【作者】 孙永健；

【导师】 马均；

【作者基本信息】 四川农业大学 ， 作物栽培学与耕作学， 2010， 博士

【摘要】 水、肥在水稻生长发育过程中是相互影响和制约的两个因子。研究不同灌水方式与氮肥管理间的水氮互作机制、优化水、氮管理技术,达到以水促肥、以肥调水的目的,对减少水稻灌溉用水、高效利用肥料来实现水稻稳产高产有重要意义。本研究于2008-2009年在大田试验条件下,以代表性水稻品种杂交稻冈优527为材料,研究了“淹水灌溉”(W1)、“前期湿润灌溉+孕穗期浅水灌溉+抽穗至成熟期干湿交替灌溉”(W2)和“旱种”(W3)3种灌水方式分别与不同的施氮量、不同的氮肥运筹处理对水稻产量形成与氮素利用特征的影响及其生理机制。主要研究结果如下：1、水氮互作对水稻产量及其构成因素的影响两年不同的水氮管理方式对水稻产量的影响均达显著水平,且互作效应显著。2008年试验以W2处理和施氮量为180kg hm-2的水氮运筹处理下的水稻产量相对于其他处理优势明显,其互作存在显著的正效应；2009年在2008年试验确立合理的施氮量的基础上,在W2灌水方式下,“稳前、适时中攻”的N3氮肥运筹模式—基肥：分蘖肥：孕穗肥(倒3.5、1.5叶龄期分2次等量施入)=3：3：4与之相配套,充分发挥了水氮耦合的优势,有利于水稻对水分和氮素的协同吸收,并在保证一定数量有效穗及结实率的前提下,显著提高了穗粒数及千粒重,促进了水稻产量的增加。淹灌条件下,施氮量以180 kg hm-2为宜,其氮肥后移量可占总施氮量的40%-60%为宜,而旱作条件下施氮量可适当降低以90-180kg hm-2为宜,但应减少氮肥的后移量,氮肥后移量可占总施氮量的20%-40%为宜,以缓解水氮互作下的负效应。2、水氮互作对水稻群体质量的影响不同的灌水方式与施氮量、氮肥运筹措施均明显影响水稻群体质量,且水氮对水稻一些群体质量指标的影响存在显著或极显著的互作作用。W2灌水方式与适宜的施氮量(180kg hm-2),并结合N3的氮肥运筹措施能及时对水稻群体分蘖数进行调控,提高茎蘖成穗率,保证抽穗期水稻达到适宜的叶面积指数(LAI)和粒叶比,适当降低了上3叶叶倾角,提高了高效叶面积率及群体透光率,促进群体中下层叶片的光合作用,有利于结实期期植株光合能力的提高和光合产物的积累。3、水氮互作条件下氮代谢酶活性与氮素利用关系水与氮对水稻各生育时期氮代谢酶活性及氮素吸收利用有显著互作作用,W2相对于其他灌水处理有助于拔节至抽穗期水稻吸氮量的增加,提高氮素干物质生产效率及稻谷生产效率,而且与施氮量为180kg hm-2耦合、与氮肥运筹为N3耦合能达到提高氮代谢酶活性、提高氮肥利用效率的目的；过高的氮肥后移比例N4——基肥：分蘖肥：孕穗肥(倒3.5、1.5叶龄期分2次等量施入=2：2：6及施氮量达270 kg hm-2时水氮互作优势减弱,不利于3种灌水方式下硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、谷氨酸合酶(GOGAT)活性的提高,还会导致氮效率的下降。相关分析表明,历年试验水氮互作下各氮代谢酶活性与氮素利用特征及产量间均存在显著或极显著的相关性,据此可将各生育时期功能叶GS活性作为准确判断水稻各生育时期氮素积累量的指标；并可将抽穗期剑叶中NR、GS、GOGAT及内肽酶(EP)活性作为综合评价水稻产量及氮效率的指标。4、水氮互作对水稻结实期衰老生理的影响W2处理下,施氮量为180 kg hm-2、氮肥运筹方式为N3的水氮运筹相对于其他处理,能发挥水氮交互效应优势,使剑叶中活性氧(02-、H202)和丙二醛(MDA)增幅较慢,具有较高的光合速率(Pn),有利于可溶性蛋白等渗透调节物质的积累和超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性及根系活力的提高；旱作、施氮量过高及氮肥后移比例过大各水氮处理交互效应优势减弱,影响结实期水稻正常的生理机能。此外,水氮互作下各指标间有显著的相关性,剑叶中02-、H202和MDA间呈极显著正相关,与保护酶活性、Pn及可溶性蛋白均呈显著或极显著负相关。两年不同的水氮管理方式对各生理指标在抽穗后7-14 d的影响均存在显著互作效应,且此期间各指标与产量均呈极显著相关,衰老过程中地下与地上部也密切相关;根系活力与剑叶保护酶活性、Pn及可溶性蛋白呈显著或极显著正相关,与02-、H202和MDA呈显著负相关。5、水氮互作对水稻结实期物质转运的影响水氮互作对水稻抽穗至成熟期物质运转的影响也存在显著或极显著的互作效应,但本研究在对水氮互作效应的分析中表明,不同灌水方式和施氮量下最优耦合处理为W2N180,而不同灌水方式和氮肥运筹下最优耦合处理为W2N3,有利于水稻根系对水分和氮素的协同吸收,促进了结实期水稻地上部物质的转运,与抗衰老水氮调控措施所得到的最佳的水氮运筹方式结论相一致；而其他各水氮处理,出现交互效应优势减弱甚至出现负效应,导致结实期水稻衰老指标与物质转运的相关性减弱,均不利于水稻后期的灌浆结实；且抽穗期茎鞘物质及非结构性碳水化合物(NSC)的累积量、结实期间茎鞘物质及NSC的转运量与最终产量均呈极显著正相关。根据水氮互作效应还可看出,旱作和氮肥的互作效应对物质转运的影响多数为负效应,且过量施用氮素及氮肥后移比例过大均会导致负效应的加重,不仅不会起到延缓结实期水稻衰老的作用,还会导致抽穗后物质转运、籽粒灌浆速率下降,进而减产。6、水氮互作条件下水稻养分吸收、转运间及其与产量间的关系水与氮对水稻主要生育时期氮、磷、钾的累积、转运及分配均存在显著的互作作用,各生育时期氮、磷、钾间的吸收与累积均有显著或极显著的相关性,且随生育进程相关性加强。此外,抽穗期氮、磷、钾的累积与各养分在结实期转运总量间、以及各养分转运间均有极显著相关性,而抽穗前期氮累积量与结实期氮、磷、钾转运贡献率间极显著负相关性,表明本试验水氮互作条件下,抽穗前期各养分累积量的多少与结实期各养分的向籽粒转运量呈正比,但施氮过多(270 kg hm-2)、氮肥后移比例过重(N4)和旱作条件下(W3处理)均会造成抽穗前期氮累积量过高或过低,均会显著加重转运贡献率的负效应。水氮互作下各生育时期氮、磷、钾吸收、转运及其与产量间也存在显著或极显著的正相关关系,施氮量不同的水氮互作条件下抽穗前期氮、磷的累积以及分蘖盛期对钾的吸收状况与产量呈极显著正相关,而前氮后移的水氮互作条件下会使磷、钾的累积与产量最大相关性的时期有所延后,而氮的累积与产量最大相关性仍在抽穗期。更多还原

