Planting method for preventing and treating yellowing and regreening of tree leaves in drought saline-alkali soil under reclaimed water irrigation condition

Abstract

The invention discloses a planting method for preventing and treating yellowing and regreening of tree leaves under the condition of reclaimed water irrigation in drought saline-alkali soil, which can prevent the yellowing of transplanted nursery stock leaves through the measures of backfilling planting soil in planting holes, raising soil ball height (shallow planting), heavy pruning and the like. The survival rate of transplanted trees under the condition of high-salt reclaimed water irrigation in arid and saline-alkali areas is increased, the survival rate can reach 90% or above, and the method is suitable for reclaimed water irrigation management.

Description

Technical Field

[0001] This invention relates to the field of tree planting technology, and in particular to a planting method for preventing and treating yellowing of tree leaves and promoting greening under the irrigation conditions of reclaimed water in arid and saline land. Background Technology

[0002] Xinjiang is largely arid with little rainfall, and evaporation rates far exceed precipitation. A typical example is Urumqi, a city with a temperate continental climate characterized by dryness, abundant sunshine, and high annual evaporation. The average annual rainfall is 194.6 mm, with 59.6 mm occurring during the growing season (April-October). Annual evaporation is 2760.3 mm, with 2372.5 mm occurring during the same period. In Urumqi, evaporation generally exceeds precipitation, leading to severe drought. Hot, dry winds are a major natural disaster in spring and summer, occurring from May to September. These winds occur when temperatures reach above 35°C, daily evaporation is 12-14 mm, relative humidity is below 20-30%, and wind speeds are below 3 m / s. Furthermore, in most parts of Xinjiang, such as the Urumqi area, the current soil conditions are as follows: the strata are mainly silt, gravel and mudstone, and the soil salinization is severe and unevenly distributed, ranging from medium to strong salinity; and the reclaimed water has a high salt content.

[0003] During tree transplantation, the key factors affecting tree survival are maintaining a balance between transpiration from the above-ground parts of the tree and water and nutrient absorption by the underground root system. In the arid and hot-dry climate of Xinjiang, newly transplanted trees are prone to yellowing leaves due to excessive transpiration, impacting their survival rate. Furthermore, if reclaimed water is used for irrigation, its higher salt content compared to regular domestic water, combined with the high salt and pH levels in the planting soil, creates a hypertonic environment that hinders root water absorption. This leads to leaf yellowing due to malnutrition, wilting, and water loss. Therefore, in the arid regions of Xinjiang, the survival rate of transplanted trees under reclaimed water irrigation conditions is currently low. Existing technologies for preventing leaf yellowing and improving transplant survival rates during tree planting include, for example, the study "Research on the Effect of Foliar Fertilizer Spraying on Improving Chlorosis in Populus tomentosa Leaves" (Protective Forest Science and Technology, December 2020, Issue 12, Li Yan). This study used Populus tomentosa seedlings as the research object. After measuring and comparing the nutrient elements of normal green leaves and chlorotic leaves, nutrient deficiency was diagnosed, and foliar fertilizer was prepared and sprayed on chlorotic leaves in the second year. The chlorophyll content of normal green leaves, chlorotic yellow leaves, and sprayed leaves was measured. Combined with the seedling growth, the study analyzed whether the foliar fertilizer spraying promoted the growth of Populus tomentosa seedlings, aiming to provide a theoretical basis for the rapid growth and high yield of poplar seedlings. The experimental area was Heilongjiang (annual average precipitation 755.2 mm), which is not an arid region and has higher precipitation than Xinjiang (annual average precipitation 150.0 mm). However, no methods for preventing and controlling salt-alkali damage to trees were mentioned. The literature does not mention the application of reclaimed water. Other reports are mostly descriptive and lack supporting data, such as studies on the effects of foliar fertilizer application. Furthermore, no reports have been found on comprehensive measures to address leaf yellowing in trees under reclaimed water management conditions in heavily saline-alkali areas. Summary of the Invention

[0004] Therefore, based on the above background, the present invention provides a planting method for preventing and treating yellowing of tree leaves and promoting greening under the irrigation of reclaimed water in arid and saline-alkali land. The present invention takes measures from both above-ground and underground parts to maintain the water balance of transplanted trees and ensure the absorption of nutrients by the above-ground leaves and underground roots, so as to prevent yellowing of tree leaves under the irrigation of reclaimed water in arid and saline-alkali land and improve the survival rate of transplanted trees.

