Abstract: Rock wool, as a soilless cultivation substrate, is non-toxic, sterile, and chemically stable, and can be safely used for fruit and vegetable cultivation. However, it is necessary to distinguish between industrial and agricultural rock wool and cooperate with scientific management.
1〠Composition and safety of rock wool
Rock wool is mainly made of natural ores such as basalt and dolomite, which are melted at a high temperature of 1600 ℃ to form fibers. It is an inorganic material and does not contain heavy metals or organic pollutants. During the processing of agricultural rock wool, hydrophilic components are added to make it highly absorbent (water absorption rate>95%) and breathable (porosity>90%). At the same time, slag balls (diameter<0.25mm) are removed through strict processes to avoid physical damage to plant roots. Research shows that the pH value of agricultural rock wool is stable between 6.5-7.5, and it will not disrupt the nutrient balance due to chemical changes, ensuring normal plant growth.
It is worth noting that there is a fundamental difference between industrial rock wool and agricultural rock wool. The former may contain harmful resins such as phenol and formaldehyde, while agricultural rock wool uses environmentally friendly adhesives (such as acrylic salts) to ensure non toxicity and harmlessness. Therefore, plant cultivation must choose professional agricultural rock wool products.
2〠The advantages of rock wool in plant cultivation
Physical safety: The diameter of rock wool fiber is only 0.005mm, forming a uniform porous structure that can fix the root system and prevent root rot due to oxygen deficiency. Experiments have shown that the root density of tomatoes in rock wool substrate is 30% higher than that in soil cultivation, and the yield is increased by 40%.
Biosafety: Rock wool is an inert material that does not breed bacteria, fungi, or insect eggs. The greenhouse experiment in Netherlands showed that the incidence rate of strawberry gray mold with rock wool was reduced by 70%, and the use of pesticides was reduced.
Environmental adaptability: Rock wool can be recycled, and after being discarded, it can be crushed and sprinkled into the soil to improve breathability, or recycled as a building material to reduce resource waste.
3〠Key points of scientific use of rock wool
Although rock wool itself is safe, it needs to be operated in accordance with regulations:
Nutrient solution management: Rock wool does not contain nutrients and requires precise supply of nutrient solution through drip irrigation system. For example, during the growth period of cucumber, it is necessary to adjust the nitrogen phosphorus potassium ratio (NPK=3:1:4) and control the EC value at 2.0-2.5 mS/cm.
Disinfection and replacement: After continuous use for 1-2 years, steam (above 80 ℃) or ultraviolet disinfection should be used to avoid salt accumulation. The pH of rock wool that has not been replaced for a long time may shift and needs to be monitored and adjusted.
Protective measures: Wear gloves and masks during construction to avoid fiber irritation to the skin or respiratory tract. Processed rock wool poses no health risks, but direct contact with uncured products may cause temporary itching.
4〠Application Cases and Future Trends
In Europe, rock wool cultivation has accounted for over 60% of the soilless cultivation market. In the Netherlands, the annual yield of tomatoes grown with rock wool reaches 70kg/m ², which is 5 times higher than traditional soil. In China's facility agriculture, rock wool is gradually replacing coconut coir and perlite, especially in three-dimensional planting. Its lightweight characteristics (density 0.08g/cm ³) can reduce the load-bearing pressure of supports. In the future, nano coated rock wool (such as adding antibacterial silver ions) and intelligent drip irrigation systems will further enhance their safety and efficiency.
conclusion
Rock wool, as a plant cultivation substrate, has high safety in terms of composition, structure, and application, especially suitable for large-scale, high standard modern agriculture. As long as qualified agricultural products are selected and scientific management is followed, rock wool can not only ensure the healthy growth of plants, but also promote the transformation of agriculture towards efficiency and environmental protection.