摘要：

为探讨东北典型黑土种植密度与钾肥用量对玉米干物质积累转运、产量及钾素利用效率的影响,在吉林省公主岭市,通过连续2 a定位试验,研究了不同密度(D1:5.5×10⁴株/hm²,D2:7.0×10⁴株/hm²,D3:8.5×10⁴株/hm²)和钾肥用量(K0、K40、K80、K120和K160)对玉米干物质积累转运、钾素利用效率及产量的影响。结果表明,种植密度和钾肥用量的交互作用对玉米干物质积累的影响达到显著或极显著水平,其中D2密度下K120处理干物质最大积累速率和平均积累速率均为最高,并且干物质转运量和转运贡献率维持在较高水平。相同密度下,钾素回收率、农学利用率和偏生产力均随施钾量增加呈下降趋势,相同施钾量下均以D2密度最高。相同施钾量下,玉米产量以D2密度最高,2 a玉米平均产量较D1和D3分别提高6.9%,3.0%,相同密度下,施钾均显著提高了玉米产量,其中D1密度下施钾量增至80 kg/hm²后增幅不再显著;D2和D3密度下施钾量增至120 kg/hm²后增幅不再显著。通过线性加平台模型得出,D1、D2和D3密度下适宜施钾范围分别为72~80 kg/hm²,104~115 kg/hm²,105~116 kg/hm²。而D2处理钾肥用量在较D1处理提高44.5%以及与D3处理相持平条件下,玉米产量分别提高9.8%,3.2%。钾素回收率分别提高4.1,4.9百分点。综上,在东北典型黑土区,以玉米种植密度70 000 株/hm²,钾肥用量104~115 kg/hm²较为适宜。

关键词: 玉米, 黑土, 种植密度, 施钾量, 干物质积累转运, 产量, 钾素利用效率

Abstract:

In order to explore the effects of different planting densities and potassium(K)application rates on dry matter accumulation and translocation,yield and K use efficiency of maize in the typical black soil region of Northeast China,the two-year continuous located experiment was studied the effects of different planting densities(D1:5.5×10⁴ plants/ha,D2:7.0×10⁴ plants/ha and D3:8.5×10⁴ plants/ha)and K application rates(K0,K40,K80,K120 and K160)on dry matter accumulation and translocation,K use efficiency and yield of maize in Gongzhuling City of Jilin Province.The results showed that there was a significant or extremely significant interaction between planting density and K application rate on dry matter accumulation of maize.The maximum and average accumulation rates of dry matter in D2K120 treatment were at the highest values,and the translocation amount and contribution rate of dry matter remained at higher levels.K recovery efficiency(REK),agronomic efficiency(AEK)and partial factor productivity(PFPK)at the same planting densities decreased with increasing K application rate,and the values reached the highest in D2 under the same amount of K application.Under the same K application rate,the maize yield in D2 was at the highest value.The average yields in two years under D2 were increased by 6.9%,3.0% than D1 and D3,respectively.At the same density,maize yield was significantly improved due to K fertilizer application.Among them,the yield increasing was no longer significant exceeding 80 kg/ha of K application rates under D1,and it was no longer significant exceeding 120 kg/ha of K application rates under D2 and D3.According to fitting a linear-plateau model,the appropriate ranges of K application rates were 72-80 kg/ha,104-115 kg/ha,105-116 kg/ha under D1,D2 and D3,respectively.Under the condition that K application rate in D2 was increased by 44.5% than that in D1 and was equal to that in D3,the maize yield in D2 was increased by 9.8%,3.2%,and REK was increased by 4.1,4.9 percentage points than D1 and D3,respectively.In conclusion,the planting density of 70 000 plants/ha and K application rate of 104-115 kg/ha are appropriate in the typical black soil region of Northeast China.

Key words: Maize, Black soil, Planting density, Potassium application rates, Dry matter accumulation and translocation, Yield, Potassium use efficiency