[0005] The technical solution of this invention is as follows:

[0006] A planting method for preventing leaf yellowing and promoting vegetative growth in trees under reclaimed water irrigation conditions in arid and saline-alkali land includes the following steps:

[0007] S1. Before planting the trees, dig planting holes with a depth of 100-150cm. Backfill the bottom of the planting holes with gravel or sand as the base frame.

[0008] S2. When digging up seedlings, dig up the seedlings with a soil ball. The diameter of the soil ball should be determined by 10-12 times the diameter at breast height of the tree. The depth of the soil ball should be 4 / 5 or equal to the diameter of the soil ball.

[0009] After the seedlings are dug up, spray the root ball with a root-promoting nutrient solution A diluted 100-200 times with water, spray the fresh root cuts, and wet the entire bottom of the root ball.

[0010] S3. After mixing the planting soil with organic fertilizer, backfill the planting hole with 20-30cm of soil. After transplanting the seedling with soil ball dug up in step S2 into the planting hole, straighten the seedling and backfill with planting soil. When the planting soil is half backfilled, dilute the soil ball with 100-200 times the amount of root-promoting nutrient solution B. After ensuring that the roots of the soil ball are thoroughly wet, continue to backfill and compact the soil. After the seedling is planted, the soil ball should be 20cm above the ground surface. Make a watering embankment around the soil ball that is 10-15cm higher than the soil ball.

[0011] S4. After the seedlings are transplanted, apply tree growth regulator solution daily for 9-30 days, using 1000ml per tree. Also, spray the trees with water 1-2 times daily for 21 days after transplanting to keep the seedlings moist.

[0012] S5. Drill holes 10cm away from the outer edge of the soil ball in four directions. The hole diameter is 10-12cm and the drilling depth exceeds the thickness of the soil ball by 10cm. Then check the soil accumulation in the hole in time and re-drill the hole if necessary.

[0013] S6. Continuously observe the growth of trees. When the trees show initial signs of yellowing leaves, spray foliar fertilizer or measure the leaf moisture content and chlorophyll content. Spray foliar fertilizer every 5-7 days. In accordance with routine management, use reclaimed water for irrigation.

[0014] Furthermore, the arid saline-alkali land mentioned refers to a severely saline-alkali land environment in Xinjiang with a soil pH value of 9 or higher and a salt content exceeding 3‰.

[0015] Furthermore, in step S1, the planting season is spring.

[0016] Furthermore, the seedlings in step S2 are selected from at least one of the following: summer oak, crabapple, large-leaved ash, small-leaved ash, large-leaved elm, and round-crowned elm.

[0017] Furthermore, in step S2, the trunk is tightly wrapped with straw rope before the seedlings are lifted to ensure the integrity of the root ball and avoid damage to the root ball and root system during transportation.

[0018] Furthermore, in step S3, when transplanting the seedlings to the planting hole, double-layered slings are used to support the bottom of the root ball and the trunk to prevent the root ball from loosening and avoid damage to the trunk.

[0019] Furthermore, in step S3, after transplanting the tree to the planting hole, it is heavily pruned: the main branches are retained, the tree framework is preserved, and the fine branches and leaves are removed.

[0020] Furthermore, the amount of all branches and leaves removed should not exceed 30%.

[0021] Furthermore, the root-promoting nutrient solution A in step S2 contains indolebutyric acid and naphthaleneacetic acid at a combined concentration of 5%.

[0022] Furthermore, the root-promoting nutrient solution B in step S3 contains 5% naphthaleneacetic acid.

[0023] The beneficial effects achieved by adopting this invention are as follows:

[0024] This invention prevents yellowing of transplanted seedling leaves by backfilling planting soil in planting holes, raising the height of the root ball (shallow planting), and heavy pruning, thereby improving the survival rate of transplanted trees under high-salt reclaimed water irrigation conditions in arid and saline-alkali areas, with a survival rate that can reach over 90%.

