What to Do About Stunted Rice Seedlings? Causes and Solutions
Stunted rice seedlings, also called "zuodou" (sitting stumps), is a fairly common phenomenon during the growth of rice seedlings. It shows up as slow or halted growth of rice seedlings after transplanting, seriously affecting rice yield and quality and causing serious economic losses for farmers. So what causes stunted rice seedlings? How should they be dealt with? Come take a look at the detailed introduction from Qinnongwang.
1. Groundwater level too high
During the growth of rice seedlings, if transplanting is too deep and the rice seedlings are submerged in deep water for a long time, or if drainage is poor, the soil will become oxygen-deficient. This enhances reducing conditions, and the base fertilizer applied will decompose under such conditions, releasing large amounts of hydrogen sulfide substances, causing poisoning of the rice seedling root system and resulting in stunted seedlings.
Solution: Drain in time to remove toxins, dig ditches to drain water, lower the groundwater level, and remove the toxic substances.
2. Excessive application of green manure
If too much green manure is turned under, or it is turned under too late, the decomposition process of the green manure will also produce large amounts of reducing substances, such as hydrogen sulfide and acetic acid. These substances can also poison the rice seedling root system and trigger stunted seedling symptoms.
Solution: Green manure is generally turned under about half a month before sowing, which can avoid overlap between the green manure decomposition period and the period when rice seedlings take root and grow. At the same time, the application rate of green manure must also be controlled. Generally, green manure application should be within 1500 kg per mu. Too large an application rate will release large amounts of toxic substances during decomposition and have the opposite effect.
3. Heavy clay soil
Before planting rice, plots with loose and fertile soil should be selected. If planted in plots with heavy soil clay content, the soil particles are fine and dense, and after irrigation the permeability is extremely poor, which can also lead to soil oxygen deficiency or accumulation of toxic substances and trigger stunted seedling symptoms.
Solution: Before planting, choose plots with coarser soil clods and loose soil for planting. Before planting, plow the soil deeply, strengthen management, and do not transplant too deeply. Once stunted seedlings caused by soil problems are found, drain water in time, loosen the soil, increase permeability, and then let water back in.
4. Lack of trace elements
Stunted rice seedlings can also be caused by a lack of certain trace elements. For example, zinc deficiency, potassium deficiency, and phosphorus deficiency can all cause stunted seedlings.
Solution: To determine whether stunted seedlings are caused by a lack of a certain trace element, only then can the right remedy be applied and the corresponding fertilizer increased. When rice is deficient in zinc, it shows as dry, withered leaf tips, new leaves that are short and narrow, slow growth, no tillering or very little tillering, and dwarfed, shrunken plants. Potassium deficiency shows as stagnant growth, dark green leaf color but few tillers, yellow-brown or reddish-brown spots on the leaves that eventually form streaks, and in severe cases leaf death. Phosphorus deficiency shows as dark green new leaves, purple-red lower parts of the leaves, and part of the root system turning brown. As long as the corresponding characteristics are used to identify the problem, the right remedy can be applied. During the growth stage of rice seedlings, attention must be paid to the supply of nitrogen fertilizer to prevent premature aging.
The above are the causes and solutions for stunted rice seedlings brought to you by Qinnongwang. That is all for the content on stunted rice seedlings. To learn more about rice, please stay tuned to Qinnongwang.