Effects Of Different Fertilizer Levels On Greenhouse Tomatoin Aerated Irrigation

In view of the traditional agricultural production facilities in the subsurface drip irrigation is easy to cause soil oxygen content is reduced,affect the root problem of water and nutrient absorption,this study of greenhouse tomato as the experimental material,through the micro-nano bubble generator for irrigation water gas processing,and through the subsurface drip irrigation,geared to the needs of the development of modern,efficient agriculture requirements of the quality,and the efficiency,improvement of soil moisture environment,improve the utilization ratio of sewage sludge.In order to explore the suitable amount of fertilizer for crops under aerated irrigation,two irrigation methods,aerated and unaerated(as the control),were designed in the experiment.Three fertilization levels,namely,high nitrogen,medium nitrogen and low nitrogen,were applied.The effects of aerated and unaerated irrigation methods and different fertilization levels on plant height,stem diameter,root growth,dry matter quality,yield quality and soil enzyme in greenhouse tomato were studied.The optimal irrigation and fertilization strategy for efficient utilization of water and fertilizer in greenhouse tomato under aerated subsurface drip irrigation was proposed,and the following conclusions were obtained:(1)Aeration treatment can improve soil aeration and promote the growth and development of tomatoes in the middle growth period(50 days after planting).Gas processing plant height,stem diameter less gas treatment significantly increased by 7.11%,12.34%,among them with the increase of fertilizer rate,the tomato plant height presents the positive response,aerated irrigation high nitrogen fertilizer processing tomato plant height to the maximum,and nitrogen fertilizer application in aerated irrigation treatment of thick stems to the maximum,high nitrogen treatment increased by 3.68%,low nitrogen treatment increased by 6.29%.Aeration and fertilization had significant effects on plant height and stem diameter.Under the interaction,aeration and fertilization had no significant effect on tomato stem diameter(P>0.05),but significant effect on plant height(P<0.05).(2)Aeration treatment in all the reproductive period to improve the content of chlorophyll,to speed up the net photosynthetic rate are helpful,but aerated irrigation at different stages to improve the effect of lycopene content of chlorophyll is not exactly the same,flower fruit period,mature period under low nitrogen fertilizer levels aerated irrigation works best,fruit enlargement period aerated irrigation works best under nitrogen fertilizer levels.Except for flowering and fruit-setting stage,the chlorophyll content and net photosynthetic rate in other growth stages increased first and then decreased with the increase of fertilizer amount,and nitrogen fertilization in aerated irrigation played the most significant role.(3)Aeration treatment can improve root morphology(total root length,surface area,volume,number of root tips)distribution of tomato and improve root vitality.In the flowering and fruiting stage,the morphological indexes of root system increased with the increase of fertilizer application,and the root activity decreased with the increase of fertilizer application.The results showed that the nitrogen fertilization was the best during the period of fruit expansion and ripening,and significantly improved the total root length,root surface area,root volume and root activity.(4)Aeration treatment can significantly increase dry matter accumulation and crop yield,among which dry matter accumulation in overground part increased by 11.40%,dry matter accumulation in underground part increased by 17.40%,root to crown ratio increased by 6.60%,and yield per plant increased by 7.22%.At the same time,dry matter accumulation in overground part,dry matter accumulation in underground part,root-crown ratio and yield per plant of nitrogen treatment in aerated irrigation were the highest,which showed that proper amount of fertilizer promoted dry matter accumulation and yield of tomato plants,and too much or too little fertilizer inhibited the formation of dry matter and yield of plants.(5)Aeration treatment had an obvious effect on improving the VC content,soluble sugar and organic acid of greenhouse tomato,and moderate nitrogen fertilization level could also improve the quality of tomato.After variance analysis,it was found that in addition to VC content,aeration treatment had a greater effect on quality than fertilizer application.(6)Compared with no gas processing,aerated irrigation improves the greenhouse tomato rhizosphere soil catalase,urease and alkaline phosphatase activity,but the reproductive period of enzyme activity was completely consistent performance,flowering period of fruit while increases with the increase of fertilizer rate urease activity and catalase,alkaline phosphatase activity increased before;The three enzymes of fruit at the stage of fruit enlargement and ripening all increased first and then decreased with the increase of fertilizer application.To sum up,the nitrogen in the aerated irrigation fertilization treatment of greenhouse tomato growth physiological indexes,the optimal fruit yield and quality,soil environment,explain aerated irrigation can effectively solve the problem of root zone hypoxia,at the same time,the study results for greenhouse tomato given the appropriate fertilizer rate,is advantageous to the tomato growth,increase production and improve quality,can be replicated in production practice.