[0025] This invention, during the transplanting and planting of seedlings, isolates saline-alkali soil at the bottom of the planting hole by replacing the planting soil and laying gravel or sand at the bottom of the planting hole, preventing the saline-alkali soil from rising upwards due to capillary action. Furthermore, the diameter of the root ball is determined to be 10-12 times the tree's diameter at breast height (DBH), and the tree is planted 20cm above the ground surface to reduce contact between the main root layer and the saline-alkali soil. Root-promoting nutrient solution A is sprayed onto the root ball, and root-promoting nutrient solution B is applied during backfilling to ensure nutrient absorption by the underground roots. After planting, foliar fertilizer is sprayed on trees showing signs of saline-alkali damage to ensure nutrient absorption by the above-ground leaves. Thus, this invention maintains the water balance of transplanted trees from both above-ground and underground perspectives, ensuring nutrient absorption by both above-ground leaves and underground roots, preventing leaf yellowing under reclaimed water irrigation conditions in arid saline-alkali land, and improving the survival rate of transplanted trees. Attached Figure Description

[0026] Appendix Figure 1 This is a diagram showing the planting soil and untreated soil of summer oak trees in an embodiment of the present invention.

[0027] Appendix Figure 2 These are diagrams illustrating shallow-planted crabapple and conventionally planted crabapple according to an embodiment of the present invention.

[0028] Appendix Figure 3 These are diagrams showing the heavily pruned and unpruned crabapple trees according to an embodiment of the present invention.

[0029] Appendix Figure 4 The images show the crabapple trees with and without foliar fertilizer application according to an embodiment of the present invention.

[0030] Appendix Figure 5This is the first test result of reclaimed water in an embodiment of the present invention (tested by Xinjiang Changyuan Water Science Research Institute (Co., Ltd.), water sample delivered by Urumqi Botanical Garden).

[0031] Appendix Figure 6 This is the second case of reclaimed water testing according to an embodiment of the present invention (tested by Xinjiang Changyuan Water Science Research Institute (Co., Ltd.), water sample delivered from Urumqi Botanical Garden).

[0032] Appendix Figure 7 This is the second case of reclaimed water testing according to an embodiment of the present invention (tested by Xinjiang Changyuan Water Science Research Institute (Co., Ltd.), water sample delivered from Urumqi Botanical Garden).

[0033] Note: Attached Figure 5 To be continued Figure 7 The results show the water sample testing results for different months. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to its embodiments; it should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0035] This invention prevents tree leaves from turning yellow and improves transplant survival rate by taking measures such as soil replacement, raising the height of the root ball, and heavy pruning. It can not only spray foliar fertilizer on trees that have already turned yellow to promote leaf greening, but is also applicable to irrigation management using high-salt and alkaline reclaimed water.

[0036] This invention is suitable for transplanting and planting trees in severely saline-alkali soils with a soil pH value of 9.0 or higher and a salt content of more than 3‰.

[0037] Example 1: A planting method for preventing leaf yellowing and promoting vegetative growth in trees under reclaimed water irrigation conditions in arid and saline-alkali land includes the following steps:

[0038] S1. Before planting the trees, dig planting holes with a depth of 100-150cm. Backfill the bottom of the planting holes with gravel and sand as the base frame.

[0039] The gravel used in this step has a particle size of less than 10cm, mainly 5cm, accounting for more than 85%, and the remaining particle sizes are less than 15%; for example, the proportion of sand and gravel with a particle size of 5cm is 87%, and the remaining particle sizes are 13%. The specific proportion can be adjusted according to the transplanted seedlings.

[0040] The planting soil in this step is the topsoil or planting layer of fruit trees or vegetables that have been continuously planted in orchards or fields for 2-3 years, for example, soil with a depth of 30-50 cm or more in orchards or fields.

[0041] S2. Transplant seedlings by digging them up with a soil ball. The diameter of the soil ball should be 10-12 times the diameter at breast height of the seedling. The depth of the soil ball should be 4 / 5 or equal to the diameter of the soil ball. Before digging the seedlings up, wrap the trunk tightly with straw rope to ensure the integrity of the soil ball and avoid damage to the soil ball and root system during transportation.

[0042] After the seedlings are dug up, spray the root-promoting nutrient solution A diluted 100 times with water onto the soil ball, spray the fresh root cuts, and wet the entire bottom of the soil ball.

[0043] The root-promoting nutrient solution A in step S2 contains indolebutyric acid and naphthaleneacetic acid at a combined concentration of 5%. For example, root-promoting nutrient solution A is composed of the following raw materials in the following weight ratios:

[0044] The sum of the concentrations of indolebutyric acid and naphthaleneacetic acid is 5%, with the remainder being water.

[0045] In this step, tap water is used to dilute the root-promoting nutrient solution A.

