Effects Of N,P And K Fertilizers Combined Application On The Dry Matter Accumulation And Distribution,Formation And Quality Of Whole Film Mulched Potato

In order to screen out the appropriate ratio of nitrogen,phosphorus and potassium fertilization and provide a theoretical basis for further improving potato yield and quality,field experiments were conducted to investigate effects of N,P and K fertilizers combined application on the potato growth,dry matter accumulation and distribution,yield and quality of tuber under fully mulched ridge cropping according to the design of?3414‘with the potato variety?Xin Daping‘.The main conclusions are as follows:1.Combined application of N,P and K increased the plant height of potato significantly.There was significant difference in plant height between the treatment 6?N2P2K2?and treatment 2?N0P2K2?at the stage of potato starch accumulation.However,there was no significant difference in plant height between treatments at the stage of potato seedling,tuber formation and tuber expansion.Combined application of N,P and K had no significant effect on stem diameter of potato.Except seedling stage,in the rest of the potato growth period,the stem diameter of treatment 6?N2P2K2?is maximum.Combined application of N,P and K increased the relative content of chlorophyll of potato obviously.There was significant difference in the relative content of chlorophyll between the treatment 6?N2P2K2?and treatment 1?N0P0K0?at the stage of potato tuber expansion.2.During the whole growth period of potato,the dry matter accumulation of potato tuber and whole plant conformed to the?S‘curve growth pattern.The dry matter accumulation of whole plant and potato tuber was fitted by Logistic equation,and the effect of N,P and K fertilizers combined application on the dry matter accumulation of potato was significant.Combined application of N,P and K significantly increased the number of days of the duration for the potato plant dry matter fast accumulation period??t?,the maximum increasing rate of dry matter(v_max)and the average rate of dry matter during the rapid accumulation period(v_mean).With the increase levels of N,P and K,the?t,v_max and v_mean of potato tuber and whole plant dry matter showed a single peak trend that first increased and then decreased.The days of the maximum rate of dry matter accumulation?t₀?in potato tubers occurred 3 to 19 days later than that of the whole plant.The starting point?t₁?and the end point?t₂?of the fast accumulation period of tuber dry matter were 12²3d and 0¹9d later than the t₁ and t₂ of the whole plant,respectively.The number of days of the duration for the potato plant dry matter fast accumulation period??t?of tuber was shortened by 1²5 days than that of the whole plant.Combined application of N,P and K apparently affected the dry weight balance period of potato,which can be advanced under treatment 6?N2P2K2?.Combined application of N,P and K affected the distribution of the potato dry matter significantly. The proportion of dry matter distribution in different organs of potato varies with the transfer of the growth center of the potato,and the end period of the tuber formation is a turning point.With the development of the potato growth period,the proportion of dry matter in the stem+leaves and roots decreased gradually,and the proportion of distribution in the tuber increased rapidly,and then increased slowly.3.Combined application of N,P and K significantly increased the content of starch.The starch content of treatment 9?N2P2K1?was significantly higher than that of other treatments.Combined application of N,P and K significantly increased the content of soluble protein.The content of soluble protein of treatment 6?N2P2K2?was significantly different from that of treatment 1?N0P0K0?,5?N2P1K2?and 13?N1P2K1?respectively.There was no significant difference between the soluble protein content of treatment 6?N2P2K2?and that of the other treatments.Combined application of N,P and K increased the content of reducing sugar apparently.The reducing sugar content of treatment 5?N2P1K2?was significantly higher than that of other treatments.The content of reducing sugar of treatment6?N2P2K2?no significant difference from that of treatment 7?N2P3K2?,and there was significant difference between the soluble protein content of treatment 6?N2P2K2?and that of the other treatments.Combined application of N,P and K increased the content of Vc significantly.The Vc content of treatment 14?N2P1K1?was apparently higher than that of treatment 1?N0P0K0?and treatment 2?N0P2K2?,and there was no significant difference between the other treatments.The content of starch,soluble protein,reducing sugar and Vc could reach a high level under the treatment 6?N2P2K2?.4.Combined application of N,P and K significantly increased the mass rate of big tuber and per plant yield of potato.The application of the suitable ratio of nitrogen,phosphorus and potassium fertilizer could increase the yield of potato significantly.The big tuber mass rate,single plant yield and potato tuber yield under treatment 6?N2P2K2?were obviously higher than those of other treatments.In conclusion,the suitable ratio of N,P and K for potato production in this study was pure N 150 kg/hm²,P₂O₅ 75 kg/hm² and K₂O 120 kg/hm².