Effects Of Phosphorus Rate And Organic Substitution On Growth And Yield Of Potato

In order to discover the feasibility and alternative effects of organic fertilizer instead of inorganic fertilizer in potato production,the effects of organic fertilizers and inorganic phosphate fertilizers on the growth as well as the yield of potato wa s studied.In 2017,A field experiment was conducted by using ‘Youjin' and ‘Kexin 23' varieties,five treatments are set up,including single application of inorganic or organic fertilizers and combined application of organic fertilizer and inorganic fertilizer,which were represented by O,OP1,P1,P2 and P3.the effects of different fertilization schemes on the growth and development of potato organs,the changes of dry matter accumulation during the whole growth period,the accumulation and distribution of phosphorus?P?,the components of tuber yield and the enzyme activity of tubers were studied.The results show:Organic fertilizers are more effective in promoting the growth of the vines of ‘Youjin' and ‘Kexin 23',and the effect of organic fertilizer is more significant?p<0.05?.The plant height,stem diameter and leaf area index?LAI?of the two varieties with applicaiton of organic fertilizer?O,OP1?were higher than those of inorganic fertilizer?P1,P2,P3?only.Application of organic fertilizer also increased the SPAD value of ‘Youjin' significantly?p<0.05?and delayed the senescence of vines and roots of ‘Youjin',while the effects on the ‘Kexin 23' were not significant.The application of inorganic phosphate fertilizer promoted the elongation of roots and increased the ratio of root to shoot of the two varieties.Among the 5 treatment,‘P2' treatment had the highest root-shoot ratio,which was 14.57% and 12.98% higher than ‘O' treatment,respectively.Compared with applied organic fertilizer,single application of inorganic fertilizer increased the dry matter accumulation and P distribution ratio in tubers of two varieties,but decreased the dry matter and P accumulation of the whole plant.The dry matter accumulation curves of all treatments of the 2 varieties showed an "S" curve.In the 30-46 days after the seedling,the accumulation rate of the dry matter of the tubers of ‘Youjin' treated by the single-inorganic fertilizer was higher than that of the organic fertilizer.From 46 to 60 days after the seedling,the accumulation rate of the dry matter of the tubers treated by organic fertilizer was higher than that of the single application of inorganic fertilizer.The accumulation of dry matter in tubers of ‘Kexin 23' treated by P3 was the highest in all periods than others,and the difference in dry matter accumulation of tubers treated in the same period was not significant except for P3 treatment.Before tuber enlargement?13-30 days after seedling?,The difference in photosynthetic productivity of all treatments of ‘Youjin' and ‘Kexin 23' was not significant;after tuber enlargement?30-60 days after seedling?,The highest photosynthetic productivity of the two varieties was treated with OP1 and P2,and OP1>P2.Fertilizer types had relatively little effect on the enzyme activity of ‘Youjin' tubers,but excessive application of inorganic P fertilizer resulted in a significant decrease in the polyphenol oxidase activity of the ‘Youjin' tuber?p<0.05?.The application of organic fertilizer helps to increase the activity of polyphenol oxidase and peroxidase in ‘Kexin 23' tuber,thereby improving tuber disease resistance and storability,The activity of polyphenol oxidase and peroxidase in tubers increased first and then decreased with the increase of P rate.Except for the P1 treatment of ‘Kexin 23',the number of tubers per plant treated with single inorganic fertilizer was higher than that of organic fertilizer,and the highest number of tubers per plant of ‘Youjin' treated with P2 was 6.20 per plant,while The highest number of tubers per plant of ‘Kexin 23' treated with P3 was 4.84 per plant.Although the number of tubers per plant treated with organic fertilizer was small,the average tuber weight and commercial tuber rate were higher.Among them,the average tuber weight of O and OP1 treatment of ‘Youjin' increased by 27.31%?p<0.05?and 15.50%,respectively,compared with P1 treatment.The difference of average tuber weight between the treatments of ‘Kexin 23' was not significant.The same processed ‘Youjin' has a higher number of potatoes per plant than ‘Kexin 23',but ‘Kexin 23' has a higher average tuber weight.The highest yields of the two varieties were treated with single application of inorganic fertilizer,but the demand for phosphorus in t he two varieties was different.The highest yield of ‘Youjin' was P2 treatment?90 kg P₂O₅ / ha?,which was 15.5% higher than the lowest yield P1 treatment.The highest yield of ‘Kexin 23' was P3 treatment?135 kg P₂O₅ / ha?,which was 20.8% higher than the lowest yield P1 treatment.Under the conditions of this experiment,although the yield of organic substitution treatment?OP1?did not reach the highest level,it was higher than P1 treatment?45 kg P₂O₅ / hm²?.