The Effection On The Growth And The Content Of Crude Protein Of Different Duckweed By The Discrepancy Application Of Nitaogen And Phosphorus

Duckweed could be utilized as a kind of new-style fodder to provide quality cheap protein, It showed wide application.This research take four duckweed as the material of the experiment.And 2 of them which had a higher mass growth and protein content were selected.The different effection to the mass growth of the two duckweed under a different concentrations of nitaogen and phosphorus were studied.with the design of the rotation-regression-orthogonal combination. Set up a mathematics model consisting of original amount of duckweed,application of the nitrogen and phosphor, Analyzed the effection on the total increment and content of crude protein by the 3 fators .To point out the ideal combination of each fator and a reasonable range of each factor and concluding a optimal planting technique.By analying the increasing biomass and protein production capacity of Lemna aequlnocttalts and Spirodela polyrrhiza, the result showed, with the same medium the Lemna aequlnocttalts and Spirodela polyrrhiza showed a good performance and better than the other two duckweed in the biomass increment and protein production capacity per unit area. the Lemna aequlnocttalts and Spirodela polyrrhiza could be utilized as a high protein feed.By analying the effection of different concentration of N and P on the biomass increasmentof Lemna aequlnocttalts and Spirodela polyrrhiza,the result showed,both the Lemna aequlnocttalts and Spirodela polyrrhiza were inhibited with the increasing of the concentration of ammonian,and the withstanding ability of Spirodela polyrrhiza was higher than Lemna aequlnocttalts .nitrate nitrogen could be used by Lemna aequlnocttalts and Spirodela polyrrhiza, as inorganic nitrogen source, when the nitrogen source was plenteous,the increasing of the application of nitrate nitrogen had less influence on the biomass production. In the culture fluid mainly on nitrate nitrogen ,The relative leaves number growth rate of Lemna aequlnocttalts was bigger than Spirodela polyrrhiza's and the relative fresh weight growth rate of Spirodela polyrrhiza was higher than Lemna aequlnocttalts's .The biomass production of the two varieties in the the culture fluid mainly on nitrate nitrogen ,were better than that in the in the the culture fluid mainly on ammonium nitrogen. Both the two varieties had a high adaptability to the variation of phosphorus density but when it reached the value of 5mg/L,the growth rate of the two varieties would decreased. Lemna aequlnocttalts was showed a better performance in a higher phosphorus density condition.Studing the different amount of original duckweed,application of nitrogen and phosphate fertilizer.Effected on the biomass production and content of crued protein,the result showed :(1)The importance to the Spirodela polyrrhiza's biomass production of the three factors was the P application>the N application> amount of original duckweed.As the increasing of amount of original duckweed,application of nitrogen fertilizer and phosphate fertilizer, they could promote the biomass production of Spirodela polyrrhiza, and the biomass production would decreased when the three factors were over used. The interaction effection between the original Spirodela polyrrhiza amount and the application of phosphor and the interaction effection between the application of phosphor and nitrogen were significant. The high bioass production of agronomy measure were:The amount of original duckweed. 22.22～25.826g, application of nitrogen 147.78～182.46kg/hm~2, the application of phosphor 88.14～103.715kg/hm~2;(2)The importance to the Spirodela polyrrhiza's content of crude protein of the three factors was the N application>the P application> amount of original duckweed. The content of crude protein of Spirodela polyrrhiza would reach its maximum,when the application of nitrogen at level 0,the application of phosphor at level1, the amount of original duckweed at the level 1. the interaction effection of the content of crude protein of Spirodela polyrrhiza between the application of phosphor and nitrogen were significant. The high content of crude protein of agronomy measure were:The amount of original duckweed. 18.45～21.55g, application of nitrogen 154.38～186.24kg/hm~2, application of phosphor64.45～88.04kg/hm~2;(3)The importance to the Lemna aequlnocttalts''s biomass production of the three factors was the N application>the P application> amount of original duckweed. The biomass production of Lemna aequlnocttalts would reach its maximum,when the application of nitrogen at level 0,the application of phosphor at level 0, the amount of original duckweed at the level 1. the interaction effection of the content of crude protein of Lemna aequlnocttalts between the amount of original duckweed.and the application of phosphor. The high bioass production of agronomy measure were:The amount of original duckweed 24.12～27.00g, application of nitrogen 163.74～191.58kg/hm~2, application of phosphor 66.86～89.96kg/hm~2;(4)The importance to the Lemna aequlnocttalts's content of crude protein of the three factors was the N application>the P application> amount of original duckweed. The content of crude protein of Lemna aequlnocttalts would increase when the application of nitrogen,the application of phosphor and the amount of original duckweed were from level-1.682 to levlel, and then dropped. The interaction effection of the content of crude protein of between the original Lemna aequlnocttalts amount and the application of phosphor and the interaction effection between the application of phosphor and nitrogen were significant. The high content of crude protein of agronomy measure were:The amount of original duckweed 21.33～25.27g, application of nitrogen 164.94～192.12kg/hm~2, application of phosphor 83.03～99.55kg/hm~2;...