The transition from sowing dry rice seeds to transplanting seedlings, from relying on rain to actively managing irrigation, can be seen as the first form of “civilization” in the culture of rice cultivation.
A unique cultivation system in the Mekong Delta
The culture of rice cultivation and rice consumption has existed for thousands of years across Asia. Therefore, it is understandable that the first settlers who came to reclaim the Mekong Delta (ĐBSCL) brought with them this agricultural tradition. However, in just over three centuries, numerous rice-growing techniques have emerged that can only be found in this region — a testament to the creativity and adaptation of early pioneers to its unique environmental conditions.
In upland areas where farmers rely entirely on rainfall, they traditionally sowed dry rice seeds. After clearing and burning the land, farmers planted the dry seeds into holes and covered them with ash or soft soil. When the rains arrived, the seeds absorbed moisture, germinated, and grew. This form of cultivation, entirely dependent on rainfall, is known as “upland rice farming.”
In regions with surface water flow, people built terraced fields in the highlands and embanked paddies in the lowlands. Seedlings were first sown in nursery plots, then transplanted into plowed and moistened fields — this is known as “wet rice cultivation.”
Upland rice farming depends solely on rainfall, which means a good harvest in years of favorable weather but total loss in years of drought. Wet rice cultivation, on the other hand, allows partial control of irrigation, ensuring consistently higher yields.
Thus, the shift from dry seeding to transplanting, and from dependence on natural rainfall to proactive water management, represents the first major “civilization” in rice culture.
The Mekong Delta is a region of extraordinary environmental diversity — sometimes parched dry, sometimes flooded under 4–5 meters of water; at times with muddy, nutrient-rich freshwater, at others with clear but acidic or saline water. The soil, too, varies widely: loose and fertile in some places, dense with organic matter or hardened clay in others. This diversity has driven farmers to continuously innovate, resulting in what can rightly be called a “civilization of rice cultivation.”
In the past, upland rice fields were small and suited to family labor. Today, with fields spanning tens of hectares, hand-sowing is no longer practical — giving birth to the “dry broadcasting” (sạ khô) method.
In this technique, fields are plowed and left to dry before the rainy season. When rain approaches, dry seeds are broadcast and lightly harrowed to cover them, preventing bird and rodent damage. Early rains moisten the soil, prompting seeds to germinate and grow. When floods arrive, the young rice has already grown tall enough to adapt.
Dry broadcasting is particularly common in saline areas, where early-season water is too salty for plowing. By the time seedlings establish, later rains dilute the salinity, allowing farmers to pump freshwater into their fields.
This method is also used in deeply flooded areas, where farmers grow floating rice — varieties that can elongate by 20 centimeters a day. The dry seeds, once sown, germinate with the first rains, taking root deeply before the floodwaters rise. As the waters swell, the rice grows upward, keeping pace. When the flood recedes, the long stems lie flat, sprouting new shoots that eventually bear grain.
In areas with controlled irrigation, farmers use the wet broadcasting method (sạ ướt), scattering pre-germinated seeds onto muddy, drained fields. Within a week, the fields turn green, and water levels can then be managed until harvest.
In regions where the floodwaters arrive early, leaving insufficient time for two full rice crops, farmers developed the submerged broadcasting (sạ ngầm) technique. Here, seeds are pre-germinated and mixed with phosphate fertilizer to deter aquatic pests, then sown directly into shallow water. The seeds germinate underwater and gradually rise as the stems elongate, later maturing when the water subsides.
When floods or saltwater intrusion come even earlier, farmers adopt stubble broadcasting (sạ chai) or relay broadcasting (sạ gác). In sạ chai, straw from the first harvest is spread and lightly burned to sterilize the field before sowing dry seeds directly, followed by shallow flooding. This shortens land preparation time by about two weeks.
If the land cannot dry for burning, sạ gác is used — dry seeds are sown among ripening rice plants of the first crop. By the time the first crop is harvested, the next crop has already begun to sprout. This method requires careful variety selection to ensure synchronized growth and ripening.
For areas where water levels rise rapidly, even standard transplanting fails. Farmers there use double transplanting (cấy hai lần): first transplanting seedlings into shallow beds (the “nursing” phase), then replanting the stronger, elongated seedlings into deep water fields. This helps the plants withstand water depths of up to a meter.
Among Asian rice-growing countries, dry broadcasting, wet broadcasting, and transplanting are common. However, double transplanting occurs only in the Mekong Delta and India — while submerged, stubble, and relay broadcasting techniques are unique to the Mekong Delta.
Land and water as the core of rice civilization
It can be said that the Mekong Delta has contributed more rice-growing innovations than any other place in the world. This reflects the ancient philosophy of “taking land and water conditions as the foundation” — selecting varieties and techniques suited to the environment, along with appropriate farming tools to improve efficiency.
In just 300 years, the Delta’s farmers have developed over 3,000 seasonal rice varieties, hundreds of cultivation techniques, and thousands of tools adapted to various soils and water conditions.
Unfortunately, in recent decades, society has overlooked this rich rice civilization, focusing narrowly on annual yield targets while disrupting the delicate land–water balance that ancestors carefully preserved.
Fortunately, Resolution 120 (NQ120) was introduced — a wake-up call that Vietnam has reached the environmental limits of the Mekong Delta’s agricultural system. The resolution places the “nature-based” (thuận thiên) approach at the heart of agricultural restructuring.
In essence, thuận thiên means harmonizing with local land and water conditions when selecting crops, livestock, and farming methods — echoing the wisdom of ancient farmers.
The culture of rice cultivation and consumption in Vietnam and across Asia will endure for centuries. Yet as natural environments rapidly change — including soil and water — so too must cultivation methods evolve. Still, any new technique, no matter how modern, must be rooted in an understanding of local conditions and the inherited wisdom of our ancestors. Otherwise, it cannot truly be called civilized.