水氮运筹对棉花花后生物量和氮素利用率的影响

在池栽和大田条件下,以‘美棉33B’为材料,研究不同水分(自然降水、自然降水 灌水)和氮素(0、240、480kgN/hm2)运筹下棉花花后生物量和养分累积及氮素利用率动态变化特征。结果表明:施氮使棉花(整株、营养器官、生殖器官)生物量和养分快速累积期持续时间缩短、最大累积速率增大且出现时间提前、累积量及皮棉产量增加。灌水使240 kgN/hm2处理棉花(整株、营养器官、生殖器官)生物量和养分快速累积期持续时间缩短、最大累积速率出现时间提前、最大累积速率和累积量增大、氮素累积利用率和产量提高;而使480 kgN/hm2处理棉花营养器官生物量和养分快速累积期持续时间延长、最大累积速率出现时间推迟、生物量和养分最大累积速率及累积量增大、氮素累积利用率提高,而生殖器官相应指标呈降低趋势;灌水对不施氮处理棉花生物量和养分累积各项特征参数影响较小。营养器官生物量和氮磷钾最大累积速率出现时间较生殖器官早23 d左右,而快速累积期持续时间长于生殖器官11 d左右。研究发现,水分和氮素运筹可通过影响棉花生物量和养分累积的动态特征参数来影响棉花生长,进而影响最终产量品质形成;在本实验条件下,以灌水的240 kgN/hm2处理棉花的生长特征参数最为协调,皮棉产量和氮素利用率最高,品质较优。

Effects of Different Water and Nitrogen Application on Biomass and Nutrients Accumulation and Nitrogen Fertilization Recovery Rate of Cotton after Anthesis

The pond and field experiments were conducted to research dynamic characters of biomass,nutrients(nitrogen,phosphor,potassium) uptake and nitrogen fertilization recovery rate of cotton after anthesis under different water and nitrogen applications.The dynamic curves of biomass and nutrients accumulation of cotton after anthesis were all in accordance with the model of logistic.Based on the logistic model,some eigenvalues(the duration of speed accumulation,the maximal accumulation rate and its appearing time) were gained.The results indicated that the duration of speed accumulation of biomass and nutrients of cotton were obviously shortened and the appearing time of the maximal accumulation rate were advanced,the maximal accumulation rate and accumulation amount were increased by nitrogen application.Compared with nature rainfall,irrigation shortened the duration of speed accumulation of biomass and nutrients of cotton in 240 kgN/hm2 and advanced the appearing time of the maximal accumulation rate and increased the maximal accumulation rate and accumulation amount and nitrogen fertilization recovery rate.However,irrigation prolonged the duration of speed accumulation of biomass and nutrients of cotton in 480 kgN/hm2 and postponed the appearing time of the maximal accumulation rate and increased the maximal accumulation rate and accumulated amount and nitrogen fertilization recovery rate of vegetative organ and decreased the maximal accumulation rate and accumulated amount and nitrogen fertilization recovery rate of reproductive organ.Irrigation did not significantly(P<0.05) effect on everyone eigenvalues of biomass and nutrients of cotton in 0 kgN/hm2.Although growth of vegetative organ were synchronous with reproductive organ after anthesis,but the appearing time of the maximal accumulated rate of biomass and nutrients of vegetative organ were earlier for 23 days than that of reproductive organ.The duration of speed accumulation were longer for 11 days than that of reproductive organ.Eigenvalues of the dynamic accumulation model of cotton(irrigation,240 kgN/hm2) was more harmonious,lint yield and nitrogen recovery rate is the highest.