1. Climate conditions determine whether it is a high-quality producing area.
Walnut trees like warm and cool climate, with an average temperature of 10 ~ 14℃, an altitude of 500 ~ 1000 meters, annual rainfall of 600 ~ 900 mm, annual illumination hours of more than 2,000 hours and frost-free period of more than 200 days.
In Shangluo City, the altitude is basically above 500 meters, and most areas meet this basic requirement, except for the alpine mountainous areas. Locals all know that walnuts are also distributed in alpine mountainous areas and have a certain yield. However, nuts in most years are not full, taste astringent and have poor quality. Sometimes, the flowers and young fruits of walnuts will freeze to death at the end of spring, and they will not bear fruit in a large area in that year, but will continue to bear fruit in the next year.
Solution:
Practice has proved that the area at an altitude of 600 ~ 900 meters is suitable for walnut trees to build gardens, but it must also meet the soil conditions and other conditions. There is no guarantee that it will blossom and bear fruit only in suitable areas.
Second, suitable plots are the basis for the growth and development of walnut trees.
Walnut is a deep-rooted fruit tree, which requires loam and sandy loam with deep soil layer, high organic matter content, neutral or slightly alkaline soil and groundwater level of more than 2 meters. Therefore, the plants with good performance planted sporadically are basically concentrated in Sichuan Road, hilly areas and the middle and lower parts of gentle slopes.
1. Walnut trees like light: According to the performance of Yang Shan in Shangluo City, there are certain rules, that is, shady slopes in low altitude areas and sunny slopes in high altitude areas grow better. This may be related to the uneven distribution of local rainfall. The temperature is high in summer and autumn in low mountainous areas, and the soil evaporation is large. In the case of soil drought, walnut trees will have wilting and other symptoms, and their growth and development will stagnate or slow down. However, the temperature of shady slope land is 2 ~ 5℃ lower than that of flat land and sunny slope land, which can greatly slow down the evaporation of soil water and basically will not affect the growth and development. The area with relatively high altitude has lower temperature and less light and heat resources, and the sunny slope plot can better meet the growth and development requirements of walnut trees.
Solution: In areas below 800 meters above sea level, walnuts should be planted on shady slopes, and in areas above 800 meters above sea level, walnuts must be planted on sunny slopes.
2. Walnut trees like loose and breathable soil environment. In the heavy soil environment, the root system of walnut is poorly developed, the main root is shallow, and the lateral branches are only distributed in the topsoil 20 ~ 30 cm, which reduces the absorption of water and nutrient energy. However, planting walnuts in sandy land has low soil nutrient content, poor plant nutrition and hindered growth and development.
Solution: Choose loam and sandy loam to plant walnuts. Planting walnuts can be solved by soil improvement. Sandy land is covered with a layer of garden soil or forest soil every year, while clay land can be improved by mixing sand and ploughing into the soil by applying organic fertilizer, so as to thicken the soil layer and change the soil properties.
3. Walnut trees are not resistant to flooding: the roots of walnuts are developed and deep, but they are afraid of high groundwater level and soil water accumulation, otherwise the roots will get sick and rot, which will eventually lead to plant death.
Solution: Walnut orchards should avoid planting in low-lying areas, gullies, ditches and rivers. For those that have been planted, try to clear the drain, open a drain on the flat ground, and open a deep ditch in the low-lying area to ensure smooth drainage.
3. What should I do if the walnut tree has been planted for 10 years without bearing fruit?
Through the investigation of a large number of plots of returning farmland to forests and planting walnuts without flowering and fruiting, the following effective methods are summarized:
1. Increase soil thickness.
The main reasons for the failure of walnut trees in the plot of returning farmland to forests are poor soil layer, insufficient soil fertility and low soil water content, which are characterized by slow plant growth and poor root development. How can walnut trees blossom and bear fruit when they have not completed vegetative growth?
Solution: Planting green manure such as grass and sweet-scented osmanthus in walnut orchard, and harvesting after one year. You can also cut green manure, and all kinds of wormwood, yam cotton and Sophora flavescens are pressed into the fertilization ditch. You can also collect leaves and weeds and put them in the fertilization ditch, and then cover each plant with a layer of rotten human feces.
Generally, the fertilization ditch is about 10 cm from the crown, 1 m deep and 50 cm wide, or radial ditches are dug along the main branches. For 2 ~ 3 years in a row, every time the fertilization ditch moves out, the flowering and fruiting conditions can be met, and plants can bear fruit in the next year. The ditching time is determined according to the free time, and the fertilization time is from September to 10, not later than before the soil freezing.
2. High-branch grafting of fine varieties.
Seedlings naturally bear fruit late, generally flowering and fruiting only 6 ~ 10 years, and the yield will be low if they bear fruit late. If high branch grafting is adopted, not only the fruiting period will be advanced, but also the quality of walnut will be greatly improved, especially the varieties with thin shell, astringent white and high oil content are deeply welcomed by the market, with high yield and good quality.
3. reasonable pruning.
The pruning period is mainly from September to 10, and it germinates in spring to set fruit. Walnut trees cultivated in the plot of returning farmland to forests are basically weak and malnourished, which is not suitable for large-scale logging. According to the tree potential, only the main branches and lateral branches need to be cultivated, and according to the soil fertility, evacuation layered pruning and natural happy pruning can be selected.
4. Balanced fertilization.
Farmhouse manure, 25-50k g/ plant before fruiting, 50- 100kg/plant after fruiting, and 200-250kg/ plant at full fruiting stage. For many years, the fertilization amount per plant is not less than 400 kg. Before the quick-acting fertilizer bears fruit, each plant is applied with 50g of nitrogen fertilizer, 20g of phosphorus fertilizer10g, and 0g of potassium fertilizer10g; after the fruit bears fruit, 50g of nitrogen fertilizer, 20g of phosphorus fertilizer and 20g of potassium fertilizer are applied annually. Farmhouse manure should be applied in spring and autumn, preferably after harvest and before defoliation. Quick-acting fertilizer is mainly applied in the growth period to ensure that walnut trees do not lack fertilizer and grow in vain.
5. Walnut trees are sensitive to boron fertilizer.
While ensuring the basic nutrition of the walnut tree, there are also phenomena of no flowering and no fruit, or only flowering and no fruit. By applying boron fertilizer, a miracle was born. Walnut trees are sensitive to boron fertilizer, and soil boron deficiency will affect the differentiation and pollination of walnut flower buds, resulting in poor flower bud development, short flowering time, reduced pollination rate, flashy flowers and fruits, and high empty fruit rate. Application amount and time of boron fertilizer: when applying base fertilizer, according to the situation of soil fertilizer deficiency, add boron fertilizer 15 ~ 25g per plant, spray 1000 times boron fertilizer solution on the leaves at the early flowering stage, and spray it again at the fruit-setting stage. It should be noted that boron fertilizer is mainly based on base fertilizer, and foliar spraying is selected when necessary, and the earlier the base fertilizer is applied, the better. After all, it takes a while for roots to contact boron fertilizer.
Due to serious soil erosion, shallow topsoil, low soil depth, serious decline in soil fertility, climate type and soil type are not suitable for walnut growth, and walnut trees are deep-rooted plants, so it is difficult to blossom and bear fruit. Only by changing the present situation in various ways, combined with effective water and fertilizer management, plastic pruning and pest control, can we reverse this embarrassing situation, promote industrial development and increase the income of local farmers. ?