Studies The Effect Of Planting Density And Nitrogen Management On Population Structure Of North Japonica Rice

This thesis by using the materials which Mudanjiang30(rice panicle number type).Songjing14(rice panicle weight type) and Dongnong426(rice panicle intermediate type), designing three treatments of planting density: D1(30cm×16.7cm), D2(30cm×13.3cm), D3(30cm×10cm), four nitrogen application treatmentand: N0(no nitrogen), N1(low fertilizer area), N2(medium fertilizer area), N3(high fertilizers area). Studies on the effect of planting density and nitrogen management on cold japonica population, formation of dry matter accumulation, canopy structure and light energy utilization and yield formation.reveal variation under different nitrogen levels and population structure, in order to provide theoretical basic for a reasonable group of northern japonica rice in cold region construction, to lay the foundation for high yield rice cultivation. The main conclusions of this experiment are as follows:(1).Mudanjiang30 range in height 70.3cm-95.6cm.Songjing14 the height range of 76.5cm-102.7cm, Dongnong426 the height range of 76.0cm-101.9cm, rice panicle number type varieties height less than weight type and intermediate type. Density and height are increased with the amount of nitrogen increased planting. Between early tillering plant height was not significantly different, with the advance of the rice growing period, plant height differences began to emerge, until the full heading stage maximized.(2).With the advancement of reproductive processes the number of single points tiller showed a single peak curve after full heading stage. After start turning green rice tiller, tiller number increased gradually decreases after reaching a peak after a spike tiller stabilized. All varieties of single point tillers increased with planting density increase and decrease with the increase of nitrogen increases. But the number of tillers per square meter with the density and increasing the nitrogen increases. The peak time and the time to reach consensus the number of single points tiller. Rice panicle number type tiller grow faster than rice panicle weight type.the highest number of tillers and effective tillers were higher than rice panicle weight type.(3).Different planting density and nitrogen application rate on the cold ground rice leaf length, leaf width and leaf area efficiency reached a significant level of influence. Consistent with the clover leaf length and width of the average trend. Leaf length performance: 3rd leaf> 2nd leaf> flag leaf. Leaf width as follows: flag leaf> 2nd leaf> 3rd leaf.With increasing amount of nitrogen on the clover leaf length, leaf width and leaf area efficiency was significantly increased in the same planting density conditions. Under the same conditions of nitrogen rate, with the increase of planting density on the clover leaf length, leaf width and leaf area efficiency significantly reduced(4).Three varieties of rice changes consistent trend, Leaf area index increases with the planting density and nitrogen fertilizer, heading stage reached decline after the peak, the decline due to the variety and treatment varies Leaf area index showed maturity spike number type varieties under the same conditions of nitrogen fertilizer rate, medium-density higher than low-density and high-density processing. High spike weight and intermediate species density treatment was significantly higher than medium-density and high-density processing.(5).With the advance of the rice growing period, the accumulation of dry matter per square meter three varieties increased. Under the same heading and density accumulation and leaf maturity, spike and above ground dry matter per square meter of dry matter accumulation increases with the amount of nitrogen. under the same level, with increasing density decreases..Mudanjiang 30 output percent of stem-sheath store matter rate increases with the increase of planting density. Within a certain range with increasing nitrogen rate increases. In N2D3 maximum processing. Songjing 14 and Dong Nong 426 show the same trend, stem and sheath output rate with increasing planting density and the amount of nitrogen increases, Songjing 14 and DongNong 426 in the highest value N3D3 handling, processing and N3D2 difference was not significant, but with a significant other treatments. Stem and sheath material transport rate and output rate of all varieties of the same trend. Spike type output rate is less than the maximum spike heavy varieties, the maximum transfer rate is higher than the spike heavy varieties.(6).With the growth progress at tillering stage to full heading three rice canopy width has increased and then decreased after the first, starting from the tillering stage to hold the tiller of the biggest increase, down from after active tillering stage. Under the same conditions the amount of nitrogen, three species of canopy width increased with increased planting density decreases. Planting density under the same conditions, the width of the canopy with increasing nitrogen rate increases. Different parts of the extinction coefficient varies by species. At heading Mudanjiang30 in photosynthetic potential of 135.4-276.4. Songjing 14 in photosynthetic potential of 60.5-216.2. Dong Nong 426 in photosynthetic potential of 79.6-255.6. With the increase of planting density and nitrogen fertilizer increases. Spike varieties were significantly higher than the right ear light heavy and intermediate.(7).Increase of planting density with Mudanjiang30 grain-leaf ratio reduced, but the amount of nitrogen is too high, grain-leaf ratio declined. Songjing 14 and DongNong 426 showed increased with planting density grain-leaf ratio reduced and nitrogen fertilizer increased. Grain varieties leaf ratio compares less than ear heavy spike type and intermediate type. Mudanjiang 30 reached the highest value in N2D1 processing. Songjing 14 reached the highest value in N3D1 processing. Dong Nong 426 reached the highest value in N3D1 processing. Cold region rice grain filling characteristics between treatment parameters are quite different, due to lower rice planting density and increased nitrogen fertilizer can increase strength, and inferior grains, grain filling tends to make synchronization, thereby increasing grain weight and grain setting rate.(8).Panicles, primary branches and yield were significantly positive correlation between per ear, per panicle, grain weight, seed rate and yield a significant positive correlation. There spike rice varieties Mudanjiang 30 was the highest in N2D1 with N2D2 treatments were not significantly different from other treatments significantly. High spike weight rice varieties processing Songjing 14 N3D3 highest significant difference with other treatments. Intermediate Dong Nong 426 was the highest in N3D2, significant differences with the other treatments. Consolidate the factors, Mudanjiang 30 is more suitable for low seedling density, Dong Nong 426 more suitable medium density, and is more suitable for high density Songjing 14.