Study On Different Density And Fertilization Technology Of Silage Maize And Sweet Sorghum

In order to explore the high-yield,high-quality planting density and fertilization cultivation techniques of silage corn and forage sweet sorghum in Hunan region,this experiment used Yayu silage No.26 corn seeds and Alto 901 sweet sorghum seeds as the experimental materials,using a two-factor split-zone design and research The yield of silage corn at 60,000 plants/hm~2,75000 plants/hm2,90,000 plants/hm~2 and N:0kg/hm~2,120kg/hm~2,240 kg/hm~2,360 kg/hm~2nitrogen fertilizer application level,Effects of quality and photosynthetic characteristics and planting density of sweet sorghum at 90,000 plants/hm~2,120,000 plants/hm~2,150,000 plants/hm~2 and N:0 kg/hm2,150 kg/hm~2,300 kg/hm~2,450kg/hm~2nitrogen fertilizer Effects of yield,quality and photosynthetic characteristics at the application levelPlanting density and nitrogen fertilizer had no significant effect on the growth period and leaf number of silage maize,but had significant effects on plant height,stem thickness and leaf area.Silage corn can be harvested at the heading stage to obtain higher yields.The optimal combination is a combination of density of 90,000 plants/hm~2 and nitrogen fertilizer of 360 kg/hm~2,and the yield reaches 67500 kg/hm~2.The interaction of planting density and nitrogen fertilizer has a significant effect on the yield of silage corn,and there is an interaction effect.Silage corn phi2 and phino showed a slow decreasing trend with the growth period,and reached a higher level during jointing and heading.NPQ had a higher value during the wax maturity period,and the PSII opening degree was greater in the later growth period of silage corn.The relative chlorophyll content is the highest at the heading stage,and it increases first and then decreases as the growth period progresses.The photosynthetic indexes of silage maize performed better at a density of 75000 plants/hm~2 and nitrogen application rates of 120 kg/hm~2.The effects of planting density and nitrogen fertilizer on the growth period of sweet sorghum forage did not reach a significant level,and the plant height,stem thickness,leaf number and leaf area reached a significant level.The interaction effect of planting density and nitrogen fertilizer on sweet sorghum reached a significant level,and there was an interaction effect.The increase of density can significantly increase the biological yield of forage sorghum,and the application level of nitrogen fertilizer has little effect on the biological yield of sweet sorghum.In terms of yield,sweet sorghum forage is more suitable for harvesting during milk maturity.And at this time,the optimal density fertilization combination was 150,000 plants/hm~2+150kg/hm~2,and its yield was 144159kg/hm~2.Forage sweet sorghum phi2 reached a higher level at the heading stage,and the density and nitrogen application level had little effect on it.As the growth period progresses,phino is inversely proportional to density and directly proportional to the amount of nitrogen applied.NPQ reached a higher level at the heading stage and milk maturity stage,and the PSII opening ratio of sweet sorghum reached the maximum in the two periods,and was proportional to the nitrogen application level within a certain threshold and inversely proportional to the density.The relative content of chlorophyll is the highest at heading stage,which is proportional to the amount of nitrogen applied.