施钾量对夏玉米氮、磷、钾吸收利用和籽粒产量的影响

Effects of potassium application rate on NPK uptake and utilization and grain yield in summer maize(Zea mays L.)

于2019—2020年在山东省泰安市东平农科所以登海605(DH605)为试验材料进行大田试验,在统一氮、磷肥用量(N 225 kg hm^(-2)、P_(2)O_(5)110 kg hm^(-2))的条件下,设置5个K_(2)O施用量,分别为0 kg hm^(-2)(K0)、150 kg hm^(-2)(K_(1))、225 kg hm^(-2)(K_(2))、300 kg hm^(-2)(K_(3))和375 kg hm^(-2)(K_(4)),研究连续多年秸秆还田条件下施钾量对夏玉米籽粒产量、养分吸收转运及利用的影响。结果表明,施钾显著提高了夏玉米籽粒产量,2年均在225 kg K_(2)O hm^(-2)时增幅最高,2019年和2020年籽粒产量分别增加13.64%和15.27%;施钾显著提高了叶面积指数、生物量及干物质向穗部转运的强度,促进植株对氮、磷、钾的吸收,提高玉米氮、磷、钾积累量及花后氮、磷积累比例,但当施钾量>225 kg hm^(-2)时增效降低。玉米养分转运量随施钾量的增加也呈现出先升后降的趋势,在施钾300 kg hm^(-2)时养分转运量及其对籽粒的贡献率最高。施钾也提高了夏玉米养分利用效率。225 kg K_(2)O hm^(-2)时玉米养分收获指数,氮、磷、钾肥表观利用率和钾肥农学利用率都维持在较高水平,施钾量超过300 kg hm^(-2)后肥料利用效率则明显下降。适量施钾可促进夏玉米地上部生长,显著提高植株生物量和夏玉米氮、磷、钾素吸收效率与积累量,并优化花后养分积累与分配,提高养分转运对籽粒产量形成的贡献率,进而提高了夏玉米产量与养分利用率。综合考虑玉米产量、养分积累与转运及肥料利用等因素,本试验条件下以施钾量为225 kg hm^(-2)较为适宜。

Field experiments were conducted at Dongping Agricultural Science Institute,Tai’an city,Shandong province from 2019 to 2020,using Denghai 605(DH605)as the experimental material.To study the effects of K application on summer maize grain yield,nutrient uptake and transportation,and utilization under continuous multi-year straw return conditions,five K_(2)O application rates of 0 kg hm^(-2)(K0),150 kg hm^(-2)(K_(1)),225 kg hm^(-2)(K_(2)),300 kg hm^(-2)(K_(3)),and 375 kg hm^(-2)(K_(4))were set under uniform N and P fertilizer rates(N 225 kg hm^(-2) and P_(2)O_(5)110 kg hm^(-2)).The results showed that K application significantly increased grain yield with the highest increase at 225 kg hm^(-2) in both years,13.64% and 15.27% in 2019 and 2020,respectively.K application significantly increased maize leaf area index,biomass and the intensity of dry matter transfer to the ears,promoted plant uptake of N,P and K,and increased maize N,P and K accumulation and the proportion of N and P accumulation after flowering,but the efficiency gain decreased when the K application was less than 225 kg hm^(-2).With the increase of K application,the nutrient transport of maize increased and then decreased,with the highest amount of nutrient translocation and the contribution rate of nutrient translocation at 300 kg hm^(-2).The nutrient harvest index,apparent utilization efficiency of N,P,and K,and agronomic utilization efficiency of K remained at a high level when K application rate was at 225 kg hm^(-2),and the fertilizer utilization efficiency decreased significantly when K application rate exceeded 300 kg hm^(-2).The appropriate amount of K application promoted the shoot growth of summer maize,increased biomass accumulation,significantly improved the uptake efficiency and plant N,P,and K accumulation of summer maize,optimized post-flowering nutrient accumulation and distribution,and improved the contribution of nutrient translocation to the formation of grain yield,thus improving the grain yield and nutrient utilization of summer maize.Considering the factors of grain yield,nutrient accumulation and transport,and fertilizer utilization,the K application rate of 225 kg hm^(-2) was suitable for this experiment.