利用再生水进行农业、园林灌溉是解决水资源短缺的重要举措。定量评价再生水灌溉对作物产量和氮素利用效率(nitrogen use efficiency,NUE)的效应,以及影响机制,可为再生水灌溉应用提供理论依据。本文以清水灌溉为对照,采用Meta-analysis...利用再生水进行农业、园林灌溉是解决水资源短缺的重要举措。定量评价再生水灌溉对作物产量和氮素利用效率(nitrogen use efficiency,NUE)的效应,以及影响机制,可为再生水灌溉应用提供理论依据。本文以清水灌溉为对照,采用Meta-analysis(整合分析)定量研究了不同水质、土壤和管理因素条件下,再生水灌溉对作物产量和氮素利用效率的影响。结果表明:与清水灌溉相比,再生水灌溉显著提高了作物产量16.8%(CI:12.6%~21.1%,P<0.001)和氮素利用效率16.2%(CI:9.5%~23.4%,P<0.001),但其效应高度依赖于水质、土壤和管理因素;在土壤初始含氮量介于200~2000 mg/kg,再生水pH<7,或再生水含氮量<100 mg/L条件下,有利于发挥再生水灌溉增产效应和提高氮素利用效率;采用滴灌系统,施氮肥<1000 kg/ha进行充分灌溉是较为合适的管理策略。展开更多
Nitrogen （N） application before transplanting, where N fertilizers are applied in seedling-bed and carried to the paddy field with seedlings, is a novel method proposed in this article aiming for improving nitrogen ...Nitrogen （N） application before transplanting, where N fertilizers are applied in seedling-bed and carried to the paddy field with seedlings, is a novel method proposed in this article aiming for improving nitrogen utilization efficiency （NUE） in rice. The effect of this method on mineral N distribution in the rhizosphere soil was investigated in a field experiment with a japonica variety, Ningjing 2, in seasons of 2004 and 2005. There were four levels of N applied 16 h before transplanting： zero N （NO）, 207 kg ha^-1 （NL）, 310.5 kg ha^-1 （NM）, and 414 kg ha^-1 （NH）. The result indicated that N fertilizer before transplantation had positive effect of increasing mineral N content in the rhizosphere soil of rice. Generally, N content in the rhizosphere soil of rice tended to increase with the amount of N fertilizer before transplanting, with the NH treatment having the largest effect. Additionally, N fertilizer before transplanting had significant influence on rice NUE and grain yield. Compared with other treatments, the NM treatment showed the largest influence, with basal-tillering NUE, total NUE, and grain yield being 15%, 12%, and 529.5 kg ha^-1 higher than those of NO treatment. This result indicated that N fertilizer before transplantation had positive effect on mineral N distribution in the rhizosphere soil of rice, thus improving NUE and grain yield.展开更多
The unreasonable nitrogen(N)supply and low productivity are the main factors restricting the sustainable development of processing tomatoes.In addition,the mechanism by which the N application strategy affects root gr...The unreasonable nitrogen(N)supply and low productivity are the main factors restricting the sustainable development of processing tomatoes.In addition,the mechanism by which the N application strategy affects root growth and nitrate distributions in processing tomatoes remains unclear.In this study,we applied four N application levels to a field(including 0(N0),200(N200),300(N300),and 400(N400)kg/hm^(2))based on the critical N absorption ratio at each growth stage(planting stage to flowering stage:22%;fruit setting stage:24%;red ripening stage:45%;and maturity stage:9%).The results indicated that N300 treatment significantly improved the aboveground dry matter(DM),yield,N uptake,and nitrogen use efficiency(NUE),while N400 treatment increased nitrate nitrogen(NO_(3)^(-)-N)residue in the 20–60 cm soil layer.Temporal variations of total root dry weight(TRDW)and total root length(TRL)showed a single-peak curve.Overall,N300 treatment improved the secondary root parameter of TRDW,while N400 treatment improved the secondary root parameter of TRL.The grey correlation coefficients indicated that root dry weight density(RDWD)in the surface soil(0–20 cm)had the strongest relationship with yield,whereas root length density(RLD)in the middle soil(20–40 cm)had a strong relationship with yield.The path model indicated that N uptake is a crucial factor affecting aboveground DM,TRDW,and yield.The above results indicate that N application levels based on critical N absorption improve the production of processing tomatoes by regulating N uptake and root distribution.Furthermore,the results of this study provide a theoretical basis for precise N management.展开更多
