Nitrogen-calcium nutrient solution for promoting growth of woody plants and application thereof

Abstract

The invention relates to the technical field of forestry, in particular to a nitrogen-calcium nutrient solution for promoting the growth of woody plants and application thereof. The nutrient solution comprises a nitrogen source and a calcium source, and the stoichiometric ratio of N to Ca is (1-2): The nutrient solution comprises the following components: 2.5 to 10 mmol / L of sodium nitrate, 2.5 to 10 mmol / L of ammonium chloride, 0 to 20 mmol / L of calcium chloride, 5 mmol / L of potassium chloride, 2 mmol / L of magnesium sulfate, 1 mmol / L of monopotassium phosphate, 0.1 mmol / L of disodium ethylene diamine tetraacetate, 0.1 mmol / L of ferrous sulfate, 0.5 mmol / L of boric acid, 0.5 mmol / L of manganese chloride, 0.0003 mmol / L of copper sulfate, 0.0008 mmol / L of zinc sulfate and 0.0005 mmol / L of molybdic acid The proper calcium-nitrogen ratio is controlled, the growth of woody plants is promoted, and particularly, the stoichiometric ratio of N to Ca is 2: 1, and the growth of poplar seedlings reaches the extreme value.

Description

Technical Field

[0001] The invention relates to the technical field of forestry, in particular to a nutrient solution with an optimal nitrogen-calcium ratio capable of promoting the growth of trees and application thereof. Background Art

[0002] The supply of nutrients is crucial in the growth and development of plants. Among them, nitrogen and calcium, as two key elements for plant growth, have a significant impact on plant growth, development, yield and quality. Nitrogen is a component of macromolecules such as proteins and nucleic acids, and plays an important role in the growth and photosynthesis of plant leaves; calcium participates in the formation of cell walls, regulates the activity of various enzymes in plants, and is essential for maintaining the stability of cell structure and function.

[0003] In the existing nutrient solution formula, various nutrients are compounded without considering the effect of the ratio of nitrogen and calcium on plant growth. Usually, each nutrient element is compounded evenly to provide comprehensive nutrition. In the cultivation of woody plants, if the nitrogen-calcium ratio is unreasonable, it is likely to cause slow plant growth, decreased stress resistance, and even symptoms of nutritional imbalance, such as yellowing and wilting of leaves. In addition, excessive nitrogen fertilizer may cause environmental pollution, and insufficient calcium will cause most of the photosynthetic products to be discharged from the roots, resulting in a reduction in biomass. On the contrary, excessive calcium supply will cause stomata to close and photosynthesis to decrease.

[0004] Therefore, it is necessary to develop a new nitrogen-calcium ratio nutrient solution to increase plant growth rate, improve fruit quality, enhance plant stress resistance, and reduce negative impacts on the environment. Such technology not only helps to improve agricultural production efficiency, but also has important significance for promoting sustainable agricultural development. Summary of the invention

[0005] To solve the above technical problems, the inventors found that an unreasonable nitrogen-calcium ratio in the nutrient solution would affect the growth of woody plants. The present invention provides a nutrient solution with an optimal nitrogen-calcium ratio that can promote the growth of woody plants.

[0006] The present invention adopts the following technical solutions:

[0007] The invention provides a calcium-nitrogen ratio nutrient solution for promoting the growth of woody plants. The nutrient solution comprises a nitrogen source and a calcium source, and the stoichiometric ratio of N:Ca is 1-2:1.

[0008] In the above technical solution, further, the woody plant is poplar.

[0009] In the above technical solution, further, the stoichiometric ratio of N:Ca is 2:1.

[0010] In the above technical solution, further, the nitrogen source is sodium nitrate and ammonium chloride, and the calcium source is calcium chloride.

