松土促根剂和秸秆腐熟剂对砂姜黑土农田夏玉米生长及产量的影响

Effects of soil loosening and root promoting agent and straw decomposing inoculants on growth and yield of summer maize in lime concretion black soil

砂姜黑土农田由于土壤僵闭,耕层浅薄,玉米生长常常受到严重影响,从而导致产量下降。为了改善耕层土壤环境,提高砂姜黑土农田的生产力,本研究于2018—2019年在河南省驻马店市西平县二郎乡开展了连续2 a的大田试验,研究松土促根剂(RP)和秸秆腐熟剂(SD)对土壤容重、玉米植株生长和叶片光合生理特性、子粒灌浆特征和玉米产量的影响。结果显示,与对照农田(CK)相比,施用RP和SD的农田土壤容重在夏玉米开花期后均明显下降;增加夏玉米单株叶面积,使株高和茎粗增加,穗位系数降低;开花期后叶片叶绿素相对含量(SPAD值)、净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)均提高,胞间CO2摩尔分数(Ci)降低;子粒灌浆能力明显提升,百粒质量显著增加。施用RP和SD的农田,两年产量分别增加了11.27%和9.40%,15.73%和9.62%。相关性分析结果表明,产量和净光合速率、百粒质量呈极显著正相关关系;与达到最大灌浆速率的时间、灌浆速率最大时百粒质量、穗粒数呈显著正相关关系,通径分析显示,净光合速率对产量的决定程度最高,因此保证较高的光合速率有利于夏玉米产量增加。综上,在砂姜黑土农田施用松土促根剂和秸秆腐熟剂能够改善夏玉米的生长状况并实现增产。

Due to the rigid soil and shallow plough layer in lime concretion black soil,the growth of maize is often seriously affected,resulting in a decrease in yield.In order to improve the topsoil environment and increase the productivity of lime concretion black soil,a field experiment was conducted in Erlang Township,Xiping County,Zhumadian City,Henan Province from 2018 to 2019 to study the effects of soil loosening and root promoting agent(RP)and straw decomposing inoculants(SD)on soil bulk density,maize plant growth and leaf photosynthetic physiological characteristics,grain filling characteristics and maize yield.The results showed that compared with the control field(CK),the soil bulk density decreased significantly after flowering in summer maize treated with RP and SD.With the increase of leaf area per plant,plant height and stem diameter increased,ear position coefficient decreased,leaf chlorophyll relative content(SPAD),net photosynthetic rate(Pn),stomatal conductance(Gs)and transpiration rate(Tr)increased after the flowering stage,while intercellular CO2 mole fraction(Ci)decreased.The grain filling ability and 100-grain weight increased significantly.The yield of farmland applying RP and SD increased by 11.27%and 9.40%,and by 15.73%and 9.62%respectively in two years.The results of correlation analysis showed that the yield was significantly positively correlated with net photosynthetic rate and 100-grain weight,and positively correlated with the time of reaching the maximum filling rate,100-grain weight at the maximum filling rate and the number of grains per spike.Path analysis showed that the net photosynthetic rate had the highest degree of determination on yield,and ensuring a higher photosynthetic rate was beneficial to the increase of summer maize yield.To sum up,the application of soil loosening and root promoting agent and straw decomposing inoculants in lime concretion black soil can improve the growth status of summer maize and increase the yield.