Hybrid broussonetia papyrifera planting method

Abstract

The invention relates to a planting method of hybrid broussonetia papyrifera, which comprises the following steps: planting in an area with the altitude of 2200m or below, controlling the field planting density, selecting urea, calcium superphosphate and potassium sulfate as nitrogen-phosphorus-potassium fertilizers, controlling the fertilizing amount, performing field management and disease and pest prevention and control, and controlling the cutting height and stubble height. The broussonetia papyrifera planted by the method is short in growth cycle, low in stalk lignification degree, rich in leaf quantity and high in leaf-stem ratio, the yield reaches 40275.6 kg.hm <-2 >, and the broussonetia papyrifera has good nutritional quality and feeding value.

Description

Technical Field

[0001] The invention relates to the technical field of biological planting, and in particular to a planting method for hybrid paper mulberry. Background Art

[0002] Broussonetia papyrifera, also known as "paper mulberry" or "mulberry tree", is a fast-growing and highly adaptable plant that is often used for windbreak and sand fixation, soil improvement, and greening and beautification. Hybrid Broussonetia papyrifera is a hybrid of different varieties of Broussonetia papyrifera to breed new and better varieties of Broussonetia papyrifera, which usually has advantages in improving plant characteristics, enhancing disease resistance, or increasing economic value.

[0003] Hybrid Broussonetia sp. is a new tree species bred by experts from the Institute of Botany, Chinese Academy of Sciences, through a combination of space breeding and hybrid breeding techniques. It has high nutritional value, fast growth and high yield, strong adaptability, and very few diseases and insect pests. Studies have shown that the leaves of hybrid Broussonetia sp. are rich in flavonoids and crude protein, and the contents of amino acids, vitamins and trace elements are higher than those of general crops. It is a protein feed resource with great development value, so it is also called protein tree and feed tree. At the same time, hybrid Broussonetia sp. is also an important tree species for soil and water conservation. The planting of hybrid Broussonetia sp. in saline-alkali areas, rocky desertification areas, and coal mining areas has a significant improvement on important ecological indicators such as carbon and nitrogen cycles in the atmosphere and soil, and carbon sinks.

[0004] The planting of hybrid paulownia in Guizhou has shown positive progress and potential. At present, more scientific and meticulous management techniques are needed in the cultivation of hybrid paulownia seedlings, seedling management, planting, water and fertilizer management, and mowing and stubble retention. In addition, although hybrid paulownia has strong stress resistance, its adaptability in different regions is still different, and the planting technology needs to be adjusted according to specific environmental conditions. Summary of the invention

[0005] The purpose of the invention is to provide a planting method for hybrid paper mulberry.

[0006] A hybrid paper mulberry planting method comprises the following steps: S1 site selection and planting; S2 field management and topdressing; S3 pest control; S4 mowing and stubble retention.

[0007] Furthermore, the step S1 includes site selection and planting, specifically, selecting an area below 2200m above sea level for planting, with a row spacing of 40-60cm, a nest spacing of 23-43cm, and a planting density of 54,000-64,000 plants / hm2. -2 After planting, superphosphate with P2O5≥14% and fertilizer were used at a rate of 825-975 kg·hm -2 and 13500~16500kg·hm-2 Apply once as basal fertilizer.

[0008] Preferably, choose an area below 1460m above sea level for planting, with a row spacing of 50cm, a nest spacing of 33cm, and a planting density of 59831 plants / hm2. -2 After planting, superphosphate with P2O5≥14% and fertilizer were used, with the fertilizer application rate of 899kg·hm -2 and 15000kg·hm -2 Apply once as basal fertilizer.

[0009] Preferably, the area below 1170 m above sea level is selected for planting, with a row spacing of 50 cm, a nest spacing of 33 cm, and a planting density of 59831 plants / hm2. -2 After planting, superphosphate with P2O5≥14% and fertilizer were used, with the fertilizer application rate of 899kg·hm -2 and 15000kg·hm -2 Apply once as basal fertilizer.

[0010] Further preferably, the area with an altitude below 600m is selected for planting, with a row spacing of 50cm, a nest spacing of 33cm, and a planting density of 59831 plants / hm2. -2 After planting, superphosphate with P2O5≥14% and fertilizer were used, with the fertilizer application rate of 899kg·hm -2 and 15000kg·hm -2 Apply once as basal fertilizer.

[0011] Furthermore, in step S2, field management and topdressing, in March and April and after each mowing and harvesting, when the seedlings grow to 12-15 cm, inter-cultivation, soil loosening, weeding and topdressing are carried out. In spring and summer, attention should be paid to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigation should be carried out in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, urea with N ≥ 46% and potassium sulfate with K2O ≥ 46% are selected, and urea 1050-1350 kg·hm2 is applied three times. -2 Potassium sulfate 825~975kg·hm -2 .

[0012] Preferably, in step S2, field management and topdressing, in March and April and after each mowing and harvesting, when the seedlings grow to 12-15 cm, inter-cultivation, soil loosening, weeding and topdressing are carried out. In spring and summer, attention should be paid to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigation should be carried out in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, urea with N≥46% and potassium sulfate with K2O≥46% are selected, and 1200 kg·hm2 of urea is applied three times. -2 、Potassium sulfate 897.6kg·hm -2

[0013] Furthermore, the step S3 of pest control includes: first, when the number of adults of the Lepidoptera Lymantriaidae and Noctuidae begins to increase, black light and sweet and sour liquid are used to lure and kill them; second, the sweet and sour liquid in small pots is placed around the crops and replaced every 5 to 7 days; third, 1500 to 2000 times of biological BT and 800 to 1500 times of pyrethroid insecticide are used for spraying; when the damage of aphids reaches more than 10%, 800 to 1000 times of pharmaceutical insecticide are used for spraying; fourth, systemic fungicide is used to prevent and control root rot, 800 to 1000 times of liquid is used for foliar spraying and 500 to 800 times of liquid is used for soil root irrigation treatment, and the application of insecticide is stopped more than 7 days before harvest.

[0014] The insect pests that harm paper mulberry are mainly Lysimachia, Noctuidae and aphids of Lepidoptera, and the main disease is root rot. The biological BT is a Bacillus thuringiensis microbial pesticide insecticide, which is highly efficient, low-toxic, low-residue, and has little impact on natural enemies. The pyrethroid insecticides are cypermethrin, chlorpyrifos, etc. The pharmaceutical insecticides include omethoate, pirimicarb, methyldimethoate, etc. The systemic fungicides are root rot, carbendazim and metalaxyl, etc.

[0015] Furthermore, the mowing and stubble leaving step S4 specifically includes mowing at a height of 110-170 cm and leaving stubble at a height of 10-30 cm, weeding immediately after mowing, digging furrows 20 m deep between rows after the last crop is harvested each year, and applying 13,500-16,500 kg·hm2 of fertilizer. -2 and superphosphate 825~975kg·hm -2 .

[0016] Preferably, the mowing and stubble leaving step S4 is specifically to mow at a height of 110 cm each time and leave stubble at a height of 30 cm, weed immediately after mowing, dig 20 cm deep furrows between rows after the last crop is harvested each year, and apply 15000 kg·hm2 of fertilizer. -2 and superphosphate 899kg·hm -2 .

[0017] The beneficial effects of the present invention are:

[0018] 1. The present invention provides a method for planting hybrid paulownia, which controls the planting altitude, site conditions, planting density, and fertilization, mowing, and stubble leaving steps. The hybrid paulownia planted using this method has a shorter growth cycle, a low degree of stem lignification, abundant leaves, and a leaf-stem ratio of 1.66.

[0019] 2. The hybrid paper mulberry planted using this method has a high yield, reaching 40275.6kg·hm -2 .

[0020] 3. The hybrid paulownia planted using this method has good nutritional quality and feeding value in terms of trunk matter, crude protein (CP), starch, total phosphorus, non-protein nitrogen (NPN), acid detergent fiber (ADF), neutral detergent insoluble protein (NDFIP), and acid detergent insoluble protein (ADFIP). BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The leaf-to-stem ratio of plants at different altitudes;

[0022] Figure 2 The leaf-stem ratio of plants under different site conditions;

[0023] Figure 3 is the number of branches of hybrid paper mulberry at different cutting heights;

[0024] Figure 4 This is the leaf-to-stem ratio of hybrid paper mulberry at different mowing heights.