[0046] S3. When planting seedlings, use double-layered slings to support the bottom of the root ball and the trunk to prevent the root ball from loosening and avoid damage to the trunk. Mix the planting soil with 5kg of organic fertilizer and backfill 20cm in the planting hole. After transplanting the seedling with the root ball dug in step S2 into the planting hole, straighten the seedling and backfill with planting soil. When the planting soil is half backfilled, water the root ball with water diluted with 100 times the amount of root-promoting nutrient solution B to ensure that the roots of the root ball are thoroughly wet. After backfilling, compact the soil. After the seedling is planted, the root ball should be 20cm above the ground surface, and a watering embankment should be built around the root ball 10-15cm higher than the root ball.

[0047] The weight composition of the organic fertilizer used in this step is as follows:

[0048] Well-rotted sheep manure or similar organic fertilizers, or commercially available bagged bio-organic fertilizers.

[0049] Rooting nutrient solution B contains 5% naphthaleneacetic acid. For example, rooting nutrient solution B is composed of the following raw materials in the following weight ratio: 5% naphthaleneacetic acid and the remainder water.

[0050] In this step, purified water is used to dilute the root-promoting nutrient solution B.

[0051] Step S3: After transplanting to the planting hole, perform heavy pruning: retain the main branches, preserve the tree framework, and remove fine branches and leaves.

[0052] S4. After the seedlings are transplanted, apply tree growth regulator solution daily for 30 days, using 1000ml per tree. Also, spray the trees with water once a day for 21 days after transplanting to keep the seedlings moist.

[0053] The main components of the tree growth regulator infusion (aqueous solution) are tree infusion water containing effective ingredients and bioactive enzymes (market products).

[0054] Of course, the specific composition of the tree growth regulator solution can also be adjusted according to different tree species.

[0055] Specifically, for tree species with strong growth, the infusion should be administered for about 30 days. For tree species with weak growth (such as elm with round crown), it is recommended to switch to clean water for infusion after 9 days.

[0056] S5. Drill holes 10cm away from the four sides of the soil ball, with a hole diameter of 10cm and a depth of about 10cm beyond the thickness of the soil ball. Then check the soil accumulation in the holes in time and re-drill the holes if necessary.

[0057] This step mainly targets the transplantation of large trees for roadside planting, which have relatively large root balls. Drilling holes helps to thoroughly water the root ball, promotes root respiration, and is an indispensable measure to improve the survival rate of trees in saline-alkali land.

[0058] S6. Foliar treatment measures: After the seedlings are transplanted, continuously observe the growth of the seedlings, measure the water content and chlorophyll content of the leaves, and spray foliar fertilizer according to the actual situation. Specific requirements: Spray the trunk and crown of the seedlings from bottom to top once every 5 days before the sun is about to set, concentrate on spraying the back of the leaves, and adjust the ratio of the fertilizer in a timely manner according to the growth of the seedlings.

[0059] In accordance with routine management, reclaimed water is used for irrigation management.

[0060] Specifically, immediately after planting, water the trees thoroughly to help them establish themselves, using a small, slow irrigation method. After watering, promptly cover any cracks in the surface soil with soil, following the principle of watering only when the soil is completely dry. The first three waterings should be done on the day of planting, the fourth day after planting, and the eleventh day after planting. After completing the first three waterings, the watering interval can be extended. After the first three waterings, in hot weather on saline-alkali land, water the trees every 7-15 days, depending on the weather conditions.

[0061] By using foliar fertilizer, the ratio of the fertilizer is adjusted according to the growth of the seedlings (leaf color, leaf area, leaf quantity) to ensure that the seedlings have the nutrients they need for growth.

[0062] The weight ratio of the basal foliar fertilizer is as follows:

[0063] 1‰ FeSO4, 1‰ amino acids, 1‰ ZnSO4, 1.5‰ boric acid, 0.5‰ of soluble compounds containing Ca and Mg, and the balance being water.

[0064] Add 1-2‰ urea to the basal foliar fertilizer;

[0065] Add 1‰ KH2PO4 to the base foliar fertilizer to ensure sufficient main fertilizer.

[0066] The foliar fertilizer used in this step is prepared using tap water.

[0067] If the specific raw materials or materials used are not mentioned or described in detail in the following embodiments, they are consistent with Embodiment 1.

[0068] Example 2: A planting method for preventing leaf yellowing and promoting vegetative growth in trees under reclaimed water irrigation conditions in arid and saline-alkali land includes the following steps:

[0069] S1. During the planting season (spring), before planting trees, dig planting holes, backfill the bottom of the planting holes with gravel as the base frame, and then do the preparatory work for transplanting seedlings.

