【目的】探明籼粳杂交稻甬优2640的氮素吸收利用特点。【方法】籼粳杂交稻甬优2640、常规粳稻连粳7号和常规籼稻扬稻6号种植于大田,设置6种施氮量处理(0、100、200、300、400、500 kg/hm^(2))和^(15)N示踪微区试验。【结果】在0~400 N k...【目的】探明籼粳杂交稻甬优2640的氮素吸收利用特点。【方法】籼粳杂交稻甬优2640、常规粳稻连粳7号和常规籼稻扬稻6号种植于大田,设置6种施氮量处理(0、100、200、300、400、500 kg/hm^(2))和^(15)N示踪微区试验。【结果】在0~400 N kg/hm^(2)范围内,甬优2640的稻谷产量随施氮量的增加而提高;连粳7号和扬稻6号的产量则是先增加后降低,在施氮量300 kg/hm^(2)时产量最高;相同施氮量下,甬优2640的产量均高于连粳7号和扬稻6号。甬优2640产量较高,这得益于地上部较高的干物质量和库容量(总颖花量)。适量增施氮肥提高了籽粒中^(15)N积累量,但其在籽粒中的分配比例却随施氮量的增加而降低。甬优2640穗中的^(15)N分配比例高于连粳7号和扬稻6号。高施氮量降低水稻氮收获指数。增施氮肥明显提高3个水稻品种穗分化期、抽穗期和灌浆中期叶片的硝酸还原酶、谷氨酰胺合成酶和谷氨酸合酶活性;相同施氮量下,甬优2640的各种酶活性显著高于连粳7号和扬稻6号。【结论】籼粳杂交稻甬优2640较常规水稻品种具有更强的氮素吸收与利用能力。展开更多
Wetlands are important for the protection of water quality of rivers and lakes, especially those adjacent to agricultural landscapes, by intercepting and removing nutrients in runoff. In this study, the ^15N tracer te...Wetlands are important for the protection of water quality of rivers and lakes, especially those adjacent to agricultural landscapes, by intercepting and removing nutrients in runoff. In this study, the ^15N tracer technique was applied to study the distribution and fate of anthropogenic nitrogen (^15N-fertilizer) in Calamagrostis angustifolia Kom wetland plant-soil microcosms to identify the main ecological effects of it. ^15NH4^15NO3 solution (14.93 mg N/L, 20.28 at.% ^15N) was added to each microcosm of the first group, which was approximate to the current nitrogen concentration (CNC) of farm drainage, and 29.86 mg NIL ^15NH4^15NO3 solution was added to another group, which was approximate to the double nitrogen concentration (DNC) of farm drainage, while no nitrogen (NN) was added to the third group. The results suggest that the input of anthropogenic nitrogen has positive effects on the biomass and total nitrogen content of plant, and the positive effects will be elevated as the increase of its input amount. The increase of ^15N-fertilizer can also elevate its amounts and proportions in plant nitrogen. Soil nitrogen is still the main source of plant nitrogen, but its proportion will be reduced as the increase of ^15 N-fertilizer. The study of the fate of ^15N-fertilizer indicates that, in CNC treatment, only a small proportion is water-dissolved (0,13 ± 0.20%), a considerable proportion is soil-immobilized (17.02 ± 8.62%), or plant-assimilated (23.70 ± 0.92%), and most is lost by gaseous forms (59.15 ± 8.35%). While in DNC treatment, about 0.09 ± 0.15% is water-dissolved, 15.33 ± 7.46% is soil-immobilized, 23.55±2.86% is plant-assimilated, and 61.01±5.59% is lost by gaseous forms. The double input of anthropogenic nitrogen can not elevate the proportions of plant-assimilation, soil-immobilization and water-dissolution, but it can enhance the gaseous losses.展开更多
文摘【目的】探明籼粳杂交稻甬优2640的氮素吸收利用特点。【方法】籼粳杂交稻甬优2640、常规粳稻连粳7号和常规籼稻扬稻6号种植于大田,设置6种施氮量处理(0、100、200、300、400、500 kg/hm^(2))和^(15)N示踪微区试验。【结果】在0~400 N kg/hm^(2)范围内,甬优2640的稻谷产量随施氮量的增加而提高;连粳7号和扬稻6号的产量则是先增加后降低,在施氮量300 kg/hm^(2)时产量最高;相同施氮量下,甬优2640的产量均高于连粳7号和扬稻6号。甬优2640产量较高,这得益于地上部较高的干物质量和库容量(总颖花量)。适量增施氮肥提高了籽粒中^(15)N积累量,但其在籽粒中的分配比例却随施氮量的增加而降低。甬优2640穗中的^(15)N分配比例高于连粳7号和扬稻6号。高施氮量降低水稻氮收获指数。增施氮肥明显提高3个水稻品种穗分化期、抽穗期和灌浆中期叶片的硝酸还原酶、谷氨酰胺合成酶和谷氨酸合酶活性;相同施氮量下,甬优2640的各种酶活性显著高于连粳7号和扬稻6号。【结论】籼粳杂交稻甬优2640较常规水稻品种具有更强的氮素吸收与利用能力。
基金the Knowledge Innovation Program of the Chinese Academyof Science (KZCX2-YW-309 and KZCX3-SW-332)the National ScienceFoundation of China (90211003)
文摘Wetlands are important for the protection of water quality of rivers and lakes, especially those adjacent to agricultural landscapes, by intercepting and removing nutrients in runoff. In this study, the ^15N tracer technique was applied to study the distribution and fate of anthropogenic nitrogen (^15N-fertilizer) in Calamagrostis angustifolia Kom wetland plant-soil microcosms to identify the main ecological effects of it. ^15NH4^15NO3 solution (14.93 mg N/L, 20.28 at.% ^15N) was added to each microcosm of the first group, which was approximate to the current nitrogen concentration (CNC) of farm drainage, and 29.86 mg NIL ^15NH4^15NO3 solution was added to another group, which was approximate to the double nitrogen concentration (DNC) of farm drainage, while no nitrogen (NN) was added to the third group. The results suggest that the input of anthropogenic nitrogen has positive effects on the biomass and total nitrogen content of plant, and the positive effects will be elevated as the increase of its input amount. The increase of ^15N-fertilizer can also elevate its amounts and proportions in plant nitrogen. Soil nitrogen is still the main source of plant nitrogen, but its proportion will be reduced as the increase of ^15 N-fertilizer. The study of the fate of ^15N-fertilizer indicates that, in CNC treatment, only a small proportion is water-dissolved (0,13 ± 0.20%), a considerable proportion is soil-immobilized (17.02 ± 8.62%), or plant-assimilated (23.70 ± 0.92%), and most is lost by gaseous forms (59.15 ± 8.35%). While in DNC treatment, about 0.09 ± 0.15% is water-dissolved, 15.33 ± 7.46% is soil-immobilized, 23.55±2.86% is plant-assimilated, and 61.01±5.59% is lost by gaseous forms. The double input of anthropogenic nitrogen can not elevate the proportions of plant-assimilation, soil-immobilization and water-dissolution, but it can enhance the gaseous losses.