[0025] Explanation of the accompanying figures: Different lowercase letters indicate significant differences between the same crops (P<0.05), and the same lowercase letters indicate no significant differences (P>0.05). DETAILED DESCRIPTION

[0026] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0027] Example 1

[0028] A method for planting hybrid paper mulberry comprises the following steps:

[0029] S1 Site selection and planting: The area with an altitude of 600m was selected as the planting site, with a row spacing of 50cm, a nest spacing of 33cm, and a planting density of 59831 plants / hm2 -2 , superphosphate and manure with P2O5≥14% were selected, and the fertilizer application rate was 899kg·hm -2 and 15000kg·hm -2 Apply once as basal fertilizer.

[0030] S2 Field management and topdressing: In March and April and after each mowing and harvesting, when the seedlings grow to 15cm, carry out inter-row cultivation, loosening, weeding and topdressing. In spring and summer, pay attention to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigate in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, use urea with N ≥ 46% and potassium sulfate with K2O ≥ 46%, and apply urea 1200kg·hm in three times. -2 、Potassium sulfate 897.6kg·hm -2 .

[0031] S3 Disease and pest control: First, when the number of adults of the Lepidoptera Lymantriasis and Noctuidae begins to increase, use black light and sweet and sour liquid to lure and kill them; second, place small pots of sweet and sour liquid around the crops and replace them every 6 days; third, use 1800 times diluted biological BT and 1200 times diluted Levofloxacin for spraying; when the damage of aphids reaches more than 10%, use 900 times diluted omethoate for spraying; fourth, use root rot to prevent and control root rot, use 900 times diluted foliar spray and 750 times diluted soil for root irrigation treatment. Stop applying insecticides more than 7 days before harvest.

[0032] S4 Mowing and stubble: Mowing at a height of 110 cm each time, leaving stubble at a height of 30 cm, weeding immediately after mowing, digging 20 cm deep furrows between rows after the last harvest each year, and applying 15,000 kg·hm2 of fertilizer -2 and superphosphate 899kg·hm -2 .

[0033] Example 2

[0034] A method for planting hybrid paper mulberry comprises the following steps:

[0035] S1 Site selection and planting: The area with an altitude of 1170m was selected as the planting site, with a row spacing of 60cm, a nest spacing of 43cm, and a planting density of 64,000 plants / hm2. -2 , superphosphate and manure with P2O5≥14% were selected, and the fertilizer application rate was 825kg·hm -2 and 13500 hm -2 Apply once as basal fertilizer.

[0036] S2 Field management and topdressing: In March and April and after each mowing and harvesting, when the seedlings grow to about 12 cm, carry out inter-row cultivation, loosening the soil, weeding and topdressing. In spring and summer, pay attention to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigate in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, use urea with N ≥ 46% and potassium sulfate with K2O ≥ 46%, and apply urea 1050 kg·hm in three times. -2 、Potassium sulfate 825kg·hm -2 .

[0037] S3 Disease and pest control: First, when the number of adults of the Lepidoptera Lymantriasis and Noctuidae begins to increase, use black light and sweet and sour liquid to lure and kill them; second, place small pots of sweet and sour liquid around the crops and replace them every 5 days; third, use 1500 times diluted biological BT and 800 times diluted cypermethrin for spraying; when the damage of aphids reaches more than 10%, use 800 times diluted anthelmintic for spraying; fourth, use carbendazim to prevent and control root rot, with 800 times diluted foliar spray and 500 times diluted soil for root irrigation.

[0038] S4 Mowing and stubble: Mowing at a height of 140 cm each time, leaving stubble at a height of 10 cm, weeding immediately after mowing, digging 20 cm deep furrows between rows after the last harvest each year, and applying 13,500 kg·hm2 of circle fertilizer -2 and superphosphate 825kg·hm -2 .

[0039] Example 3

[0040] A method for planting hybrid paper mulberry comprises the following steps:

[0041] S1 Site selection and planting: The area with an altitude of 1460m was selected as the planting site, with a row spacing of 40cm, a nest spacing of 23cm, and a planting density of 54,000 plants / hm2. -2 When planting for the first time, superphosphate and fertilizer with P2O5≥14% were selected, with a fertilizer rate of 975kg·hm -2 and 16500kg·hm -2 Apply once as basal fertilizer.

[0042] S2 Field management and topdressing: In March and April and after each mowing and harvesting, when the seedlings grow to 15 cm, carry out inter-row cultivation, loosening the soil, weeding and topdressing. In spring and summer, pay attention to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigate in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, use urea with N ≥ 46% and potassium sulfate with K2O ≥ 46%, and apply urea 1350 kg·hm in three times. -2 、Potassium sulfate 975kg·hm -2 .

[0043] S3 Disease and pest control: First, when the number of adults of the Lepidoptera Lymantriasis and Noctuidae begins to increase, use black light and sweet and sour liquid to lure and kill them; second, place small pots of sweet and sour liquid around the crops and replace them every 7 days; third, use 2000 times diluted biological BT and 1500 times diluted cypermethrin for spraying; when the damage of aphids reaches more than 10%, use 1000 times diluted carbendazim for spraying; fourth, use metalaxyl to prevent and control root rot, with 1000 times diluted foliar spray and 800 times diluted soil for root irrigation.

[0044] S4 Mowing and stubble: Mowing at a height of 170 cm each time, leaving stubble at a height of 30 cm. Immediately after mowing, the soil is loosened and weeded. After the last crop is harvested each year, a 20 cm deep furrow is dug between the rows and 16,500 kg hm2 of manure is applied. -2 and superphosphate 975kg·hm -2 .

[0045] Example 4

[0046] A method for planting hybrid paper mulberry comprises the following steps:

[0047] S1 Site selection and planting: The area with an altitude of 2000m was selected as the planting site, with a row spacing of 55cm, a nest spacing of 40cm, and a planting density of 59831 plants / hm2 -2 , superphosphate and manure with P2O5≥14% were selected, and the fertilizer application rate was 950kg·hm -2 and 16000kg·hm -2 Apply once as basal fertilizer.

[0048] S2 Field management and topdressing: In March and April and after each mowing and harvesting, when the seedlings grow to 14 cm, carry out inter-row cultivation, loosening the soil, weeding and topdressing. In spring and summer, pay attention to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigate in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, use urea with N ≥ 46% and potassium sulfate with K2O ≥ 46%, and apply urea 1300 kg·hm in three times. -2 、Potassium sulfate 900kg·hm -2 .

[0049] S3 Disease and pest control: First, when the number of adults of the Lepidoptera Lymantriasis and Noctuidae begins to increase, use black light and sweet and sour liquid to lure and kill them; second, place small pots of sweet and sour liquid around the crops and replace them every 6 days; third, use 1800 times diluted biological BT and 1200 times diluted Levofloxacin for spraying; when the damage of aphids reaches more than 10%, use 900 times diluted omethoate for spraying; fourth, use root rot to prevent and control root rot, use 900 times diluted foliar spray and 750 times diluted soil for root irrigation treatment. Stop applying insecticides more than 7 days before harvest.

[0050] S4 Mowing and stubble: Mowing at a height of 110 cm each time, leaving stubble at a height of 30 cm, weeding immediately after mowing, digging 20 cm deep furrows between rows after the last harvest each year, and applying 16,500 kg·hm2 of fertilizer -2 and superphosphate 945kg·hm -2 .

[0051] Example 5

[0052] A method for planting hybrid paper mulberry comprises the following steps:

[0053] S1 Site selection and planting: The area with an altitude of 800m was selected as the planting site, with a row spacing of 45cm, a nest spacing of 28cm, and a planting density of 57,000 plants / hm2. -2 , superphosphate and manure with P2O5≥14% were selected, and the fertilizer application rate was 835kg·hm -2 and 14000kg·hm -2 Apply once as basal fertilizer.

[0054] S2 Field management and topdressing: In March and April and after each mowing and harvesting, when the seedlings grow to 13 cm, carry out inter-row cultivation, loosening the soil, weeding and topdressing. In spring and summer, pay attention to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigate in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, use urea with N ≥ 46% and potassium sulfate with K2O ≥ 46%, and apply urea 1080 kg·hm in three times. -2 、Potassium sulfate 850kg·hm -2 .

[0055] S3 Disease and pest control: First, when the number of adults of the Lepidoptera Lymantriasis and Noctuidae begins to increase, use black light and sweet and sour liquid to lure and kill them; second, place small pots of sweet and sour liquid around the crops and replace them every 6 days; third, use 1550 times diluted biological BT and 850 times diluted Levofloxacin for spraying; when the damage of aphids reaches more than 10%, use 850 times diluted omethoate for spraying; fourth, use root rot killer to prevent and control root rot, use 900 times diluted foliar spray and 750 times diluted soil for root irrigation treatment. Stop applying insecticides more than 7 days before harvest.

