淮北地区高产小麦植株吸氮及土壤供氮特性

1984–1986年在不同施氮水平下，研究了植株吸氮及土壤供氮特性，试验结果：亩产400–450公斤，植株每亩总吸氮量15公斤左右。各生育期植株含氮率为：出苗至分蘖期5%左右，拔节期3%左右，孕穗期2.5%，灌浆期1.8%左右。小麦一生应在分蘖至越冬始期和拔节孕穗期出现两个吸氮高峰，前者约占总吸氮量23%，后者占33.6%。吸氮强度：每日每亩吸氮量以拔节至孕穗期最大，依次为返青至拔节和分蘖至越冬始期；氮的相对积累速率则以分蘖至越冬始期最高，其次是拔节至孕穗期。土壤氮素供应量为18–20公斤/亩；土壤供氮与植株吸氮比值：分蘖期最高为11–12∶1，拔节后为1.6–1.8∶1，孕穗期为1.2∶1。土壤供氮与生育进程之间呈4次方程，据此可求得各生育期土壤供氮指标和补差施氮量。

CHARACTERISTICS OF NITROGEN UPTAKE BY WINTER WHEAT PLANTS AND SOIL NITROGEN SUPPLY IN AREAS NORTH TO THE HUAIHE RIVER

In a study on the characteristics of nitrogen uptake by winter wheat (CV. Huaimai 11) and supply of available soil nitrogen (NH_4~+ and No_3~- ) at the different application rate of nitrogen fertilizers at the experimental center of Nanjing Agricultural University in Shuyang County, Jia gsu Province during 1984 1986,the nitrogen concentration of wheat (?)ants for high grain yield was about 5% from emergence to tillering, 3% at jointing, 2.5 at booting, and 1.8% at filling.The total nitrogen uptake was about 16 kg mu for a grain yield of 450-500 kg mu, of which 23.3% at emergence to the beginning of overwinter, 5.8% at overwinter to recovery, 19.1% at recovery to jointing, 33.6% at jointing to booting, 19.1% at reco tveery to jointing, 33.6% at jointing to b flowering and 9.4% at flowering to mature. There were 2 N uptake peaks, one (23% of the total) was at emergence to the beginning of ovorwinter while the other (33.6%) was at jointing to booting N uptake intensity was the highest at jointing to booting, and the next highest at recovery to jointing and the third at tillering to the beginning of overwinter when the relative N accumulation rate was the highest. The soil N supply was 18-20 kg mu with its ratio to N uptake 11-12:1 at tillering , 1.6-1.8:1 at jointing and 1.2 :1 at booting, which together with the compensates for deficits could be cal-culated by a quartic equation.