【作者】 翟晶；

【导师】 曹凑贵；

【作者基本信息】 华中农业大学 ， 作物栽培学与耕作学， 2009， 硕士

【摘要】 以两优培九和扬两优6号为材料分别于武汉市华中农业大学和随州市均川镇进行大棚盆栽和大田试验。分别设置不同的土壤水势、灌溉条件和施氮水平,比较不同水肥条件下水肥交互作用对水稻生长发育特性,养分吸收情况及产量品质的影响。结果表明:1、对水稻生长状况的影响:水稻的分蘖数、株高、每株叶面积、植株各部分受氮肥影响较大,均随施氮量的提高而提高,分蘖、株高受灌溉条件的影响不明显。总体上来说,增施氮肥可以改善水稻的群体生长质量。但过高的氮肥并不表现为更利于水稻的生长,大棚盆栽条件下,每盆施氮2.5g（相当于大田施氮量375kg/hm²）以上,而土壤水势低于—30kPa时,则表现为严重的水分胁迫,造成水稻成熟期显著延迟,降低株高、单株叶面积、植株各部分的干重。2、对水稻生理的影响:不同灌溉处理下叶片SPAD值在各生育期基本随施氮量的增加而增加,施氮360kg/hm²条件下分蘖期时SPAD值就已经达到44左右,并且到齐穗期仍然保持此水平,而低氮处理叶色较浅,SPAD值经历了分蘖期到孕穗期的下降过程后至齐穗期又保持升高的势态。水分胁迫抑制了水稻氮素的吸收,从而降低水稻叶片SPAD值。盆栽条件下,除淹水灌溉伤流强度随着施氮水平的提高增强外,其他水分条件下伤流强度在各施氮水平下差异不明显。叶片中丙二醛含量总体上随氮肥水平的提高呈先降低后提高的趋势,施氮量不高时,同一氮肥水平下各水分处理下叶片丙二醛含量差异不大,均保持在4μmol·g^-1左右,而高氮水平下（N4、N5）水稻叶片丙二醛含量受水分条件影响明显,湿润灌溉（土壤水势0kPa）和土壤水势在—30kPa时丙二醛含量保持3～3.5μmol·g^-1,在淹水灌溉和严重干旱胁迫中含量较高,达到4～4.5μmol·g^-1,水稻叶片衰老明显。3、水肥互作对水稻干物质及养分积累的影响:水稻的干物质量也是随施氮量的增加而增加,总体表现为孕穗后至齐穗期是干物质总量积累较缓慢的一段时期。水稻中氮素及磷素的积累和干物质的积累很相似,均随施氮量的增加而增加。含钾量则表现为施氮过高含量较低,抗倒伏能力较差。4、水肥互作对水稻产量及品质的影响:在土壤肥力较低时,增施氮肥可以提高水稻的总粒数、有效穗数、穗长、一次支梗、结实率、千粒重,使水稻增产。但如果施氮过多而土壤水势没有相应的提高时,则表现为严重的水分胁迫现象,使水稻减产,如土壤水势为—30kPa时N5水平较N4水平产量降低23.9%。N2处理下0kPa时水稻的实际产量最高,比淹水灌溉高6%,而—30kPa、—60kPa时水稻实际产量较淹水灌溉下降28%和37%。对品质的影响表现为,同一灌溉处理下蛋白质含量随施氮量的增加而增加,说明高施氮量为水稻氮素营养吸收及蛋白质的合成提供了丰富的氮源,而同一氮素水平下各水分处理间差异不显著。直链淀粉含量各个灌溉处理下随施氮量的增加而减少,而同一施氮水平下,各灌溉处理间差异不显著。更多还原

【Abstract】 Rice Liangyoupeijiu and Yangliangyou 6 hao were chosen to do experiments separately in plastic greenhouse’s pot in Huazhong Agriculture University and in the fields in Junchuan, Suizhou. Set different soil water potential, irrigation condition and nitrogen level to study the effect of water and fertilizer interaction on rice growth and physiology characters, nutrient absorption situation, yield and quality. The results show:1. The effects on rice growth status: the tillers, plant height, per plant leaf area, each part of plant of the rice are influenced by nitrogen fertilizer obviously, and raise by the increase of nitrogen rate, but irrigation condition has little influence on tillers and plant height. Conclusively, nitrogen increasing tend can improve the group growth quality. However, too much nitrogen is not beneficial to the growth of rice. In plastic greenhouse’s pot, if over 2.5g nitrogen is used in each pot (equivalent to 375kg/hm2 in fields), and the soil water potential is lower than -30kPa, serious water stress phenomenon will appear, rice growth period will delay obviously, and plant height, per plant leaf area and dry weight of plant’s every part will decrease inversely.2.The effect on rice physiology: under different irrigation treatments the leaf SPAD value increases with the nitrogen rate increases in each growth period, Under low nitrogen level SPAD value turn to lower from tillering stage to booting stage and from heading stage process to increase.Water stress inhibits rice’s absorption of nitrogen, thus rice’s leaf SPAD value decreases. Under pot condition, except that flooding irrigation bleeding intensity improves with the nitrogen rate increases, in other water conditions under different nitrogen rate the differences of bleeding intensity are not obvious. Generally the MDA content in leaf first decreases and then increases as the improvement of nitrogen rate. When the nitrogen rate is low, under the same nitrogen level but different water conditions, the differences of MDA content are not obvious. However, when the nitrogen level is high(N4, N5), rice’s leaf MDA content is influenced by water condition obviously, and the content is higher when the rice is in flooding irrigation and serious dry stress, which shows that rice leaves get old obviously in the adversities above.3. The effects of Water-Fertilizer interaction on the dry matter contents and nutrient accumulation of rice: rice’s dry matter quantity also increase as the increase of nitrogen rate, and it shows that the period between booting and full heading stage dry matter quantities accumulate slowly. The accumulation of nitrogen and phosphorus in rice are similar with day matter, and they increase with the nitrogen rate’s improvement. Potassium content is low as the nitrogen rate is high, and lodging resistance ability is also poor.4. The effects of Water-Fertilizer interaction on the yield and quality of rice: When the soil fertility is low, the increase of nitrogen rate can improve the grains, effective panicles, ear length, first panicle branch, seed setting rate and 1000-grain weight of rice, and makes increasing yield. For example, when soil water potential is -30kPa and in the level of N5 the yield decreases by 23.9% comparing with the level of N4.When in the condition of N2 and the soil water potential is 0kPa, the yield is the highest and higher than 6% of flooding irrigation. When soil water potential is-30kPa and-60kPa, the rice yield decreases by 28% and 37% comparing with the flooding irrigation. The effects on quality shows that under the same irritation condition the protein contents increase as the nitrogen rates increase, which shows that high nitrogen rate provides rich nitrogen source for the absorption of nitrogen and the synthesis of protein, but under the same nitrogen rate, the differences of different water conditions are not obvious. The amylose contents under each irrigation treatment reduce as the nitrogen rates increase, but under the same nitrogen rate, the differences of different irrigation treatments are not obvious.更多还原