选用水稻氮高效基因型IR72和9311及氮低效基因型Lemont和PECOS,采用土培方法,在5个施氮量（0、0.51、1.02、1.53、2.04 g N钵-1,分别相当于0、75、150、225、300 kg Nhm-2）处理下,研究了生理生化特性对氮肥的反应及与氮效率的关系。结...选用水稻氮高效基因型IR72和9311及氮低效基因型Lemont和PECOS,采用土培方法,在5个施氮量（0、0.51、1.02、1.53、2.04 g N钵-1,分别相当于0、75、150、225、300 kg Nhm-2）处理下,研究了生理生化特性对氮肥的反应及与氮效率的关系。结果表明,在幼穗分化期,氮高效基因型水稻的可溶性蛋白含量相对低,而谷氨酰胺合成酶（GS）活性高;不同氮效率基因型间1,5-二磷酸核酮糖羧化酶/加氧酶（Rubisco）含量的差异不大;两种氮效率基因型间的净光合速率（Pn）在幼穗分化期差异不明显。而在齐穗期,氮低效基因型的Pn比高效基因型的低28.66%左右;氮低效基因型在两个时期的单位叶绿素光合速率（Pn/Chl）比氮高效基因型分别低18.51%和29.67%左右。在成熟期,氮高效基因型干物质积累能力强,籽粒产量高。这些结果说明氮效率不同的基因型对氮肥的生理反应差异大。相关性分析表明,低氮水平时（0-1.53gN钵-1）,GS酶活性与收获时生物量呈显著或极显著正相关;氮肥偏生产力（PFP）、氮肥农学利用率（AE）及氮素生理利用率（NUEb）分别与GS活性、Pn/Chl和齐穗期的Pn呈显著正相关,而与可溶性蛋白含量、Rubisco含量显著负相关;氮肥吸收效率（RE）与这些生理指标没有显著相关。结果表明水稻光合特征及氮代谢与水稻氮效率间存在紧密的关系,GS活性和可溶性蛋白含量对评价水稻氮肥利用率具有重要的参考价值。展开更多
文摘Nitrogen （N） application before transplanting, where N fertilizers are applied in seedling-bed and carried to the paddy field with seedlings, is a novel method proposed in this article aiming for improving nitrogen utilization efficiency （NUE） in rice. The effect of this method on mineral N distribution in the rhizosphere soil was investigated in a field experiment with a japonica variety, Ningjing 2, in seasons of 2004 and 2005. There were four levels of N applied 16 h before transplanting： zero N （NO）, 207 kg ha^-1 （NL）, 310.5 kg ha^-1 （NM）, and 414 kg ha^-1 （NH）. The result indicated that N fertilizer before transplantation had positive effect of increasing mineral N content in the rhizosphere soil of rice. Generally, N content in the rhizosphere soil of rice tended to increase with the amount of N fertilizer before transplanting, with the NH treatment having the largest effect. Additionally, N fertilizer before transplanting had significant influence on rice NUE and grain yield. Compared with other treatments, the NM treatment showed the largest influence, with basal-tillering NUE, total NUE, and grain yield being 15%, 12%, and 529.5 kg ha^-1 higher than those of NO treatment. This result indicated that N fertilizer before transplantation had positive effect on mineral N distribution in the rhizosphere soil of rice, thus improving NUE and grain yield.
基金supported by the National Natural Science Foundation of China (42077011).
文摘The unreasonable nitrogen(N)supply and low productivity are the main factors restricting the sustainable development of processing tomatoes.In addition,the mechanism by which the N application strategy affects root growth and nitrate distributions in processing tomatoes remains unclear.In this study,we applied four N application levels to a field(including 0(N0),200(N200),300(N300),and 400(N400)kg/hm^(2))based on the critical N absorption ratio at each growth stage(planting stage to flowering stage:22%;fruit setting stage:24%;red ripening stage:45%;and maturity stage:9%).The results indicated that N300 treatment significantly improved the aboveground dry matter(DM),yield,N uptake,and nitrogen use efficiency(NUE),while N400 treatment increased nitrate nitrogen(NO_(3)^(-)-N)residue in the 20–60 cm soil layer.Temporal variations of total root dry weight(TRDW)and total root length(TRL)showed a single-peak curve.Overall,N300 treatment improved the secondary root parameter of TRDW,while N400 treatment improved the secondary root parameter of TRL.The grey correlation coefficients indicated that root dry weight density(RDWD)in the surface soil(0–20 cm)had the strongest relationship with yield,whereas root length density(RLD)in the middle soil(20–40 cm)had a strong relationship with yield.The path model indicated that N uptake is a crucial factor affecting aboveground DM,TRDW,and yield.The above results indicate that N application levels based on critical N absorption improve the production of processing tomatoes by regulating N uptake and root distribution.Furthermore,the results of this study provide a theoretical basis for precise N management.
文摘选用水稻氮高效基因型IR72和9311及氮低效基因型Lemont和PECOS,采用土培方法,在5个施氮量（0、0.51、1.02、1.53、2.04 g N钵-1,分别相当于0、75、150、225、300 kg Nhm-2）处理下,研究了生理生化特性对氮肥的反应及与氮效率的关系。结果表明,在幼穗分化期,氮高效基因型水稻的可溶性蛋白含量相对低,而谷氨酰胺合成酶（GS）活性高;不同氮效率基因型间1,5-二磷酸核酮糖羧化酶/加氧酶（Rubisco）含量的差异不大;两种氮效率基因型间的净光合速率（Pn）在幼穗分化期差异不明显。而在齐穗期,氮低效基因型的Pn比高效基因型的低28.66%左右;氮低效基因型在两个时期的单位叶绿素光合速率（Pn/Chl）比氮高效基因型分别低18.51%和29.67%左右。在成熟期,氮高效基因型干物质积累能力强,籽粒产量高。这些结果说明氮效率不同的基因型对氮肥的生理反应差异大。相关性分析表明,低氮水平时（0-1.53gN钵-1）,GS酶活性与收获时生物量呈显著或极显著正相关;氮肥偏生产力（PFP）、氮肥农学利用率（AE）及氮素生理利用率（NUEb）分别与GS活性、Pn/Chl和齐穗期的Pn呈显著正相关,而与可溶性蛋白含量、Rubisco含量显著负相关;氮肥吸收效率（RE）与这些生理指标没有显著相关。结果表明水稻光合特征及氮代谢与水稻氮效率间存在紧密的关系,GS活性和可溶性蛋白含量对评价水稻氮肥利用率具有重要的参考价值。
