播期、氮肥和密度对油菜冠层结构特性及群体生长发育的影响

发布时间：2018-07-24 10:46

【摘要】：本试验以华油杂9号和华油杂62为试验材料,设置不同播期(B1和B2)、氮肥(N0、N6、N12、N18、N24和N30)、密度(D1、D2、D3、D4、D5)处理,通过研究油菜不同群体发育及冠层结构变化特征,探讨不同栽培措施其对油菜群体光合生产效率和籽粒产量的影响。研究结果表明:1.随着播期的推迟和密度的增加油菜个体发育能力减弱,随着施氮量的增加可以使油菜个体生长发育能力加强。2.油菜光合面积指数(CAI)随生育进程呈单峰曲线变化,在盛花期时光合面积指数达到最大值。随播期提前、密度和氮肥增加光合面积指数表现增大的趋势。二年的数据表明,光合面积指数的最大值,10月1号播种比10月30日播种增加1左右;在同一氮肥处理条件下,不同密度间光合面积指数最大值的变化范围为4-5.9;在同一密度处理条件下,不同氮肥间光合面积指数最大值的变化范围为0.7-6.14。初花期分层测定的数据表明,在20 cm-50 cm层次的CAI的值差异最大,说明不同播期、氮肥和密度处理影响的主要是油菜群体中下部冠层CAI,进而影响油菜生长发育。3.油菜从苗期开始,油菜的光合有效辐射截获率(RI)不断上升,在苗后期由于冬季降温的影响导致RI略有下降,在盛花期时达到了最大值,之后到达角果成熟期时又逐渐下降。增加氮肥以及提高密度能够显著提高油菜群体冠层的RI。对不同冠层高度进行分层测定,表明RI随冠层高度的增加呈现递减的趋势。随着种植密度和氮肥施用量的增加,在相同高度冠层内的RI呈上升趋势;而随着播期的推迟,在相同高度冠层内的RI呈下降趋势。4.随着氮肥的提升,早播条件下,随着氮肥的提升,结角层厚度呈递增趋势,每增加6 kg/667 m2,结角层厚度上升14 cm左右。晚播条件下,在N0~N18水平,结角层厚度呈递增趋势,每增加6 kg/667 m2,结角层厚度上升12 cm左右,但是随着氮肥的进一步提升,油菜群体的结角层厚度增加趋势减缓,从N18增加到N24和N30,其结角层厚度只增加了0.3 cm和3.3 cm。5.油菜籽粒产量均随着播期推迟而降低,随氮肥增加而升高,随密度增加呈先升后降趋势。油菜种植密度在1-5万株/667 m2的范围内,早播条件下,随着密度的增加,油菜产量呈先上升而后下降的趋势,N18处理,1-3万株/667 m2密度内,每增加1万株/667 m2,D2和D3相对于D1处理的产量增加13.4%和17.4%,3-5万株/667 m2密度内,每增加1万株/667 m2,D4和D5相对于D3处理的产量减少3.9%和7.9%。6.综合分析比较表明,要获得3000kg/ha的高产,油菜群体的冠层结构指标需要满足:每平方米的结角密度9000个左右,分枝数达到250~300个,且结角层厚度达到85~90 cm左右,生物量1600 g/m2~1700 g/m2,整个油菜生长发育期的平均光合面积指数应达到3~3.5,平均光能有效截获率达到90%以上,最大光合面积指数为5~6,并且,早播条件下最大叶面积指数与最大角果皮面积指数的比值接近于1.8,晚播条件下最大叶面积指数与最大角果皮面积指数的比值接近于1.1。
[Abstract]:In this experiment, Huayuza 9 and Huayuza 62 were treated with different sowing dates (B1 and B2), nitrogen fertilizer (N0N6N12N18N24 and N30), density (D1D2D3D3D4D5). The effects of different cultivation measures on photosynthetic efficiency and grain yield of rape were studied. The results of the study show that 1: 1. With the delay of sowing date and the increase of density, the individual development ability of rapeseed decreased, and the individual growth and development ability of rape increased with the increase of nitrogen application rate. The photosynthetic area index (CAI) of Brassica napus showed a single peak curve with the growth process, and reached the maximum at the flowering stage. With the advance of sowing date, the density and nitrogen fertilizer increased the photosynthetic area index increased. The data of two years showed that the maximum photosynthetic area index was increased by about 1 when sowing on October 1 was compared with that on October 30, and under the same nitrogen fertilizer treatment, The range of the maximum photosynthetic area index between different densities was 4-5.9, and that between different nitrogen fertilizers was 0.7-6.14 under the same density treatment. The data of stratified determination of early flowering stage showed that the difference of CAI value at 20 cm-50 cm level was the largest, which indicated that nitrogen fertilizer and density treatment mainly affected the middle and lower canopy CAI of rape population at different sowing date, and then affected the growth and development of rape. 3. The interception rate of photosynthetic effective radiation (RI) of rapeseed increased continuously from seedling stage, and RI decreased slightly at late seedling stage due to the effect of cooling in winter, reached its maximum value at peak flowering stage, and then decreased gradually at pod ripening stage. Increasing nitrogen fertilizer and increasing density could significantly increase the canopy RII. of rapeseed (Brassica napus L.) The stratification measurement of different canopy heights shows that RI decreases with the increase of canopy height. With the increase of planting density and nitrogen application rate, RI increased in the canopy at the same height, but decreased in the canopy at the same height with the delay of sowing date. With the increase of nitrogen fertilizer and early sowing condition, the thickness of corner layer increased with the increase of nitrogen fertilizer. For each increase of 6 kg/667 m2, the thickness of corner layer increased about 14 cm. Under the condition of late sowing, the thickness of corner layer increased gradually at N0~N18 level. With the increase of 6 kg/667 m ~ 2, the thickness of corner layer increased about 12 cm, but with the further improvement of nitrogen fertilizer, the increasing trend of corner layer thickness of rapeseed population slowed down. From N18 to N24 and N30, the thickness of corner layer increases only 0.3 cm and 3.3 cm 路5. The grain yield of rapeseed decreased with the delay of sowing date, increased with the increase of nitrogen fertilizer, and increased first and then decreased with the increase of density. The planting density of rapeseed was in the range of 1 to 50 000 plants / 667 m2. Under the condition of early sowing, with the increase of density, the rape yield increased first and then decreased. The density of rape under N18 treatment was within the density of 1-3 million plants / 667 m2. The yield of D _ 2 and D _ 3 increased by 13.4% and 17.4 million plants / r ~ (667) m ~ (2) per 10 000 plants / r ~ (2) and D _ (3), respectively, and the yield of D _ (4) and D _ (5) decreased by 3.9% and 7.9% respectively compared with that of D _ (3) treatment per 10 000 plants / r _ (667) m ~ (2) D _ (2) and D _ (3) treatments. The comprehensive analysis and comparison showed that in order to obtain high yield of 3000kg/ha, the canopy structure index of rapeseed population should be satisfied: the density of knot angle per square meter is about 9,000, the number of branches is 250 ~ 300, and the thickness of corner layer is about 85 ~ 90cm. With biomass of 1600 g/m2~1700 / m ~ (2), the average photosynthetic area index (PIAI) of the whole growth and development period of rapeseed should be 3 ~ 3. 5%, the average effective interception rate of light energy is more than 90%, and the maximum photosynthetic area index is 5 ~ (6). The ratio of the maximum leaf area index to the largest hornpetal area index was close to 1.8 under early sowing, and the ratio of maximum leaf area index to maximum Cortex area index was close to 1.1 under late sowing.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S565.4

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