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
为定量评估区域设施菜地土壤氮素的输入输出平衡状况,探明土壤中氮素的基本去向和氮素潜在污染,从CNKI中文数据库和Web of Science等英文数据库中检索筛选出针对设施菜地氮循环研究的可用数据648组,对我国设施菜地表观氮素平衡进行了分...为定量评估区域设施菜地土壤氮素的输入输出平衡状况,探明土壤中氮素的基本去向和氮素潜在污染,从CNKI中文数据库和Web of Science等英文数据库中检索筛选出针对设施菜地氮循环研究的可用数据648组,对我国设施菜地表观氮素平衡进行了分析,并根据《全国设施蔬菜重点区域发展规划(2015-2020年)》中的蔬菜分区,探索了不同区域的氮平衡分布特征。结果表明,我国设施菜地每一生长季总体上表观氮平衡为正值,盈余量为49~1154 kg N·hm-2,均值为324 kg N·hm-2,氮肥利用率平均为18.6%。从氮素的输入途径来看,每季氮素总投入约为863 kg N·hm-2,以化肥和有机肥投入为主,分别为471、306 kg N·hm-2,灌溉水带入的氮也不容忽视,达到86 kg N·hm-2。从氮素的支出途径来看,每季氮素总支出为539 kg N·hm-2,其中除了作物生长从土壤中吸取大量的氮素(230 kg N·hm-2)外,以淋溶、硝化反硝化和氨挥发等形式损失的氮达到309 kg N·hm-2,占输出量的57.4%,超过了作物吸收带走的氮(42.6%)。每季区域氮平衡差异显著,其中,黄淮海与环渤海暖温区氮素盈余最高,达到441 kg N·hm-2,其较高氮投入和较低的作物吸收是造成农田土壤氮素大量盈余的主要原因,同时也存在较高的氮素损失,通过淋溶流失的氮达到186 kg N·hm-2。总体上,当前我国设施菜地整体表观氮平衡为正盈余,主要由于化肥和有机肥投入量大,但同时存在较高的氮素损失风险。降低氮素投入水平和提高作物的吸收利用率是有效的氮优化管理途径,尤其是在黄淮海与环渤海暖温区,应减少氮素投入,重点关注氮素淋溶损失。展开更多
From July 2008 to August 2008, 72 leaf samples from 22 species and 81 soil samples in the nine natural forest ecosystems were collected, from north to south along the North-South Transect of Eastern China （NSTEC）. B...From July 2008 to August 2008, 72 leaf samples from 22 species and 81 soil samples in the nine natural forest ecosystems were collected, from north to south along the North-South Transect of Eastern China （NSTEC）. Based on these samples, we studied the geographical distribution patterns of vegetable water use efficiency （WUE） and nitrogen use efficiency （NUE）, and analyzed their relationship with environmental factors. The vegetable WUE and NUE were calculated through the measurement of foliar δ 13C and C/N of predominant species, respectively. The results showed： （1） vegetable WUE, ranging from 2.13 to 28.67 mg C g-1 H2O, increased linearly from south to north in the representative forest ecosystems along the NSTEC, while vegetable NUE showed an opposite trend, increasing from north to south, ranging from 12.92 to 29.60 g C g-1 N. （2） Vegetable WUE and NUE were dominantly driven by climate and significantly affected by soil nutrient factors. Based on multiple stepwise regression analysis, mean annual temperature, soil phosphorus concentration, and soil nitrogen concentration were responding for 75.5% of the variations of WUE （p0.001）. While, mean annual precipitation and soil phosphorus concentration could explain 65.7% of the change in vegetable NUE （p0.001）. Moreover, vegetable WUE and NUE would also be seriously influenced by atmospheric nitrogen deposition in nitrogen saturated ecosystems. （3） There was a significant trade-off relationship between vegetable WUE and NUE in the typical forest ecosystems along the NSTEC （p0.001）, indicating a balanced strategy for vegetation in resource utilization in natural forest ecosystems along the NSTEC. This study suggests that global change would impact the resource use efficiency of forest ecosystems. However, vegetation could adapt to those changes by increasing the use efficiency of shortage resource while decreasing the relatively ample one. But extreme impacts, such as heavy nitrogen deposition, would break this trade-off mech展开更多