【Abstract】 The water and fertilizer are two factors with mutual interaction and restriction in the process of rice growth and development. Elucidation of their influences and coupling effects on different irrigation regime and nitrogen fertilizer management, optimization water and nitrogen interaction management technology on grain yield and growing development of rice would have great significance in reducing irrigation water and fertilizer efficient utilization for high and stable yields. In this study, hybrid rice Gangyou 527 was used to investigate the effects of three irrigation regimes (submerged irrigation, W1; dry cultivation, W3; and damp irrigation before booting stage plus shallow irrigation at booting stage plus wetting-drying alternation irrigation from heading stage to mature stage, W2) and different nitrogen rate, and different nitrogen application on yield formation and characteristics of nitrogen utilization in rice and its physiological mechanism. The main results are as follows:1. Effects of water-nitrogen interaction on yield and yield componentsThe result indicated that the grain yield was influenced by different water-nitrogen treatment regimes in past years experiments, and there was an obvious interaction between irrigation regime and nitrogen management mode. The regime for highest yield was W2 and suitable nitrogen application amount (180 kg ha-1) in 2008. Under this condition, water- nitrogen interaction had significant positive effect on grain yield. Reasonable amount of nitrogen was established in 2009 through the experiment for previous one year. W2 irrigation regime and "Stable application at early stage, large application timely at middle stage" pattern of N3 nitrogen application regime (the ratio of base fertilizer to tillering fertilizer and to panicle fertilizer was 3:3:4, and split panicle fertilizer were applicated at 3.5 and 1.5 leaf age from top) gave full play to water-nitrogen interaction advantage, and was beneficial to absorb and utilize water and nitrogen fertilizer at different growth period of rice, and on the premise of a certain amount of effective panicle and seed-setting rate, this condition of W2 and N3 nitrogen application regime had significantly increased grain number per spike and 1000-kernel weight, then to promoted yield. Optimum amount of nitrogen was 180 kg ha-1 under submerged irrigation, and the ratio of postponing nitrogen application to the total amount of nitrogen was suitable for 40%-60%. However, the treatment of dry cultivation with the proper decrement of nitrogen application amount at 90-180 kg ha-1, nitrogen rate of panicle fertilizer should be properly reduced in nitrogen application, and the ratio of postponing nitrogen application to the total amount of nitrogen was suitable for 20%-40%, could ease the negative effect of water- nitrogen interaction.2. The effect of water-nitrogen interaction on rice population qualityThe result indicated that the rice population quality was also influenced by different water-nitrogen treatment regimes, and there was an obvious interaction between irrigation regime and nitrogen management mode on some index of population quality. W2 and suitable nitrogen application amount (180 kg ha-1) with N3 nitrogen application regime could control the number of rice tillering in time; improve the rate of tiller panicle; guarantee the rice of heading to reach the appropriate leaf area index (LAI) and grain-leaf ratio; reduce the inclination of the top three leaves suitably; increase leaf area ratio and group efficient light transmission rate; promote leaf photosynthesis of the lower population, and it would improve plant