Effects Of Planting Densities On Light And Heat Resource Utilization Of The Wheat Colony

Agricultural climate resource is the most potential natural resources in agricultural development of the 21st century. Improving climate resource utilization rate is one of the symbols of evaluation of meteorological level and a national agricultural comprehensive capability. Reasonable density is important measure of full use of light and fertility and increasing seedling, spike and yield. A field experiment was conducted to evaluate radiation resource utilization of colony in different planting densities of a winter wheat cultivar Shixin 828 and han 7086. It was studied under four different density levels(210×10~4(D1),270×10~4(D2),330×10~4(D3) and 390×10~4(D~4) basis seedlings per hm2). The results as that:1. The dsnsity can influence the wheat solar-thermal useTwo year test results indicate that: In 2008-2009 year , the radiation use efficiency(RUE) and the heat use efficiency (HUE) of the two varieties first rises then descends as the increase of density the 330×10~4 basis seedlings per hm2 treament was higher than that of the others. But In 2009-2010 year, wheat grain yield, HUE and the RUE of the two varieties present a rising trend with the increase of density, and the 390×10~4 basis seedlings per hm2 treament was higher than that of the others.2. The dsnsity could remarkably influence the radiation utilization of a winter wheat.Test results analysis in 2008-2009 year shows that: The 330×10~4 basis seedlings per hm2 treatment had the rational size of colony and Leaf area index and had apparent advantages in Light distribution,coefficient and radiation use efficiency of total biological yield at late growth period,with the grain yield and radiation use efficiency of grain yield of it being higher than that of the others significantly.The 210×10~4 and 270×10~4 basis seedlings per hm2 treatments had apparent advantages in light transmission rate and net assimilation rate,but it had less Leaf area and dry matter accumulation as a result of less colony; Leaf area index and photosynthetic potential of the 390×10~4 basis seedlings per hm2 treatment was higher than that of the others significantly, but it had apparent disadvantages in net assimilation rate,extinction coefficient and radiation use efficiency of total biological yield at late growth period with close microclimate as a result of great colony; both above reducing yield and radiation use efficiency of grain yield.3.The dsnsity can remarkably influence the photosynthesis characteristies of flag leaf of a winter wheat.Test results analysis in 2008-2009 year shows that: The 330×10~4 basis seedlings per hm2 treatment had apparent advantages in chlorophyll content,photosynthesis rat, PSⅡpotential activity(Fv/Fo) and the maximal quantum efficiency of PSⅡphotochemistry (Fv/Fm) of the flag leaf at late growth period and the grain yield of it was higher than that of the others significantly.The 210×10~4 and 270×10~4 basis seedlings per hm2 treatments represent franfibility for gently drought as a result of less colony and the 390×10~4 basis seedlings per hm2 treatment influence individual growth with close microclimate as a result of great colony,both above reducing yield.