| Soilless cultivation has now become an important part of protected agriculture, it is also an important form of manufacturing agricultural crops and a new way to develop high-efficiency agriculture. As the basis for soilless cultivation, horticultural substrate is the most important environmental factors which deciding the plant root growth。Some components in the current fine horticultural substrate such as peat, tree bark and other organic materials, because of the existence of waxy surface caused they have water repellency. Since the existence of water repellency, it is very difficult to make these surbstrate wet when watered them, and it will cause water waste. If water can not infiltrate the substrates rapidly and make it wet , it will cause germination rate and quality of plant decreace. Therefore, settle the water repellent problem is particularly important.This experiment was conducted to study the effects of applying three different wetting agents on the wetting & rewetting ability and basic physical & chemical properties of water- repellent substrate-peat, and estimat the germination & growth instances of some plants growed in peat medium that was added wetting agent. After application of three wetting agents- Fenxi Chun - Analytical Nonylphenol polyoxyethylene ethers (OP-10), industrial OP-10 and Fenxi Chun- Analytical Polysorbate 80 (SP), the main test conducted on the following:(1)Studied the influences of three wetters which commonly used on wetting and rewetting time,penetration rate of peat. The results showed that all the three wetting agents improved wetness of peat, of which OP-10 got best results, and SP worked most weakly. Taking into account the costs, industrial OP-10 have a brighter prospect, which not only increased the infiltration rate but also enhanced irrigation efficiency, and concentration 2% received best results comparing with other treatments.(2) Studied the influences of industrial OP-10 on pore property and moisture property and other basic physical and chemical properties of peat. The results showed that adding fit amount of wetting agent in peat can increase the water-holding properties, but with increasing concentration of wetting agent water-holding capacity decreased gradually, ventilation enhanced gradually. Wetting agent at 1% concentration level can keep the peat keep more water, that will be very beneficial to the growth of crops.Wetting agent can significantly improve the height of capillary water and reduce water lost time, this showed that wetting agent can increase water content of capillary water and the water-holding ability of peat. The influences of industrial OP-10 on the density, pH of peat were little.(3) Studied the influences of industrial OP-10 on the state of germination of Cornflower and Festuca arundinacea. Test results showed that the germination rate of the two plant had a significant reduction on 0.5 percent concentration of the wetter solution, we can conclude that exorbitant use of the wetter will produce poison to crops and inhibit the growth of crops. The germination and seedling growth test showed that: the fit amount of wetting agent can increase crop germination rate and promot the growth of plant. Wetting agent at 1.5%-6% of the concentration levels had not adversely affected of Festuca arundinacea's growth, and at 3 percent of the concentration level has the best effect; but the wetting agent in the concentration level of 0.5 percent would enable the Cornflower have the best growth conditions.4) Studied the influences of industrial OP-10 on wetting ability and nutrients quick-impact changes of peat during the growth period of Echinacea and on the growth instance of Echinacea planted in pot, results showed that wetting agent in crop cultivation for 85 days can significantly improve the wetting time and penetration rate of substrate. This showed the effects of wetting agent was still valid in 85 days after transplanting, but its effectiveness has been weakened by repeated leaching, it should be supplemented in the first 35 days after transplanting to achieve the best wetting effect. Wetting agent can make the content of available nitrogen, potassium nutrients in substrate reduced slightly, this may because wetting agent can make these nutrients dissolved in water more easily, under normal irrigation mode, more nutrients would be eluviated along with the water. So we shoud reduce the volume of each time irrigation to reduce the nutrients leaching. Suitable amount of wetting agent (concentration of less than 3 percent) can increase the height, crown breadth, root length, shoot dry weight, root dry weight and G values (seedling index) of Echinacea purpurea, in the concentration level of 0.75 percent had the best growth state, when the concentration level was more than 3%, it would poison and inhibit the growth of the Echinacea purpurea.5) Studied the influences of wetting agent under different irrigation volumes on the growth status of Echinacea purpurea, the results show that under whole volume irrigation conditions, wetting agent have little effect on the growth and development of the Echinacea purpurea, but under 170 ml and 140 ml of low irrigation volumes conditions, wetting agent can significantly improve the growth of the plant, and at the concentration level of 1.5 percent, wetting agent have the best effect. This had proved that wetting agent can save water distinctly. The amount of wetting agent at the concentration level of 1.5 percent can save 30 percent water, at the same time increase plant growth. This report provided a basis theoretical data to extend use of wetting agent.
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