The Effects Of Planting Density And Drip Irrigation Under Film On Photosynthetic Characteristics And Yield In Spring Maize

This experiment optimizes the combination of planting density and drip irrigation under film.In order to clarify the yield increase effect and mechanism,different cultivation management models were designed.Meanwhile,this experiment helps to increase group yield and narrow the gap between yield and resource efficiency.The corn varieties Hengdan 188 was used as the test material in the experiment.There are five treatments in the experiment,T1:drip irrigation+mulching+60,000 plants/hm~2,T2:drip irrigation+mulching+75,000 plants/hm~2,T3:drip irrigation+no mulching+60,000 plants/hm~2,T4:drip irrigation+no mulching+75,000 plants/hm~2,CK:sitting water species+no mulching+60,000 plants/hm~2.The research is concerning the effects of planting density and drip irrigation under film on dry matter accumulation and distribution,diurnal variation of photosynthesis,leaf fluorescence parameters,yield and their constituent factors and economic benefits.As a result,the following conclusions are obtained,1.The net photosynthetic rate of CK,T1 and T3 treatment will reach the peak later than T2 and T4 treatment all day.During the same period,the net photosynthetic rate,stomatal conductance,intercellular carbon dioxide concentration and transpiration rate of corn are the best in T1 treatment.2.The film mulching can effectively improve the plant's photochemical activity.Compared with drip irrigation under film,The photosystem II reaction center without film drip irrigation has lower activity,and the stress was more severe.As the planting density increases,the process of electron transfer is inhibited.The photosystem II absorbs less of the light energy for photochemical reactions and more for fluorescence and heat dissipation,and the photosynthetic activity is reduced.3.High planting density leads to increased competition within the group,and the growth of ears are more seriously inhibited.As a result,the proportion of ears with a T1 and T3treatment to dry matter was better than T2 and T4 treatment.When the planting density was60,000 plants/ha,T1 treatment had the highest dry matter accumulation.4.At the same density,in the aspect of ear weight,ear length,ear diameter,ear number per ear,ear number and 100-grain weight,T1 and T2 treatment is better than T3 and T4treatment.In the aspect of plant height,ear height,ear coefficient and bald tip length,T3 and T4treatment is better than T1 and T2 treatment.When drip irrigation under film under different planting densities,the plant height,ear height and rows per ear were positively related to planting density.In the research,the ear weight,ear length,ear diameter,bald tip length,ear coefficient,kernels per row,ear number and 100-grain weight were negatively correlated with planting density.In summary,under drip irrigation mode,T1 and T2 treatments are higher than T3 and T4treatments;The planting density of 75,000 plants/hm~2combined with drip irrigation under film has the highest maize yield and economic benefit(T2 treatment increased 87.34%,17.64%,25.83%and 18.10%of CK,T1,T3 and T4 respectively).