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【目的】温江地区高产水稻的推荐施氮量为180 kg/hm~2,以此为基础,机插稻缓释氮肥与常规尿素适宜配比为7∶3基础上,进一步研究密度和缓释氮肥配施量对机插稻分蘖特性、干物质积累量、光合物质生产特性、群体生长率及产量的影响。【方法】采用二因素裂区设计进行了机插杂交稻田间试验。在行距为30 cm下,设3种株距处理为16 cm、18 cm、20 cm;在尿素氮施用量54 kg/hm~2下,设4个缓释氮用量为36、66、96和126kg/hm~2,总施氮量相应为90、120、150和180 kg/hm~2。在插秧时缓释肥与尿素混合,一次性追施。调查了主要生育期水稻生长和氮素吸收运移量。【结果】缓释氮肥配施量和株距对主要生育期的水稻干物质积累量、光合特性及产量均存在显著或极显著的调控效应,且互作效应显著;缓释氮肥配施量的效应明显高于株距。在机插行距30 cm下,株距为18 cm,总施氮量为150和180 kg/hm~2时,可有效提高叶面积指数(LAI)、单茎茎鞘与叶片干物重,叶面积衰减慢,拔节至齐穗期光合势大,群体生长率高,光合特性强,促进干物质累积,在足够穗数的基础上,显著增加了穗粒数,提高了群体颖花量,保持了稳定的结实率和千粒重,从而显著提高机插稻产量。株距为16 cm,施氮量为150 kg/hm~2时,水稻群体茎蘖数增长快,拔节后群体茎蘖数缓慢消减,有效穗数足,虽穗粒数显著降低,但有较高的结实率和千粒重,从而协调出较高的产量。而株距为20 cm,配施总氮量为180 kg/hm~2处理,在保证有效穗数的基础上,促壮秆和攻大穗,增加了穗粒数,干物质积累量多,灌浆充实量大,千粒重增加。相关性分析表明,株距与缓释氮肥配施量耦合下,尤其以拔节至齐穗期光合势、齐穗期高效LAI与产量相关性较高(r=0.87**~0.91**),对促进增产更为重要。【结论】在机插行距30 cm下,株距为18 cm,缓释氮肥(96 kg/hm~2)与常规尿素(54 kg/hm~2)配施总氮量为150 kg/hm~2时,能充分发挥本区域机插杂交籼稻高产的优势、提高光合物质生产,产量最高可达11463.8 kg/hm~2,为本试验的最佳肥密运筹处理。
【Objective】 The recommended nitrogen application rate for high-yielding rice in Wenjiang area was 180 kg / hm ~ 2. Based on this, the suitable proportion of slow-release nitrogen fertilizer and conventional urea was 7: 3, Effects of nitrogen rates on tillering characteristics, dry matter accumulation, photosynthate production characteristics, population growth rate and yield of rice. 【Method】 Two-factor fracturing design was used to carry out intercropping rice hybrid experiment. At the row spacing of 30 cm, three kinds of plant spacing treatments were set as 16 cm, 18 cm and 20 cm, respectively. Under the urea nitrogen application rate of 54 kg / hm ~ 2, four slow release nitrogen doses were set at 36, 66, 96 and 126 kg / hm ~ 2, the total amount of nitrogen applied is 90,120,150 and 180 kg / hm ~ 2 respectively. Slow release fertilizer and urea mixed in transplanting, one-time topdressing. The main growth period of rice growth and nitrogen uptake were investigated. 【Result】 The results showed that there was a significant or very significant regulation effect on the dry matter accumulation, photosynthetic characteristics and yield of rice at the main growth stages with the amount and spacing of slow-release nitrogen fertilizers, and the interaction effect was significant. The effect of slow- Significantly higher than the plant spacing. The leaf area index (LAI), dry matter weight of stems, sheaths and leaves of a single stem, and leaf area decayed at the plant spacing of 18 cm and the total nitrogen application rate of 150 and 180 kg / hm ~ 2, Slow and jointing to heading stage photosynthetic potential, population growth rate, photosynthetic characteristics, and promote the accumulation of dry matter, in a sufficient number of spikes, significantly increased the number of grains per spike, increasing the population spike amount, maintaining a stable The seed-setting rate and 1000-grain weight, so as to significantly increase the yield of machine-inserted rice. When the plant spacing was 16 cm and the nitrogen application rate was 150 kg / hm ~ 2, the tiller number of rice population increased rapidly and the tiller number of the population slowed down after jointing. The effective panicle number was enough. The seed-setting rate and 1000-grain weight, thus coordinating a higher yield. While the plant spacing was 20 cm and the total nitrogen content was 180 kg / hm ~ 2. On the basis of assuring the effective panicle number, the stalks and spikes were increased, the number of grains per ear increased, the accumulation of dry matter was more, Enrichment volume, 1000 grain weight increase. Correlation analysis showed that the correlation between plant spacing and the amount of slow-release nitrogen fertilizer, especially the correlation between LAI and yield at full-heading stage and jointing stage (r = 0.87 ** ~ 0.91 **) To promote more important is more important. 【Conclusion】 The plant spacing of 18 cm was obtained at the plant spacing of 30 cm. The combined N application of 96 kg / hm ~ 2 and conventional urea (54 kg / hm ~ 2) was 150 kg / hm ~ 2 , It can give full play to the advantages of high yield of indica hybrid rice in this region and increase the production of photosynthetic material with the highest yield of 11463.8 kg / hm ~ 2, which is the best treatment of this experiment.