Fertilizer should be applied deep and early, and deep application can reduce nitrogen volatilization, prolong fertilizer supply time and increase nitrogen utilization rate. Early application is beneficial to early plant growth, prolonging fertilizer efficiency and reducing nitrate accumulation. Generally, ammonium nitrogen is applied to soil below 6 cm, and urea is applied to soil below 10 cm.
It should be combined with biological nitrogen fertilizer to increase phosphorus and potassium fertilizer. The application of biological nitrogen fertilizer can effectively solve the problem of limiting chemical fertilizer. Phosphorus and potassium fertilizer have obvious effects on increasing the resistance of vegetables.
Fertilization should be applied flexibly according to the type of vegetables and cultivation conditions. The accumulation of nitrates varies greatly among different types of vegetables. Generally, leafy vegetables are higher than fruits and vegetables. The same vegetable has different nitrate content under different climatic conditions. Generally, under high temperature and strong light, nitrate accumulation is less. On the contrary, in low temperature and low light, nitrate is accumulated in large amounts. In the process of fertilization, the type of vegetables, cultivation season and climatic conditions should be considered, and the reasonable amount of chemical fertilizer should be mastered to ensure that the nitrate content is within the prescribed range of pollution-free vegetables.
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Traffic Barrier, also known as a boom gate, is a bar, or pole pivoted to allow the boom to block vehicular access through a controlled point. Typically the tip of a boom gate rises in a vertical arc to a near vertical position. Boom gates are often counterweighted, so the pole is easily tipped. Boom gates are often paired either end to end, or offset appropriately to block traffic in both directions. Some boom gates also have a second arm which hangs 300 to 400 mm below the upper arm when lowered, to increase approach visibility, and which hangs on links so it lies flat with the main boom as the barrier is raised. Some barriers also feature a pivot roughly half way, where as the barrier is raised, the outermost half remains horizontal, with the barrier resembling an upside-down L when raised.
Traffic Barrier
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