What are the functions of anti-bird nets?
1. Prevent birds from damaging fruits. By covering the bird-proof net over the orchard, an artificial isolation barrier is formed, so that the birds cannot fly into the orchard, which can basically control the damage of the birds and the fruits that are about to ripen, and the rate of good fruit in the orchard is significantly improved.
2. Effectively resist the invasion of hail. After the bird-proof net is installed in the orchard, it can effectively resist the direct attack of hail on the fruit, reduce the risk of natural disasters, and provide a solid technical guarantee for the production of green and high-quality fruit.
3. It has the functions of light transmission and moderate shading. The anti-bird net has high light transmittance, which basically does not affect the photosynthesis of the leaves; in the hot summer, the moderate shading effect of the anti-bird net can create a suitable environmental condition for the growth of fruit trees.
Is there any technical consideration in the selection of anti-bird nets?
At present, there are many kinds of anti-bird net materials on the market, with different quality and price. When choosing a bird-proof net, you should focus on three aspects: color, mesh size and the service life of the net.
1. The color of the net. The colored anti-bird net can reflect red or blue light through sunlight, forcing the birds to dare not approach, which can not only prevent the birds from pecking at the fruit, but also prevent the birds from hitting the net, so as to achieve the effect of repelling. Studies have found that birds are more alert to colors such as red, yellow, and blue. Therefore, it is recommended to use yellow anti-bird nets in hilly and mountainous areas, and blue or orange-red anti-bird nets in plain areas. Transparent or white wire mesh is not recommended.
2. Mesh and net length. There are many specifications of bird-proof nets. Orchards can choose the size of the mesh according to the species of local birds. For example, small individual birds such as sparrows and mountain wagtails are mainly used, and 2.5-3cm mesh can be used; For larger individual birds, 3.5-4.0cm mesh can be used; the wire diameter is 0.25mm. The length of the net can be determined according to the actual size of the orchard. Most of the wire mesh products on the market are 100-150m long and about 25m wide. After installation, the net should cover the entire orchard.
3. The life of the net. It is best to use a mesh fabric made of polyethylene and heald wire as the main raw materials with chemical additives such as anti-aging and anti-ultraviolet added. This kind of material has high strength, heat resistance, water resistance and corrosion resistance. , anti-aging, non-toxic and tasteless. Generally, after the fruit is harvested, the anti-bird net should be removed and stored in time, and kept indoors. Under normal use conditions, the life of the wire mesh can reach about 5 years. If the labor cost of loading and unloading the bird-proof net is considered, it can also be fixed on the shelf for a long time, but the service life will be reduced.
What are the key technical points in the construction process of the anti-bird net?
The construction of anti-bird nets in orchards generally consists of three steps: installing columns, erecting net surfaces, and laying rack surfaces. The following key technical points must be grasped during the construction process.
1. Planning and design. The orchard can be divided into several districts. Each district in hilly and mountainous areas should be about 20 mu, and the plain area can be about 50 mu, and each district should be built independently. Generally, a column is installed every 7-10m between the rows, and one column is installed every 10-15m between the plants, in vertical and horizontal rows. The height of the column depends on the height of the tree, which is generally 0.5 to 1m higher than the height of the tree.
2. Prepare the frame material. The column is mostly made of hot-dip galvanized steel pipe with a diameter of 5cm and a length of 6m; the mesh surface is mostly erected with 8# galvanized steel wire; the bottom end of the column is welded with a triangle iron to stabilize the column.
3. Make uprights. Cut and weld steel pipes reasonably according to the tree height. At present, the height of small crown-shaped fruit trees is less than 4m. The 6m steel pipe can be cut into 4m and 2m, and then the 2m section can be welded into 4m; the 4m long steel pipe can also be ordered directly from the manufacturer. The upper end of the column is drilled 5cm away from the top of the pipe. The double holes are cross-shaped and the diameter of the hole is about 0.5mm.
4. Mark the column location. According to the planning and design, first determine the positions of the pillars at the four corners of the orchard, then connect the two pillars on the adjacent side into a line, and the vertical and horizontal angles are 90o; then determine the positions of the surrounding pillars along the straight line, and finally determine the field pillars position, and finally achieve vertical and horizontal rows.
5. Install the column. After determining the position of each column, use a hole puncher to dig a hole on the ground. Generally, the diameter of the hole is 30cm and the depth is 70cm. At the bottom of the pit, pour concrete with a thickness of 20cm, and then put the columns into the ground and pour the concrete to the surface, so that the columns are buried 0.5m underground and 3.5m above the ground. To keep the column perpendicular to the ground, the overall height of the same, vertical and horizontal lines.
6. Bury ground anchors. Since the four corners and the surrounding columns bear a large tensile force, these columns should be buried with ground anchors. Each of the four corners of the column is equipped with 2 ground anchors, and each of the surrounding columns is equipped with 1 ground anchor, which is fixed with a cable-stayed steel wire. 70cm.
7. Set up the mesh surface. Use 8# galvanized steel wire, pass through the threading hole at the top of the column in the vertical and horizontal directions, and pull one wire in each row of the vertical and horizontal directions, which is crossed in the vertical and horizontal directions.
8. Lay the network cable. First put the anti-bird net on the shelf, fix the two sides of the net wire, then unfold the net, find the side of the width, and thread the grid with the net wire, and reserve a piece of rope at each end to tie on both sides of the grid. During the installation process, first unfasten the tied rope buckle, and tie the net wire to one end of the rope. After passing through it at one time, slowly pull it along the reinforcing edge. After setting the length and width of the net wire, tighten it. fix. The junction of the sky net on the upper part of the canopy should be close without leaving a gap; the junction of the outer side net of the canopy should be tight, and the length should reach the ground without leaving a gap.
Article source: 915 Rural Radio