[0056] S4 Mowing and stubble: Mowing at a height of 110 cm each time, leaving stubble at a height of 30 cm, weeding immediately after mowing, digging 20 cm deep furrows between rows after the last harvest each year, and applying 14100 kg·hm2 of circle fertilizer -2 and superphosphate 840kg·hm -2 .

[0057] Example 6

[0058] A method for planting hybrid paper mulberry comprises the following steps:

[0059] S1 Site selection and planting: The area with an altitude of 200m was selected as the planting site, with a row spacing of 48cm, a nest spacing of 33cm, and a planting density of 61,000 plants / hm2. -2 , superphosphate and manure with P2O5≥14% were selected, and the fertilizer application rate was 910kg·hm -2 and 15700kg·hm -2 Apply once as basal fertilizer.

[0060] S2 Field management and topdressing: In March and April and after each mowing and harvesting, when the seedlings grow to 15 cm, carry out inter-row cultivation, loosening the soil, weeding and topdressing. In spring and summer, pay attention to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigate in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, use urea with N ≥ 46% and potassium sulfate with K2O ≥ 46%, and apply urea 1220 kg·hm in three times. -2 、Potassium sulfate 930kg·hm -2 .

[0061] S3 Disease and pest control: First, when the number of adults of the Lepidoptera Lymantriasis and Noctuidae begins to increase, use black light and sweet and sour liquid to lure and kill them; second, place small pots of sweet and sour liquid around the crops and replace them every 6 days; third, use 1750 times diluted biological BT and 850 times diluted cypermethrin for spraying; when the damage of aphids reaches more than 10%, use 850 times diluted omethoate for spraying; fourth, use root rot killer to prevent and control root rot, use 900 times diluted foliar spray and 750 times diluted soil for root irrigation treatment; stop applying insecticides more than 7 days before harvest.

[0062] S4 Mowing and stubble: Mowing at a height of 170 cm each time, leaving stubble at a height of 30 cm, weeding immediately after mowing, digging 20 cm deep furrows between rows after the last harvest each year, and applying 15,600 kg·hm2 of fertilizer -2 and superphosphate 920kg·hm -2 .

[0063] Example 7

[0064] A method for planting hybrid paper mulberry comprises the following steps:

[0065] S1 Site selection and planting: The area with an altitude of 2000m was selected as the planting site, with a row spacing of 48cm, a nest spacing of 28cm, and a planting density of 54,000 plants / hm2. -2 When planting for the first time, superphosphate and fertilizer with P2O5≥14% were selected, with a fertilizer rate of 975kg·hm -2 and 16500kg·hm -2 Apply once as basal fertilizer.

[0066] S2 Field management and topdressing: In March and April and after each mowing and harvesting, when the seedlings grow to 15 cm, carry out inter-row cultivation, loosening the soil, weeding and topdressing. In spring and summer, pay attention to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigate in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, use urea with N ≥ 46% and potassium sulfate with K2O ≥ 46%, and apply urea 1350 kg·hm in three times. -2 、Potassium sulfate 975kg·hm -2 .

[0067] S3 Disease and pest control: First, when the number of adults of the Lepidoptera Lymantriasis and Noctuidae begins to increase, use black light and sweet and sour liquid to lure and kill them; second, place small pots of sweet and sour liquid around the crops and replace them every 7 days; third, use 2000 times diluted biological BT and 1500 times diluted cypermethrin for spraying; when the damage of aphids reaches more than 10%, use 1000 times diluted carbendazim for spraying; fourth, use metalaxyl to prevent and control root rot, with 1000 times diluted foliar spray and 800 times diluted soil for root irrigation.

[0068] S4 Mowing and stubble: Mowing at a height of 170 cm each time, leaving stubble at a height of 30 cm. Immediately after mowing, the soil is loosened and weeded. After the last crop is harvested each year, a 20 cm deep furrow is dug between the rows and 16,500 kg hm2 of manure is applied. -2 and superphosphate 975kg·hm -2 .

[0069] Example 8

[0070] A method for planting hybrid paper mulberry comprises the following steps:

[0071] S1 Site selection and planting: The area with an altitude of 1000m was selected as the planting site, with a row spacing of 53cm, a nest spacing of 33cm, and a planting density of 58,000 plants / hm2. -2 , select superphosphate with P2O5≥14% and ring fertilizer, and apply 900kg·hm -2 and 14500 hm -2 Apply once as basal fertilizer.

[0072] S2 Field management and topdressing: In March and April and after each mowing and harvesting, when the seedlings grow to about 14 cm, carry out inter-row cultivation, loosening the soil, weeding and topdressing. In spring and summer, pay attention to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigate in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, use urea with N ≥ 46% and potassium sulfate with K2O ≥ 46%, and apply urea 1250 kg·hm in three times. -2 、Potassium sulfate 875kg·hm -2 .

[0073] S3 Disease and pest control: First, when the number of adults of the Lepidoptera Lymantriasis and Noctuidae begins to increase, use black light and sweet and sour liquid to lure and kill them; second, place small pots of sweet and sour liquid around the crops and replace them every 5 days; third, use 1500 times diluted biological BT and 800 times diluted cypermethrin for spraying; when the damage of aphids reaches more than 10%, use 800 times diluted anthelmintic for spraying; fourth, use carbendazim to prevent and control root rot, with 800 times diluted foliar spray and 500 times diluted soil for root irrigation.

[0074] S4 Mowing and stubble: Mowing at a height of 170 cm each time, leaving stubble at a height of 20 cm, weeding immediately after mowing, digging 20 cm deep furrows between rows after the last harvest each year, and applying 14500 kg·hm2 of circle fertilizer -2 and superphosphate 900kg·hm -2 .

[0075] In order to further verify the effectiveness of the present invention, the inventor conducted a series of verification experiments, the excerpts of which are as follows:

[0076] 1. Determination of planting height and site conditions

[0077] 1.1 Overview of the test site

[0078] The experimental site is located in Wuxian County, Guizhou Province, in the northeast of Guizhou Province, between 107°3*′ and 108°1*′ east longitude and 28°1*′ and 29°0*′ north latitude. It belongs to the mid-subtropical humid monsoon climate, with no severe cold in winter and no extreme heat in summer. The climate is mild, the rainfall is abundant, and the water and heat are in the same season, with four distinct seasons. The frost-free period is 287 days throughout the year, the average annual rainfall is 1284.4 mm, the average temperature is 15.6℃, and the three-dimensional climate difference in the mountainous area is obvious. The territory is mainly composed of medium and low hills, with an altitude of 600m to 1500m. This experiment will select three different altitudes and three different site conditions to study the ecological adaptability and production performance of hybrid paper mulberry. The specific test site conditions are set in Table 1.

[0079] Table 1 Test point condition settings

[0080]

[0081] 1.2 Experimental materials and methods

[0082] 1.2.1 Test materials

[0083] Hybrid paper mulberry was used as the experimental material, and local paper mulberry and fodder mulberry were used as controls.

[0084] 1.2.2 Experimental design

[0085] A plot with medium soil fertility was selected and a randomized block experiment was conducted with three replicates and a plot area of ​​38.4 m 2 (6m×6.4m), basic seedlings are 59831 plants / hm 2 , the aisle between cells is 50cm, and protection rows are set. Fertilizer 15000kg·hm -2 , superphosphate 899.0kg·hm -2 As base fertilizer, urea 1200.0kg·hm -2 、Potassium sulfate 897.6kg·hm -2As topdressing, weeding and topdressing should be done immediately after mowing and yield measurement. 480 kg·hm2 should be applied after the first and second mowing respectively. -2 、359kg·hm -2 After the third mowing, apply 240 kg hm -2 、179.6kg·hm -2 The field management, pest and disease control, etc. were the same for each treatment group.

[0086] 1.2.3 Measurement indicators

[0087] The plants were mowed and measured for yield when they were 80-110 cm tall. Ten plants were randomly selected from each plot to measure plant height and number of branches. The stubble height was 30 cm, and samples were taken to measure the leaf-stem ratio. SPSS 20.0 was used for one-way analysis of variance and new multiple comparisons. The data for each group were expressed as "mean ± standard deviation".

