两年的田间试验结果完全证明水田灌溉水呈碱性反应,而且在一天中其pH值随温度的提高而提高。其提高幅度为0.7—1.0单位,当含铵或能形成铵的氮肥追施于田面水层中时,水中的铵态氮含量比先施于干土表面后再上水的高一倍左右。其最终结果是,先施肥后上水的植株含氮量比施于水层中的一般较高,生物产量也有所增加。干土施追肥又省工易行。 Two years of field test results fully proved that paddy field irrigation water showed a basic reaction, and its pH value increased with temperature during the day. The rate of increase is 0.7-1.0 units. When ammonium or ammonium-forming nitrogen fertilizer is applied to the surface water layer, the content of ammonium nitrogen in the water is about twice higher than that of the first applied to dry soil surface. The end result is that the plants that were initially fertilized to produce Sheung Shui were generally more nitrogen-intensive than those that were applied to the water and their bio-yield was also increased. Dry top soil fertilizers and easy to work.