Deep delving the fruit trees
Deep delving method is a particular local placing for organic and chemical fertilizers in soils. Winter deep delving causes fertilizers to be prepared in soils to be consumed by the trees at the beginning of growing season. The reasons that fruit trees are mainly suffering from different types of deficiencies are the presence of active lime in lime soils, excessive bicarbonate in irrigating water, organic materials shortage, incorrect fertilizers usage in superficial dispersing, slight mobility of most of the used fertilizers particularly the phosphate and micronutrient ones, not optimum use of fertilizer and water. Applying fertilizers via this method is far more efficient and proficient than top dressing method. The other advantages of this method are the capacity of better absorption by roots, better respiration and better water lead through the pit around the root.
The advantages of deep delving:
Preventing the shoot tip of fruit trees from dieback
Expanding fruit trees' roots in lime soils
Increasing the leaf area in fruit trees.
Improving the quantity and quality of fruits
Increasing water infiltration by the pores fraught with organic materials
Place of digging hole in deep delving method
The best place to dig a hole is the last one third of shadow of the tree. There is the most density of young and active roots in this area. Delving in this area causes least damage to the main and thick roots. As a result the roots are able to absorb their favored nutrients directly and weed growth lowers.
The places of holes are better to be along the water flow. The number of the holes differ depending on the type of the tree, soil condition, age of the tree etc. but generally 2-4 holes would be appropriate for the trees older than 10 years. The holes depth vary being determined by the type of the tree considered 30-50 cm deep. It must be noticed that the holes are not filled up by the previous soil but they are filled up with the fertilizer and an organic material such as rotted manure or peat.
This method is particularly adequate for arid regions. If the holes are kept in a proper condition, digging once would be adequate for several years.
Since Khazra chelated nano fertilizers possess special structure for deep delving, they cause less leaching and higher availability percentages to roots.