水保所知识产出(1956---)知识库

土壤水分和氮素是影响小麦高产的主要因素。小麦生产中水、肥之间存在着明显的交互作用，水、氮合理配合才能有效提高小麦的产量。本试验选用旱地小麦品种长武134和长旱58，在盆栽试验条件下设置了四个氮肥处理： (1)不施氮肥(N0)；(2)施氮量为0.12gN/kg (N1)；(3)施氮量为0.24gN/kg(N2)；(4)施氮量为0.36gN/kg (N3)。于花后采用称重控水方式设置了三个水处理：(1)整个生育期正常供水(W1)，土壤含水量保持为田间持水量的75%-85%；(2)中度水分胁迫处理(W2)，前期处理同对照，从开花期开始控水到灌浆期土壤含水量保持为田间持水量的55%-65%；(3)重度水分胁迫处理(W3)，前期处理同对照，从开花期开始控水到灌浆期土壤含水量保持为田间持水量的35%-45%。于灌浆期对小麦进行不同程度水分胁迫处理，测定并分析了水氮互作对花后强、弱势籽粒灌浆特性和不同源器官干物质、氮素代谢及产量指标的影响，以此为基础，对小麦在水氮互作条件下花后干物质和氮素积累转运展开了系统的研究和探讨。
本研究主要结论如下：
1. 氮肥处理下和花后水分胁迫显著影响小麦的最终产量，中度水分胁迫增加了长武134的产量，而水分胁迫降低了长旱58的产量；小麦产量随着施氮量的增加而增大，而重度水分胁迫下，长旱58的产量随着施氮量的增加出现了降低。.穗粒数和生物量均随着施氮量的增加而增加，且随水分胁迫的加剧而降低。除了N0千粒重明显低于其他处理外，N1、N2、N3处理的千粒重没有差异，千粒重对水分胁迫的响应也不明显。长武134和长旱58的收获指数都是随着施氮量呈现先增加降低后升高的趋势，并随着水分胁迫的加剧呈现出先升高后降低的趋势，说明适度的施氮和中度水分胁迫可增加小麦收获指数。长武134和长旱58的最高产量分别为W2N3和W1 N3处理。
2. 氮肥处理下和花后水分胁迫显著影响了不同品种强势粒和弱势粒的灌浆特性。施氮增加了长武134和长旱58强势粒和弱势粒的最大理论干重(W0)，水分胁迫使得最大理论干重有所下降，且同一处理的强势粒最大理论干重明显高于弱势粒。长武134强、弱势粒的W0也均高于长旱58。强势粒灌浆速率在整个过程中明显高于弱势粒。相关性分析表明，强势粒千粒重主要与灌浆过程的平均速率和总灌浆时间呈正相关；弱势粒千粒重主要与最大灌浆出现的天数显著相关。
3. 氮肥处理下和花后水分胁迫下长武134和长旱58所有处理花后植株干物质的动态变化类似，均随灌浆的推移，干物质先增后降。适度提高施氮量可增加干物质的积累，而水分胁迫则减少了干物质的累积，长武134叶、茎、鞘器官花前和花后的干物质积累两均高于长58。花后干物质对籽粒的贡献显著高于花前。
4. 氮肥处理下和花后水分胁迫下强势粒和弱势粒中氮含率具明显差异，花后5天弱势粒含氮率整体高于强势粒而成熟期强势粒含氮率要高于弱势粒，且强势粒和弱势粒含氮率的动态变化都是先降低后升高。水氮互作对长武134和长旱58开花期和成熟期营养器官和总籽粒的氮素积累量，花后营养器官氮素的转移量的影响都达到极显著水平，且随着施氮量的增加而增加，随水分胁迫的加剧而降低。长旱58营养器官氮素积累量和成熟期籽粒氮素积累量高于长武134，而营养器官氮素转运量低于长武134。
5. 氮肥和花后水分胁迫对长武134和长旱58氮素积累量(TNA)、氮素生产效率(NMPE)、氮肥农艺效率(NAE)、氮肥利用效率(NUE)、氮肥偏生产率(PFPN)和氮肥收获指数(NHI)的影响均达到极显著水平，且存在显著或极显著水氮互作效应。长武134氮素积累总量、氮肥农艺效率、氮肥利用效率和氮肥偏生产率均表现为W1>W2>W3；氮素生产效率在N0、N1、N2上表现出W3>W1>W2的趋势，而在N3处理上升高；氮肥收获指数在N0上表现出降低的趋势，在N1、N2、N3表现为先升高后降低的趋势，长旱58在TNA和NPE上跟长武134有着相同的趋势， 但是在NAE、NUE和PFPN上表现出先升高后降低的趋势，NHI总体呈现升高的趋势。各水分处理上，长武134和长旱58氮素积累量、氮素生产效率、氮肥农艺效率、氮肥利用效率和氮肥偏生产率随施氮量的增加而降低；长武134氮肥收获指数却随着施氮量的增加而表现出先增加后降低的趋势，拐点出现在N2处理，而长旱58NHI随着施氮量的增加增大。
关键词：冬小麦；水氮互作；灌浆特性；干物质转运；氮素转运；籽粒产量

Soil water content and nitrogen are the main factors that affect crop yield formation, moreover, water and fertilizer are obviously relevant to each other during the production of wheat. Only more reasonable use of nitrogen and water could enhance the yield of wheat effectively. In this experiment, wheat cultivar ChangWu 134 and ChangHan 58 were selected, and four nitrogen levels were set for pot experiment: (1) No nitrogen (N0); (2) nitrogen application amount 0.12gN/kg (N1); (3) nitrogen application amount 0.24gN/kg(N2);(4)nitrogen application amount0.36gN/kg (N3). Water contents of pots were weighing during post-anthesis and three water levels were set: (1) Normal water supply during the whole growth period (W1), the soil water contents maintained 75 %-85 % of field capacity; (2) moderate water stress (W2), soil water contents kept the same level to W1 before anthesis, and then maintained 55 %-65 % of field capacity from anthesis to filling stage; (3) serious water stress (W3), soil water contents kept the same level to W1 before anthesis, and then maintained 35 %-45 % of field capacity from anthesis to filling stage; In the filling stage, two wheat cultivars were exposed to different water stresses, and we assayed and analyzed the effects of the interaction of nitrogen and water on the grain filling characteristics of superior and inferior grain, the metabolism of dry matter and nitrogen in post-anthesis. Basing on these investigations, we could systematically study and discuss the transport of dry matter and nitrogen of wheat under the interaction of water and nitrogen in post-anthesis.