[0011] In the above technical scheme, further, the nutrient solution components include: 2.5-10mmol / L sodium nitrate, 2.5-10mmol / L ammonium chloride, 0-20mmol / L calcium chloride, 5mmol / L potassium chloride, 2mmol / L magnesium sulfate, 1mmol / L potassium dihydrogen phosphate, 0.1mmol / L disodium ethylenediaminetetraacetic acid, 0.1mmol / L ferrous sulfate, 0.5mmol / L boric acid, 0.5mmol / L manganese chloride, 0.0003mmol / L copper sulfate, 0.0008mmol / L zinc sulfate and 0.0005mmol / L molybdic acid.

[0012] In the above technical scheme, further, the nutrient solution components include: 2.5mmol / L sodium nitrate, 2.5mmol / L ammonium chloride, 2.5-5mmol / L calcium chloride, 5mmol / L potassium chloride, 2mmol / L magnesium sulfate, 1mmol / L potassium dihydrogen phosphate, 0.1mmol / L disodium ethylenediaminetetraacetic acid, 0.1mmol / L ferrous sulfate, 0.5mmol / L boric acid, 0.5mmol / L manganese chloride, 0.0003mmol / L copper sulfate, 0.0008mmol / L zinc sulfate and 0.0005mmol / L molybdic acid.

[0013] In the above technical scheme, further, the nutrient solution components include: 5mmol / L sodium nitrate, 5mmol / L ammonium chloride, 2.5-5mmol / L calcium chloride, 5mmol / L potassium chloride, 2mmol / L magnesium sulfate, 1mmol / L potassium dihydrogen phosphate, 0.1mmol / L disodium ethylenediaminetetraacetic acid, 0.1mmol / L ferrous sulfate, 0.5mmol / L boric acid, 0.5mmol / L manganese chloride, 0.0003mmol / L copper sulfate, 0.0008mmol / L zinc sulfate and 0.0005mmol / L molybdic acid.

[0014] In the above technical scheme, further, the nutrient solution components include: 10mmol / L sodium nitrate, 10mmol / L ammonium chloride, 5-10mmol / L calcium chloride, 5mmol / L potassium chloride, 2mmol / L magnesium sulfate, 1mmol / L potassium dihydrogen phosphate, 0.1mmol / L disodium ethylenediaminetetraacetic acid, 0.1mmol / L ferrous sulfate, 0.5mmol / L boric acid, 0.5mmol / L manganese chloride, 0.0003mmol / L copper sulfate, 0.0008mmol / L zinc sulfate and 0.0005mmol / L molybdic acid.

[0015] The present invention also provides application of the above nutrient solution in cultivating woody plant seedlings to promote the growth of the woody plants.

[0016] The present invention also provides a method for promoting tree growth, which includes applying a nutrient solution during the cultivation process and regulating the stoichiometric ratio of nitrogen and calcium in the nutrient solution; preferably, the stoichiometric ratio of nitrogen and calcium in the nutrient solution is controlled to be 1 to 2:1.

[0017] In the above technical scheme, further, the nutrient solution components include: 2.5-10mmol / L sodium nitrate, 2.5-10mmol / L ammonium chloride, 0-20mmol / L calcium chloride, 5mmol / L potassium chloride, 2mmol / L magnesium sulfate, 1mmol / L potassium dihydrogen phosphate, 0.1mmol / L disodium ethylenediaminetetraacetic acid, 0.1mmol / L ferrous sulfate, 0.5mmol / L boric acid, 0.5mmol / L manganese chloride, 0.0003mmol / L copper sulfate, 0.0008mmol / L zinc sulfate and 0.0005mmol / L molybdic acid.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention discovered the effect of the ratio of calcium to nitrogen on plant growth, and proposed for the first time that the photosynthesis and growth of woody plants can be promoted by controlling the appropriate calcium-nitrogen ratio in the nutrient solution, and the optimum calcium level increases with the increase of nitrogen level;