photosynthetic capacity of grain-filling stage and the accumulation of photosynthetic products.3. Relationship of activities of key enzymes involved in nitrogen metabolism with nitrogen utilization in rice under water-nitrogen interactionThe results showed that there was an obvious interaction between irrigation regime and nitrogen management mode on activities of key enzyme and nitrogen utilization. Compared with other irrigation treatments, the treatment W2 promoted the nitrogen uptake from tillering to heading, nitrogen dry matter production efficiency (NMPE) and nitrogen production efficiency (NPE). W2 and suitable nitrogen application amount (180 kg ha-1) in 2008, and W2 and suitable N3 application regime in 2009 enhanced activities of nitrogen metabolism enzymes, yield, and nitrogen use efficiency, being the best model in this paper referred as the water-nitrogen coupling management model. N4 nitrogen application regime (the ratio of base fertilizer to tillering fertilizer and to panicle fertilizer was 2:2:6, and split panicle fertilizer were applicated at 3.5 and 1.5 leaf age from top) and applying nitrogen 270 kg ha-1 resulted in negative effect of water-nitrogen interaction, slowing down the increase of activities of nitrate reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT), decreasing nitrogen agronomy efficiency (NAE), nitrogen recovery efficiency (NRE), and yield. Correlation analysis indicated that there existed significantly or highly significantly positive correlations of activities of nitrogen metabolism enzymes with indices of nitrogen uptake and utilization and yield, with different correlation coefficients of different growth stages. According to the conditions above, GS activity in function leaves might be a candidate indicator for nitrogen uptake and accumulation at different growth stages, and activities of NR, GS, GOGAT and endopeptidase (EP) in flag leaves at heading stage for rice yield and NMPE, NPE, NAE, NRE.4. Effects of water-nitrogen interaction on rice senescence physiology during grain-filling periodThe results showed that W2 and suitable nitrogen application amount (180 kg ha-1) in 2008, and W2 and suitable N3 application regime in 2009 gave full play to water-nitrogen interaction advantage. Compare with other treatments, this condition of W2 and the best nitrogen application regime in different water-nitrogen interaction experiments from the past years delayed the increase of reactive oxygen species and malondialdehyde (MDA), had high photosynthetic rate (Pn) and promoted the accumulation of soluble protein content, etc., and enhanced the superoxide (SOD), catalase (CAT) and peroxidase (POD) activities, consequently, promoted material accumulation and promote yield. Applying nitrogen (270 kg ha-1) and nitrogen rate of panicle fertilizer account for too large proportion (N4) would result in a negative effect of water-nitrogen interaction and influence the normal physiological function of rice during grain-filling period. In addition, there was significant correlation between the physiological index, in which significant positive correlations was observed between O2, H2O2 and MDA, and a significant negative correlation