How can fertilizer use efficiency in apple orchards be improved?

1. Increase soil organic matter content

Soil organic matter content is an important indicator for measuring the soil fertility of an orchard, and it is also a basic condition for producing pollution-free fruit. Soil organic matter can promote the formation of soil aggregate structure, increase soil aeration, and improve the soil's fertilizer- and water-holding capacity and buffering performance. The slow release of available nutrients from organic matter is beneficial to the absorption by fruit tree roots and causes less pollution to the environment. Measures to increase orchard organic matter include orchard grass mulching, planting green manure, returning fallen fruit tree leaves to the soil, and applying organic fertilizer, etc.

2. Balanced fertilization

There are synergistic and antagonistic effects among nutrient elements, so a certain proportion must be maintained when fertilizing. When essential mineral nutrients are lacking in the soil, apple trees cannot grow and develop normally. Excessive amounts are also unfavorable to the growth and development of apple trees: when trace elements are excessive, apple trees will show symptoms of toxicity. Therefore, only balanced fertilization can maintain the nutrient elements necessary for the normal growth and development of apple trees.

3. Topdressing at the right time, in small amounts and multiple times

Apple trees have 3 growth peaks within one year: the first from early April to early May, the second mostly from early June to early-to-mid July, and the third after mid-September, lasting for a relatively long time, and in Ninglang it can be extended to mid-to-late November. Topdressing should be carried out during these 3 growth peaks.

4. Scientific fertilization

When applying fertilizer, determine the width of the ditch according to the amount of fertilizer applied. Organic fertilizer and soil should be backfilled in separate layers. Where conditions permit, soluble chemical fertilizers can be applied through the drip irrigation system in the orchard.

Urea, borax, zinc sulfate, amino acid calcium, etc. can all be applied by foliar spraying. Foliar spraying is best done on cloudy days or on sunny days before 9:00 and after 16:00, so that the fertilizer remains moist on the leaves for a long time and the absorption time is also long.

5. Water appropriately

Fertilizer can only be absorbed by apple tree roots after dissolving in water, but excessive water in the soil will not only make the roots anaerobic and unable to carry out absorption, but can also leach the fertilizer away. After fertilizing, irrigate appropriately according to the soil water content.

6. Do not be superstitious about fruit tree special-purpose fertilizer

Fruit tree special-purpose fertilizer is not a universal fertilizer for all kinds of fruit trees, nor is it suitable for all regions; it is only relatively suitable for a certain tree species at a certain age stage in a certain region. Therefore, one should not be superstitious about fruit tree special-purpose fertilizer, and there is no “all-purpose” fruit tree special-purpose fertilizer.