[0020] 2. The nutrient solution prepared by the present invention has a perfect ratio of raw materials, which improves the absorption and utilization rate of various nutrient elements by woody plants; enables the growth of woody plant seedlings to reach the maximum biomass; especially when the stoichiometric ratio of N and Ca is 2:1, the growth of poplar seedlings reaches an extreme value. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Sodium nitrate: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0023] Ammonium chloride: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0024] Calcium chloride: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0025] Potassium chloride: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0026] Magnesium sulfate: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0027] Potassium dihydrogen sulfate: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0028] Disodium ethylenediaminetetraacetate: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0029] Ferrous sulfate: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0030] Boric acid: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0031] Manganese chloride: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0032] Copper sulfate: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0033] Zinc sulfate: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0034] Molybdic acid: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0035] The present invention is further explained below in conjunction with specific implementation modes.

[0036] The following examples are based on the following nutrient solution: potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L;

[0037] The preparation method of the nitrogen-calcium ratio is as follows:

[0038] S01 calcium treatment was provided by anhydrous calcium chloride (CaCl2), and a total of 5 exogenous calcium gradients were set, namely 0, 2.5, 5, 10, and 20 mmol / L;

[0039] The S02 nitrogen treatment was prepared by sodium nitrate (NaNO3) and ammonium chloride (NH4Cl) in a 1:1 ratio, and three exogenous nitrogen gradients were set, namely 5, 10, and 20 mmol / L;

[0040] S03 set five calcium levels under three nitrogen levels, for a total of 15 treatments.

[0041] Example 1

[0042] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0043] Sodium nitrate (NaNO3) 2.5mmol / L, ammonium chloride (NH4Cl) 2.5mmol / L, calcium chloride (Ca Cl2) 0mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0044] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0045] Cultivation of poplar seedlings:

[0046] Six poplar cuttings of uniform size were placed in a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fixed with a planting basket and a sponge. 7L of nutrient solution was added to each pot and replaced every 5 days. After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were measured.

[0047] Example 2

[0048] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0049] Sodium nitrate (NaNO3) 2.5mmol / L, ammonium chloride (NH4Cl) 2.5mmol / L, calcium chloride (Ca Cl2) 2.5mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0050] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0051] Cultivation of poplar seedlings:

[0052] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0053] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0054] Example 3

[0055] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0056] Sodium nitrate (NaNO3) 2.5mmol / L, ammonium chloride (NH4Cl) 2.5mmol / L, calcium chloride (Ca Cl2) 5mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0057] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0058] Cultivation of poplar seedlings:

[0059] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0060] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0061] Example 4

[0062] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0063] Sodium nitrate (NaNO3) 2.5mmol / L, ammonium chloride (NH4Cl) 2.5mmol / L, calcium chloride (Ca Cl2) 10mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0064] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0065] Cultivation of poplar seedlings:

[0066] Six poplar cuttings of uniform size were placed in a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fixed with a planting basket and a sponge. 7L of nutrient solution was added to each pot and replaced every 5 days.

[0067] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0068] Example 5

[0069] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0070] Sodium nitrate (NaNO3) 2.5mmol / L, ammonium chloride (NH4Cl) 2.5mmol / L, calcium chloride (Ca Cl2) 20mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0071] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0072] Cultivation of poplar seedlings:

[0073] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0074] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0075] Example 6

[0076] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0077] Sodium nitrate (NaNO3) 5mmol / L, ammonium chloride (NH4Cl) 5mmol / L, calcium chloride (CaCl2) 0mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0078] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0079] Cultivation of poplar seedlings:

[0080] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0081] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0082] Example 7

[0083] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0084] Sodium nitrate (NaNO3) 5mmol / L, ammonium chloride (NH4Cl) 5mmol / L, calcium chloride (CaCl2) 2.5mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0085] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0086] Cultivation of poplar seedlings:

[0087] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0088] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0089] Example 8

[0090] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0091] Sodium nitrate (NaNO3) 5mmol / L, ammonium chloride (NH4Cl) 5mmol / L, calcium chloride (CaCl2) 5mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0092] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0093] Cultivation of poplar seedlings:

