基肥(~(15)N)施用时间对烤烟产量、产值及氮素利用率的影响

采用15N同位素示踪微区试验与田间试验,在湖北襄樊2个不同海拔的植烟生态区(赵家山和老湾)研究了不同基肥施用时间(提前0、15和30d)条件下,施用氮肥对烤烟产量、产值及氮素吸收、利用和分配的影响。结果表明,施用氮肥显著增加烤烟产量和产值,增幅分别为13%～40%(低海拔赵家山地点)和14%～35%(高海拔老湾地点)。与移栽当天施用基肥相比,提前施用基肥15～30d有利烤烟产值的提高,其中高海拔试验点增幅为10%～30%,达到显著水平(P0.05)。与移栽当天或者提前15d相比,提前30d施用基肥还提高2个海拔地区烤烟对氮素的吸收累积量8%～26%。提前基肥施用时间对低海拔地区氮肥利用率的影响不显著,但显著提高高海拔地区烤烟生育中后期氮肥利用率3%～6%。结果说明,在光、温条件较差的高海拔地区,适当提前施用基肥(15d),有利于提高肥料利用率,从而提高烤烟产量产值。

YIELDS, MARKET VALUES AND N USE EFFICIENCY IN FLUE-CURED TOBACCO INFLUENCED BY TIME OF BASAL N FERTILIZATION

Abstract：A field experiment with 15N isotope tracing micro plots was carried out to study the effects of basal N fertilizer application time (0d, 15d, 30d before the transplanting) on the yields, market values and N uptake, utilization and distribution in different organs of flue cured tobacco (FCT) in two ecological tobacco production areas (Zhaojiashan and Laowan) of Xiangfan City, Hubei Province. The results showed that supplying N fertilizer significantly increased the yields and market values of FCT by 13%～40% and 14%～35% for the experimental site of Zhaojiashan (lower altitude) and Laowan (higher altitude), respectively. Compared to applying basal fertilizer at 0 d before transplanting, applying basal fertilizer at 15d or 30d before transplanting increased the market values by 10%～30% (P＜005). And early application of basal N fertilizer (30 d before transplanting) increased N accumulation by 8%～26% as compared with that of applying basal N fertilizer at 0d or 15d before transplanting in the two ecological areas. There was no significant effects of basal N application time on N fertilizer efficiency in lower altitude site, but increasing by 3%～6% in higher altitude site. These results indicated that properly earlier (15d for example) supplication of basal N fertilizer could improve the N fertilizer efficiency, and thus increase the yields and market values of FCT, especially in higher altitude areas with less sunshine and lower temperature.