technology to change the traditional filtering position from next to the previous crystallization cell to the middle of the sand drying field, creating favorable conditions for the operations of putting in salty sand and taking out light sand. Therefore, labor costs are reduced, the sand is evenly distributed on all sides, so salty sand with a higher concentration of brine is obtained. The most important thing is that the quality of the salt grains is larger and whiter than that of conventional production, resulting in higher productivity and ensuring the purity of the salt. Currently, the salt production model using the method of drying on canvas is receiving great support from the people and local authorities.

Through the implementation of the model "Cooperative group and application of technical advances in clean salt production", it shows that salt productivity reaches 120-150 tons/ha, the amount of salt dried on the tarpaulin yard increases by 130-150% compared to the old yard, especially reducing a lot of work and labor, when moving the filter position to the middle of the drying yard, there is no need to use a wheelbarrow to carry sand, reducing labor intensity by 45-50%; the sand drying yard floor has high porosity, increasing water capillaries, high evaporation rate so the salinity of the filtered water is higher, the bamboo filter system has been replaced by plastic pipes so it is more hygienic, the filtered water is clear so the salt is whiter and cleaner. And at the meeting to summarize and evaluate the results, discuss measures to replicate the model of the Provincial Agricultural Extension Center, delegates and salt farmers all highly appreciated the results of the model, not only bringing higher economic value but also contributing to protecting traditional salt fields, providing clean salt products that ensure quality and safety for consumers. In addition, the implemented model is also the basis to help people raise awareness in converting production practices from individuals to cooperative groups of households, supporting each other to develop together in production, contributing to increasing income, creating clean products to serve the increasing market demand.

With an area of ​​over 600 hectares, Quynh Luu produces about 65,000 tons of salt each year; the value reaches over 110 billion VND. Because the quality standards have not been announced and there is no brand, the products often sell very slowly at low prices, while the supply of clean salt in the market is still not enough to meet the demand. The successful construction of a clean salt production model here not only transfers scientific and technical advances to production but also motivates the government and salt farmers to have more directions for development in the coming time.

Ngoc Anh