What are the precautions for acidifying rice seedling beds?
Adjust the nutrient soil to about pH 5. Adjust the acidification of the seedbed (use 500ml of concentrated sulfuric acid per 100 sq m, dilute it and pour evenly). Acidification during the seedling stage (after the one-leaf-one-heart stage, depending on the seedbed soil conditions, spray diluted acidified water at about 3000 times dilution in several applications, and be careful to wash the seedlings)
Rice seedlings are suitable for growing under slightly acidic conditions with a soil pH of 4.5 to 5.5. If the pH is too low or too high, it is not conducive to seedling growth. Acidification brings the main indicators such as the rice root system and stem width to an ideal state, not only promoting strong seedlings, but also having the effect of suppressing damping-off during the seedling stage.
Where salinity and alkalinity are severe, it is recommended to acidify in three aspects to adjust the entire seedling growth period environment to the most suitable degree:
First, adjust the nutrient soil to about pH 5;
Second, adjust the acidification of the seedbed (use 500ml of concentrated sulfuric acid per 100 sq m, dilute it and pour evenly);
Third, acidification during the seedling stage (after the one-leaf-one-heart stage, depending on the seedbed soil conditions, spray diluted acidified water at about 3000 times dilution in several applications, and be careful to wash the seedlings).
Method:
(1) Pour 3 kg of 98% concentrated sulfuric acid per 100 sq m (1 hectare of paddy field) into 300 kg of water, and one day before placing the trays and sowing, spray the prepared 1% concentration sulfuric acid water onto the 100 sq m seedling bed. Make the pH value of the seedbed soil reach between 4.5 and 5.5.
(2) Pour 9 kg of 98% concentrated sulfuric acid per 100 sq m (1 hectare of paddy field) into 30 kg of water to prepare about 25% acidified water, divide it and pour it onto 500 kg of already sieved seedbed soil, let it sit for 24 hours, mix thoroughly 6 to 8 times to make a small sample of acidified soil, then mix evenly with 1500 kg of sieved soil, pile it up, cover it tightly, and set aside for later use.