为了夺取水稻丰产,每年要向水稻地里施用大量氮素化肥。试验证明.采用普通的表层撤施法.水稻一般只能利用氮肥40～50%,另一半却白白地随水流失或淋失。实行水稻全层施肥.深施球肥.施用长效包膜肥料等。都是提高氮素化肥利用率的有效措施。稻田氮肥全层施肥是根据土壤对铵态氮(铵离子)具有较强的吸附作用.将氮素化肥在播种或栽秧前以基肥形式施人土壤耕作层。它的好处是.肥效高。比用等氮量的表层撒施增产效果显著。肥劲长,肥力可维持50～70天.而且水稻 In order to seize high yields of rice, a large amount of nitrogenous fertilizer is applied to paddy fields every year. Tests show that the use of ordinary surface withdrawal method. Rice generally can only use 40 to 50% of nitrogen, the other half but with the water loss or leaching. The implementation of full-depth fertilization of rice. Deep ball of fertilizer. Application of long-term coated fertilizer. All are effective measures to improve the utilization of nitrogenous fertilizer. Full-scale fertilization of nitrogen fertilizer in paddy soil is based on the strong adsorption of ammonium nitrogen (ammonium ion) by the soil, and nitrogen fertilization is applied to the soil tillage layer as basal fertilizer before sowing or transplanting. Its benefits are. Than with the amount of nitrogen on the surface of the spread of yield significantly. Fertile long, fertility can be maintained for 50 to 70 days. And rice