The main conclusion:
1. The nitrogen treatments and post-anthesis water stressessignificantly affected the final yield formation of wheat, the moderate stress on the one hand enhanced the yield formation of ChangWu 134, but on the other hand reduced that of ChangHan 58. The wheat yield formation could be enhanced by the increased application of nitrogen, but it also declined under serious water stress in ChangHan 58. The kernels per spike and biomass all rose with the increased nitrogen application and declined with the increased water stresses. The thousand seed weight was significantly lower under the treatment of N0 than the other treatments including N1, N2 and N3, and under these treatments it showed no difference. The  harvest indexes of both ChangWu 134 and ChangHan 58 all firstly declined and then rose with the increased application of nitrogen, and another tendency showed that the harvest indexes finally dropped after a temporary increase with the increase of water stress. The results indicated that appropriate nitrogen application and moderate water stress could enhance the wheat harvest index.
2. The nitrogen treatments and post-anthesis water stresses significantly affected the filling characteristics of inferior and superior grain of both two cultivars. The application of nitrogen increased the maximum theoretic grain weight and the maximum theoretic dry weight (W0) of both inferior and superior grains of the two cultivars, while water stress played an opposite role. Under the same treatment, the maximum theoretic dry weight showed significantly higher in superior grain than in inferior grain, and significantly higher in ChangWu 134 than in ChangHan 58. During the whole growth stage, the filling rate was significantly higher in superior grain than in inferior grain. The correlation analysis indicated that, the thousand seed weight of superior grain was positively related to the average rate and the total time of filling stage, while the thousand seed weight of inferior grain was related to the date that the maximum filling showed up.
3. Under the both nitrogen treatments and water treatments, there was a similar dynamic change in post-anthesis plant dry matter in both ChangWu 134 and ChangHan 58, they all firstly rose and then dropped during filling. The accumulation of dry matter was enhanced by the application of nitrogen while reduced by water stresses. The dry matter accumulation in leaf, stem and sheath of ChangWu 134 all showed higher than ChangHan 58 in both pre-anthesis and post-anthesis stages. The contribution made by the post-anthesis dry matter to grain was significantly higher than that of pre-anthesis dry matter.
4. Under the both nitrogen treatments and water treatments, the N concentration of inferior and superior grain were significantly differed from each other, although at the fifth day the N concentration of inferior grain was higher than superior grain, the N concentration of superior was ultimately dominated. The dynamic change of the N concentration in both inferior and superior grain all increased after the first decreases. The development of plant organ, the accumulation of N in the total grain and the transport amount of N in the post-anthesis nutritive organ of both ChangWu 134 and ChangHan58 were significantly affected by the interaction of nitrogen and water during anthesis and mature stages, they all rose with the increase of the amount of supplied N and dropped with the decrease of soil water content. The accumulated N contents in the nutritive organ and mature seeds of ChangHan58 took an advantage of ChangWu134, but the transport amount of N in nutritive organ of ChangHan58 was lower tha ChangWu134.  5. The effects of nitrogen and water stress that impacted on the amount of accumulated nitrogen(TNA), nitrogen production efficiency(NPE), nitrogen agronomic efficiency(NAE), nitrogen use efficiency(NUE), Nitrogen production efficiency（PFPN） and nitrogen harvest index (NHI) of ChangWu 134 and ChangHan 58 all reached a highly significant level. Under the same N level, TNA, NAE, NUE and PFPN of ChangWu 134 all showed a tendency of W1>W2>W3. While under different N treatments of N0, N1 and N2, NPE showed a trend of W3>W1>W2, and on the contrary increased in the N3 treatment. NHI dropped gradually under the nitrogen treatment of N0, while declined after an increase under N1, N2 and N3. In terms of TNA and NPE, ChangHan 58 has the similar trend with ChangWu 134, however, NAE, NUE and PFPN of it showed a fall after a temporary rise and NHI was overall increased. Under different water treatments, in both two cultivars of CahngWu 134 and CahngHan 58, TNA, NPE, NAE, NUE and PFPN all dropped with the increase of the amount of the supplied nitrogen. The NHI of ChangWu 134 firstly rose and then declined with the increase of the amount of the supplied nitrogen, the maximum showed under N2 treatment.
KEY WORDS: Winter wheat (Triticum aestivum L.), Nitrogen and water intercation, Grain-filling characteristics ,Dry matter mobilization, Nitrogen mobilization, Grain yield.