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。
文摘为定量评估区域设施菜地土壤氮素的输入输出平衡状况,探明土壤中氮素的基本去向和氮素潜在污染,从CNKI中文数据库和Web of Science等英文数据库中检索筛选出针对设施菜地氮循环研究的可用数据648组,对我国设施菜地表观氮素平衡进行了分析,并根据《全国设施蔬菜重点区域发展规划(2015-2020年)》中的蔬菜分区,探索了不同区域的氮平衡分布特征。结果表明,我国设施菜地每一生长季总体上表观氮平衡为正值,盈余量为49~1154 kg N·hm-2,均值为324 kg N·hm-2,氮肥利用率平均为18.6%。从氮素的输入途径来看,每季氮素总投入约为863 kg N·hm-2,以化肥和有机肥投入为主,分别为471、306 kg N·hm-2,灌溉水带入的氮也不容忽视,达到86 kg N·hm-2。从氮素的支出途径来看,每季氮素总支出为539 kg N·hm-2,其中除了作物生长从土壤中吸取大量的氮素(230 kg N·hm-2)外,以淋溶、硝化反硝化和氨挥发等形式损失的氮达到309 kg N·hm-2,占输出量的57.4%,超过了作物吸收带走的氮(42.6%)。每季区域氮平衡差异显著,其中,黄淮海与环渤海暖温区氮素盈余最高,达到441 kg N·hm-2,其较高氮投入和较低的作物吸收是造成农田土壤氮素大量盈余的主要原因,同时也存在较高的氮素损失,通过淋溶流失的氮达到186 kg N·hm-2。总体上,当前我国设施菜地整体表观氮平衡为正盈余,主要由于化肥和有机肥投入量大,但同时存在较高的氮素损失风险。降低氮素投入水平和提高作物的吸收利用率是有效的氮优化管理途径,尤其是在黄淮海与环渤海暖温区,应减少氮素投入,重点关注氮素淋溶损失。
基金National Natural Science Foundation of China No.30590381 No.31000211 National Basic Research Program of China No.2010CB833504
文摘From July 2008 to August 2008, 72 leaf samples from 22 species and 81 soil samples in the nine natural forest ecosystems were collected, from north to south along the North-South Transect of Eastern China （NSTEC）. Based on these samples, we studied the geographical distribution patterns of vegetable water use efficiency （WUE） and nitrogen use efficiency （NUE）, and analyzed their relationship with environmental factors. The vegetable WUE and NUE were calculated through the measurement of foliar δ 13C and C/N of predominant species, respectively. The results showed： （1） vegetable WUE, ranging from 2.13 to 28.67 mg C g-1 H2O, increased linearly from south to north in the representative forest ecosystems along the NSTEC, while vegetable NUE showed an opposite trend, increasing from north to south, ranging from 12.92 to 29.60 g C g-1 N. （2） Vegetable WUE and NUE were dominantly driven by climate and significantly affected by soil nutrient factors. Based on multiple stepwise regression analysis, mean annual temperature, soil phosphorus concentration, and soil nitrogen concentration were responding for 75.5% of the variations of WUE （p0.001）. While, mean annual precipitation and soil phosphorus concentration could explain 65.7% of the change in vegetable NUE （p0.001）. Moreover, vegetable WUE and NUE would also be seriously influenced by atmospheric nitrogen deposition in nitrogen saturated ecosystems. （3） There was a significant trade-off relationship between vegetable WUE and NUE in the typical forest ecosystems along the NSTEC （p0.001）, indicating a balanced strategy for vegetation in resource utilization in natural forest ecosystems along the NSTEC. This study suggests that global change would impact the resource use efficiency of forest ecosystems. However, vegetation could adapt to those changes by increasing the use efficiency of shortage resource while decreasing the relatively ample one. But extreme impacts, such as heavy nitrogen deposition, would break this trade-off mech
