Effects Of N, P, K Fertilizers Application Rate And Time On Accumulation And Distribution Of Nutrients And Dry Matter In Potato

Using Kexin13as experimental materials, Plot experiments were conducted to study theeffects of fertilizer application rates and time on the growing development, accumulation,translocation and distribution of nitrogen（N）, phosphorus（P）and potassium（K） as well as thetuber yield of potato. The potato to indicate the best fertilizer application rates and time assemblefor the local promotion, provided the basis for the potato production, the main conclusions were asfollows:In the whole growth period, the potato plant height were gradually rising, From seedling stageto early tuber bulking stage, The plant height and leaf area index of potato shows a negativecorrelation with N and P fertilizer, and a positive correlation with K fertilizer; From starchaccumulation stage to harvest period, The plant height and leaf area index of potato shows apositive correlation with N and P fertilizer, and a negative correlation with K fertilizer. LAI reachedthe peak in early tuber bulking stage. In the harvest stage, N and P fertilization was in favor ofLAI’s increasing. The N, P, K increase fertilizer application rates had no obvious effect on leafnumber. Increasing potassium fertilization or splited nitrogen fertilizer can increase a single tuber’sweight, but it had no obvious effect on tuber number per plant. The treatment of low N, P, high Kwhile top dressing with N or while top dressing with N, K (T3and T4) the yield per plant werehigher.In the whole growth period, The dry matter accumulation of root, stem and leaf showed asingle peak curve, stem and leaf （T1and T2）peak was at the starch accumulation stage,(T3andT4) the peak reached the early tuber bulking stage. Dry matter accumulation of potato whole plantand tuber was "S" shaped curve, and when tuber formed and that of tubers was always a lineargrowth. In the conditions of one rate nitrogen topdressing nitrogen increased dry matteraccumulation of the whole plant and tuber whole growth period, and promoted dry matterdistribution ratio in tubers at harvest. Compared to T1and T2treatments, dry matter accumulationof the tubers and dry matter distribution ratio of tubers (T3and T4) were always higher, dry matteraccumulation of the tubers (T3) increased by11.7%than T1at harvest.The NPK accumulation in the different organs and harvest periods, and the highest in the tubers and lowest in the roots, showing the order tuber>leave>stem>root during the harvest period;The NPK accumulation in the roots, stems and leaves before the dry balance period, showing theorder leaf>stem>root, after that NPK accumulation and distribution transferred to tubers mainly,continued to increase to maturity period, leading to a storage of more than57.19%,77.23%,79.08%accumulation NPK in the tubers. Nitrogen and phosphorus applications can increase theaccumulation of N and P in stem and leaf, but reduce N and P accumulation in tuber; Splited Nfertilizer can increase the accumulation and accumulation rate of N, P and K in tubers, and splitedK fertilizer can increase the accumulation of N, P and K in tubers, but had less effect on the N, Pand K accumulation. Increasing potassium fertilization and reduce N, P fertilization was in favor ofearly growth N and P accumulation rate in tubers, N accumulation rate had obvious effect on N, P,K fertilization.The result showed that tuber yield of different treatments were ranged from33.5to38.6t/hm2,N agronomic efficiency (AE) ranged from12.3%to50.3%.The treatment of low N, P with high Khad a significantly higher total tuber yield, marketable tuber yield, marketable tuber ratio than thetreatment of high N, P with low K（P＜0.05）and the treatment of low N, P, high K while topdressing with N was the best one. There were no differences on the tendency of nutrientsaccumulation, but significant difference on the nutrients accumulation and distribution in differentorgans at different growth stages between four treatments. The treatment of low N, P with high Kcould boost the accumulation and distribution proportion of N, P and K in tuber while enhance theirtranslocation from vine to tuber. Top dressing N before tuber bulking stage could improve thedistribution of nutrients in tuber, but top dressing K based on top dressing N could only improvethe ratio of marketable tuber slightly.