Select a good seed fertilizer for autumn sowing

Seed fertilizer is used for sowing, soaking or transplanting, locally applied to seeds or seedlings near the fertilizer. It can supplement the deficiency of base fertilizer and provide nutrition in the early stage of crop growth, which is beneficial to the cultivation of strong seedlings. However, some chemical fertilizers are toxic to seeds and seedlings, so attention should be paid to the selection and taboo of seed fertilizers.

1. Chemical fertilizer suitable for use as fertilizer

Generally, quick-acting chemical fertilizers or fully mature farm manure are used as seed fertilizers, and there are several kinds of fertilizers that can be used as seed fertilizers:

1. Ammonium sulfate. Referred to as ammonium sulfate, when making seed fertilizer, you should avoid contact with seeds, and ensure that seeds and ammonium sulfate are in a dry state when applied, with a dosage of 2.5 kg per mu, and sowing with mixing, not for a long time.

two。 calcium superphosphate. Referred to as common calcium, making seed fertilizer can reduce the fixation of phosphorus in soil and help seedlings absorb phosphorus. When using, first crush and sift, contact with the seeds and burn the seedlings. Because common calcium contains more than 5% free sulfuric acid and phosphoric acid, it is harmful to seed germination and seedling growth, so it is best to mix it with farm manure to avoid toxicity. The appropriate dosage is 5 to 10 kilograms.

3. Heavy superphosphate. Referred to as heavy calcium, when used as seed fertilizer, it is appropriate to use 2.5 kilograms per mu. Because heavy calcium does not contain calcium sulfate, the application effect of heavy calcium on sulfur-loving crops is not as good as that of common calcium. In addition, the effect of application in alkaline soil is not as good as that of calcium.

Second, chemical fertilizer which is not suitable for growing fertilizer.

1. There are volatile corrosive fertilizers. Ammonia, ammonium bicarbonate, etc., have strong volatility and are easy to damage seeds or seedlings. To make a kind of fertilizer, ammonium bicarbonate and ammonia can be applied to cover the soil under the sowing ditch to avoid toxicity.

two。 Chemical fertilizer that has a direct toxic effect on seeds. Urea in the production process, often produce a small amount of biuret, when its content is more than 20%, it will be toxic to seeds and seedlings. In addition, urea molecules with high nitrogen content will also infiltrate into the protein molecular structure of seeds and seedlings, causing protein denaturation and affecting seed germination, so urea can not be used as seed fertilizer.

3. Strongly alkaline fertilizer. Strong alkaline fertilizers such as steel slag phosphate fertilizer and kiln ash potash fertilizer are easy to burn seedlings, so it is not suitable to be used as fertilizer. Such as kiln ash potash fertilizer, contains more calcium, strong hygroscopicity, after water absorption into mature lime, give off a lot of heat, easy to burn seeds and young roots. When making seed fertilizer, it is necessary to mix an appropriate amount of chemical fertilizer and organic fertilizer into the sowing ditch and hole, and then sow and cover the soil to prevent fertilizer damage.

4. Fertilizer containing harmful ions. Chemical fertilizers such as ammonium chloride and potassium chloride contain a large number of harmful chloride ions, which produce water-soluble nitrides after being applied to the soil and burn seeds and seedlings. Some of the compound fertilizers are produced with ammonium chloride and potassium chloride as raw materials. When choosing compound fertilizer as seed fertilizer, it is not suitable to choose compound fertilizer containing chloride ion.

Jia Youjiang, Agricultural Bureau of Juancheng County, Shandong Province