[0070] S2. Transplant seedlings by digging them up with a soil ball. The diameter of the soil ball should be determined by 12 times the diameter at breast height of the tree. The depth of the soil ball should be 4 / 5 or equal to the diameter of the soil ball. Before digging the seedlings up, wrap the trunk tightly with straw rope to ensure the integrity of the soil ball and avoid damage to the soil ball and root system during transportation.

[0071] After the seedlings are dug up, spray the root-promoting nutrient solution A diluted 200 times with water onto the soil ball, spray the fresh root cuts, and wet the entire bottom of the soil ball.

[0072] S3. When planting seedlings, use double-layered slings to support the bottom of the root ball and the trunk to prevent the root ball from loosening and avoid damage to the trunk. After mixing the planting soil with organic fertilizer, continue to backfill the planting hole for 20-30cm. After transplanting the seedlings with root balls dug up in step S2 into the planting hole, straighten the trees and backfill the planting soil. When the planting soil is halfway backfilled, water the root ball with water diluted with 200 times the amount of root-promoting nutrient solution B to ensure that the roots of the root ball are thoroughly wet. After the backfilling is completed, compact the soil. After the seedlings are planted, the root ball should be 20cm above the ground surface, and a watering embankment should be built around the root ball 10-15cm higher than the root ball.

[0073] After transplanting to the planting hole, perform heavy pruning: retain the main branches, preserve the tree framework, and remove fine branches and leaves.

[0074] S4. After the seedlings are transplanted, apply tree growth regulator solution daily for 30 days, using 1000ml per tree. Also, spray the trees with water twice a day for 21 days after transplanting to keep the seedlings moist.

[0075] S5. Drill holes 10cm away from the four sides of the soil ball, with a diameter of 12cm and a depth of about 10cm beyond the thickness of the soil ball. Then check the soil accumulation in the holes in time and re-drill the holes if necessary.

[0076] S6. Foliar treatment measures: After the trees are transplanted, continue to observe the growth of the trees, measure the leaf water content and chlorophyll content, and spray foliar fertilizer according to the actual situation. The specific requirements are as follows: spray the trunk and crown of the trees from bottom to top once every 5 days before the sun is about to set, concentrate on spraying the back of the leaves, and adjust the ratio of the fertilizer in a timely manner according to the growth of the trees; and carry out irrigation management with reclaimed water as irrigation water according to routine management.

[0077] Specifically, immediately after planting, water the trees thoroughly to help them establish themselves, using a small, slow irrigation method. After watering, promptly cover any cracks in the surface soil with soil. Water only when the soil is completely dry before watering again. The first three waterings should be done on the day of planting, the fourth day after planting, and the eleventh day after planting. After completing the first three waterings, the watering interval can be extended. After the first three waterings, in hot weather on saline-alkali land, water the trees every 7-15 days, depending on the weather conditions.

[0078] By using foliar fertilizer, the ratio and concentration are adjusted according to the tree's growth (leaf color, leaf area, leaf quantity) to ensure the nutrients required for tree growth.

[0079] Example 3: A planting method for preventing leaf yellowing and promoting vegetative growth in trees under reclaimed water irrigation conditions in arid and saline-alkali land includes the following steps:

[0080] S1. During the planting season (spring), before planting trees, dig planting holes, backfill the bottom of the planting holes with gravel or sand as the base frame, and then do the preparatory work for transplanting seedlings.

[0081] S2. Transplant seedlings by digging them up with a soil ball. The diameter of the soil ball should be determined by 11 times the diameter at breast height of the tree. The depth of the soil ball should be 4 / 5 or equal to the diameter of the soil ball. Before digging the seedlings up, wrap the trunk tightly with straw rope to ensure the integrity of the soil ball and avoid damage to the soil ball and root system during transportation.

[0082] After the seedlings are dug up, spray the root-promoting nutrient solution A diluted 150 times with water onto the soil ball, spray the fresh root cuts, and wet the entire bottom of the soil ball.

[0083] S3. When planting seedlings, use double-layered slings to support the bottom of the root ball and the trunk to prevent the root ball from loosening and avoid damage to the trunk. After mixing the planting soil with organic fertilizer, continue to backfill 20-30cm in the planting hole. After transplanting the seedlings with root balls dug up in step S2 into the planting hole, straighten the trees and backfill with planting soil. When the planting soil is half backfilled, water the root ball with water diluted with 150 times the amount of root-promoting nutrient solution B to ensure that the roots of the root ball are thoroughly wet. After the backfilling is completed, compact the soil. After the seedlings are planted, the root ball should be 20cm above the ground surface, and a watering embankment should be built around the root ball 10-15cm higher than the root ball.