[0094] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0095] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0096] Example 9

[0097] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0098] Sodium nitrate (NaNO3) 5mmol / L, ammonium chloride (NH4Cl) 5mmol / L, calcium chloride (CaCl2) 10mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0099] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0100] Cultivation of poplar seedlings:

[0101] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0102] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0103] Example 10

[0104] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0105] Sodium nitrate (NaNO3) 5mmol / L, ammonium chloride (NH4Cl) 5mmol / L, calcium chloride (CaCl2) 20mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0106] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0107] Cultivation of poplar seedlings:

[0108] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0109] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0110] Embodiment 11

[0111] The present embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include: sodium nitrate (NaNO3) 10mmol / L, ammonium chloride (NH4Cl) 10mmol / L, calcium chloride (CaCl2) 0mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA -Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0112] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0113] Cultivation of poplar seedlings:

[0114] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0115] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0116] Example 12

[0117] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0118] Sodium nitrate (NaNO3) 10mmol / L, ammonium chloride (NH4Cl) 10mmol / L, calcium chloride (CaCl2) 2.5mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0119] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0120] Cultivation of poplar seedlings:

[0121] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0122] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0123] Embodiment 13

[0124] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0125] Sodium nitrate (NaNO3) 10mmol / L, ammonium chloride (NH4Cl) 10mmol / L, calcium chloride (CaCl2) 5mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0126] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0127] Cultivation of poplar seedlings:

[0128] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0129] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0130] Embodiment 14

[0131] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0132] Sodium nitrate (NaNO3) 10mmol / L, ammonium chloride (NH4Cl) 10mmol / L, calcium chloride (CaCl2) 10mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0133] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0134] Cultivation of poplar seedlings:

[0135] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0136] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0137] Embodiment 15

[0138] This embodiment provides a nitrogen-calcium ratio nutrient solution that can promote the growth of woody plants. The raw materials for preparing the nutrient solution include:

[0139] Sodium nitrate (NaNO3) 10mmol / L, ammonium chloride (NH4Cl) 10mmol / L, calcium chloride (CaCl2) 20mmol / L, potassium chloride (KCl) 5mmol / L, magnesium sulfate (MgSO4·7H2O) 2mmol / L, potassium dihydrogen phosphate (KH2PO4) 1mmol / L, disodium ethylenediaminetetraacetic acid (EATA-Na2) 0.1mmol / L, ferrous sulfate (FeSO4·7H2O) 0.1mmol / L, boric acid (H3BO3) 0.5mmol / L, manganese chloride (MnCl2·4H2O) 0.5mmol / L, copper sulfate (CuSO4·5H2O) 0.0003mmol / L, zinc sulfate (ZnSO4·7H2O) 0.0008mmol / L and molybdic acid (H2MoO4·H2O) 0.0005mmol / L.

[0140] The above raw materials are mixed evenly at room temperature to prepare a nutrient solution for use.

[0141] Cultivation of poplar seedlings:

[0142] S01 Place six poplar cuttings of uniform size into a hydroponic pot with a length of 320 mm, a width of 18 mm, and a height of 140 mm, and fix them with a planting basket and a sponge. Add 7L of nutrient solution to each pot and replace it every 5 days.

[0143] After 120 days of cultivation, the growth was measured, the seedlings were harvested, and subsequent physiological indicators were determined.

[0144] Functional testing

[0145] Growth measurement: Before adding nutrient solution, use ruler and vernier caliper to measure the initial plant height and base diameter of the plant respectively. When harvesting seedlings, measure the final plant height and base diameter. Finally, use the difference between the final and the initial to calculate the growth of plant height and base diameter. When harvesting seedlings, select three plants that have not been destructively sampled, wash them, and use pruning shears to separate them into three parts: roots, stems and leaves. Put them in an envelope, put them in an oven at 105℃ for half an hour, and then dry them at 65℃ to constant weight. Use an analytical balance to measure the biomass of roots, stems and leaves, and calculate the total biomass. The measurement results are shown in Table 1.

