Testing asparagus on sandy soil

From shallots to asparagus

After years of relying on shallots, chili peppers, and other vegetable crops with unstable incomes, several members of the Vinh Chau Shallot Cooperative in Vinh Hai Commune, Can Tho City, have begun shifting to asparagus cultivation on coastal sandy soils. Although the crop is only in its first harvest season, the model has shown promising results, with produce secured through contract farming and providing growers with an almost daily source of income.

These days, the first asparagus shoots are being harvested from Thach Vuong's 5,000-square-meter farm in Huynh Ky Hamlet, Vinh Hai Commune, about six months after planting.

According to Vuong, shallots take more than three months to reach harvest, while asparagus provides an almost daily income once production begins, making household finances much easier to manage.

His asparagus field currently yields around 10-15 kg/1,000m2/day. At a farm-gate purchase price of VND 50,000/kg, the farm generates a daily profit of approximately VND 1.25-1.88 million after production costs.

Vuong is not alone in making the transition. Ly Hoang, who has cultivated shallots for many years, is also converting more than 2,000m2 of land to asparagus. He explained that shallot production is highly dependent on weather conditions, with prolonged rainfall posing a significant risk of crop losses. In contrast, asparagus offers a stable market, while the cooperative provides seedlings, production inputs, and technical support, allowing farmers to focus on cultivation and significantly reducing production risks.

According to Thach Dil, Director of the Vinh Chau Shallot Cooperative, the initial investment required to grow asparagus is approximately VND 40 million per 1,000 m2. This represents a considerable financial burden for many households in the coastal sandy region, where economic conditions remain challenging.

To ease that burden, the cooperative provides seedlings, fertilizers, and other production inputs upfront, allowing farmers to repay the costs gradually after selling their harvest. This support has encouraged many households to adopt the new crop without facing significant upfront capital constraints.

The cooperative is currently partnering with Linh Dan Ninh Thuan Co., Ltd. in Khanh Hoa Province, a company with extensive experience in developing asparagus-growing areas and exporting green asparagus, to purchase all of the cooperative's output at a fixed price of VND 50,000/kg.

As the cultivation area expands and production increases, the asparagus will be graded by quality, with purchase prices expected to range from VND 45,000 to VND 65,000/kg, depending on product grade.

Sandy coastal soils offer a competitive advantage

Thach Dil added that before introducing asparagus to Vinh Hai's sandy coastal area, the cooperative spent nearly two years testing the crop under different soil conditions, including loamy soils, sandy loam, and coastal sandy soils.

The trials showed that asparagus can grow well on various soil types, but the sandy coastal ridges in Vinh Hai produced the best results thanks to their well-drained, elevated terrain.

"The plants grow vigorously, producing thick, attractive spears with average yields of around 12-15 kg/1,000m2/day, outperforming all of our previous trial sites. At this level of productivity, farmers can achieve profit margins of about 50% after production costs," Dil said.

According to Dang Hiep Phu, a technical officer at the Vinh Chau Shallot Cooperative, monitoring of the pilot models showed that asparagus grown on sandy soils produces thicker stalks, straighter spears, a more vibrant green color, and a higher proportion of export-grade produce than crops grown in other trial areas. These characteristics are key to meeting exporters' quality requirements.

Based on these encouraging results, the cooperative has selected Vinh Hai as its core asparagus production area. Under its development plan, the cooperative aims to establish approximately 100ha of asparagus, including around 50ha in Vinh Hai Commune, to meet growing demand from its business partner.

One planting, years of harvest

Compared with many vegetable crops, asparagus cultivation is relatively straightforward but requires consistent care throughout the production cycle. Proper land preparation is essential from the outset. Planting beds are approximately 1.2m wide and 30cm high, with 20-cm drainage furrows between rows to improve water runoff. Plants are spaced about 45cm apart.

The cooperative is responsible for raising seedlings for around three months before supplying them to farmers for field planting. Once transplanted, growers install support wires or netting to keep the plants upright and prevent lodging caused by strong coastal winds. This is a critical step to ensure that the asparagus spears grow straight, thereby increasing their commercial value.

According to local growers, asparagus cultivation mainly involves pruning old stems, weeding, fertilizing, and adjusting the support wires as the plants grow. The production model prioritizes the use of organic fertilizers and biological crop protection products to develop a growing area that meets both domestic and export market standards.

Unlike many vegetables that are cultivated on a seasonal basis, asparagus begins producing harvestable spears about six months after planting and can remain productive for seven to eight years before replanting is required. Each harvesting cycle lasts two to three months, followed by about one month of plant recovery before the next production cycle begins. As a result, most investment costs are incurred in the first year, while subsequent years require mainly expenditures on fertilizers, crop protection, and field management, leading to progressively higher economic returns.

During cultivation, farmers must regularly monitor for pests such as thrips, stink bugs, leafhoppers, and common cutworms, while maintaining good field ventilation to minimize pest and disease pressure.

To meet export requirements, the company tests every batch of harvested asparagus for pesticide residues before it enters the supply chain. Only produce that complies with the required standards is approved for export to markets such as Taiwan and Japan.

Initial results indicate that asparagus is well suited to the sandy coastal soils and has strong potential for expansion as a high-value crop. Through close collaboration covering seedling supply, technical assistance, and guaranteed purchasing, Vinh Hai Commune is gradually developing a large-scale asparagus production area, providing farmers with a more stable source of income amid continued price volatility affecting many traditional crops.

$ 1 = VND 26,480 - Source: Vietcombank.