有机资源等氮替代化肥对免耕稻田N_(2)O排放及水稻产量的影响

Effects of Equal Nitrogen Replacement of Chemical Fertilizer Organic Resources on N_(2)O Emissions and Rice Yield in No-tillage Field

试验设置两种稻田免耕模式[常规免耕(C)、粉垄免耕(F)],两种免耕模式下各设置四种施肥方式,绿肥与化肥配施(C3、F3)、蚕沙与化肥配施(C4、F4),同步设置不施肥的空白对照(C1、F1),施全量化肥的常规对照(C2、F2)处理,采用分离式静态箱−气象色谱法测定双稻季水稻生育期内稻田N_(2)O排放通量,并测定水稻收获期干物质量、产量和根冠比等,以探讨集约化稻作下有机氮替代化学氮对稻田N_(2)O排放及水稻产量的影响,为稻田有机资源与化肥配施提供科学依据。结果表明:(1)有机资源替代化学氮肥能够显著降低稻田N_(2)O累计排放量。C3、C4、F3、F4的N_(2)O累计排放量较C2、F2在早稻季分别降低69.1%、86.3%、69.9%和63.4%,晚稻季分别降低7.3%、67.2%、38.5%和60.4%;(2)免耕稻田下绿肥替代化肥利于水稻稳产。粉垄免耕下F3较F2产量提升0.6%~10.0%,F4较F2产量下降1.7%~6.6%;常规免耕下C3较C2产量降低1%~1.1%,C4较C2产量下降1.1%~8.4%。(3)有机资源等氮替代化肥影响水稻根系生长,显著提高植株干物质量、有效穗数和穗粒数。早、晚稻生长季C3、F3的植株干物质量较C2、F2分别提高22.6%和5.4%;有效穗数和穗粒数分别提高6.3%~13.5%和0.3%~6.2%。稻田免耕下两种有机资源替代化学氮肥均能有效降低N_(2)O排放,粉垄免耕下绿肥替代化学氮肥显著提高水稻干物质量及根系活力,能够维持水稻产量稳定并减少稻田N_(2)O排放,采用绿肥等氮替代化肥可作为一种集约化稻作可持续生产调控技术。

It was set up conventional no-tillage and smash ridging no-tillage in this experiment.In conventional no-tillage rice field was set green manure combined application chemical fertilizer(C3)and silkworm-excrement organic fertilizer combined application chemical fertilizer(C4),synchronously set blank contrast(C1)and conventional contrast of total fertilization(C2).And smash ridging no-tillage was set green manure combined application chemical fertilizer(F3)and silkworm-excrement organic fertilizer combined application chemical fertilizer(F4),synchronously set blank contrast(F1)and conventional contrast of total fertilization(F2).The results showed that:(1)in this experiment,organic fertilizer combined with chemical fertilizer significantly reduced the cumulative N_(2)O emission.The cumulative N_(2)O emission of organic fertilizer combined with chemical fertilizer(C3,C4,F3,F4)compared with fertilizer contrast(C2)respectively decreased 69.1%,86.3%,69.9%and 63.4%in early rice season,and decreased 7.3%,67.2%,38.5%and 60.4%in the late rice season.(2)Green manure combined with chemical fertilizer applied to rice field can keep rice yield stable in Smash ridging no-tillage.In Smash ridging no-tillage,the yield of F3 compared with F2 increased by 0.6%−10.0%,and the yield of F4 compared with F2 decreased by 1.7%−6.6%.In conventional no-tillage,the yield of C3 and C4 compared with C2 decreased by 1.0%−1.1%and 1.1%−8.4%.(3)Organic fertilizers combine with chemical fertilizers applied to rice fields can affect the growth of rice roots,it significantly improve the dry-matter of plant and the number of effective panicles and grains per panicle.The dry-matter of plant accumulation of F3 and C3 compared with F2 and C2,it increased 22.6%and 5.4%in the early and late rice season.The number of effective panicles and grains per panicle was increasing by 6.3%−13.5%and 0.3%−6.2%in this experiment.In no-tillage rice field use of organic resources instead of chemical fertilizers into the rice fields can effectively reduce N_(2)O emission.Green manure combined with chemical fertilizer applied to rice field can improved root quality of rice,increase rice dry matter,and it can reduced N_(2)O emission while kept the rice yield.It can be used as a sustainable production regulation technology for intensive rice farming.