For high quality and high yield, peach trees must not be given one-sided nitrogen fertilizer
Case study: Nowadays consumers have higher requirements for the quality of peaches. Some peaches are small and unpopular, and some peaches do not store well and rot after a few days. In order to meet market needs and improve the quality of fresh peaches, fruit growers try every means to increase fertilization and irrigation of peach trees, hoping to achieve high yield and high quality, especially to produce more large peaches and improve the storage tolerance of fresh peaches.
They mainly rely on increasing the number of topdressings during the fruiting period and raising the application rate of nitrogen fertilizer, for example, often spreading urea on the ground and then watering. A peach grower in Pinggu, Beijing, has had a fairly high peach yield in recent years, and the economic benefits are also good. Last year, during topdressing in the peach orchard, this farmer increased the amount of urea to as much as 500 kg/mu. With such heavy nitrogen and heavy water, he fully expected to get large peaches and good peaches, but after picking that year the yield did not increase much, and the proportion of large peaches did not increase either.
Agricultural expert Cao Yiping believes: the nutritional characteristic of peach trees is that their demand for and uptake of phosphorus and potassium are both higher than those of apple and pear trees. Therefore, in fertilizing peach trees, in addition to ensuring an adequate nitrogen supply, more attention should be paid to the application of phosphorus and potassium fertilizers, and this case study precisely overlooked this point. It is not enough to focus only on applying large amounts of nitrogen fertilizer during topdressing in the vigorous growth period of peach trees; especially in the full fruiting period, nitrogen must be controlled while attention is also paid to potassium topdressing. The one-sided nitrogen application method used in this case study does not match the nutritional rules of peach trees, so the effect is unsatisfactory. If the practice of one-sided nitrogen application continues, it will also lead to worsening pests and diseases in the future and even poorer storage tolerance of fresh peaches.
For this reason, the following 3 suggestions are put forward for fertilizing peach trees:
1. Apply base fertilizer in autumn. Attach importance to the application of organic fertilizer, and at the same time apply nitrogen, phosphorus and potassium chemical fertilizers, 1-2 kg per tree. The application method should preferably be radial trench application. Autumn application is better than spring application, because it allows deep application and also helps root recovery.
2. Grasp the two topdressings before and after flowering. The flowering topdressing is carried out when spring buds sprout, and the fertilizer should be a compound fertilizer based mainly on nitrogen and potassium, 1-1.2 kg per tree. Never apply only urea. For the topdressing method, open a trench, spread the fertilizer and cover it with soil. The post-flowering topdressing is carried out during the fruit expansion period, and the amount of this topdressing should be slightly larger. The ratio of nitrogen to potassium should have more potassium than nitrogen, and the amount per tree should preferably be 1.2-2 kg.
3. Foliar topdressing. High-yield peach trees are relatively sensitive to trace elements, and on calcareous soils in North China they react especially strongly to iron deficiency. When peach trees lack iron, the new leaves become chlorotic. If longitudinal curling of peach leaves is found, it is a sign of calcium deficiency in peach trees. This can be addressed by spraying a 0.5%-0.8% calcium nitrate solution or a 0.3%-0.5% calcium chloride solution. Foliar topdressing must be sprayed continuously 2-4 times to be effective.