[0084] S4. After the trees and seedlings are transplanted, apply tree growth regulator solution daily for 30 days, using 2000ml per tree. Also, spray the trees with water twice a day for 21 days after transplanting to keep them moist.

[0085] S5. After the tree is transplanted, make holes 10cm away from the four sides of the root ball. The holes should be 11cm in diameter and about 10cm deeper than the thickness of the root ball. Then check the soil accumulation in the holes in time and re-drill the holes if necessary.

[0086] S6. Foliar Treatment Measures: After tree transplantation, continuously observe tree growth, measure leaf moisture content and chlorophyll content, and spray foliar fertilizer every 5 days. Specific procedures are as follows: Every 5 days, before sunset, spray the trunk and crown from bottom to top, focusing on the underside of the leaves. Adjust the fertilizer ratio according to tree growth. Follow routine management practices, using reclaimed water for irrigation. Specifically, water immediately after planting, using a small, slow irrigation method. After watering, promptly cover any cracks in the surface soil. Water thoroughly only when the soil is completely dry. The first three waterings are on the day of planting, the 4th day after planting, and the 11th day after planting. After the first three waterings, the watering interval can be extended. After the first three waterings, in hot weather in saline-alkali soil, water the planted trees every 7-15 days, depending on the weather conditions.

[0087] By using foliar fertilizer, the ratio and concentration are adjusted according to the tree's growth (leaf color, leaf area, leaf quantity) to ensure the nutrients required for tree growth.

[0088] The following implementation example focuses on the greening of the Hemaquan New District in Urumqi. Salt damage reached 3g / kg, and hot, dry winds frequently occurred from May to September. Effective rainfall was scarce during the plant's growing season. A total of 2324 mu (approximately 154 hectares) of trees were transplanted from saline-alkali land, including over 100,000 trees, primarily red-leaved crabapple, large-leaved ash, small-leaved ash, large-leaved elm, summer oak, and round-crowned elm. Figure 5 and attached Figure 6 The reclaimed water tested was irrigation water, with a survival rate exceeding 90%, including 93% for summer oak and over 95% for red-leaf crabapple. The experimental and control groups in the following examples were analyzed using data from 15 seedlings each. Specific Implementation Example 4:

[0090] In this embodiment, summer oak seedlings were transplanted and planted. The planting was carried out according to the steps of Example 1. Transplanting was carried out in spring, and experimental groups and control groups were formed according to the different planting soils replaced in the planting holes in step S1.

[0091] The experimental group was replaced with nutrient-rich, mature planting soil that had been cultivated for many years; the control group was replaced with ordinary soil (soil from non-cultivated land; specifically, the ordinary soil in the control group was taken from soil that had not been planted for many years).

[0092] The other steps are the same as in Example 1.

[0093] Thirty days after foliar fertilization, the number of new leaves per plant and the total leaf area of ​​*Quercus acutissima* were statistically analyzed in both the experimental and control groups. Chlorophyll content was also measured in the leaves of both groups. The results are shown in Table 1. Table 1 shows that the average number of new leaves per plant in the experimental group (*Quercus*, Fagaceae family, deciduous tree, diameter at breast height 10-12 cm) was 29 times that of the control group. The average chlorophyll content in the experimental group was 1.5 times that of the transplanted *Quercus acutissima* in the control group (P < 0.01), the total leaf area was 1.2 times that of the transplanted *Quercus acutissima* in the control group, and the area of ​​a single leaf was 1.5 times that of the transplanted *Quercus acutissima* in the control group (P < 0.01).

[0094] Table 1 Comparative experimental data of different backfilling measures under the condition of reclaimed water management in saline-alkali land in arid areas.

[0095]

[0096] See attached for planting details. Figure 1 As shown.

[0097] As can be seen in this embodiment, replacing the planting hole with mature soil can not only effectively promote the growth of garden trees, but also greatly reduce the rate of yellowing leaves.

[0098] Example 5: In this example, red-leaf crabapple seedlings were transplanted and planted. According to Example 2, the planting was carried out in spring. Based on the difference in the height of the root ball above the ground after the seedlings were planted in step S3, the seedlings were divided into an experimental group and a control group. The experimental group was planted according to Example 2, that is, after the backfilling was completed, the root ball of the seedlings was 20cm above the ground after planting, i.e., shallow planting.

