Rice seedlings often rot in the seedling fields. Why does this happen?
There are many reasons for seedling rot, and the conditions vary. For example, some die from freezing, some from starvation, some from drowning, some from suffocation, some from burning, and some from disease.
If, after sowing, the weather fluctuates between cold and hot and suddenly there is an invasion of cold waves or frost, the young sprouts cannot withstand it and often freeze to death.
Sometimes, when rice seeds are submerged in deep water, they struggle to root in the soil and lack sunlight. Over time, if the nutrients in the seeds are depleted, they will starve to death.
If the seedling field is not leveled properly, water accumulates in the low areas, causing the seedlings to drown easily.
If sowing is done early and is followed by cold, rainy weather, deep water is often used in the seedling field to protect the newly sown seeds. However, the seeds or sprouts may suffocate due to prolonged submersion in deep water lacking oxygen. Also, if the mud in the seedbed is too soft, the seeds may get buried too deep in the mud and suffocate.
If the manure and compost applied to the seedling field are not fully decomposed, they continue to ferment in the field, releasing harmful gases like methane and hydrogen sulfide, which blacken the young roots and poison them, causing them to burn.
If the rice seeds carry pathogens, diseases like rice blast, sesame leaf spot, and bad seedling disease often occur in the seedling field. Sometimes, pathogens in the water or soil can infect the rice seeds, causing the sprouts to die from disease.
Additionally, the growth of algae in the seedling field can also cause seedling rot.
Although there are many causes of seedling rot, this issue is not unpreventable. With careful management of the seedling field, identifying the causes of rot, understanding its patterns, and taking appropriate measures, healthy rice seedlings can be cultivated.
Moreover, if the seedbed is made into smooth, leveled ridges, with seeds sown on top and covered with a layer of cultivating soil, and if there are ditches alongside for irrigation and drainage—where water is present in the ditches but does not soak the ridge surfaces—it prevents both drying and over-wetting. This type of seedling field, called a semi-dry seedling field, is ideal and can essentially prevent seedling rot.