Deep tillage is an effective measure to improve soil, especially with the application of organic fertilizer, which can improve soil structure, enhance soil water and fertilizer conservation ability and ventilation and water permeability, and is beneficial to root growth and cultivate deep, wide and dense root groups. Deep ploughing also reduced the base of overwintering pests and diseases. Practice has proved that deep ploughing and soil improvement is an important measure to ensure high and stable yield of fruit trees and improve their cold and drought resistance. The specific method is as follows:

Deep tillage and soil improvement period: the best time for deep tillage is before the peak of root growth, which is beneficial to the healing of root-cutting wounds. It is usually carried out in autumn and winter, and autumn is the best. At this time, deep ploughing wounds are easy to heal and new roots will be issued. Deep ploughing can also be carried out after thawing in early spring. At this time, the aboveground part is still dormant, and the root system has just started to move, growing slowly, and it is easy to heal and regenerate after root injury. After the soil is thawed in spring, the water moves up, and the soil is loose and labor-saving. There are many spring droughts in the north, so irrigation should be done in time after deep ploughing. It is not easy to turn over in windy, dry and water-deficient areas.

Depth of deep ploughing and soil improvement: The depth of deep ploughing and soil improvement should be slightly deeper in the distribution layer of main roots of pear trees. Considering soil structure, soil quality, climate, labor force and other factors, it is generally required to reach 60 ~ 100 cm to promote root growth and expand absorption range.

The way of deep ploughing and soil improvement: deep ploughing and hole enlargement, also Screaming Trees's nest. After the pear trees are planted, they can gradually turn deep outwards, dig an annular ditch about 40 cm deep, expand the planting holes, and apply base fertilizer in combination with the soil. In places where there are many gravels, sand should be pumped for soil replacement. Deep ploughing should be done every year until all rows are deeply ploughed. The whole garden is deeply ploughed, and the land outside the planting hole is deeply ploughed once in combination with fertilization. This method needs a lot of soil and labor, but it is convenient to level the land and is beneficial to the cultivation of pear orchards. Young tree orchards are generally deeply ploughed at one time, because there are few small roots and few damaged roots, which has little effect on the trees.

Matters needing attention in deep tillage to improve soil: Deep tillage must be combined with the application of organic fertilizer to achieve the purpose of improving soil and increasing fertilizer. It is best to use local and nearby materials as organic fertilizers, such as green manure, manure and compost. Coarse organic matter can be mixed with topsoil to fill the bottom layer, then mixed with green manure and manure to fill the middle layer, and finally the excavated subsoil is covered on it. In addition, lime can be applied to the soil with high acidity to neutralize the acidity of the soil, with an average of 35 ~ 40 kg of lime applied per 667 m2. The deep ploughing and soil improvement of pear orchard should be completed in the young tree period to avoid causing great damage to the root system.