农田养分调控对冀中南冬小麦生育期群体动态和养分浓度的影响

在冀中南中低产农田,采用对比试验设计,以农民习惯养分管理为对照(CK),对农田养分管理模式进行了优化调控(OPT,氮素追施时间后移至拔节期),通过田间养分试验,分析了小麦返青至拔节期的群体数量、籽粒产量以及植株氮磷钾养分浓度的变化规律。结果表明:氮素适当后移至拔节期的养分优化管理模式,最终成穗率达到了生育期最高总茎数的33.0%,明显高于农民习惯养分管理的成穗率(26.9%),从而促进了产量的提高。优化处理的植株氮浓度、氮素吸收量分别在拔节期和孕穗期显著高于农民习惯处理;植株磷浓度在全生育期均低于农民习惯处理,但磷吸收量则从孕穗期开始高于农民习惯处理;植株钾浓度在全生育期呈先上升后下降的变化趋势,农民习惯处理的植株钾浓度均显著高于优化处理。总体来看,优化处理在拔节期植株氮素浓度显著高于农民习惯处理,这可能是促进优化处理群体成穗数提高的关键;而磷钾浓度则无明显影响。

Effects of Nutrient Management on Population Dynamics and Nutrient Concentration of Winter Wheat Growing Period in Central and South Hebei Province

In order to understand the effects of nutrient management on winter wheat colony and nutrients contents dynamics, a field experiment was conducted in the middle-south Hebei Province. The results showed the optimized (OPT) treatment significantly increased the spikes number than the conventional (CK) treatment by putting off the topdressing N to shooting stage. The percentage of ear tiller significantly increased from 26.9% of CK to 33.0% of OPT. The plant N content and N uptake for OPT treatment were significantly higher than CK treatment at shooting stage and booting stage,respectively. The plant P content for OPT was lower than that of CK in the whole wheat growth period, while the P uptake was higher from booting stage to harvest. The plant K content increased from regreen stage to booting stage and then drop down from booting to harvest stage. The plant N concentration for OPT treatment was sig-nificantly higher than that of CON at shooting stage, which may suggest the plant N concentration at shooting stage was the key factor which influenc-ing the tiller percentage.