不同形态氮肥对棉花^(15)N回收率和产量的影响

Effects of different nitrogen forms on^(15)N recovery and yield of cotton

采用盆栽试验,保证土壤水分含量不低于田间持水量的60%,在等量施氮条件下,研究尿素、硫酸铵、硝酸钙3种氮肥在播前、蕾期、初花期施用对棉花^(15)N回收率和产量的影响,旨在为棉花氮肥合理施用提供理论依据。结果表明,在3个施肥时期单施尿素、硫酸铵籽棉产量显著优于单施硝酸钙,分别高15.3%、14.0%。不同种类氮肥组合硫酸铵+尿素+硝酸钙、硫酸铵+硝酸钙+硝酸钙籽棉产量最高,分别比单施尿素高10.5%、9.0%。基肥^(15)N回收率28.8%~32.2%,硫酸铵>尿素>硝酸钙,蕾期追肥^(15)N回收率57.2%~73.2%,硝酸钙>尿素>硫酸铵,初花期追肥^(15)N回收率71.8%~82.7%,硝酸钙>硫酸铵>尿素。本试验条件下,硫酸铵基施,蕾期施用尿素或硝酸钙,初花期施用硝酸钙,增加了单株成铃数,获得了较高的籽棉产量和氮肥回收率。

In order to study the effects of urea,ammonium sulfate,and calcium nitrate applied before sowing,at budding period,and at initial flowering period with equal total nitrogen(N)application rate on the^(15)N recovery and the seed cotton yield,a pot trial using^(15)N trace technique with soil water levels beyond 60%of field capacity was carried out by a random block design,and the results would provide a theoretical basis for rational N fertilizer application of cotton.The results showed that the seed cotton yield with single application of urea and ammonium sulfate during the whole growth period of cotton was significantly higher than that of single application of calcium nitrate in the three fertilization periods,by 15.3%and 14.0%,respectively.The treatment“ammonium sulfate+urea+calcium nitrate”and“ammonium sulfate+calcium nitrate+calcium nitrate”achieved the highest seed cotton yield,which was 10.5%,and 9.0%higher than that of the treatment“single application of urea in the three fertilization periods”.For N applied as base fertilizer,the order of^(15)N recovery rate of cotton plants(28.8%~32.2%)was ammonium sulfate>urea>calcium nitrate.For N fertilizer applied at budding period,the order of^(15)N recovery rate of cotton plants(57.2%~73.2%)was calcium nitrate>urea>ammonium sulfate.For N fertilizer applied at initial flowering period,the order of^(15)N recovery rate of cotton plants(71.8%~82.7%)was calcium nitrate>ammonium sulfate>urea.Under the conditions of this experiment,ammonium sulfate applied as base fertilizer,urea or calcium nitrate applied at the budding period,and calcium nitrate applied at the initial flowering period increased the number of bolls per cotton and achieved higher seed cotton yield and N fertilizer recovery.