Effect Of Micro-Irrigation Method And Fertilizer On Growth Of Ehime 28

In recent years,the emerging citrus variety,Red Beauty(Ehime 28),has been rapidly expanding in China and is well liked by consumers.However,the lack of scientific guidance on fertilizer application by fruit farmers in different regions has led to the emergence of some problems such as poor performance of the introduced species and low utilization of agricultural resources.Therefore,there is an urgent need for in-depth research in the nutrient management of Red Beauty.The purpose of this paper is to investigate the micro-irrigation method,fertilizer application and the type of amino acid fertilizer biosource applicable to the cultivation of Red Beauty in Hubei,and to provide a theoretical basis for the introduction of Red Beauty in Hubei.Three experiments were set up with micro-irrigation method,fertilizer application rate and amino acid fertilizer bio-source type as test factors,and the effects of each factor on soil nutrients(organic matter,total nitrogen,effective phosphorus,effective potassium),fruit tree growth(canopy diameter,plant height,main stem circumference,main stem height),leaf photosynthetic characteristics(leaf net photosynthetic rate,transpiration rate,intercellular carbon dioxide concentration,stomatal conductance,instantaneous water use efficiency,carboxylation rate),and fruit size were analyzed.(net photosynthetic rate,transpiration rate,intercellular carbon dioxide concentration,stomatal conductance,instantaneous water use efficiency,carboxylation rate),fruit quality(fruit shape index,color difference index,edibility,fruit weight,soluble solids content,titratable acid content,solid to acid ratio,vitamin C content)and yield of individual plants,and based on the "entropy-weight-TOPSIS" model,we conducted a multi-objective evaluation and ranking,and finally obtained the optimal micro-irrigation method The optimal micro-irrigation method,fertilizer application rate,and biological source of amino acid fertilizer were finally obtained.The main findings and conclusions of this paper are as follows:(1)The micro-irrigation method applicable to the cultivation of Red Beauty in Hubei was clarified.With large water irrigation(CK)as the control,three micro-irrigation methods,drip tape irrigation(T1),micro-spray tape irrigation(T2)and 8-hole small red cap drip head irrigation(T3),were set up to analyze the mechanisms of micro-irrigation methods on soil nutrients,fruit tree growth,leaf photosynthetic characteristics,fruit quality and yield.The results showed that the microirrigation methods caused significant effects(p<0.05)on the accumulation of organic matter,total nitrogen,effective phosphorus and effective potassium in the 0-40 cm soil layer,and their maximum values appeared on T3,T2,T1 and T2 with 37.783 g/kg,2.670 g/kg,50.423 mg/kg and 882.850 mg/kg,respectively;the microirrigation methods had significant effects on The net photosynthetic rate,instantaneous water use efficiency and carboxylation rate of leaves were significantly affected by microirrigation method(p<0.05),and the maximum values were 4.3633 μmol·(m2s)-1,3.6833 μmol·mmol-1,0.0257 mol·(m2s)-1 on T2 treatment,respectively.The micro-irrigation method had a significant effect(p<0.05)on the crown diameter of fruit trees,with its maximum value appearing on the T2 treatment at 171.04 cm;the micro-irrigation method caused a significant effect(p<0.05)on fruit weight per fruit,edibility,soluble solids content,and yield per plant,with its maximum value appearing on the T2 treatment at 163 g,84.4%,15.497%,and 8164.767 g,respectively,The results then showed that the T2 treatment,i.e.,the micro-sprinkler treatment,performed best based on the "entropy-TOPSIS" model for evaluating different micro-irrigation methods.(2)The amount of fertilizer applied to Red Beauty based on the water and fertilizer integration model was clarified.Different fertilizer application rates were used as experimental factors,and four levels were set:LF(low fertilizer),MF(medium fertilizer),HF(high fertilizer)and CK(no fertilizer),to analyze the patterns of fertilizer application rates on soil nutrients,fruit tree growth,leaf photosynthetic characteristics,fruit quality and yield.The results showed that the fertilizer application rate caused significant effects(p<0.05)on organic matter,total nitrogen and effective phosphorus accumulation in the 0-40 cm soil layer,and their maximum values were all found in the HF treatment,39.99 g/kg,2.817 g/kg and 50.56 mg/kg,respectively;different fertilizer application rates caused significant effects(p<0.05)on the crown diameter and plant height of fruit trees The maximum values were 152.25 cm and 185.30 cm for MF and HF treatments,respectively;different fertilizer application rates caused significant effects(p<0.05)on fruit shape index,single fruit weight,edibility,soluble solids content,solid to acid ratio,vitamin C content,and yield per plant,with the maximum values appearing in HF,HF,MF,MF,MF,HF treatments with 0.966,160.7 g,84.4%,16.02%,17.346,48.907 mg/(100 ml),and 8374.1 g,respectively.finally,the comprehensive evaluation of different fertilizer application rates resulted in the ranking of each fertilizer application rate as:medium>high>low fertilizer.(3)The biological source of amino acid fertilizer suitable for cultivation of Red Beauty in Hubei region was clarified.Three treatments,DY(animal source amino acid fertilizer),ZY(plant source amino acid fertilizer)and CK(clear water spray),were set up with amino acid fertilizer bio-source as the experimental factor,and this experiment was conducted only at the fruit expansion stage as a chasing measure.The results showed that amino acid fertilizer biogenic source had a significant effect(p<0.05)on organic matter accumulation in the 0-40 cm soil layer,with the maximum value of 43.143 g/kg in the ZY treatment;amino acid fertilizer biogenic source had a significant effect(p<0.05)on instantaneous water use efficiency and carboxylation rate of leaves,with the maximum value of 4.2914 and 4.528 in the ZY treatment,respectively.(p<0.05),with the maximum values of 4.2914μmol·mmol-1 and 0.0260mol·(m2s)-1,respectively;different amino acid fertilizer biogenic sources had significant effects(p<0.05)on crown diameter and stem circumference of fruit trees,with the maximum values of 180.50 cm and 49.31 mm,respectively,in ZY treatment;different amino acid fertilizer biogenic sources had significant effects(p<0.05)on fruit vitamin C The maximum values were 56.783 mg/(100 ml)and 11726.167 g in ZY treatment.(4)revealed the correlation between soil nutrients,fruit quality and yield,and fruit tree growth.Based on Pearson’s calculation of correlation coefficients,it was found that there is a certain correlation between soil nutrients in 0-40 cm soil layer and fruit quality and yield,and fruit tree growth,and there is a certain difference between the correlation between nutrient content in 0-20 cm soil layer and 20-40 cm soil layer and fruit quality and yield,and fruit tree growth,which can provide a theoretical basis for high quality and high yield of Red Beauty fruit and fruit tree growth,and guide the nutrient management of different soil layers in Red Beauty orchard.