[0088] 1.3 Results and Analysis

[0089] 1.3.1 Variance analysis of yield

[0090] A variance analysis was performed on the yield results of the three test points at different altitudes. As shown in Table 2, there were extremely significant differences among the altitudes, and there were significant differences among the varieties and the altitude × variety interaction, indicating that altitude, variety and interaction had a significant impact on yield.

[0091] Table 2 Results of variance analysis of yield at the test points at altitude

[0092]

[0093] Note: * indicates significant correlation at the 0.05 level (bilateral), ** indicates significant correlation at the 0.01 level (bilateral).

[0094] Variance analysis was performed on the yield results of the three test points under different site conditions. As shown in Table 3, the site conditions and the site condition × variety interaction reached extremely significant differences, and the variety reached a significant difference, indicating that the site conditions, variety and interaction all had a significant impact on yield.

[0095] Table 3 Results of yield equation analysis for test sites under site conditions

[0096]

[0097] Note: * indicates significant correlation at the 0.05 level (bilateral), ** indicates significant correlation at the 0.01 level (bilateral).

[0098] 1.3.2 Analysis of productivity and stability at different altitudes

[0099] The yield of each test variety is shown in Table 4. The yield of mulberry for feeding is the highest, with an average yield of 27208.62 kg·hm -2 The local paper mulberry yield is the lowest, with an average yield of 19363.03 kg·hm -2 . Comparing the differences between varieties at different altitudes, at an altitude of 600m, the yield of hybrid paper mulberry was higher than that of local paper mulberry and fodder mulberry, and the difference was not significant (p>0.05); at an altitude of 1170m, the yield of hybrid paper mulberry was lower than that of fodder mulberry (p<0.05) and local paper mulberry (p>0.05); at an altitude of 1460m, the yield of local paper mulberry was the lowest, and the difference was not significant (p>0.05). Comparing the differences between the same varieties at different altitudes, the yields of hybrid paper mulberry, local paper mulberry, and fodder mulberry at an altitude of 600m were all higher than those at the other two altitudes (p<0.05).

[0100] Table 4 Multiple comparisons of yield differences among varieties at different altitudes (kg·hm -2 )

[0101]

[0102] Note: Data in the same column with different lowercase letters indicate significant differences (P<0.05); Data in the same column with different uppercase letters indicate significant differences (P<0.05).

[0103] The results of the yield and stability analysis are shown in Table 5. The yield of fodder mulberry is the highest and the yield effect value is the largest, followed by hybrid paper mulberry. The local paper mulberry performs the worst and has the smallest yield effect. The hybrid paper mulberry has the largest variance and the highest variability, indicating that the coefficient of variation of the hybrid paper mulberry at different altitudes is large and relatively unstable. The regression coefficient of hybrid paper mulberry and local paper mulberry is greater than 1, indicating that the two varieties are suitable for a better environment, and the larger the regression coefficient, the greater the impact of the altitude and the worse the stability. The variance of fodder mulberry is the smallest and the variability is the lowest, indicating that the coefficient of variation of the yield at different altitudes is small, and the regression coefficient is 0.509, indicating that fodder mulberry is suitable for a poor environment and has better stability. Overall, hybrid paper mulberry is better than local paper mulberry, but worse than fodder mulberry.

[0104] Table 5 Analysis of the yield and stability of varieties at different altitudes

[0105]

[0106] 1.3.3 Analysis of productivity and stability under different site conditions

[0107] The yield of each variety is shown in Table 6. The yield of mulberry for feeding is the highest, with an average yield of 30218.52 kg·hm -2, the average yield of hybrid paper mulberry is close to that of local paper mulberry. Comparing the differences between varieties under different site conditions, the yield of hybrid paper mulberry in flat land and sloped land returned to farmland is higher than that of the other two varieties, while the yield in rocky desertification is much lower than that of the other two varieties (p>0.05). Comparing the differences between the same varieties under different site conditions, the yield of hybrid paper mulberry in flat land and sloped land returned to farmland is much higher than that in rocky desertification (p>0.05), and the yield of local paper mulberry and fodder mulberry gradually decreases as the site conditions deteriorate, with the lowest yield in rocky desertification.

[0108] Table 6 Multiple ratios of yield differences among varieties under different site conditions (kg·hm -2 )

[0109]

[0110] The results of the yield and stability analysis are shown in Table 7. The yield of fodder mulberry is the highest and the yield effect value is the largest, followed by local paper mulberry, and hybrid paper mulberry performs the worst and has the smallest yield effect. Hybrid paper mulberry has the largest variance and the highest variability, indicating that the coefficient of variation of hybrid paper mulberry under different site conditions is large and relatively unstable. The regression coefficient of hybrid paper mulberry is greater than 1, indicating that it is suitable for a better environment, and the larger the regression coefficient, the greater the impact of the site conditions and the worse the stability. The variance of fodder mulberry is the smallest and the variability is the lowest, indicating that the coefficient of variation of yield under different site conditions is small, and the regression coefficient is 0.616, indicating that fodder mulberry is suitable for a poorer environment and has better stability.

[0111] Table 7 Analysis of the yield and stability of varieties under site conditions

[0112]

[0113] 1.3.4 Effects on hybrid paper mulberry plant height

[0114] The results are shown in Table 8. Altitude has a significant effect on the height of hybrid papaya. At an altitude of 600m, the height of the first mowing was significantly higher than that of the other two altitudes (p<0.01), and three yield measurements were completed during the same growth period, indicating that hybrid papaya grew fastest and had the best regeneration speed at this altitude; only two mowings were completed at altitudes of 1170m and 1460m, indicating that the growth was slow. The average plant height of each crop at the three altitudes was 109.30cm, 102.28cm, and 108.05cm, respectively, showing that altitude 1170m < altitude 1460m < altitude 600m.

[0115] Site conditions have a great influence on the height of hybrid papyrus. At different measurement times, the first crop height of flat land, decultivated sloping land, and rocky desertification land was significantly higher than the second and third crops (p<0.05). Under different site conditions, the plant height of each crop in flat land was significantly higher than that in decultivated sloping land and rocky desertification land (p<0.05). The average plant height in various places was 109.30cm, 102.03cm, and 95.47cm, respectively, showing that rocky desertification land < decultivated sloping land < flat land.

[0116] Table 8 Plant height of hybrid paper mulberry under different conditions (cm)

[0117]

[0118] Note: Data in the same column with different lowercase letters on the shoulders indicate significant differences (P<0.05); data in the same column with different uppercase letters on the shoulders indicate significant differences (P<0.05), and no shoulder indicates no significant difference (P>0.05).

[0119] 1.3.5 Effect on the number of branches of hybrid paper mulberry

[0120] At different altitudes, the number of branches at 600m and 1170m gradually decreased with the increase of mowing times, and the number of branches at 1460m increased with the increase of mowing times, but the difference was not significant (P>0.05). The average number of branches at the three altitudes was 14.58, 9.10, and 8.42, respectively, showing a trend of decreasing with increasing altitude.

[0121] Site conditions had little effect on the number of branches of hybrid paper mulberry. The number of branches in flat land and rocky desertification land decreased with the increase of mowing times, and the difference was not significant (P>0.05). As shown in Table 9, the number of branches in the second crop of flat land and retired sloping land was significantly higher than that of rocky desertification land (P<0.05). The average number of branches in the three site conditions was 13.58, 13.63, and 12.18, respectively, which shows that the number of branches was close.

[0122] Table 9 Number of branches of hybrid paper mulberry under different conditions

[0123]

[0124]

[0125] Note: Data in the same column with different lowercase letters on the shoulders indicate significant differences (P<0.05); data in the same column with different uppercase letters on the shoulders indicate significant differences (P<0.05), and no shoulder indicates no significant difference (P>0.05).

[0126] 1.3.6 Effect on leaf-to-stem ratio

[0127] from Figure 1It can be seen that the altitude has a great influence on the leaf-stem ratio of hybrid paper mulberry, with the highest leaf-stem ratio at 600m above sea level being 1.66, which is higher than that of local paper mulberry and fodder mulberry, indicating that its leaves are most abundant at this altitude. The highest leaf-stem ratio of local paper mulberry is 1.77 at an altitude of 1170m, and the highest leaf-stem ratio of fodder mulberry is 1.57 at an altitude of 1460m.

