What is the best time for topdressing crops?
When is the best time to topdress crops? Please give guidance. For topdressing crops, you can refer to the following list: 1. Corn. For corn, the period from after jointing to the large trumpet stage is the peak period of nutrient uptake. Generally, the first fertilization can be applied around jointing, with 150 kg of ammonium nitrate or 120 kg of urea per hectare; at tasseling...
When is the best time to topdress crops? Please give guidance.
For topdressing crops, you can refer to the following list:
1. Corn. For corn, the period from after jointing to the large trumpet stage is the peak period of nutrient uptake. Generally, the first fertilization can be applied around jointing, with 150 kg of ammonium nitrate or 120 kg of urea per hectare; 7 to 10 days before tasseling, a second fertilization should be applied, with another 225 kg of ammonium nitrate or 180 kg of urea per hectare. If the base fertilizer and seed fertilizer are relatively sufficient and the soil is also very fertile, a single concentrated topdressing can be applied, with deep fertilization combined with the second hoeing and ridging. Three days before tasseling, spraying corn Zhuangfengling on the leaves will achieve a higher yield.
2. Sorghum. In order to meet the nutrient needs of sorghum from jointing to heading, the first fertilization should be applied at jointing, with 150 to 225 kg of ammonium nitrate or 120 to 180 kg of urea per hectare; a second fertilization should be applied at the booting and flag-leaf stage, with 120 kg of ammonium nitrate or 75 kg of urea per hectare.
3. Rice. The uptake of nitrogen fertilizer by rice gradually increases starting from the regreening stage, and reaches its peak at the full tillering stage. In order to promote early tillering and early tiller development in rice, tillering fertilizer should be applied early and heavily. Generally, 7 to 10 days after transplanting, 225 kg of ammonium sulfate can be applied per hectare, and at heading, another 100 kg of urea can be applied.
4. Wheat. Wheat should be topdressed at the three-leaf stage, generally with 195 to 270 kg of ammonium nitrate or 135 to 180 kg of urea per hectare. In the later stage of wheat, because the ability of the root system to absorb nutrients from the soil weakens, a foliar topdressing should be carried out at the heading and flowering stage. Per hectare, 2250 g of potassium dihydrogen phosphate and 22.5 ml of triacontanol stock solution can be mixed with 300 kg of water to prepare a mixed solution for spraying, or per hectare, 3000 g of potassium dihydrogen phosphate plus 15 kg of urea can be mixed with 450 kg of water for spraying.
5. Soybean. Soybean is a crop that requires relatively more nitrogen fertilizer. Usually, a nitrogen fertilizer topdressing is applied once at the early flowering stage of soybean. This can reduce its flower and pod shedding rate, prolong the life of the plant, increase grain weight, and improve quality. Generally, 150 to 225 kg of ammonium nitrate or 120 to 180 kg of urea can be applied per hectare; at the pod-setting stage of soybean, a foliar topdressing can be carried out, and the yield-increasing effect is even more obvious.
6. Sunflower. In addition to applying sufficient base fertilizer, sunflower cultivation also requires topdressing. Generally, topdressing is carried out at the bud stage, with 225 kg of ammonium nitrate or 180 kg of urea per hectare. Farmers with the conditions can also carry out a foliar topdressing at the flowering stage.
7. Sugar beet. After thinning and fixing the seedlings, sugar beet quickly enters a stage of lush growth. In the early growth period of sugar beet, combined with the second hoeing and ridging, 150 to 225 kg of ammonium nitrate or 120 to 180 kg of urea can be applied per hectare.
8. Potato. Generally, topdressing can be carried out before the flowering stage of potato. For early-maturing varieties, topdressing at the seedling stage is preferable, and for mid-to-late-maturing varieties, topdressing before the bud stage is better. Apply 195 to 225 kg of ammonium nitrate or 150 kg of urea per hectare.
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