What fertilizer should be used for topdressing foxtail millet? Key points for high-yield fertilization

Foxtail millet is a crop with a relatively high fertilizer requirement, and fertilization must be handled well to achieve a good harvest. So what fertilizer should be used for topdressing foxtail millet? What should be noted in fertilization? How should foxtail millet be fertilized for high yield? The specific details are as follows:

1. Phosphate fertilizer: promotes the growth and maturity of foxtail millet. After flowering, sufficient phosphate fertilizer helps reduce empty grains and increase 1000-grain weight. The period of greatest phosphorus uptake by foxtail millet coincides with the period of greatest nitrogen uptake. The uptake from jointing to the panicle differentiation stage accounts for 50% of the total uptake over its life cycle, and the uptake from heading to flowering accounts for about 20% of the total uptake. Research shows that in the early growth stage of foxtail millet, that is, the young panicle differentiation stage, the phosphorus absorbed from the soil accumulates in large amounts in young tender new tissues such as stems, leaves, young roots, and young panicles. After flowering and grain filling, the grains need a large amount of phosphorus, mainly relying on the phosphorus accumulated in the plant in the early stage being transferred to the grains. Therefore, the phosphorus nutrition conditions in the early growth stage have a major impact on yield.

2. Nitrogen fertilizer: promotes lush stems and leaves, large panicles, and many grains. Before jointing, foxtail millet absorbs very little nitrogen because the seedlings are small and grow slowly. Within the 1 month from jointing to the panicle differentiation stage, because stem and leaf growth and young panicle development proceed simultaneously, nitrogen uptake increases rapidly, and nitrogen uptake during this period accounts for 1/3 of the total uptake during the whole growth period. From heading to flowering, the panicle grows rapidly, and nitrogen uptake accounts for 20% of the total uptake; afterward, nitrogen uptake is very small.

3. Potassium fertilizer: enhances the toughness of foxtail millet stems, reduces lodging, and improves resistance. It also promotes the transport of nutrients to the grains and increases grain weight. The uptake of potassium by foxtail millet is greatest before heading. Foxtail millet is a densely planted crop, and both the grain and the millet straw are very nutritious. The plants are lush, the root system is well developed, and it extends in the shallow soil layer, requiring the absorption of large amounts of nutrients from the surface soil. According to data, for every 100 kg of spring foxtail millet grain produced, about 4.7 kg of nitrogen, 1.6 kg of phosphorus, and 5.7 kg of potassium are absorbed from the soil; for every 100 kg of summer foxtail millet grain produced, about 2-5 kg of nitrogen, 1.2 kg of phosphorus, and 2.4 kg of potassium are absorbed. The pattern of fertilizer demand throughout the life of foxtail millet is that fertilizer demand is relatively low at the seedling stage and maturity stage, and high from jointing to heading. The ratio of nitrogen, phosphorus, and potassium is about 2:1:2.

1. Base fertilizer and seed fertilizer. Applying sufficient base fertilizer is the foundation for achieving high yield in foxtail millet. All organic fertilizer, phosphate fertilizer, potassium fertilizer, micronutrient fertilizer, and about 1/3 of the nitrogen fertilizer can be applied as base fertilizer. Applying seed fertilizer well is also an effective measure to increase yield. Use about 3 kg of diammonium phosphate or urea per 667 sq m, applied with the seeds in the furrow during sowing. If the soil is dry, be sure to reduce the amount of seed fertilizer and properly separate the seeds from the fertilizer to avoid affecting emergence.

2. Jointing fertilizer. Under medium and low fertility conditions and in fields showing fertilizer deficiency, topdressing should be carried out immediately after jointing. The application amount accounts for 45%-50% of the total nitrogen fertilizer. In areas with a short frost-free period and for varieties with a long growth period, the jointing fertilizer should be applied early and heavily to avoid delayed maturity due to excessive vegetative growth. For high-yield fields with good soil fertility and sufficient base fertilizer, the jointing fertilizer should be applied lightly, and it is advisable for the jointing fertilizer to account for less than 30% of total nitrogen. For simplified cultivation, the jointing fertilizer and panicle fertilizer can be combined into a single application, applied later than the jointing fertilizer but no later than the booting stage.

3. Panicle fertilizer. Panicle fertilizer is applied 7-10 days before heading. High-yield fields must increase the amount of panicle fertilizer, applying 40%-50% of total nitrogen as panicle fertilizer, while low-yield fields use 20%-25% of total nitrogen as panicle fertilizer. Applying panicle fertilizer can be combined with intertillage, hilling, and watering. If fertilizer deficiency occurs during the flowering stage of foxtail millet, a small amount of nitrogen fertilizer should be applied as topdressing together with watering. In particular, sandy soils with poor fertilizer retention capacity should increase the number of topdressings and supplement fertilizer at any time. During the grain filling stage, foliar spraying can be used as appropriate, spraying a 0.5%-1% urea solution or a 0.2% potassium dihydrogen phosphate solution, 50-60 kg per 667 sq m, which can extend the functional period of leaves and increase grain weight.

4. Foliar boron spraying. When using foliar boron spraying, the concentration, dosage, spraying period, and frequency of the boric acid solution must be correctly applied.

Reasonable fertilization for high-yield foxtail millet. Before sowing, combine with deep plowing and land preparation and apply base fertilizer at one time, generally mainly farmyard manure; if phosphate fertilizer is mixed with it, the effect is better. Applying seed fertilizer can meet the nutrient needs of foxtail millet after emergence. Generally, apply 5 kg of ammonium phosphate per mu.