In ancient China, rice was cultivated very early on. Over time, with the continuous development of ancient water management, rice cultivation expanded. For instance, during the Eastern Han dynasty in the second century, large-scale irrigation projects were initiated in Shaanxi and Henan, promoting the development of rice cultivation in the Yellow River Basin. By the Northern Song dynasty, rice was predominantly grown south of the Yangtze River. By the time of the Southern Song dynasty, the south had become a major rice-producing region. The names of the rice fields in the Jiangnan region, such as Xutian, Hutian, and Shatian, reflect this heritage.
Some ancient methods involved direct sowing of seeds, while others used seedling cultivation and transplanting. Books from as early as the Eastern Han period mention the practice of cultivating young rice plants. Even today, most rice cultivation involves transplanting seedlings, with only a minority using direct sowing.
Interestingly, why do they wash the mud off the roots of the seedlings before transplanting? When planting flowers, vegetables, or tree saplings, it’s often easier for them to survive if they are transplanted with soil attached. This is because the young plant’s roots remain intact with the soil, allowing them to absorb water and nutrients well after transplanting, preventing the leaves from wilting and dying. However, transplanting rice seedlings is the opposite. When pulling out the seedlings, they even flood the area with extra water, pick out a handful, discard some, and thoroughly wash the roots clean.
Is this practice smart or not? Does it benefit or harm the growth of rice?
After rice seedlings are pulled up, they are carried in bundles to the rice fields for planting. Soil is heavy. If the roots carry a lot of mud, the weight of the seedlings increases, making them heavier to carry. After the rice seedlings are pulled up, they need to be neatly bundled. If the roots carry mud, they take up more space. For example, if one bundle can typically consist of one hundred roots, with mud, you wouldn’t be able to fit as many. Also, suppose one load can carry one hundred bundles, with mud on the roots, you couldn’t carry as many. From this perspective, washing the mud off the roots lightens the weight of the seedlings, reduces the space they occupy, and decreases the workload of transporting them, thus improving the efficiency of transporting the seedlings.
Washing the mud off the roots also prevents the delicate roots from tangling together, making the seedlings easier to bundle and separate. Especially during planting, it allows for quicker, more uniform, and consistent planting depths. This can increase the speed of planting, and the rice seedlings can also grow better.
Moreover, cleaning the mud off the roots has another important reason. As the rice seedlings grow larger and their roots develop, most of the nutrients in the soil around the roots are depleted; additionally, as the roots grow, they may secrete chemicals that are detrimental to their growth. Therefore, washing the roots clean can remove these secreted chemicals and the depleted soil, which benefits the future growth and nutrient absorption of the rice.
Thus, washing the mud off the roots before planting is a wise practice. Especially when using a rice planting machine, it is essential to wash the mud off thoroughly; otherwise, separating the seedlings and inserting them can be hindered.