Effects Of Combined Application Of Nitrogen And Phosphorus On Photosynthetic Characteristics,Yield And Quality Of Maize

Maize is largest food crop in the world and is also in China.The production and quality of corn are directly related to the national food security and people's living standards.In order to study how to reduce the "fertilizer" through the combination of nitrogen and phosphorus,the maximum fertilizer efficiency can be achieved,and the yield and quality of corn can be kept unchanged,and stable production can be achieved.The maize Dafeng 30 is chosen as a material and a two-factor cracking zone design was using to study the changes in the yield,quality and photosynthetic characteristics of maize by adjusting the ratio of nitrogen and phosphorus.In this experiment,we set four levels of nitrogen application,three levels for phosphorus application,a total of 12 treatments,three repetitions.The result is showed as follows:By observing the corn seedlings at the jointing stage,filling stage and maturity,it can be found that under the combination of 12 treatments,when the nitrogen application rate is 300 kg hm-2 and the application of phosphorus is 120 kg hm-2,the indicators are the most ideal during the jointing and filling stages.Meanwhile,the performance of these two periods is consistent with the final yield indicators.We also found that the growth status and yield level of the corn are the highest,when the nitrogen application rate is 300 kg hm-2 and the phosphorus application rate is 120 kg·hm-2 and the fertilizer application is excessive.Or insufficient will affect the normal growth of corn,thereby reducing production.It is showed that the photosynthetic rate,stomatal conductance,and transpiration rate of corn increase with the increasing of fertilizer application amount,but the amount of fertilizer application exceeds a certain level by investigating the photosynthetic indexes at the two key stages(joining stage and filling stage).The photosynthetic parameters of the leaves began to decline,since the leaf growth has a direct relationship with nitrogen,the photosynthetic index is more affected by the amount of nitrogen applied than the amount of phosphorus applied.Over amount nitrogen and phosphorus will inhibit the absorption of nitrogen and phosphorus in maize.Both of the amount of nitrogen and phosphorus applied are insufficient will promote the absorption of corn to each other.According to the performance of the photosynthetic index of maize,the results showed that the nitrogen application amount was 300 kg hm-2 and the phosphorus application amount was 120kg hm-2,the photosynthetic index of maize under the combined application of nitrogen and phosphorus performed best,and the leaf growth was the most vigorous.By comparing to the crude protein and starch content in the final harvested,we found that when the N application rate was less than 300 kg·hm-2 and the P application amount was less than 120 kg·hm-2,the protein and starch contents in the maize grain increased with the amount of fertilizer applied.When the amount of fertilizer exceeds this amount,the content of crude protein and crude starch will decrease.The amount of crude protein and crude starch under the combined application of nitrogen of 300 kg·hm-2 and 120kg·hm-2 of nitrogen and phosphorus were the highest in maize grain,reaching 81.96%.At this time,the quality of corn kernels and the nutritional value were all the best,otherwise,excessive or insufficient will reduce its quality.