[0146] Determination of photosynthetic indicators:

[0147] Determination of photosynthetic parameters: A photosynthetic instrument (Li-6400, Li-Cor, Inc., USA) was used to measure the photosynthetic parameters of plant leaves, such as net photosynthetic rate, stomatal conductance, transpiration rate and intercellular carbon dioxide concentration. The results are shown in Table 2.

[0148] Determination of photosynthetic pigment content: After soaking in 95% ethanol solution for 48 hours, the chlorophyll content of the leaves was determined using an ultraviolet spectrophotometer. The calculation formula is as follows:

[0149] Ca=13.95A663-6.88A646

[0150] Cb=24.96A646-7.32A663

[0151] Ca and Cb are the contents of chlorophyll a and chlorophyll b, respectively. A663 and A646 represent the absorbance values ​​of photosynthetic pigment extract at 663 and 646 nm, respectively. The results are shown in Table 3.

[0152] Determination of photosynthetic products: The soluble sugar and starch content of plant leaves was determined using the anthrone method. The results are shown in Table 4.

[0153] Determination of antioxidant enzyme activity: The activity of peroxidase (POD) was determined by the guaiacol method, the activity of catalase (CAT) was determined by the UV absorption method, and the activity of superoxide dismutase (SOD) was determined by the methionine method. The results are shown in Table 5.

[0154] Table 1 Determination of growth indexes of poplar seedlings under different nitrogen-calcium ratios

[0155] Example Plant height / cm Base diameter / mm Leaf biomass / g Stem biomass / g Root biomass / g Total biomass / g Example 1 60.10 7.14 9.60 8.57 8.00 26.18 Example 2 66.03 7.69 11.65 10.23 8.76 30.65 Example 3 58.77 7.22 10.58 9.14 7.63 27.34 Example 4 53.50 6.89 10.16 8.14 6.96 25.26 Example 5 50.33 6.37 8.41 7.42 7.07 22.90 Example 6 63.53 7.19 10.96 9.13 8.50 28.59 Example 7 69.77 8.12 10.83 10.04 9.40 30.27 Example 8 74.93 9.05 12.39 11.34 9.81 33.54 Example 9 64.17 7.33 11.08 9.32 8.06 28.60 Example 10 56.93 7.01 8.78 8.71 7.66 25.15 Embodiment 11 43.53 6.25 5.69 6.16 5.42 17.28 Example 12 54.90 7.22 9.49 8.48 7.68 25.65 Embodiment 13 65.10 8.53 10.82 9.85 9.44 30.11 Embodiment 14 72.93 8.18 12.85 10.92 9.28 33.05 Embodiment 15 66.00 7.65 9.54 7.85 7.44 24.83

[0156] Table 2 Determination of photosynthetic parameters of poplar seedlings under different nitrogen-calcium ratios

[0157] Example <![CDATA[Net photosynthetic rate / μmol·m -2 ·s -1 > <![CDATA[Stomatal conductance / mol·m -2 ·s -1 > <![CDATA[Transpiration rate / mmol·m -2 ·s -1 > <![CDATA[Intercellular carbon dioxide concentration / μmol·mo -1 > Example 1 4.33 0.05 1.45 215.72 Example 2 10.62 0.12 2.36 264.81 Example 3 7.29 0.09 1.86 225.50 Example 4 3.72 0.05 1.15 207.91 Example 5 2.89 0.03 0.99 181.64 Example 6 5.75 0.06 1.61 225.58 Example 7 8.86 0.11 2.26 242.19 Example 8 14.36 0.18 2.99 277.78 Example 9 9.03 0.14 2.05 236.73 Example 10 3.83 0.05 1.16 226.94 Embodiment 11 1.54 0.02 0.67 154.96 Example 12 6.24 0.07 1.81 175.35 Embodiment 13 11.05 0.19 2.50 250.65 Embodiment 14 12.38 0.15 2.42 209.29 Embodiment 15 8.58 0.09 1.92 177.26