[0128] from Figure 2 It can be seen that the leaf-to-stem ratio of hybrid paper mulberry shows an increasing trend, with the highest value of 2.37 in rocky desertification land, and the leaf-to-stem ratio of hybrid paper mulberry in different site conditions is higher than that of local paper mulberry and fodder mulberry in the same location; the leaf-to-stem ratio of local paper mulberry under the three site conditions is not much different, which are 1.45, 1.41 and 1.39 respectively; the highest value of fodder mulberry is 1.51 in rocky desertification area and the lowest is 1.16 in abandoned farmland.

[0129] 1.4 Summary

[0130] This study planted hybrid papaya in different test areas and found that the altitude and site conditions had a great influence on the growth performance of hybrid papaya, and its yield, plant height, and leaf-stem ratio showed great differences. Plant height and yield are key indicators of hybrid papaya production performance. Plant height can reflect the growth rate and yield of hybrid papaya. The higher the plant height, the faster it grows and the higher the relative yield. In this experiment, the average plant height of hybrid papaya under different conditions was basically proportional to the yield.

[0131] At different altitudes, hybrid paulownia grew faster at the test site at an altitude of 600m, with a total of three mowings and the highest yield, while only two mowings were completed at the other two altitudes, and the yield decreased significantly with the increase in altitude. Among them, the yield of the test site at an altitude of 1170m was much lower than that of the test site at an altitude of 1460m, which may be related to the adaptability of hybrid paulownia to environmental conditions. The regeneration was slow after the first mowing, and the number of branches was significantly less than that of the test sites at an altitude of 600m and 1460m. Under different site conditions, the annual yield results show that the yield of hybrid paulownia is the lowest in rocky desertification, which may be due to its poor adaptability under these conditions. In addition, the yield of hybrid paulownia in flat land and retired sloping land is similar, which shows that it can adapt well to these two site conditions.

[0132] The leaf-to-stem ratio can better reflect the palatability and quality of forage. The more leaves there are, the better the quality is, and the more conducive it is to livestock feeding and utilization. In this experiment, hybrid paulownia has a higher leaf-to-stem ratio at an altitude of 600m and in rocky desertification areas, but the causes are slightly different. The hybrid paulownia was measured more times at the test point at an altitude of 600m than at the other two altitudes, and it has a shorter growth cycle, low degree of stem lignification, and abundant leaves. Therefore, the leaf-to-stem ratio is higher than that at the other two altitudes. Hybrid paulownia grows slowly in rocky desertification areas, has thinner stems, and the average plant height and average number of branches are lower than those in the other two sites. Therefore, the leaf-to-stem ratio is higher than that in the other two areas.

[0133] This experiment used local paper mulberry and fodder mulberry as controls. Under different altitudes and site conditions, the yield of hybrid paper mulberry was somewhat different from that of fodder mulberry, but the leaf-stem ratio of hybrid paper mulberry at altitudes of 600m and 1460m was higher than that of fodder mulberry, indicating that hybrid paper mulberry had a higher feeding value. Compared with local paper mulberry, the yield of hybrid paper mulberry was slightly higher or lower, and fluctuated greatly between different crops, which may be because local paper mulberry is a native plant and has a strong adaptability to local climate conditions and soil environment.

[0134] Li Cheng et al.'s study "Analysis of the Stability of Beer Barley Varieties Using the AMMI Model" showed that the higher the main effect, the better the yield of the variety; the regression coefficient is used as a reference for variety adaptability. When the value is 1, it means that the variety has wide adaptability and is not strict with the environment. The coefficient of variation reflects the degree of variation of the variety. The smaller the value, the better the stability of the variety in each pilot. The results show that hybrid paulownia has a poor main effect in different pilots, the highest coefficient of variation, and is relatively unstable. It performs better in the pilots at an altitude of 600m and on flat land. In summary, hybrid paulownia planted on flat land at an altitude of 600m shows better growth and can be promoted for planting.

[0135] 2. Planting density and N, P, K ratio fertilization determination

[0136] 2.1 Overview of the test site

[0137] The test site is located in Huabao, Wuxian County, Guizhou Province, in the northeast of Guizhou Province, between 107°3*′ and 108°1*′ east longitude and 28°1*′ and 29°0*′ north latitude. It belongs to the mid-subtropical humid monsoon climate, with no severe cold in winter and no extreme summer, mild climate, abundant rainfall, water and heat in the same season, and four distinct seasons. There are 287 frost-free days throughout the year, an average annual rainfall of 1284.4 mm, an average temperature of 15.6℃, and obvious three-dimensional differences in mountain climate.

[0138] 2.2 Test methods

[0139] Select a plot with medium soil fertility and adopt the sequential arrangement test method with a plot area of ​​30m 2 (6m×5m), set up 3 repetitions, 50cm aisle between plots, and 2 rows of protective rows planted around. The test fertilizers are urea (N≥46%) for nitrogen fertilizer, superphosphate (P2O5≥14%) for phosphorus fertilizer, and potassium sulfate (K2O≥46%) for potassium fertilizer. Phosphorus fertilizer is applied once as base fertilizer, and urea and potassium sulfate are applied at the seedling stage and after each mowing, and the topdressing is carried out three times in total. Other management measures are carried out according to the daily management measures of paper mulberry, and the management measures of each plot are the same.

[0140] Orthogonal experiment is a computational method that efficiently handles multi-factor optimization problems. The experimental plan is arranged using a standardized orthogonal table, and the results are calculated and analyzed to eventually find the optimal plan. The experiment sets four factors: nitrogen application rate (X1), potassium application rate (X2), phosphorus application rate (X3), and planting density (X4). The factor level coding reference table is shown in Table 10. A four-variable quadratic regression orthogonal design is adopted, and the fresh grass yield per hectare of hybrid paulownia is used as the objective function. A total of 25 treatment plots are set up according to the design requirements.

[0141] Table 10 Experimental factors and level coding table

[0142]

[0143] 2.3 Data Statistics and Analysis

[0144] According to the requirements of the quaternary quadratic regression orthogonal combination design, the codes of the respective variables are filled into the corresponding structure matrix, see Table 11. In order to avoid the destruction of the orthogonality of the combination design after direct squaring, the quadratic term X1 2 and X2 2 and X3 2 The code value of is centrally processed, with the central code value X ij ′ replaced the squared coding value. SPSS20.0 and DPS software were used for statistical analysis.

[0145] The formula for centralizing the quadratic term is:

[0146]

[0147] Table 11 Four-factor five-level quadratic orthogonal regression combination design structure matrix and test results

[0148]

[0149]

[0150] 2.4 Results and Analysis

[0151] The regression coefficients of various factors were calculated, and a mathematical regression model of hybrid paper mulberry yield and four factors, nitrogen fertilizer (X1), potassium fertilizer (X2), phosphorus fertilizer (X3), and density (X4), was established:

[0152] Y=33818.555+6503.306X1+551.501X2+587.613X3+7337.088X4+329.686X1*X2-

[0153] 707.119X1*X3+2311.980X1*X4-925.174X2*X3+371.703X2*X4+287.673X3*X4-2307.846X1′+349.097X2′+823.404X3′-5613.403X4′

[0154] See Table 12. The significance test of the regression equation is F = 21.866 > F 0.01 (F 0.01 =4.60), reaching an extremely significant level, and the R2 value is 0.968. This shows that the predicted value of the established model fits the actual situation well, and the equation can be used for prediction.

[0155] Since the factors have been dimensionlessly coded, the absolute values ​​of the coefficients of the regression equation can be used to compare the influence of each factor on the yield. The influence of the four factors on the yield of hybrid paulownia is in the order of potassium fertilizer < phosphorus fertilizer < nitrogen fertilizer < density.

[0156] In addition to the significance test of the regression equation as a whole, the significance test of the regression coefficient is also required. As can be seen from Table 12, X1, X4, X1X4, X1′ and X4′ have extremely significant effects on yield, while the other items have no significant effects on yield.

[0157] Table 12 Variance analysis table

[0158]

[0159]

[0160] Note: **F>F 0.01 , indicating that the difference is extremely significant.

[0161] After eliminating insignificant regression coefficients, the equation is adjusted to:

[0162] Y=33818.555+6503.306X1+7337.088X4+2311.980X1*X4-2307.846X1′-5613.403

[0163] X4′

[0164] Substitute the quadratic term centering formula into the equation to restore the factors and obtain the regression equation:

[0165] Y=27481.5558+6503.306X1+7337.088X4+2311.980X1*X4-2307.846X1 2 -5613.40

[0166] 3X4 2

[0167] On the DPS data processing platform, input the regression equation and constraint conditions (-1.414≤X j ≤1.414), the objective function value (maximum yield) is 40275.6 kg·hm -2 , the best fertilizer dosage: X1 = 1.4140, equivalent to 1200.0 kg·hm -2 ; X2 = 1.4103, equivalent to 897.6 kg·hm2 of potassium application -2 ; X3 = 1.4125, equivalent to 899.0 kg·hm2 of phosphorus application -2 , X4=1.023, that is, the density is 59830.7 plants·hm -2 .

