秸秆还田年限及施磷水平对玉米根系生长和产量的影响

Effects of Straw Returning Years and Phosphorus Application on Root Growth and Yield of Maize

以先玉335为供试材料,采用两因素裂区设计,研究了不同秸秆还田年限[连续5年(5a)和1年(1a)秸秆全量深翻还田]及不同施磷水平[P_(2)O_(5)0(P0)、45(P45)、90(P90)、135(P135)和180 kg/hm^(2)(P180)]对玉米根系构型、菌根侵染状况、植株干重、磷素积累量和产量的影响。结果表明,5a较1a明显优化了玉米根系形态,促进了根系生长、菌根侵染以及植株干物质和磷素积累,使产量提高1.94%~7.15%;磷肥水平影响玉米的生长发育,还影响菌根侵染密度(m%)、丛枝丰富度(a%)和根系丛枝丰富度(A%),并在P90处理后开始明显降低,表明当施磷水平较高时,会严重抑制AM真菌的侵染。拔节期玉米根系、茎秆、叶片的干重分别在P90、P90和P135时达到最大值,与其他施磷处理相比增幅分别为1.31%~15.07%、0.05%~25.07%和7.61%~22.42%;磷素积累量分别在P135、P90和P135时达到峰值,与其他施磷处理相比增幅分别为11.09%~95.51%、10.77%~77.39%和3.91%~29.28%。成熟期玉米茎秆、叶片和籽粒的干重分别在P90、P135和P90时达到最大值,与其他施磷处理相比增幅分别为0.18%~19.25%、5.79%~30.60%和0.90%~10.47%;磷素积累量分别在P135、P135和P90时达到峰值,与其他磷处理相比增幅分别为5.16%~54.70%、13.18%~77.22%和3.99%~56.75%。各施磷处理玉米产量均较P0显著增加,P135产量最高。综上,连续5年秸秆全量深翻还田配施磷135 kg/hm^(2)时,能够促进植株生长,玉米具有更强的养分吸收能力,产量显著提高。

Xianyu 335 was used as the test material in this experiment,and a two-factor split-plot design was used to study the effects of straw returning years[5 years(5a)and 1 year of total straw deep ploughing(1a)]and phosphorus application levels[P_(2)O_(5)0(P0),45(P45),90(P90),135(P135)and 180 kg/ha(P180)]on root architecture,mycorrhizal colonization,plant dry weight,phosphorus accumulation and final yield of maize.The results showed that compared with 1a,5a significantly optimized the root morphology of maize,promoted root growth,mycorrhizal infection and plant dry matter and phosphorus accumulation,and then increased the yield by 1.94%-7.15%.The level of phosphorus fertilizer affected the growth and development of maize,and also affected the mycorrhizal colonization density(m%),arbuscular richness(a%)and root arbuscular richness(A%),and these indexes began to decrease significantly after P90 treatment,indicating that when the phosphorus level was high,the infection of AM fungi would be seriously inhibited.The dry weights of roots,stalk and leaves of maize in jointing period reached the maximum at P90,P90 and P135,respectively,which increased by 1.31%-15.07%,0.05%-25.07%and 7.61%-22.42%compared with other phosphorus treatments.The accumulation of phosphorus reached the peak at P135,P90 and P135,respectively,which increased by 11.09%-95.51%,10.77%-77.39%and 3.91%-29.28%compared with other phosphorus treatments.The dry weight of stalk,leaves and grain of maize at mature period reached the maximum at P90,P135 and P90,respectively,and increased by 0.18%-19.25%,5.79%-30.60%and 0.90%-10.47%compared with other phosphorus treatments.The accumulation of phosphorus reached the peak at P135,P135 and P90,which increased by 5.16%-54.70%,13.18%-77.22%and 3.99%-56.75%,respectively,compared with other phosphorus treatments.Compared with P0,the maize yields of all P treatments increased significantly,and reached the highest at P135.In summary,when the total straw deep ploughing combined with 135 kg/ha phosphate fertilizer was applied for five consecutive years,maize had stronger nutrient absorption capacity,which could promote plant growth and significantly increase yield.