施氮量及密度对膜下滴灌马铃薯氮素吸收与利用的影响

Effects of N Application and Planting Density on N Uptake and Use of Mulched Drip Irrigation Potato

[目的]为了确定膜下滴灌马铃薯生产中适宜的种植密度和合理施氮量,提高氮素利用效率和块茎产量及品质,为膜下滴灌马铃薯生产提供理论和技术指导。[方法]以紫花白为试验材料,设54 000、65 550、77 100株/hm23个密度以及0、142.5、285.0、427.5纯N kg/hm24种施氮量,采用裂区设计。[结果]在膜下滴灌种植模式下,马铃薯氮素累积吸收量均随着施氮量和种植密度的增加而提高;增加施氮量,AE、RE、PFP均呈现逐渐降低趋势;而适度提高种植密度,RE、AE、PEP均有一定程度的提高;马铃薯块茎产量、淀粉产量与施氮量、氮素累积吸收量和氮素吸收利用率之间存在0.01水平显著的正相关。协同提高氮素累积吸收量和吸收利用率是决定马铃薯块茎产量的关键。[结论]适度提高种植密度且增加施氮量有利于膜下滴灌马铃薯对氮素的吸收量、利用效率,进而有利于提高块茎产量和淀粉产量。在该试验条件下,适宜的种植密度与施氮量组合以77 100或65 550株/hm2、施氮量285 kg/hm2为宜。

[Objective] The optimum planting density and reasonable nitrogen application rate under the coated drip irrigation were determined to improve nitrogen utilization efficiency and yield and quality of tubers,and to provide theoretical and technical guidance for coated drip irrigation of potato.[Method] Purple and white potato variety was used as the experimental material,and three densities （54 000,65 550,77 100 plant/hm2） and four nitrogen application rate （0,142.5,285.0,427.5 pure N kg/hm2） were arranged,using split plot design.[Result] Under mulch drip irrigation conditions,with the improvement of the amount of nitrogen fertilizer and the planting density,the cumulative uptake of N was increased.With the improvement of the amount of nitrogen fertilizer,AE,RE and PFP were decreased.When planting density was moderately improved,AE,RE and PFP were increased.There was a significant positive correlation among potato tuber production,starch production,the amount of nitrogen fertilizer,cumulative N uptake and nitrogen utilization efficiency.The key of improving the production of potato tubers was improving cumulative N uptake and utilization efficiency.[Conclusion] Moderate increase of the planting density and nitrogen application rate were in favor of improving N uptake and utilization efficiency of coated drip irrigation potatoes,and improving the yield and tuber starch yield.Under the experimental condition,the combination of suitable planting density and nitrogen application rate was 77 100 or 65 550 plant and 285 kg nitrogen fertilizer per hectare.