滨海盐碱地棉花秸秆还田和深松对棉花干物质积累、养分吸收及产量的影响

以鲁棉研36号为试验材料,在滨海盐碱地设置常规耕作(CT)、深松(ST)、秸秆还田(SR)、秸秆还田+深松(SRT)4个处理,研究棉花秸秆还田和深松对棉花产量、0～40 cm土层含盐量、棉花干物质积累动态、氮(N)磷(P)钾(K)养分积累和分配特性的影响。结果表明,秸秆还田在2年试验内均可增加棉花产量, SR产量比CT增加33.9%, SRT比ST增加32.1%;深松在2017年增加了棉花产量, 2018年对产量无影响。秸秆还田在2年试验中均降低0～40 cm土层含盐量, SR的含盐量在棉花生育后期比CT降低22.4%, SRT的土壤含盐量比ST降低20.7%;深松在2年试验内对20～40cm土层含盐量的影响不一致,ST含盐量在2017年棉花生育后期比CT降低16.5%,但在2018年深松对土壤含盐量无影响。棉花干物质和N、P、K积累动态均符合Logistic生长曲线。棉花秸秆还田后增加了棉花干物质和N、P、K的最大积累量, SR的干物质、N、P、K最大积累量比CT分别提高35.5%、38.3%、53.4%和55.0%, SRT比ST分别提高27.0%、30.7%、21.2%和42.4...

Effects of cotton stubble return and subsoiling on dry matter accumulation,nutrient uptake,and yield of cotton in coastal saline-alkali soil

To study the effects of cotton straw returning and deep loosening on cotton yield,salt content in 0–40 cm soil layer,dry matter accumulation dynamics,nitrogen(N),phosphorus(P),and potassium(K)accumulation,and distribution characteristics,four treatments including conventional tillage(CT),subsoiling tillage(ST),cotton stubble return(SR),and cotton stubble return+subsoiling tillage(SRT)were conducted using Lumianyan 36 as experimental material.The results showed that cotton stubble return increased cotton yield across two years.Lint yield of SR was 33.9%higher than CT,and SRT 32.1%higher than SR.Sub-soiling increased cotton yield in 2017 and had no effect on it in 2018.Cotton stubble return reduced the salt content of 0-40 cm soil layer.The salt content of SR was 22.4%lower than that of CT,and the soil salt content of SRT was 20.7%lower than that of ST at the late growth stage in cotton.However,the effect of subsoiling on the salt content of 20-40 cm soil layer was incon-sistent during the two-year experiment.The soil salt content of ST was 16.5%lower than of CT at late growth stage in 2017,but subsoiling had no effect on soil salt content in 2018.The accumulation dynamic of dry matter and N,P,K in cotton were consis-tent with the Logistic growth curve.Cotton stubble return increased maximal accumulation of dry matter and N,P,K in two years.The maximum accumulation of dry matter,N,P,and K in SR was 35.5%,38.3%,53.4%,and 55.0%higher than that in CT,and the accumulation of SRT was 27.0%,30.7%,21.2%,and 42.4%higher than that in ST.Compared with CT,the dry matter,N,P,and K accumulation of ST increased by 17.8%,22.2%,51.3%,and 40.6%in 2017,respectively,but had no effect in 2018.The dynamic of dry matter and nutrient accumulation were mainly affected by the maximum accumulation rate and rapid accumulation duration.Stubble return increased the amount and proportion of dry matter and N,P,K allocated to reproductive organs of cotton in the two-year experiment.Compared with CT,ST increased the allocation amount of dry matter and N,P,K to reproductive organs in 2017,but had no effect in 2018.In summary,the results revealed that cotton stubble return(SR)or cotton stubble return+subsoiling tillage(SRT)could be recommended tillage measures for soil improvement and high cotton yield in coastal sa-line-alkali cotton area.