Current status of agricultural land-use in the study area
The results synthesized from land statistics and consulted agricultural managers of Tan Thanh district showed that the farmland area year 2020 has about 37,494.98 hectares (88.68%). The distribution area of mainly agricultural land use types is shown in Fig 2.
The main distribution areas are double and triple rice production land (Fig 2). For land-use type is fruits growing jackfruit and mixed fruits that combine other fruits were developing in recent years. The high price of jackfruit has changed farmers’ psychology in farm production and affected the district’s general development. The cash crop cultivation area is mainly the lotus, about 296.5 hectares. By 2020, aquaculture land area will still dominate (occupied about 4.48%) (Fig 2). The extent of forest cultivation in the district is mainly Melaleuca forest. Besides, farmers combine fish and honey bee farming to increase their income. Therefore, to develop sustainable agriculture, the community needs a more practical solution in changing the crop structure and concerns attention to critical products suitable for local conditions and meeting market demand.
Soils of the study area
Depending to the
People’s Committee of Tan Thanh district (2020), the total study area is 37,504.9 ha, including major soil groups: Alluvial soil (1,263.82 ha); Alluvial soil with Umbric horizon (6,602 ha) and Deep potential acid soil (15,506.1 ha). Triple rice crops are primarily grown on these soils. While double rice crops predominate on the shallow acid sulfate soils (9,854.77 ha). The Peatland covers an area of 1,797.95 ha and covers primary the Melaleuca forest.
Factors affecting agricultural production in the study area
Determining the factors that affect agricultural production in Tan Thanh district
According to
Minh, et al., (2020), rice is cultivated under irrigation in the Vietnamese Mekong delta. As a result, it is usually rinsed with high productivity, leading to unsustainable water and soil exploitation, inefficient chemical inputs, the menace of disease and insect and pest problems. The results of consultation with experts and farmers directly engaged in agricultural production have identified primary factors affecting the farmer’s output shown in Table 1.
Impact factors that affect agricultural production in the study area
The level 1 assessment, which includes physical, economic, social and environmental factors that affected the farmland use process, showed that economic factors influence (W=0.3263). While Fig 3 shows that social factors impact production in the district with an impact weight of W=0.2853.
Although it affects agricultural land use in the district, the level of impact is not much (Weight W=0.2059). Experts considered the environmental factor to have little effect on farmers’ agricultural land use process in the Tan Thanh district (Fig 3). Experts believe the consumption market factor is the most influential in agricultural cultivation (Fig 4a). When there is a stable consumption market, farmers will feel secure in production and create motivation for farming development
(Phan et al., 2020). Profit is also a factor that receives much attention because farmers choose agricultural land use types, most of which only look at the initial profit, thereby leading to spontaneity in farming, breaking the general orientation planning of the district
(Phan et al., 2017; Rajendra et al., 2019; Le et al., 2019). Besides, the financial resource factor of the household also has a relatively high weight (W=0.2178) because farmers must have enough investment capital for the land use type when converting and replacing other land-use types. The agents of fertilizers and pesticides will charge an additional interest rate to increase the production cost of the farmers
(Nguyen et al., 2013; Nguyen, 2014).
Social factors
The results show that the government organization factor is believed to have the most impact on agricultural production (Fig 4b). Choosing the spontaneous land-use type is critical, especially when the planning is unsuitable or does not bring economic efficiency. It is difficult for the farmer to accept such planning
(Pham et al., 2013). In the current agricultural production, although it has been mechanized in agricultural output, the current agricultural labor source faces many difficulties. When farmers sow many seeds using fertilizers and pesticides according to their production habits, profits are reduced
(Nguyen and Hoang, 2012).
Physical factors
The results show that the weather factor significantly influences the agricultural production process of the farmer (Fig 4c). Since this is a decisive factor in crop yield and quality. Rain causes the clay to swell, water in the soil does not drain quickly, it becomes soggy, roots work poorly, fungal diseases develop and seeds get sicker
(Nguyen, 2019). Accordingly, rice yield will reach the highest value if water is provided appropriately and vice versa
(Vo et al., 2019). In addition, a lot of flooding will make the soil anaerobic, lack oxygen for root respiration and directly affect plants
(Hoang et al., 2006). However, according to
Tran et al., (2017), the Tan Thanh district belongs to the potential acid sulfate soils area. Therefore, the impacts do not have much effect on the farming efficiency of the farmers.
Environmental factors
Soil quality factors (nutrients, pollution) significantly affect agricultural production in the district (Fig 4d). In addition, intensive farming, increasing the crop has made the soil not have time to rest as well as the nutrients in the soil are increasingly depleted, especially not to release floods in the rainy season, which affects the nutrients in the soil increasingly consumed
(Nguyen et al., 2018). However, farming in the dike area for a long time has made the soil lose essential nutrients, leading to a decrease in crop yield and, at the same time, increasing production costs due to the continuous increase of fertilizer
(Duong et al., 2017). Furthermore, under rain and leaching, pesticides in the soil will accumulate and settle in the bottom mud layer in rivers, ponds and lakes, which have polluted water sources
(Vietnam environment administration, 2015). This accumulation can be so high that it is toxic to the soil, water, air and human health
(Nguyen et al., 2018).
In general, agricultural production in the study area is heavily influenced by the consumer market, the local government organizing agricultural production, profit of land use types and soil quality (Fig 5). The factors of flooding depth, acid soil, irrigation capacity, drought time and agricultural diseases have little impact. Therefore, farmers will have more capital to invest if the profit is higher and the land use type has good efficiency.
The recommendation for agricultural production
The study develops the strategies for sustainable agriculture, using land resources rationally, following natural conditions and helping people in Tan Thanh district adapt and respond to climate change conditions in the future. In addition to the agricultural recommendations in Table 2, acid sulfate soils are frequently deficient in phosphorus and hazardous for iron, aluminum, or manganese. The soil’s physical characteristics are inferior. The depth range for jarosite mottles is 2 to 50 cm or more. Draining this soil is not advised. pH significantly drops after draining. For crop production, high liming rates (> 10t/ha per 3-4 years) or long-term leaching would be necessary
(Breeman and Pons, 1978). Shallow drainage is the most profitable method for raising medium-term rice crops
(Xuan et al., 1982).
The management needs should be based on field observations and numerous experiments on soil management, reclamation, fertility adaptation, rice varieties,
etc., conducted in the Mekong delta.
