The key to increasing wheat yield is applying the jointing and booting fertilizer well

The jointing and booting fertilizer for wheat is the most critical fertilizer in its whole life. The jointing and booting stage is also the key period that determines the ear-bearing rate and seed-setting rate of wheat and secures strong stems and large ears. It is the second peak period of fertilizer demand in the life of wheat. The fertilizer demand during this period generally accounts for about 50% of the total fertilizer demand. Scientifically topdressing the jointing and booting fertilizer can ensure the growth needs of wheat and help form large ears. After the beginning of spring, the temperature gradually rises. Once wheat generally starts to grow upright, it immediately enters the jointing and booting stage, which is exactly an excellent time to apply the jointing and booting fertilizer.

According to research, for every 100 kg of wheat grain produced, about 3.1 kg of pure nitrogen, 1.1 kg of phosphorus pentoxide and 3.2 kg of potassium oxide need to be absorbed. Before overwintering, wheat has a low demand for nutrients. After overwintering, as the temperature rises and the wheat population increases, nutrient uptake increases rapidly until it slows down at the heading and flowering stages. From jointing to flowering is the peak period of nutrient uptake in wheat. 55% of the nitrogen, 80% of the phosphorus and 90% of the potassium of the whole growth period are absorbed at this stage. After flowering until maturity, wheat still needs to absorb 28% of the nitrogen and a very small amount of phosphorus, and basically no longer absorbs potassium. At present, the foundation of the wheat seedling condition is relatively good, but all localities report a high proportion of excessively vigorous seedlings and weak small seedlings. Therefore, the jointing and booting fertilizer must be applied scientifically and reasonably according to local conditions, seedling conditions and varieties.

Determine the application time according to local conditions. The jointing and booting fertilizer for wheat should generally be applied when the leaf color of the population fades, the small tillers die, the first internode at the base has reached its final length, and the second internode is elongating. For wheat fields with normal growth, this is generally in mid-to-late March. For late-sown wheat fields, late weak seedling wheat fields with insufficient growth before winter and weak individual growth, and wheat fields with yellowing leaves and severe frost damage, topdressing should be carried out as early as possible in early-to-mid March. This can effectively increase the number of grains and also plays a certain role in striving for spring tillers to bear ears and ensuring a sufficient number of ears per mu. For fields where the leaf color fades slowly and where winter fertilizer has been applied and green-up fertilizer has been topdressed in early spring, the amount of fertilizer can be reduced according to the seedling condition, and the time for topdressing the jointing fertilizer can be appropriately postponed.

Determine the fertilization amount according to seedling conditions. The jointing and booting fertilizer for wheat refers to the fertilizer applied from jointing to the emergence of the flag leaf tip. If little base fertilizer and winter fertilizer were applied at jointing, jointing fertilizer should be applied as appropriate, with about 5 kg of urea per mu and a certain amount of phosphorus and potassium fertilizer. If at jointing the population is too large, the leaf color is dark green, the leaves are drooping, the small tillers do not fade for a long time, and the shading is relatively heavy, this indicates excessive growth. For such wheat fields, fertilizer use should be appropriately controlled and applied only after the leaf color fades; if the leaf color never fades, do not apply jointing fertilizer. If at jointing the population development is insufficient, yellowing occurs too early, and the leaves are narrow, small, thin and upright, this is a typical manifestation of fertilizer deficiency. Topdressing should be carried out as early as possible, combining fertilizer with water to actively promote growth, with 6-8 kg of urea per mu. Applying fertilizer together with rainwater can allow the fertilizer to infiltrate into the soil and improve utilization.

Determine the application proportion according to variety. Generally speaking, short-stalked, fertilizer-tolerant and lodging-resistant varieties can be applied with a moderate increase; tall-stalked and non-fertilizer-tolerant varieties should be applied with less. Fields with insufficient base fertilizer and poor soil fertility should be applied with a moderate increase; fields with fertile soil and strong residual fertility can be applied with less. Generally, it is advisable to use special compound fertilizer plus urea for jointing fertilizer; for booting fertilizer, only urea may be supplemented to achieve precise fertilization. Generally, for medium-gluten wheat, the jointing fertilizer uses 4-5 kg of pure nitrogen, 3 kg of phosphorus pentoxide and 4 kg of potassium chloride per mu. Usually, 25-30 kg of 45% nitrogen-phosphorus-potassium ternary compound fertilizer is used per mu. For booting fertilizer, that is, 2-3 kg of pure nitrogen per mu, about 5-7 kg of urea per mu. For weak-gluten wheat, it is advocated to apply the jointing and booting fertilizer all at once, that is, 2.6-2.8 kg of pure nitrogen, 1.5 kg of phosphorus pentoxide and 2 kg of potassium oxide per mu, generally 10-15 kg of 45% nitrogen-phosphorus-potassium ternary compound fertilizer per mu. If the amount of nitrogen fertilizer applied earlier is large, the amount of jointing fertilizer should be appropriately reduced.

In the middle and late growth stages of wheat, root activity declines significantly, and trace element fertilizers are basically no longer absorbed from the soil. However, in the middle and late stages, the demand of wheat for micro-fertilizers is very important. It can improve the efficiency of photosynthesis and promote the transformation of stunted seedlings. We must seize the opportunity in the middle and late stages of wheat growth to spray trace element foliar fertilizer in combination with pesticide application for disease prevention. This has a significant effect on increasing yield, with a yield increase range of 3%-5%.