双季稻双直播模式不同早稻秸秆还田方式下氮肥运筹对晚稻生长发育和土壤理化性质的影响

Effects of Nitrogen Management on Growth and Development,Soil Physical and Chemical Properties of Late-Season Rice under Different Straw Retention Treatments of Early-Season Rice in Direct Seeding Mode of Double-Season Rice

在150 kg/hm^(2)施氮水平下以2种晚稻施氮比例[N_(1)(基肥:分蘖肥:穗肥=1:1:1)和N_(2)(基肥:分蘖肥:穗肥=2:1:1)]为主区,以5种不同秸秆还田方式[早稻秸秆直接还田(SR)、秸秆还田+石灰(SR+L)、秸秆还田+腐熟剂(SR+S)和秸秆还田+石灰+腐熟剂(SR+L+S)以及秸秆不还田(CK)]为副区,探究双季稻双直播模式中不同早稻秸秆还田方式下氮肥运筹对晚稻生长发育和土壤理化性质的影响。结果表明,与CK处理相比,SR处理降低了晚稻幼苗质量和土壤pH,而SR+L处理可以加快秸秆腐解速率,增加晚稻土壤速效钾含量;同时,增加晚稻基肥氮施用比例(N_(2))提高了晚稻出苗率和幼苗素质,缓解了短期秸秆还田带来的不利影响;此外,SR+L处理和N_(2)协同提高了晚稻土壤pH。因此,秸秆还田配施石灰和增加基肥氮施用比例协同增加晚稻产量,增幅达8.4%。生产上双季稻双直播早稻秸秆还田后,可通过施用石灰和增加晚稻基肥用量来降低秸秆还田的不利影响,提升晚稻产量。

The aims of this study were to explore effects of different straw retention practices of early-season rice(ESR)and nitrogen(N)management of late-season rice(LSR)on growth and development of LSR and soil physical and chemical properties in direct seeding of double-season rice(DS-DSR).The experiment was arranged in a split-plot design with N application ratio and straw retention practices.Under the total nitrogen application of 150 kg/ha in LSR,two different N application ratio were set as main plots,which was N1(base fertilizer:tillering fertilizer:panicle fertilizer=1:1:1)and N_(2)(base fertilizer:tillering fertilizer:panicle fertilizer=2:1:1).Five straw retention practices were set as subplots,including straw retention(SR),straw retention with liming(SR+L),straw retention with straw decomposing inoculant(SR+S),straw retention with liming,strawdecomposing inoculant(SR+L+S),and no straw retention(CK).The results showed that SR decreased seeding quality and soil pH of LSR compared to CK treatment.However,the treatment of SR+L accelerated straw decomposition rate of ESR,and increased soil available K content of LSR.Meanwhile,N_(2) application level increased the emergence rate and seedling quality of LSR,alleviated the adverse effects of straw retention in the short period.In addition,the treatment of SR+L and N_(2) synergistically increased the soil pH of LSR.Thus,SR+L and N_(2) synergistically increased the yield of LSR by 8.4%.The adverse effects of straw of ESR on LSR could be reduced by applying lime and increasing the amount of base fertilizer(N_(2))of LSR after the straw retention in the field,so as to increase the yield of LSR.