减氮增施DMPP对高粱氮素吸收与利用的影响

Effects of Reducing Nitrogen Fertilizers and Increasing DMPP on Nitrogen Absorption and Utilization in Sorghum

设置盆栽试验,以高粱品种辽糯10为试验材料,以常规施氮量(300 kg/hm^(2))为对照,N1~N3处理氮肥施用量呈10%梯度递减,分别为270、240和210 kg/hm^(2),N4~N6处理在N1~N3基础上增施3%的3,4-二甲基吡唑磷酸盐(DMPP),磷、钾肥施用量均为75 kg/hm2。结果表明,随着氮肥施用量减少,相对叶绿素含量(SPAD值)、干物质积累量、氮素积累总量、干物质生产效率、氮素干物质生产效率、氮素农艺效率和氮肥利用率等逐渐降低,增施DMPP后高粱生长发育恢复至常规施肥水平。与对照相比,N5处理(减氮20%配施3%DMPP)氮素积累总量增加4.67%;穗粒重和千粒重分别增加3.72%和5.58%;干物质生产效率增加8.77%;氮素干物质生产率增加1.14%,氮素农艺效率增加5.75%;氮肥利用率和氮肥农学利用率分别增加15.47%和45.12%。综上,氮肥施用量减少20%时,增施正常施氮量3%的DMPP可以提高高粱干物质生产效率及氮素利用率,具有一定的增产潜力。

This research was set as a pot experiment,the sorghum variety Liaonuo 10 was used as the experimental material,and the conventional nitrogen application rate(300 kg/ha)was used as the control(N0),N1-N3 treatments showed a 10%gradient decrease in nitrogen fertilizer application rate(270,240 and 210 kg/ha),N4-N6 treatments were combined with 3%3,4-dimethylpyrazole phosphate(DMPP)on the basis of N1-N3,the application rates of phosphorus and potassium fertilizers were both 75 kg/ha.The results showed that,with the reduction of nitrogen fertilizer application,relative chlorophyll content(SPAD value),dry matter accumulation,total nitrogen accumulation,dry matter production efficiency,nitrogen dry matter production efficiency,nitrogen agronomic efficiency,and nitrogen fertilizer utilization rate gradually decreased.After the application of DMPP,the growth and development of sorghum returned to the level of conventional fertilization.Compared with the N0,the total nitrogen accumulation of N5 treatment(20%nitrogen reduction+3%DMPP)increased by 4.67%;the grain weight per ear and 1000-grain weight increased by 3.72%and 5.58%,respectively;the dry matter production efficiency increased by 8.77%;the nitrogen dry matter production efficiency increased by 1.14%,and the nitrogen agronomic efficiency increased by 5.75%;the nitrogen fertilizer use efficiency and nitrogen fertilizer agronomic efficiency increased by 15.47%and 45.12%,respectively.In conclusion,when the nitrogen fertilizer application rate was reduced by 20%,adding 3%DMPP of the normal nitrogen application rate could improve the dry matter production efficiency and nitrogen utilization rate in sorghum,and had a certain potential for increasing yield.