锌肥和石灰对双季稻产量及土壤肥力特性的影响

Effects of Zinc Fertilizer and Lime on Yield and Soil Fertility Characteristics of Double-Season Rice

为探究锌肥和石灰对双季稻产量及土壤养分特性的影响,提出适合当地土壤和水稻种植条件的最佳施肥模式,本研究在南方典型双季稻种植区,设不施氮(PK)、无机肥(NPK)、无机肥+锌肥(NPK+Zn)、无机肥+石灰(NPK+CaO)四种施肥处理。测定了水稻土壤有效锌、碱解氮、有效磷、pH、植株产量、氮素农学利用率等指标。结果表明:(1)NPK+Zn处理提高了双季稻实际产量,2017年早晚季提升幅度分别为10.3%~56.9%、7.6%~41.7%。2018年早晚季提升幅度分别为17.6%~104.2%、8.5%~45.2%。而连年施用石灰则不利于双季稻产量提高,2018年NPK+CaO处理较NPK处理水稻有效穗显著下降,早晚季分别减产2.9%、9.2%。(2)NPK+Zn处理有效提高了土壤中速效养分含量,其中,有效磷含量比NPK处理早晚稻分别提高了29.2%和33.3%,有效锌含量较NPK处理显著提升了25.5%。NPK+CaO处理虽能显著提高土壤pH值,但土壤中有效锌含量较NPK处理显著下降了51.8%。(3)NPK+Zn相比NPK和NPK+CaO处理双季稻氮素农学利用率显著提高了57.3%和67.1%。NPK和NPK+CaO处理间无显著差异。综上所述,连年施用石灰显著降低了土壤中有效锌含量,不利于水稻增产。缺锌土壤中施锌不仅能提高土壤速效养分含量和水稻氮素农学利用率,还可使水稻高产、稳产,锌肥+无机化肥为当地最佳施肥模式。

In order to investigate the effects of zinc fertilizer and lime on the yield and soil nutrient characteristics of double cropping rice,and to propose the best fertilization mode suitable for local soil and rice planting conditions,four fertilization treatments were applied in typical double cropping rice areas in south China:no nitrogen(PK),inorganic fertilizer(NPK),inorganic fertilizer+zinc fertilizer(NPK+Zn),and inorganic fertilizer+lime(NPK+CaO).The indexes of available zinc,alkali-hydrolyzable nitrogen,available phosphorus,pH,yield and nitrogen agronomic efficiency were determined.The results showed as follows:Application of zinc fertilizer(NPK+Zn)increased the actual yield of double cropping rice by 10.3%-56.9%and 7.6%-41.7%in the early and late seasons in 2017,respectively.In 2018,the growth rates in the morning and evening quarters were 17.6%-104.2%and 8.5%-45.2%respectively.NPK+Zn treatment effectively increased the content of soil available nutrients,in which,the content of available phosphorus was 29.2%and 33.3%higher than that of NPK treatment,and the content of available zinc was 25.5%higher than that of NPK treatment,respectively.Compared with NPK and NPK+CaO,NPK+Zn significantly increased the nitrogen agronomic efficiency by 57.3%and 67.1%.In conclusion,applying lime in successive years significantly reduced the available zinc content in soil and was not conducive to rice yield increase.In zn-deficient soil,zinc application could not only improve soil available nutrient content and agronomic utilization rate of rice nitrogen,but also make rice yield higher and stable.The application of zinc fertilizer+inorganic fertilizer was the best fertilization mode.