| In order to improve the yield and benefit of sweet potato / maize crop,the effects of nitrogen application on the yield,nutrient absorption and quality formation of the sweet potato were studied.The optimum conditions for the yield and quality of sweet potato were selected.In this experiment,three different types of sweet potato varieties,Wan shu 10(red flesh),Yu zishu 7(purple flesh)and Yu shu 33(light yellow flesh)were used as the materials.In the case of phosphorus(P2O5)45 Kg / hm2,potassium(K2O)180 kg / hm2 fertilizer as the base fertilizer application rate of the same time,staging(all as base fertilizer;base fertilizer + intercropping medium-term topdressing,the ratio of 6: 4;Base fertilizer + sets of medium-term topdressing + tailure for the end of fertilizer,the ratio of 4: 3: 3)(Pure N)90 kg / hm2,fertilization time for the end of the time and 31 days after transplanting,61 days,the study of the net,intercropping mode of nitrogen application period,On the agronomic traits,photosynthetic physiological characteristics,yield,N,P,K uptake and quality of sweet potato.The results show:1 The effect of different application period on the growth of the longest long-term sweet potato was higher than that of the net,and with the delay of nitrogen application,the extension of nitrogen application period promoted the development of sweet potato longest The The effect of topdressing nitrogen fertilizer on the growth of sweet potato was higher than that of sweet potato.The effect of the first-time topdressing nitrogen fertilizer on the early growth of the base part of the sweet potato was higher than that of the cauliflower.The sweet potato was more suitable for the branching and the increase of the base branch number of the sweet potato.The growth of sweet potato during the harvest of maize was not affected by topdressing nitrogen fertilizer,while the number of sweet potato internodes was higher than that of intercropping.Topdressing nitrogen fertilizer reduced the leaf area coefficient of sweet potato,and the difference was not obvious in one stage and two stages,while the decrease rate of sweet potato leaf area was lower than that of sweet potato.The leaf area coefficient of sweet potato was lower than that of net for 120 days after transplanting,and the leaf area coefficient of sweet potato was increased.The dry matter accumulation of sweet potato was 90 days before transplanting,and the dry matter accumulation of sweet potato was more favorable for 120 days after transplanting.The dry matter accumulation of aboveground part of Wan potato 10 was more than that of Yu zishu 7The application of nitrogen fertilizer had no effect on the dry matter accumulation of aerial parts of cassava,and the dry matter accumulation of sweet potato was significantly increased.2 The net photosynthetic rate of sweet potato leaves could be improved by the addition of nitrogen fertilizer in the intercropping mode,and the net photosynthetic rate of sweet potato was not significant.The net photosynthetic rate of sweet potato was not changed under different net conditions effect.The change of CO2concentration(Ci)in sweet potato was not caused by different application period.The stomatal conductance(Gs)of sweet potato was lower than that of net,and the stomatal conductance of sweet potato was not significantly different under the same cropping pattern,and it was not affected by planting pattern.The transpiration rate(Tr)of sweet potato was lower than that of net,and the effect of different application period on transpiration rate of sweet potato was not obvious.(Fv / Fm)accumulation in the leaves of sweet potato leaves was more favorable for the topdressing of the maximum photochemical quantum yield of PS(?)in the sweet potato leaves.The topdressing and one-time There was no significant difference in nitrogen fertilizer.The relative electron transport rate(ETR)of sweet potato was increased,and the relative electron transport rate of sweet potato was not obvious during the intercropping mode.The relative electron transport rate could be improved by the topdressing nitrogen fertilizer.And the photochemical quenching coefficient(q P)of sweet potato was higher than that of the sweet potato.The photochemical quenching coefficient of the topdressing nitrogen fertilizer was higher than that of the first and second stage The difference between the application is not obvious.(q N)increased,and the effect of different nitrogen application period on non-photochemical quenching coefficient of sweet potato was not significant.3 Stages of topdressing nitrogen fertilizer on sweet potato yield to promote the role of production,sub-topdressing and two topdressing can promote the production,net for the performance of consistent.According to the one-off application of nitrogen fertilizer in 2015,it will yield 30.4% in one phase and 25.8% in two phases.In the net mode,26.9%,respectively,and the yield of 8.8% in two phases was 20.8%.In 2016,compared with the one-time topdressing nitrogen fertilizer,the yield was 22.8%,and the yield was 19.4% The first-time topdressing nitrogen fertilizer was divided into one-stage yield of 10.3% and 10.9% in two phases.The yield of sweet potato was significantly higher than that of the first-time nitrogen fertilizer,but the difference was not significant.It is considered that the treatment method is easy to operate and theconvenience of implementation is better,and the topdressing method is better.4 The effect of topdressing topdressing nitrogen fertilizer on the content of N in sweet potato plants was not significant.The P content of sweet potato plants was increased by two treatments,and the effect of nitrogen fertilizer on the P content of plant was not obvious.Topdressing nitrogen fertilizer on the plant K content has played a promotion effect,compared with the first day of nitrogen fertilizer and topdressing a better effect.The net cultivation model is more favorable for the accumulation of N,K in sweet potato plants.5 The cultivation of anthocyanin in sweet potato was improved,and the application of nitrogen fertilizer was beneficial to the formation of anthocyanin in sweet potato.There was no effect on the formation of ?-carotene in sweet potato under different N periods and planting patterns.The content of sweet potato starch in the intercropping mode was lower than that of the net,but the difference between the crop and the net was not significant.If the starch was used as the harvest index,the fertilizer could be selected as one-time or nitrogen fertilizer.In the intercropping mode,the content of cellulose in the sweet potato was higher than that in the net mode,and the cellulose content was unstable.The sweet potato content was low as the evaluation index,and the net cultivation mode should be used.N fertilizer is best.The protein content of sweet potato was higher than that of the sweet potato.The protein content of sweet potato Wan shu 10 and Yu zishu 7 was not related to the two cultivation patterns.The protein content of Yu shu 33 was significantly higher than that of the formula In addition,the net was more beneficial to the accumulation of sweet potato protein content.The application of nitrogen fertilizer in the intercropping mode reduced the protein content of sweet potato,and the net application of nitrogen fertilizer increased the sweet potato protein content in the net mode.If the protein was the target Sweet potato production can be used in the net for the first time under the top of the nitrogen fertilizer production mode. |
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