[0099] In step S3, after backfilling and planting, the upper surface of the trees in the control group is usually 5-10cm lower than the ground surface, which is the conventional planting where the root ball is not raised.

[0100] The number of new leaves per transplanted crabapple tree, the total leaf area, and the chlorophyll content of leaves in the two groups were statistically analyzed, as shown in Table 2.

[0101] As shown in Table 2, for the red-leaf crabapple (a deciduous tree of the genus Malus in the family Rosaceae, with a diameter at breast height of 8-10 cm), the chlorophyll content of a single plant in the experimental group was 1.5 times that of the control group (P < 0.01); the leaf volume was 6.1 times that of the control group (P < 0.01); the total leaf area was 12.4 times that of the control group (P < 0.01); and the area of ​​a single leaf was 2.1 times that of the control group (P < 0.01).

[0102] Table 2: Comparative experimental data on shallow planting measures under reclaimed water management conditions in arid saline-alkali land.

[0103]

[0104] See attached for planting details. Figure 2 As shown.

[0105] Example 6: This example uses red-leaf crabapple as seedlings for transplanting and planting. The planting is carried out according to the steps of Example 3, and transplanting is carried out in spring. In step S3, after transplanting to the planting hole, the seedlings are divided into an experimental group and a control group. The experimental group is specifically pruned as follows: the tree skeleton is preserved and the branches and leaves are thinned out; the main branches to be pruned are weak branches, dead branches, dry branches, crossing branches and dense branches. The pruning intensity is to preserve the crown shape and the amount of branches and leaves removed is no more than 30%. The control group is not pruned, and other procedures are the same as the experimental group.

[0106] The number of new leaves per tree, the total leaf area, and the chlorophyll content of transplanted trees under the two planting conditions were statistically analyzed (see Table 3). The results showed that the number of leaves per tree in the heavily pruned *Malus rubra* (a deciduous tree of the genus *Malus* in the family Rosaceae, with a diameter at breast height of 8-10 cm) of the experimental group was 1.2 times that of the unpruned trees with full crowns in the control group, and the chlorophyll content was 1.5 times that of the unpruned trees with full crowns in the control group (P < 0.05). The area of ​​a single leaf was 7.9 times that of the unpruned trees with full crowns in the control group (P < 0.01), and the total leaf area was 8.5 times that of the unpruned trees with full crowns in the control group (P < 0.01). (See Table 3).

[0107] Table 3. Comparative experimental data on heavy pruning measures under reclaimed water management conditions in saline-alkali land in arid areas.

[0108]

[0109] See attached for planting details. Figure 3 As shown.

[0110] Example 7: This example uses red-leaf crabapple seedlings for transplanting and planting, following the steps of Example 2, with transplanting taking place in spring. The experimental group and control group are distinguished by different treatments in step S6.

[0111] In the experimental group, foliar fertilizer was applied as in Example 2. After 20-35 days, the trees gradually recovered their vigor, and the leaf margins turned from yellow and withered to green. The control group used the same amount of purified water instead of foliar fertilizer, but otherwise remained the same as the experimental group.

[0112] The number of new leaves per tree, the total leaf area, and the chlorophyll content of transplanted trees under the two planting conditions were statistically analyzed, as shown in Table 4. Table 4 shows that the experimental group of *Malus spectabilis* (a deciduous tree of the Rosaceae family, 8-10 cm in diameter at breast height) had 4.4 times more new leaves, 4 times more new leaves, 1.4 times more chlorophyll content, 8.5 times more total leaf area, and 2 times more leaf area than the control group after foliar fertilizer application (P < 0.01). See Table 4.

[0113] Table 4. Comparative experimental data on foliar fertilization under reclaimed water management conditions in arid saline-alkali land.

[0114]

[0115] See attached for planting details. Figure 4 As shown.

[0116] In summary, the present invention is applicable to tree transplantation and planting methods in arid and saline-alkali lands under reclaimed water irrigation conditions. It can not only effectively reduce the yellowing of leaves of transplanted trees, but also significantly improve the survival rate of transplanted trees.

