一、前言小麦单位面积上产量的高低,取决于单位面积上的穗数,每穗粒数及其粒重的乘积。众所周知:影响这个乘积的因素是多方面的。但据前人研究和各地丰产经验证明,施用氮肥对小麦产量的影响是相当显著的。但是在丰产栽培追施氮肥时期上看法尚不统一。有人提出前重最好,匀施次之。有人主张分期施氮,早春控制,拔节促进。也有两头重为好的报导。这些主张在不同自然和栽培条件下可能是存在的。因此在当前化肥尚 I. INTRODUCTION The level of yield per unit area of ​​wheat depends on the number of spikelets per unit area, the number of grains per spike, and the product of their weights. As we all know: the factors that affect this product are many. However, according to previous studies and experiences of high yield around the province, the effect of applying nitrogen fertilizer on wheat yield is quite remarkable. However, the view of high-yield cultivation and topdressing nitrogen fertilizer is still not uniform. Someone put forward the best before the weight, followed by even. Some people advocate staging nitrogen, early spring control, jointing promotion. There are also two good reports. These ideas may exist under different natural and cultural conditions. So fertilizer is still in the current