[0158] Table 3 Determination of photosynthetic pigment content in poplar seedlings under different nitrogen-calcium ratios

[0159] Example Chlorophyll a content / mg·gFW Chlorophyll b content / mg·gFW Example 1 1.16 0.66 Example 2 1.49 0.80 Example 3 1.43 0.61 Example 4 1.28 0.47 Example 5 0.85 0.43 Example 6 1.293 0.75 Example 7 1.67 0.90 Example 8 1.88 1.21 Example 9 1.44 0.77 Example 10 1.33 0.68 Embodiment 11 1.12 0.41 Example 12 1.31 0.61 Embodiment 13 1.34 0.80 Embodiment 14 1.53 0.88 Embodiment 15 1.24 0.47

[0160] Table 4 Determination of photosynthetic product content of poplar seedlings under different nitrogen-calcium ratios

[0161] Example <![CDATA[Soluble sugar content / mg·g -1 > <![CDATA[Starch content / mg·g -1 > Example 1 137.0105 21.59645 Example 2 161.1405 27.81247 Example 3 146.7216 17.56841 Example 4 124.6946 10.53599 Example 5 86.48705 9.040913 Example 6 138.7253 22.10902 Example 7 146.9205 23.38261 Example 8 178.9591 29.47367 Example 9 153.8866 22.82887 Example 10 97.08451 19.00811 Embodiment 11 83.46267 16.35019 Example 12 114.9701 18.17751 Embodiment 13 112.2014 19.61722 Embodiment 14 144.1846 28.97531 Embodiment 15 112.9213 21.16767

[0162] Table 5 Determination of antioxidant enzyme activity in poplar seedlings under different nitrogen-calcium ratios

[0163] Example <![CDATA[POD activity / μmol·g -1 ·min]]> <![CDATA[CAT activity / μmol·g -1 ·min -1 > <![CDATA[SOD activity / μmol·g -1 ·min -1 > Example 1 0.40 0.27 119.58 Example 2 0.61 0.46 150.90 Example 3 0.53 0.31 125.42 Example 4 0.52 0.23 120.63 Example 5 0.36 0.16 107.08 Example 6 0.54 0.29 139.71 Example 7 0.71 0.39 148.20 Example 8 1.21 0.54 161.46 Example 9 0.71 0.33 133.96 Example 10 0.43 0.19 125.10 Embodiment 11 0.15 0.18 124.94 Example 12 0.31 0.29 136.52 Embodiment 13 0.95 0.31 145.83 Embodiment 14 1.07 0.41 158.85 Embodiment 15 0.60 0.31 149.38

[0164] As can be seen from the above examples 1-15, under different exogenous nitrogen concentrations, there are optimal Ca levels for the growth index, photosynthetic characteristics and stress resistance of poplars. The optimal Ca concentration is significantly positively correlated with the exogenous N concentration. At the same time, when the N:Ca stoichiometry reaches equilibrium, such as a ratio of 2, the growth of poplar seedlings reaches an extreme value. As a typical model plant of woody plants, the results of poplars can represent the growth and physiological conditions of woody plants. Therefore, in the future construction and management of artificial forests, it is necessary to consider the mechanism of action of the nitrogen-calcium ratio.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A calcium-nitrogen nutrient solution for promoting the growth of woody plants, characterized in that: The nutrient solution contains a nitrogen source and a calcium source, and the stoichiometric ratio of N:Ca is 1 to 2:1; preferably, the woody plant is poplar.

2. The calcium-nitrogen nutrient solution for promoting the growth of woody plants according to claim 1, characterized in that: The stoichiometric ratio of N:Ca is 2:

1.