[0117] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A planting method for preventing and promoting leaf yellowing and regrowth of trees under reclaimed water irrigation conditions in arid and saline-alkali land, characterized in that, The method comprises the following steps: S1, digging a planting hole before planting trees in the planting period, the planting hole depth is 100-150 cm, and gravel or sand soil is backfilled at the bottom of the planting hole as a base keel. S2, digging a nursery tree with soil ball, determining the soil ball diameter with 10-12 times of the tree diameter, and the soil ball depth is 4 / 5 or equal to the soil ball diameter; After the nursery tree is dug up, the soil ball is sprayed with water-diluted 100-200 times of root-promoting nutrient solution A, the fresh root incision is sprayed, and the whole soil ball bottom is sprayed wet; S3, after the planting soil is mixed with organic fertilizer, 20-30 cm is backfilled in the planting hole, the nursery tree is transplanted to the planting hole after the nursery tree with soil ball is dug in step S2, the nursery tree is backfilled with planting soil, when the planting soil is backfilled by half, the soil ball is irrigated with water-diluted 100-200 times of root-promoting nutrient solution B, after ensuring that the soil ball root system is wet, the soil is continuously backfilled and compacted, the soil ball is 20 cm higher than the ground after the nursery tree is transplanted, and a cofferdam for watering is made around the soil ball, which is 10-15 cm higher than the soil ball; S4, after the nursery tree is transplanted, a large tree growth regulator is used every day for 9-30 days, and the dosage of each tree is 1000 ml, and the nursery tree is sprayed with water 1-2 times every day for 21 days after the nursery tree is transplanted, so that the nursery tree maintains humidity; S5, holes are punched in four directions at a distance of 10 cm from the outer edge of the soil ball, the hole diameter is 10-12 cm, and the punching depth exceeds the thickness of the soil ball by 10 cm, then the soil accumulation in the hole is checked in time, and the hole is re-punched in time; S6, the tree growth is continuously observed, when the tree appears yellow leaves, foliar fertilizer is sprayed, or the water content and chlorophyll content of the leaves are measured, foliar fertilizer is sprayed every 5-7 days, and the tree is irrigated with reclaimed water for irrigation management according to the conventional management.

2. A tree leaf yellowing prevention and recovery method under the condition of reclaimed water irrigation in a drought and saline-alkali land, characterized in that The drought and saline-alkali land is a severe saline-alkali land environment with a soil pH value of more than 9 and a salt content of more than 3 ‰ in Xinjiang.

3. The tree planting method for preventing and recovering yellowing of leaves of trees under the condition of irrigation with reclaimed water in a dry saline-alkali land according to claim 1, characterized in that, The spring is taken as the planting period in step S1.

4. The tree planting method for preventing and recovering yellowing of leaves of trees under the condition of irrigation with reclaimed water in a dry saline-alkali land according to claim 3, characterized in that, The nursery tree in step S2 is selected from at least one of summer oak, Chinese crabapple, large-leaf white birch, small-leaf white birch, large-leaf elm and round-crown elm.

5. The tree planting method for preventing and recovering yellowing of leaves of trees under the condition of irrigation with reclaimed water in a regenerated arid saline-alkali land according to claim 1, characterized in that, The nursery tree is tightly wrapped with a grass rope before being dug up in step S2, so as to ensure the integrity of the soil ball and avoid damage to the soil ball and root system during transportation.

6. The tree planting method for preventing and recovering yellowing of leaves of trees under the condition of irrigation with reclaimed water in a dry saline-alkali land according to claim 1, characterized in that, When the nursery tree is transplanted to the planting hole in step S3, a double-layer sling is used to hold the bottom of the soil ball and the trunk, so as to prevent the soil ball from loosening and avoid damage to the trunk.

7. The tree planting method for preventing and recovering yellowing of leaves of trees under the condition of irrigation with reclaimed water in a droughty and saline-alkali land according to claim 5, characterized in that, After being transplanted to the planting hole, the nursery tree is pruned again in step S3: the main branches are reserved, the tree skeleton is reserved, and the fine branches and leaves are removed.

8. The tree planting method for preventing and recovering yellowing of leaves of trees under the condition of irrigation with reclaimed water in a droughty and saline-alkali land according to claim 7, characterized in that, The removal amount of all branches and leaves is less than 30%.

9. The tree planting method for preventing and recovering yellowing of leaves of trees under the condition of irrigation with reclaimed water in a regenerated arid saline-alkali land according to claim 1, characterized in that, The root-promoting nutrient solution A in step S2 comprises indole butyric acid and naphthalene acetic acid with a total concentration of 5%.

10. The tree planting method for preventing and recovering yellowing of leaves of trees under the condition of irrigation with reclaimed water in a regenerated arid saline-alkali land according to claim 1, characterized in that, The root-promoting nutrient solution B in step S3 comprises naphthalene acetic acid with a concentration of 5%.

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