[0168] 3. Determination of mowing height

[0169] 3.1 Overview of the test site

[0170] The test site is located in Wuxian County, Guizhou Province (mostly at an altitude of 600m to 1500m, 107°5*′**″ east longitude, 28°4*′**″ north latitude), which is located in the northeast of Guizhou and has a mid-subtropical humid monsoon climate. There is no severe cold in winter and no extreme summer. The climate is mild, the rainfall is abundant, and the water and heat are in the same season. There are four distinct seasons. The frost-free period is 287 days throughout the year, the average annual rainfall is 1284.4 mm, and the average temperature is 15.6℃. The three-dimensional climate difference in the mountainous area is obvious.

[0171] 3.2 Experimental design

[0172] Mowing is the main way to use and manage forage. Different mowing treatments will affect the yield and quality of the plant, which are important indicators for evaluating the production performance of hybrid paper mulberry. Many studies have shown that choosing an appropriate mowing height can better promote plant tillering and regeneration, and obtain high-yield and high-quality forage.

[0173] The experimental material is hybrid paper mulberry, which was planted in 2021. A flat plot was selected as the experimental site, and the mowing height was set to 50cm, 80cm, 110cm, 140cm, and 170cm, respectively recorded as C50, C80, C110, C140, and C170. Each group was treated with 3 replicates, arranged in sequence. The plot area is 30m 2 (6m×5m), aisle 50cm, 2 rows of protection rows planted around. Superphosphate 899.0kg·hm -2 As base fertilizer, urea 1200.0kg·hm -2 、Potassium sulfate 897.6kg·hm -2 As topdressing, weeding and topdressing were carried out immediately after mowing and yield measurement, and 600.0 kg·hm -2、448.8kg·hm -2 .

[0174] 3.3 Sample collection and quality determination

[0175] Before mowing, 10 hybrid paper mulberry trees were randomly selected in each plot, and their natural height from the ground to the highest part of the plant was measured, and the number of branches was determined. The fresh weight of stems and leaves was measured, and the hay yield and leaf-to-stem ratio were calculated after drying.

[0176] The collected samples are dried and the dry matter, crude protein, crude fat, lignin, neutral detergent fiber, acid detergent fiber, water-soluble carbohydrates, starch, total phosphorus, total calcium, non-protein nitrogen, neutral detergent insoluble protein, acid detergent insoluble protein and other indicators are determined according to the methods in "Feed Analysis and Feed Quality Testing Technology".

[0177] 3.4 Data Statistics and Analysis

[0178] Excel was used to preliminarily organize and process the experimental data, SPSS20.0 was used for one-way analysis of variance and new multiple range comparisons, and Origin software was used for drawing. The data of each group were expressed as "mean ± standard deviation".

[0179] The comprehensive evaluation of hybrid paper mulberry quality adopts the fuzzy mathematical membership function method. The membership function value of each treatment single index is calculated, and then the membership function average of each treatment is calculated. The larger the value, the better the comprehensive nutritional quality under the treatment. The membership function value calculation formula is:

[0180] Positive correlation index function value Y = (X-Xmin) / (Xmax-Xmin)

[0181] Negative correlation index function value Y = 1-(X-Xmin) / (Xmax-Xmin)

[0182] Where: X is the current processing raw data, Xmax is the maximum value of the treatment group index, and Xmin is the minimum value of the treatment group index. In this experiment, total hay yield, dry matter, crude protein, crude fat, water-soluble carbohydrates, starch, total phosphorus, total calcium, and non-protein nitrogen were positively correlated with feeding value; lignin, neutral detergent fiber, acid detergent fiber, neutral detergent insoluble protein, and acid detergent insoluble protein were negatively correlated with feeding value.

[0183] 3.5 Results and Analysis

[0184] 3.5.1 Effects of different cutting heights on the biomass yield of paper mulberry

[0185] There were significant differences in the yield of hybrid papyrus under different treatments. As shown in Table 13, the yield of fresh grass in the first crop increased with the increase of mowing height. The fresh grass yield of C170 was significantly higher than that of C50, C80, and C110 (P < 0.05). The yield of fresh grass in the second crop increased first and then decreased with the increase of mowing height. The fresh grass yield of C80 was significantly higher than that of other treatment groups (P < 0.05). The contribution rate of each treatment group to the annual yield of fresh grass was the largest in the first crop, among which C170 was the highest in the first crop at 92.17%, and the contribution rate increased with the increase of mowing height; the highest in the second crop was C50 at 45.47%, and the contribution rate decreased with the increase of mowing height. In terms of total annual yield, C170 had the highest dry and fresh weight yield, and the fresh grass yield reached 28208.34 kg·hm -2 , which was significantly different from C50 and C80 (P<0.05), and the hay yield reached 6553.40 kg·hm -2 , which was significantly different from C50, C80 and C140 (P<0.05).

[0186] Table 13 Effect of different cutting heights on hybrid papyrus yield Unit: kg·hm -2

[0187]

[0188] Note: Different lowercase letters in the same column indicate significant differences (P<0.05), and the same lowercase letters indicate no significant differences (P>0.05).

[0189] 3.5.2 Effects of different cutting heights on the botanical characteristics of hybrid paper mulberry

[0190] See also Figure 3 The first-crop C80 treatment group had the most branches, which was significantly higher than C50, C110, and C170 (P < 0.05). The second-crop branch number gradually decreased with the increase of mowing height. The C50 treatment group had the most branches, which was significantly higher than C110, C140, and C170 (P < 0.05). The leaf-to-stem ratio of hybrid paper mulberry directly affects the feeding amount of herbivorous animals. The results showed that the first-crop C50 had the highest leaf-to-stem ratio of 2.77, which was significantly higher than other treatment groups (P < 0.05). Figure 4 The leaf-to-stem ratio of the second crop increased with the increase of cutting height, with C170 having the highest leaf-to-stem ratio of 3.10, which was significantly higher than that of other treatment groups (P<0.05).

[0191] 3.5.3 Effects of different cutting heights on hybrid papyrus quality

[0192] As shown in Table 14, different mowing heights have an impact on the nutritional qualities of hybrid paper mulberry. The dry matter content was the highest in C110, but the difference was not significant with other groups (P>0.05). The crude protein content was the highest in C80, which was significantly higher than other groups (P<0.05). The starch content was the highest in C140, which was significantly higher than C50, C80, and C170 (P<0.05). The total phosphorus content was the highest in C50, and the difference was significant (P<0.05), showing a trend of gradually decreasing with the increase of mowing height. The non-protein nitrogen content was the highest in C80, and the difference was significant (P<0.05). The acid detergent fiber and neutral detergent insoluble protein contents were the lowest in C110, and showed a "high-low-high" change pattern with the increase of mowing height, and the difference was significant (P<0.05). The content of insoluble protein in acid washing was the lowest in C170, which was significantly higher than that in C50 and C80 (P<0.05). The other nutritional indexes showed no significant difference (P>0.05).

[0193] Table 14 Nutrient composition of hybrid paper mulberry at different cutting heights

[0194]

[0195] Note: Different lowercase letters in the same row indicate significant differences (P<0.05), and the same lowercase letters indicate no significant differences (P>0.05).

[0196] 3.5.4 Comprehensive evaluation of the feeding value of hybrid papyrus at different cutting heights

[0197] The fuzzy mathematical membership function method was used to comprehensively evaluate the feeding value of hybrid paper mulberry under different mowing treatments. The largest comprehensive value indicated that the feeding value of the treatment was higher. As shown in Table 15, the comprehensive value was C50<C170<C80<C140<C110. The treatment with a mowing height of 110 cm had the highest comprehensive score and high feeding value, while the feeding value was the lowest under the treatment with a mowing height of 50 cm.