3. The nutrient solution according to claim 1 or 2, characterized in that: The nitrogen source is sodium nitrate and ammonium chloride, and the calcium source is calcium chloride.

4. The nutrient solution according to claim 3, characterized in that The nutrient solution components include: 2.5-10mmol / L sodium nitrate, 2.5-10mmol / L ammonium chloride, 0-20mmol / L calcium chloride, 5mmol / L potassium chloride, 2mmol / L magnesium sulfate, 1mmol / L potassium dihydrogen phosphate, 0.1mmol / L disodium ethylenediaminetetraacetic acid, 0.1mmol / L ferrous sulfate, 0.5mmol / L boric acid, 0.5mmol / L manganese chloride, 0.0003mmol / L copper sulfate, 0.0008mmol / L zinc sulfate and 0.0005mmol / L molybdic acid.

5. The nutrient solution according to claim 4, characterized in that The nutrient solution components include: 2.5mmol / L sodium nitrate, 2.5mmol / L ammonium chloride, 2.5-5mmol / L calcium chloride, 5mmol / L potassium chloride, 2mmol / L magnesium sulfate, 1mmol / L potassium dihydrogen phosphate, 0.1mmol / L disodium ethylenediaminetetraacetic acid, 0.1mmol / L ferrous sulfate, 0.5mmol / L boric acid, 0.5mmol / L manganese chloride, 0.0003mmol / L copper sulfate, 0.0008mmol / L zinc sulfate and 0.0005mmol / L molybdic acid.

6. The nutrient solution according to claim 4, characterized in that The nutrient solution components include: 5mmol / L sodium nitrate, 5mmol / L ammonium chloride, 2.5-5mmol / L calcium chloride, 5mmol / L potassium chloride, 2mmol / L magnesium sulfate, 1mmol / L potassium dihydrogen phosphate, 0.1mmol / L disodium ethylenediaminetetraacetic acid, 0.1mmol / L ferrous sulfate, 0.5mmol / L boric acid, 0.5mmol / L manganese chloride, 0.0003mmol / L copper sulfate, 0.0008mmol / L zinc sulfate and 0.0005mmol / L molybdic acid.

7. The nutrient solution according to claim 4, characterized in that The nutrient solution components include: 10mmol / L sodium nitrate, 10mmol / L ammonium chloride, 5-10mmol / L calcium chloride, 5mmol / L potassium chloride, 2mmol / L magnesium sulfate, 1mmol / L potassium dihydrogen phosphate, 0.1mmol / L disodium ethylenediaminetetraacetic acid, 0.1mmol / L ferrous sulfate, 0.5mmol / L boric acid, 0.5mmol / L manganese chloride, 0.0003mmol / L copper sulfate, 0.0008mmol / L zinc sulfate and 0.0005mmol / L molybdic acid.

8. Use of the nutrient solution according to any one of claims 1 to 7 in the cultivation of woody plant seedlings.

9. A method for promoting the growth of woody plants, characterized in that: The method comprises applying a nutrient solution during the cultivation process, and regulating the stoichiometric ratio of nitrogen and calcium in the nutrient solution; preferably, the stoichiometric ratio of nitrogen and calcium in the nutrient solution is controlled to be 1 to 2:

1.

10. The method according to claim 9, characterized in that The nutrient solution components include: 2.5-10mmol / L sodium nitrate, 2.5-10mmol / L ammonium chloride, 0-20mmol / L calcium chloride, 5mmol / L potassium chloride, 2mmol / L magnesium sulfate, 1mmol / L potassium dihydrogen phosphate, 0.1mmol / L disodium ethylenediaminetetraacetic acid, 0.1mmol / L ferrous sulfate, 0.5mmol / L boric acid, 0.5mmol / L manganese chloride, 0.0003mmol / L copper sulfate, 0.0008mmol / L zinc sulfate and 0.0005mmol / L molybdic acid.