氮素是水稻的一种主要特性营养元素。世界各水稻裁培地区的数百个田间试验表明,产量的大幅度增长几乎总是增施氮肥的结果。而稻谷的蛋白质含量却并不一定随着施用氮肥后产量的增加而增加。如果不限定其他的环境条件,适量施氮的主要效应是增加稻谷产量,对蛋白质含量的影响很小。但如果其他必需营养元素的肥效有限,或出现不良的气候条件,或施氮量超过作物要求,则蛋白质含量可能增加而产量不一定提高。在美国条件下,通常施用的氮肥量足以使稻谷产量大幅度增长,蛋白质量也有一定增加。 Nitrogen is a major nutrient element of rice. Hundreds of field trials in various rice cutting areas around the world have shown that a substantial increase in output is almost always the result of increased N fertilization. However, the protein content of rice does not necessarily increase with the increase of N application rate. Without limiting other environmental conditions, the main effect of applying adequate amounts of nitrogen is to increase paddy yield with little effect on protein content. However, if the availability of other essential nutrients is limited, or if there are adverse climatic conditions, or if the amount of nitrogen applied exceeds crop requirements, the protein content may increase and output may not necessarily increase. Under US conditions, the amount of nitrogen normally applied is enough to produce a substantial increase in paddy yield and a certain increase in the quality of the protein.