between them with antioxidant enzyme activities, Pn and soluble protein content. Furthermore, in the process of leave senescence, underground was closely related to aboveground, and root vigor had high significant positive correlation with antioxidant enzyme activities, Pn and soluble protein, but it had high significant negative correlation with O2, H2O2 and MDA.5. Effects of water-nitrogen interaction on rice material transport during grain-filling periodEffects of water-nitrogen interaction on rice material transport in stem-sheath also have a significantly or very significantly interaction effect from heading to maturity period. Under this condition, W2 and suitable nitrogen application amount (180 kg ha-1), and W2 and suitable N3 application regime enhanced activities of the rice roots to absorb water and nitrogen coordination, promoted the grain-filling stage of material transport, and corresponding with the best way of water-nitrogen logistics conclusion that was obtained anti-aging water-nitrogen control measures; while the other water-nitrogen treatment interaction advantage decreased or even generated negative effects. Correlation analysis indicated that there existed significantly or highly significantly positive correlations between the material transport in stem-sheath and nonstructural carbohydrate transformation(NSC), and between each of them and yield under water-nitrogen interaction from heading to maturity period. According to water-nitrogen interaction effects can be showed that applying nitrogen (270 kg ha-1), W3 treatment and nitrogen rate of panicle fertilizer account for too large proportion (N4) would result in a negative effect of water-nitrogen interaction and influence the normal physiological function of rice during grain-filling period, meanwhile, material transport and grain filling rate were decreased, and then that caused rice yield reduction6. Correlations of N, P and K absorption characteristics and its relationship with grain yield under water-nitrogen interactionThe results showed that there was an obvious interaction between irrigation regime and nitrogen management mode on N, P and K absorption, transfer and distribution. Correlation analysis indicated that there existed significantly or highly significantly positive correlations between the amounts of N, P and K absorption, transfer, distribution, and between each of them and yield under water-nitrogen interaction at the mainly growth stages, and there existed highly significantly positive correlations between yield and the accumulations of N, P before heading stage and the amount of K absorption at tillering stage under water-nitrogen rate interaction, however, there existed highly significantly positive correlations between yield and the accumulations of N still at heading stage and the amount of P and K absorption relative delay of the growth stage at the experiment of water-nitrogen rate interaction under water-nitrogen application interaction. But N4 nitrogen application regime, applying nitrogen 270 kg ha-1 and W3 treatment would result in N accumulation too high or too low, which would aggravate negative effect of translocation conversion rate of vegetative organ.更多还原