[0198] Table 15 Membership function values ​​of feeding value indexes of hybrid paper mulberry

[0199]

[0200] 3.4 Summary

[0201] In this study, the annual yield of hybrid paulownia was C50<C80<C140<C110<C170, among which the contribution rate of the first crop yield to the total yield was much higher than that of the second crop, and increased with the increase of mowing height, indicating that the yield of hybrid paulownia is directly related to the mowing height, and the first crop yield is crucial in the annual production and harvesting management. The contribution rate of the second crop yield decreases with the increase of mowing height. There may be many reasons. On the one hand, the growing season of the first crop is the most suitable, with abundant rainfall. The growth environment of the second crop has higher temperature and drought conditions compared with the first crop, which leads to slow growth. On the other hand, the high mowing height weakens the regeneration ability of hybrid paper mulberry. The leaf-stem ratio gradually decreases with the increase of mowing height in the first crop. It can be seen that the stem thickness of its branches increases and the degree of lignification increases. On the contrary, the number of branches gradually decreases with the increase of mowing height, and the leaf-stem ratio gradually increases. In addition, the growth time of C140 and C170 groups is much longer than that of other groups, but the height growth is extremely slow, reflecting that the mowing height has a greater impact on the regeneration ability. In order to achieve sustainable growth of hybrid paper mulberry, the mowing height should not be too high, and a height of 110 cm is appropriate.

[0202] This study uses the fuzzy mathematical average membership function method to comprehensively evaluate the quality of hybrid paper mulberry based on multiple nutritional value indicators. The higher the average value, the higher the feeding value. In this study, the cutting height had a significant effect on dry matter, crude protein (CP), starch, total phosphorus, non-protein nitrogen (NPN), acid detergent fiber (ADF), neutral detergent insoluble protein (NDFIP), and acid detergent insoluble protein (ADFIP) (P < 0.05), and showed a certain regularity. CP is an important indicator for evaluating the nutritional quality of forage. In this experiment, the CP content of hybrid paper mulberry was between 11.94% and 15.81%. ADF and neutral detergent fiber (NDF) are related to the palatability and digestibility of forage, respectively. The higher the content of both, the lower the digestibility, the less absorption, and the worse the plant palatability. In the test results, the NDF content of hybrid paper mulberry is 56.26% to 60.51%, and the ADF content is 29.02% to 37.07%. It can be seen that the cellulose accumulation of hybrid paper mulberry increases, and the lignin is also high, at 10.52% to 12.88%, and the stem fiberization is serious. ADFIP and NDFIP are crude proteins in ADF and NDF, respectively. After these crude proteins are combined with crude fiber, the utilization efficiency of crude protein is reduced. The higher the combination rate, the lower the utilization rate.

[0203] Crude fat (EE) is the energy reserve of forage and the main energy supply of livestock. In this experiment, the EE content was 14.42% to 15.74%, and the cutting height had no significant effect on EE (P>0.05).

[0204] Phosphorus and calcium are important minerals required by livestock and poultry. The average total phosphorus content of hybrid paper mulberry is 2.50 g·kg-1 , with the increase of cutting height, it showed a decreasing trend, while the average total calcium content was 17.23 g·kg -1 , and it showed an increasing trend with the increase of mowing height. From the perspective of calcium and phosphorus supplementation for livestock, C140 was the treatment group with the highest comprehensive calcium and phosphorus content.

[0205] NPN can provide nitrogen source for rumen microorganisms to synthesize bacterial protein. Adding an appropriate amount of NPN to the diet will improve the growth performance of ruminants and increase the conversion rate of protein in feed. The average content of NPN in hybrid paper mulberry is 5.33 g·kg -1 , its effect on livestock needs further in-depth study.

[0206] 4. Determination of stubble height

[0207] 4.1 Overview of the test site

[0208] The test site is located in Wuxian County, Guizhou Province (mostly at an altitude of 600m to 1500m, 107°5*′**″ east longitude, 28°4*′**″ north latitude), which is located in the northeast of Guizhou and has a mid-subtropical humid monsoon climate. There is no severe cold in winter and no extreme heat in summer. The climate is mild, the rainfall is abundant, and the water and heat are in the same season. There are four distinct seasons. The frost-free period is 287 days throughout the year, the average annual rainfall is 1284.4 mm, and the average temperature is 15.6℃. The three-dimensional climate difference in the mountainous area is obvious.

[0209] 4.2 Experimental design

[0210] The experimental material is hybrid paper mulberry, which was planted in 2021. A flat plot was selected as the experimental site, and the stubble height was set to 10cm, 20cm, 30cm, 40cm, and 50cm. Each group was treated with 3 replicates, arranged in sequence. The area of ​​the plot is 30m 2 (6m×5m), aisle 50cm, 2 rows of protection rows planted around. Superphosphate 899.0kg·hm -2 As base fertilizer, urea 1200.0kg·hm -2 、Potassium sulfate 897.6kg·hm -2 As topdressing, weeding and topdressing were carried out immediately after mowing and yield measurement, and 600.0 kg·hm -2 、448.8kg·hm -2 .

[0211] 4.3 Sample collection and quality determination

[0212] Before mowing, 10 hybrid paper mulberry trees were randomly selected in each plot, and their natural height from the ground to the highest part of the plant was measured, and the number of branches was determined. The fresh weight of stems and leaves was measured, and the hay yield and leaf-stem ratio were calculated after drying. The collected samples were dried, and the dry matter, crude protein, lignin, neutral detergent fiber, acid detergent fiber and other indicators were determined according to the methods in "Feed Analysis and Feed Quality Testing Technology".

[0213] 4.4 Data Statistics and Analysis

[0214] Excel was used to preliminarily organize and process the experimental data, and SPSS20.0 was used for one-way analysis of variance and new multiple range comparisons. The data of each group were expressed as "mean ± standard deviation".

[0215] 4.5 Results and Analysis

[0216] 4.5.1 Effect of stubble height on hybrid paper mulberry biomass

[0217] The biomass of hybrid paper mulberry refers to the total amount of organic matter produced and accumulated during the growth period. Its level is one of the important economic indicators for judging its rationality as a feed crop, and it is of great significance for judging the organ balance and yield increase potential of hybrid paper mulberry. As shown in Table 16, the stubble height has a significant effect on the biomass of hybrid paper mulberry (P < 0.05). With the increase of stubble height, the total fresh and dry yields of hybrid paper mulberry show a trend of increasing first and then decreasing. The fresh grass yield of the first and second stubbles shows the same rule, and the highest yield is reached when the stubble is 30 cm. The contribution rate of the first stubble to the total yield gradually decreases with the increase of stubble height, and the contribution rate of the second stubble to the total yield increases with the increase of stubble height.

[0218] Table 16 Effect of different stubble heights on hybrid papyrus yield Unit: kg·hm -2

[0219]

[0220] Note: Data in the same column with different lowercase letters indicate significant differences (P<0.05), while data with the same lowercase letters indicate no significant differences (P>0.05).

[0221] 4.5.2 Effect of stubble height on agronomic traits of hybrid papyrus

[0222] As shown in Table 17, in the first crop, the stubble height had no significant effect on plant height and branch number (P>0.05), and the leaf-stem ratio increased with the increase of stubble height, and the difference was significant (P<0.05). In the second crop, plant height increased with the increase of stubble height, and the difference was significant (P<0.05). The stubble height had no significant effect on the branch number and leaf-stem ratio (P>0.05), but the leaf-stem ratio gradually decreased with the increase of height.

[0223] Table 17 Growth indexes of hybrid papyrus with different stubble heights

[0224]

[0225] Note: Different lowercase letters indicate significant differences among different treatments in the same crop (P<0.05), and the same lowercase letters indicate no significant differences (P>0.05). The same below.

[0226] 4.5.3 Effect of stubble height on the nutritional value of hybrid paper mulberry

[0227] The nutritional quality analysis of hybrid papyrus at different stubble heights is shown in Table 18. The effect of stubble height on dry matter was not significant (P>0.05). With the increase of stubble height, the crude protein content of hybrid papyrus increased, but the difference was not significant (P>0.05). Stubble height had a significant effect on lignin, neutral detergent fiber, and acid detergent fiber (P<0.05).

[0228] Table 18 Analysis of nutritional quality of hybrid papyrus at different stubble heights

[0229]

[0230] 4.5.4 Comprehensive evaluation of the feeding value of hybrid papyrus with different stubble heights

[0231] The fuzzy mathematical membership function method was used to comprehensively evaluate the feeding value of hybrid paper mulberry under different stubble treatments. The largest comprehensive value indicated that the higher the feeding value of the treatment. As shown in Table 19, the comprehensive value of the stubble height was 20cm<50cm<10cm<40cm<30cm. The treatment with a stubble height of 30cm had the highest comprehensive score and high feeding value, and the feeding value was the lowest under the treatment with a stubble height of 20cm.

