• ISSN 1008-505X
  • CN 11-3996/S
胡田田, 康绍忠, 李志军, 张富仓. 局部湿润方式下玉米对不同根区氮素的吸收与分配[J]. 植物营养与肥料学报, 2009, 15(1): 105-113. DOI: 10.11674/zwyf.2009.0115
引用本文: 胡田田, 康绍忠, 李志军, 张富仓. 局部湿润方式下玉米对不同根区氮素的吸收与分配[J]. 植物营养与肥料学报, 2009, 15(1): 105-113. DOI: 10.11674/zwyf.2009.0115
HU Tian-tian, KANG Shao-zhong, LI Zhi-jun, ZHANG Fu-cang. Uptake and allocation of nitrogen from different root zones of maize under local irrigation[J]. Journal of Plant Nutrition and Fertilizers, 2009, 15(1): 105-113. DOI: 10.11674/zwyf.2009.0115
Citation: HU Tian-tian, KANG Shao-zhong, LI Zhi-jun, ZHANG Fu-cang. Uptake and allocation of nitrogen from different root zones of maize under local irrigation[J]. Journal of Plant Nutrition and Fertilizers, 2009, 15(1): 105-113. DOI: 10.11674/zwyf.2009.0115

局部湿润方式下玉米对不同根区氮素的吸收与分配

Uptake and allocation of nitrogen from different root zones of maize under local irrigation

  • 摘要: 采用分根装置,对均匀灌水、固定灌水和交替灌水3种方式下,于1/2根区设施(15NH4)2SO4的处理;另1/2根区施入等量的 (14NH4)2SO4,研究玉米不同根区氮素的吸收与分配特征。结果表明,处理15、20、40 d时,玉米累积15N肥料氮量表现为,固定灌水下15N施在灌水区分别是非灌水区的2.37、2.95和3.41倍;交替灌水下15N施在先灌水区是后灌水区的1.57、1.08和1.06倍。作物自不同根区土壤或肥料吸收氮素占总吸氮量的百分数表明,交替灌水时,不同根区有同等贡献;固定灌水时,作物吸收的氮素绝大部分来自灌水区。根系的氮素吸收速率和根长均表现为,交替灌水两根区趋于相同;固定灌水的非灌水区明显小于灌水区,表明吸收速率和根长对作物吸收氮素都有重要作用。处理40d时,玉米各部分累积15N肥料氮占根区总吸收量百分数为地上部:均匀灌水交替灌水固定灌水;14N区根系:15N施在固定灌水的非灌水区其他4个处理;15N区根系:15N施在固定灌水的灌水区固定灌水的非灌水区和交替灌水任一根区均匀灌水。说明局部供水使根系的氮素分配明显增多,地上部减少;两种局部灌水所不同的是,固定灌水时,氮素向灌水区根系的分配大于非灌水区,交替灌水时,两根区相近。

     

    Abstract: Effects of partial root-zone irrigation on uptake and allocation of nitrogen from different root zones of maize grown in split-root containers were studied. Maize was irrigated on both halves of the container (conventional irrigation, C), on one side only (fixed partial root-zone irrigation, F), or alternatively on both sides (alternative partial root-zone irrigation, A). Isotope-labled 15N-(NH4)2SO4 was applied to one half of the pot with (14NH4)2SO4 to the other half so that N inflow could be tracked. Results showed that in the day 15, 20, 40, the ratios of N uptake from 15N-fertilizer applied in the irrigated root zone(Fw)to that from the non-irrigated zone (Fd) of F treatment were 2.37, 2.95 and 3.41, respectively. For A treatment, the ratios of N uptake from 15N-fertilizer applied in the early irrigated zone(Ae)to that from the late irrigated zone(Al)were 1.57, 1.08 and 1.06, respectively. The percentages of plant N absorbed from soil or fertilizer in different root zones to total N uptake for three irrigation methods also indicated that the amount of N absorption from two root zones of A treatment was equal whereas for F treatment, the N accumulation in plant was mainly from the irrigated root zone. Considering the fact that root N inflow and root length in the irrigated zone were larger than those of the non-irrigated zone for F treatment, it could be concluded that both of root length and N absorption capacity contribute to plant N uptake largely. At 40 day, the percentage of 15N-fertilizer N allocation in shoot to total accumulation for A treatment was higher than that for F treatment but lower than that for C. The 15N allocation percentage of the subroot supplied with 14N-fertilizer was higher for Fd than for the others. The 15N allocation percentage of the subroot supplied with 15N-fertilizer was higher for Fd, Al and Ae than for C treatment but lower than for Fw. Our results suggest that partial root-zone irrigation increased N allocation in root system but decreased N allocation in shoot. However, for A treatment, N allocation in two subroots was equal but for F treatment, N allocation of the subroot in the irrigated zone was higher than that of the non-irrigated zone.

     

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