种植密度与钾肥对甘薯新品种龙薯14号产量的影响

Effects of planting density and potassium fertilizing on yield of new sweet potato variety Longshu 14

【目的】探讨不同种植密度及钾肥施用量对龙薯14号产量的影响,为该品种的高产栽培提供参考依据。【方法】采用双因素随机区组设计,分析不同种植密度(4.20、4.95、5.70、6.45万株/ha)、硫酸钾施用量(0、150、300、450kg/ha)对甘薯性状、产量的影响。【结果】种植密度、钾肥施用量对龙薯14号鲜薯、薯干、淀粉产量、薯块干物率及大中薯率有显著影响(P<0.05)。同一种植密度下(≤5.70万株/ha),鲜薯、薯干产量和干物率随钾肥施用量的提高而提高;低钾肥水平(≤150 kg/ha)时鲜薯、薯干产量随种植密度增加而增加,高钾水平(≥300 kg/ha)时鲜薯、薯干产量随种植密度增加先增加后降低。中低种植密度下,高钾有利于提高淀粉产量。不同施钾量间块根干物率存在差异,不施钾肥处理虽然鲜薯产量和薯干产量均最低,但其薯块干物率最高。中低种植密度施钾处理有利于提高大中薯率,高种植密度高钾处理大中薯率反而下降。在土壤含钾量为111.6 mg/kg的肥力水平下,种植密度为5.70万株/ha,施尿素120kg/ha、过磷酸钙225 kg/ha、硫酸钾450 kg/ha时,龙薯14号能获得最高鲜薯产量为51483.98 kg/ha,最高薯干产量为15555.70 kg/ha,淀粉最高产量为10251.24 kg/ha。【结论】在一定范围内提高种植密度和施钾量能提高甘薯产量,而适当降低密度和增施钾肥可以提高甘薯商品率。

【Objective】The effects of planting density and potash fertilizer rate on the yield of Longshu 14 was explored to provide references for high yield cultivation. 【Method】Two-factor randomized block design was used to analyse effect of different densities（42.0,49.5,57.0,64.5 thousand plants/ha）and potassium fertilizer（0,150,300,450 kg/ha）on sweet potato traits and yield. 【Result 】 Density and potassium fertilizer were significant effect on the yield of fresh potato and dried potato,starch content,rate of tuber dry matter andrate oflargeand medium size of Longshu 14（P〈0.05）. Under the same planting density（ ≤ 57. 0 thousand plants / ha）, the yield of fresh potato, dried potato, and dry matter content in-creased with potassium application increased. The yield of fresh potato and dried potato were increased with the density increasedin low potassium levels（ ≤ 150 kg / ha）. The yield of fresh potato and dried potato were increased first and then decreased with density increased in high potassium levels（≥300 kg/ha）. High potassium fertilizer level in the lowdensity was beneficial to improve the yield of starch. There were differences rate of tuber dry matter among different potassium application,the yield of fresh potato and dry matter were the lowest in no potassium treatment,but rate of tuber dry matter was highest in the same treatment. The low-density and potassium fertilizer treatment were improved rate of largeand mediumsize of sweet potato,but the high-density and high level of potassium fertilizer decrease drate of large and medium sized of sweetpotato. The highest yield offresh potato and dried potato,starch content,was 51483.98,15555.75 and10251.24 kg/ha,respectively, under the conditions of available K（111.6 mg/kg） in soil moisture, planting density of57. 0 thousand plants/ha,urea 120 kg/ha,superphosphate 225 kg/ha,potassium 450 kg/ha. 【Conclusion 】The yield of sweet potato is increased by improving the planting density and the amount of potassium in a certain range. Commodity rate of sweet potato is increased by lower planting density and increase potassium fertilizer.