| In order to explore the effects of reducing irrigation and chemical fertilizers on carbon,nitrogen and phosphorus stoichiometric characteristics of greenhouse black soil vegetable field,eggplant under regular irrigation and fertilization treatment(WF),reducing irrigation by 20%and regular fertilization treatment(80%WF),reducing chemical fertilizer by 20%and regular irrigation treatment(W80%F)were analyzed.Using ecological stoichiometric thingking analysis the characteristics and stoichiometric changes of soil C,N and P contents in different soil layers,as well as the changes of N,P and N:P in different organs of plants,it is of great significance to understand the proportion of nutrient elements and soil quality.the main research results are as follows:(1)In terms of soil nutrients contents,under 80%WF,TC in 0-20cm surface layer was significantly higher than that in WF and W80%F.In 100-120cm soil layer,TC in80%WF was significantly higher than that in W80%F.In 0-20cm topsoil,soil TN in80%WF was significantly higher than that in W80%F.TN in W80%F was significantly higher than that under WF.In the soil layers of 40-60cm and 60-80cm,TN in 80%WF was significantly higher than that in WF and W80%F.At the depth of 20-40cm,TP in80%WF treatment was significantly higher than that in W80%F.In the 60-80cm soil layer,the soil total p content in 80%WF was significantly higher than that under WF.(2)The stoichiometric characteristics of soil C,N and P were studied and the results are as followings:compared with WF,W80%F significantly reduced soil C:N.In0-20cm surface soil,compared with WF,80%WF significantly increased soil N:P by0.29.In 0-60cm soil layer,the soil N:P in 80%WF was significantly higher than that in W80%F.(3Variance analysis showed that the difference of TN between eggplant fruit and leaves was significant.In eggplant fruit,compared with WF,TN of eggplant fruit in W80%F significantly decreased.In eggplant leaves,compared with WF,TN of eggplant leaves in 80%WF and W80%F significantly decreased.Compared with WF,80%WF and W80%F significantly reduced the TP of eggplant leaves,stems and roots.(4)The order of N:P ratio in different organs of eggplant was root>leaf>stem>fruit.There was no significant difference in N:P between fruit and root in the three treatments.The N:P of leaves in W80%F was significantly lower than that in WF,and the N:P of stems in W80%F was significantly higher than that in WF.(5)There was a significant negative correlation between root N:P and root P content(r=-0.747,p<0.05);a very significant negative correlation between stem N:P ratio and stem P content(r=-0.920,p<0.01);a significant positive correlation between leaf N:P ratio and leaf N content(r=0.685,p<0.05).Leaf N:P ratio was significantly negatively correlated with leaf P content(r=-0.749,p<0.05).Eggplant fruit N:P was significantly positively correlated with leaf P content(r=-0.735,p<0.05).Eggplant fruit N:P was significantly negatively correlated with eggplant fruit P content.(r=-0.967,p<0.01).(6)The stoichiometric correlation of N and P between soil and plant showed that in0-20cm soil layer,only leaf N:P was significantly negatively correlated with soil N:P(r=-0.765,p<0.05).In 40-60cm soil layer,leaf N:P was significantly negatively correlated with soil N:P(r=-0.710,p<0.05).In 80-100cm soil layer,stem N:P was significantly negatively correlated with soil N:P(r=-0.704,p<0.05).(7)The eggplant yield in the three treatments varied from 48.72 t/hm~2 to 53.19t/hm~2.Compared with WF,the eggplant yield in 80%WF was significantly decreased by8.40%.The yield indicated that reducing irrigation leaded to production reduction,while reducing chemical fertilizers had little effect on yield. |
PDF Full Text Request