Introduction to the specific functions of vegetable growth non-woven fabrics in agricultural non-woven fabrics

Agricultural non-woven fabrics are a major item in the non-woven fabric market. Many agricultural products require non-woven fabrics. Common ones such as greenhouse fabrics used in agricultural greenhouses and seedling raising fabrics for seedling planting are actually used. Non-woven fabric. Next, we will introduce the specific functions of non-woven fabrics needed in the growth of vegetables. The most important feature of non-woven fabrics in vegetable growth is its covering performance, which will directly affect the growth and yield of vegetables. The specific performance is: 1. Heat preservation (1) If non-woven fabrics with larger quantitative or Laying several layers of non-woven fabrics together can further improve the ability to protect against low temperatures. According to related materials, the short-term low temperature resistance of lettuce seedlings is between -5 and 6°C, and the use of agricultural non-woven fabrics to protect against low temperature can reach -9.5°C. The cold-proof and warming effect of using 20g/m2 non-woven fabric to cover is more significant. Under extremely low temperature (-7.2°C) conditions, it is 3.8°C higher than the open field temperature. The advancement of comprehensive cold protection ability and temperature have a great influence on the growth, production and income of vegetables. (2) In winter, the impact of soil temperature progress on crop growth is more important than that of above ground temperature, and the effect is more significant. In the cold winter, increasing the soil temperature is conducive to the absorption of soil moisture and nutrients by the vegetable roots, which accelerates and strengthens the growth of the roots, and then promotes the growth of shoots and leaves above the ground, and can improve the resistance of the shoots. The results show that the warming effect of sunny days is significantly higher than that of rainy days, and the warming effect of shallow soil layers is higher than that of deep soil layers. The soil layer affected by this warming effect can exceed 20 cm. Measure the warming effect of different depths of 5cm, 10cm, 15cm, and 20cm in the soil. The temperature is 1.8℃, 1.1℃, 1.1℃, and 0.7℃ on sunny days, while the lower is 0.8℃, 0.7℃, 0.4 on rainy days. ℃, 0.3℃. The improvement of the temperature in the ground still uses 20g/m2 agricultural non-woven surface to cover up the lettuce in winter. (3) The useful radiation on the ground is significantly weakened, and the heat preservation effect is better, up to 2.6℃, but the heat preservation effect on cloudy days is only about 50% of that on clear days and nights. The temperature of the ground surface is evenly increased by nearly 2°C on a sunny day, and around 1°C on a cloudy day, especially at night when the temperature is low. As the surface temperature improves, a 20g/m2 non-woven fabric is used to directly cover the lettuce in winter. (4) It is clear that the increase in leaf temperature is often beneficial to the growth of winter production. In the actual application process, in order to improve the effect of night warming, the leaf surface of the plant should not be close to the nonwoven cover. The highest temperature increase at noon can reach 3℃, and the temperature can still increase by 0.65～0.75℃ during the night cooling stage. The temperature increased by 0.75°C at 4:00 at the measurement time, 0.9°C at 8:00, 3°C at 12:00, 1.6°C at 16:00, and 0.65°C at 20:00. The improvement of vegetable leaf surface temperature is based on the measurement of lettuce on 3 sunny days and 3 cloudy days in winter under the cover of 20g/m2 non-woven fabric and open field (CK), the experiment is compared without covering, the lettuce leaves in winter after being covered by non-woven fabric Even surface temperature increase. The thermal insulation of agricultural non-woven fabrics on vegetables is mainly manifested in the certain degree of improvement in vegetable leaf temperature, ground surface temperature and ground temperature. 2. According to measurement, the air permeability of 20g/m2 non-woven fabric is 5-6m3/(m2.h), which can meet the demand of vegetable growth. The size of the air permeability is closely related to the intermittent size of the structure of the non-woven fabric, the temperature difference between the surface and the inside of the cover layer, and the wind speed. However, the air permeability is negatively related to the heat preservation, that is, the heat preservation decreases with the increase of the air permeability. The air permeability of non-woven fabric is better than that of plastic agricultural film, and it has certain air permeability. After covering it, there is no need to uncover it for ventilation, saving labor and effort. 3. Nevertheless, these four specifications of non-woven fabrics can satisfy the requirements of covering up the contrast of the vegetables. Among them, the 25g/m2 non-woven fabric is produced by the spunbond method, and the light transmittance is slightly poor. Choose the plane cover method, use the JD-3 illuminance meter to measure in the winter when the solar altitude angle is small (uniform value), the light transmittance of the non-woven fabric with a quantitative value of 20g/m2 is 87%, and the light transmittance of the non-woven fabric with a quantitative value of 20g/m2 is 87%. 79%, 72% for 40g/m2 and 73% for 25g/m2. The above is a summary of the specific functions of non-woven fabrics for vegetable growth in agricultural non-woven fabrics. If you don’t understand, you can directly contact the relevant personnel of Fujian Non-woven Fabric Co., Ltd.