[0232] Table 19 Membership function values ​​of feeding value indexes of hybrid paper mulberry

[0233]

[0234] 4.6 Summary

[0235] Stubble is a common management method in forage production and utilization. It affects the biomass and nutritional quality of forage by changing the material distribution and transportation of plants. Biomass and quality are important indicators for evaluating forage production performance. When the stubble of hybrid paulownia is 10cm to 30cm, the annual yield increases with the increase of height. When the stubble is 30cm to 50cm, the annual yield decreases significantly, and is even far lower than the annual yield of 10cm to 30cm. Among them, the contribution rate of the first stubble yield decreases with the increase of stubble height, because the stems left at the bottom of the hybrid paulownia are gradually increasing, resulting in a decrease in yield; the contribution rate of the second stubble yield increases with the increase of stubble height, which may be because the stubble height is too low, which will affect the later tillering and growth of hybrid paulownia. It can be seen from the fact that the number of branches in the stubble of 10cm and 20cm is much lower than that in the other three treatment groups. However, if the stubble is too high, the branches and leaves left on the ground cannot be used. Therefore, from the perspective of promoting the growth and economic yield of hybrid paulownia, stubble of 30cm is helpful to increase the yield of hybrid paulownia.

[0236] This study uses the fuzzy mathematical average membership function method to comprehensively evaluate the quality of hybrid paper mulberry based on multiple nutritional value indicators. The higher the average value, the higher the feeding value. Crude protein is an essential nutrient for livestock and an important evaluation indicator for measuring and reflecting the nutritional quality of forage. In this study, the crude protein content of hybrid paper mulberry did not respond significantly to stubble height, but it still increased with the increase of stubble height. This may be because the crude protein content of the whole hybrid paper mulberry plant was measured, while the degree of lignification of the stems closer to the ground was higher. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) are important determinants of forage nutritional quality. Their content affects livestock feed intake and digestibility of forage. When the stubble height is 10cm to 40cm, NDF gradually decreases with the increase of stubble height, and then increases significantly when the height is 50cm. The NDF content is the lowest at 40cm stubble; ADF does not respond significantly to stubble height, but the content is the lowest at 30cm stubble. Dry matter was not affected by stubble height, and there was no significant difference among the groups (P>0.05).

[0237] 5 Conclusion

[0238] (1) Hybrid paulownia showed better growth when planted in areas below 600 m above sea level and can be promoted for planting.

[0239] (2) The maximum yield reached 40275.6 kg·hm -2 , the best fertilizer dosage: X1 = 1.4140, equivalent to 1200.0 kg·hm -2 ; X2 = 1.4103, equivalent to 897.6 kg·hm2 of potassium application -2 ; X3 = 1.4125, equivalent to 899.0 kg·hm2 of phosphorus application -2, X4=1.023, that is, the density is 59830.7 plants·hm -2 .

[0240] (3) The cutting height has a certain impact on the yield and nutritional quality of hybrid paulownia. A height that is too low is not conducive to yield, while a height that is too high is not conducive to regeneration and will reduce nutritional quality. The annual yield of hybrid paulownia when cut at 110 cm is second only to that when cut at 170 cm, but the comprehensive score of feeding value is the highest. Cutting at this height can take into account both yield and nutritional quality.

[0241] (4) 30 cm is the optimal mowing stubble height. At this height, hybrid paulownia has the highest economic yield and the highest feeding value score, and has the best quality.

[0242] Although the present invention has been described in detail above using general descriptions, specific implementation methods and experiments, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A method for planting hybrid paper mulberry, characterized in that: The method includes the following steps: S1 site selection and planting; S2 field management and topdressing; S3 pest and disease control; S4 mowing and stubble retention.

2. The method for planting hybrid paper mulberry according to claim 1, characterized in that: The step S1 is site selection and planting, specifically, selecting an area below 2200m above sea level for planting, with a row spacing of 40-60cm, a nest spacing of 23-43cm, and a planting density of 54,000-64,000 plants / hm2. -2 After planting, superphosphate and fertilizer with P2O5≥14% were used, with the fertilizer application rate of 825~975kg·hm -2 and 13500~16500kg·hm -2 Apply once as basal fertilizer.

3. The method for planting hybrid paper mulberry according to claim 2, characterized in that: The step S1 is site selection and planting, specifically, selecting an area below 1460m above sea level for planting, with a row spacing of 50cm, a nest spacing of 33cm, and a planting density of 59831 plants / hm2. -2 After planting, superphosphate with P2O5≥14% and fertilizer were used, with the fertilizer application rate of 899kg·hm -2 and 15000kg·hm -2 Apply once as basal fertilizer.

4. The method for planting hybrid paper mulberry according to claim 3, characterized in that: The step S1 is site selection and planting, specifically, selecting an area below 1170m above sea level for planting, with a row spacing of 50cm, a nest spacing of 33cm, and a planting density of 59831 plants / hm2. -2 After planting, superphosphate with P2O5≥14% and fertilizer were used, with the fertilizer application rate of 899kg·hm -2 and 15000kg·hm -2 Apply once as basal fertilizer.

5. The method for planting hybrid paper mulberry according to claim 4, characterized in that: The step S1 is site selection and planting, specifically, selecting an area below 600m above sea level for planting, with a row spacing of 50cm, a nest spacing of 33cm, and a planting density of 59831 plants / hm2. -2 After planting, superphosphate with P2O5≥14% and fertilizer were used, with the fertilizer application rate of 899kg·hm -2 and 15000kg·hm -2 Apply once as basal fertilizer.

6. The method for planting hybrid paper mulberry according to claim 1, characterized in that: In step S2, field management and topdressing, in March and April and after each mowing and harvesting, when the seedlings grow to 12-15 cm, inter-cultivation, soil loosening, weeding and topdressing are carried out. In spring and summer, attention should be paid to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigation should be carried out in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, urea with N ≥ 46% and potassium sulfate with K2O ≥ 46% are selected, and urea 1050-1350 kg·hm2 is applied three times. -2 , Potassium sulfate 825~975kg·hm -2 .

7. The method for planting hybrid paper mulberry according to claim 6, characterized in that: In step S2, field management and topdressing, in March and April and after each mowing and harvesting, when the seedlings grow to 12-15 cm, inter-cultivation, soil loosening, weeding and topdressing are carried out. In spring and summer, attention should be paid to cleaning the drainage ditch to prevent water accumulation in the field. If the climate is dry and the field is short of water, irrigation should be carried out in time to maintain appropriate soil moisture. In the seedling stage and after each mowing, urea with N ≥ 46% and potassium sulfate with K2O ≥ 46% are selected, and urea 1200 kg·hm2 is applied three times. -2 、Potassium sulfate 897.6kg·hm -2 .

8. The method for planting hybrid paper mulberry according to claim 1, characterized in that: The step S3 of pest control includes: first, when the number of adults of the Lepidoptera Lymantriaidae and Noctuidae begins to increase, black light and sweet and sour liquid are used to lure and kill them; second, small pots of sweet and sour liquid are placed around the crops and replaced every 5 to 7 days; third, 1500 to 2000 times of biological BT and 800 to 1500 times of pyrethroid insecticide are used for spraying; when the damage of aphids reaches more than 10%, 800 to 1000 times of pharmaceutical insecticide are used for spraying; fourth, systemic fungicide is used to prevent and control root rot, 800 to 1000 times of foliar spray and 500 to 800 times of soil root irrigation are used, and the application of insecticide is stopped more than 7 days before harvest.

9. The method for planting hybrid paper mulberry according to claim 1, characterized in that: The step S4 of mowing and leaving stubble is specifically to mow at a height of 110-170 cm and leave stubble at a height of 10-30 cm, weed immediately after mowing, dig 20 cm deep furrows between rows after the last crop is harvested each year, and apply 13500-16500 kg·hm2 of fertilizer. -2 and superphosphate 825~975kg·hm -2 .

10. The method for planting hybrid paper mulberry according to claim 9, characterized in that: The step S4 mowing and stubble leaving is specifically, mowing at a height of 110 cm each time, leaving stubble at a height of 30 cm, weeding immediately after mowing, digging 20 cm deep furrows between rows after the last crop is harvested each year, and applying 15000 kg·hm2 of circle fertilizer. -2 and superphosphate 899kg·hm -2 .

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