Effects of Application Amount and Proportion of N,P and K Fertilizers on Nutrient Absorption and Distribution in Mulberry

In this paper,summer-pruned mulberry tree planted in hilly areas of Sichuan Province in spring and autumn were selected as research subjects for fertilization experiment on application amount and proportion of N.P and K fertilizers.The content,absorption amount and allocation proportion of N,P and K in leaf,branch and new shoot of mulberry tree were determined so as to provide scientific basis for rational fertilization in mulberry garden.Judging from the type of fertilizer,the content and absorption amount of nutrient in various portions of mulberry tree were all in the order of NKP.Based on the distribution of nutrients,the nutrients in different mulberry portions were all in the order of leafbranch in spring,autumn and whole year and in the order of leafnew shootbranch in spring.Application of N,P,K fertilizers with different fertilization levels and different proportions had obvious impact on the contents of N,P,K,and absorption amount and allocation proportion of nutrients in different mulberry portions.In N(X1),P(X2) and K(X3) treatment groups,the content and absorption of nutrients in various portions of mulberry tree from fertilization level 2(X12=600 kg/hm2,X22=210 kg/hm2,and X32=300 kg/hm2) and level 3(X13=900 kg/hm2,X23=315 kg/hm2,and X33=450 kg/hm2) were significantly higher than that of level 1(X11=300 kg/hm2,X21=105 kg/hm2,and X31=150 kg/hm2) and level 0(no fertilization).The results showed that N,P and K rational fertilization in mulberry field would facilitate the improvement of N,P and K contents and absorption in different mulberry portions.It is recommended to apply N,P and K fertilizers in accordance with fertilization level 2 of this study.