不同密度、氮磷钾配比对甘薯产量和商品率的影响

旨在探索不同密度和不同氮磷钾配比下对甘薯产量和商品率的影响,以期为甘薯高质高效生产提供参考。2019、2020年度以兼用型甘薯新品种‘郑红23’为材料,设置7个密度水平、7个氮磷钾配比水平、49个处理组合进行试验。结果表明：种植密度能极显著影响甘薯产量和商品率,随着密度增加产量先升后降,商品率逐渐降低;产量与商品率呈极显著的正相关,与单株结薯数呈显著正相关,与地上部茎叶鲜重、冠根比呈极显著负相关,商品率分别与茎叶鲜重、根鲜重、商品薯块鲜重、商品薯块个数、单商品薯块鲜重、单株结薯数呈极显著正相关,与冠根比呈极显著负相关;3万株/hm²产量最低,7.5万株/hm²次之,4.5万株/hm²产量最高,5.25万株/hm²产量次之,商品率虽然随密度增加有逐渐下降趋势,但在4.5万~5.25万株/hm²密度水平下也能达到90%以上;不同氮磷钾配比均极显著影响产量和商品率,N:P:K=1:1:2配比下产量和商品率均最高,N:P:K=0.8:0.8:2配比次之。通过2年的试验研究表明,甘薯种植密度为4.5万株/hm²~5.25万株/hm²,氮磷钾配比为N(0.8-1):P(0.8-1):K(2)时,产量最高,达到22611.41 kg/hm²~22933.57 kg/hm²,商品率达到90.40%~92.30%,因此在此密度和氮磷钾肥料配比下,甘薯能获得较高的产量和较好的商品率。

Planting Densities and NPK Ratios: Effects on Sweet Potato Yield and Commodity Rate

The aim is to explore the effects of different planting densities and different ratios of nitrogen, phosphorus and potassium on the yield and commodity rate of sweetpotato, in order to provide references for its high-quality and high-efficiency production. In 2019 and 2020, the new double-use sweetpotato variety ‘Zhenghong 23’ was used as the material, 7 density levels, 7 nitrogen, phosphorus and potassium ratio levels, and 49 treatment combinations were designed in the experiment. Results showed that the planting density significantly affected the yield and commodity rate of sweet potato. Along with the density increasing, the yield first increased and then decreased, and the commodity rate gradually decreased; the yield had an extremely and significantly positive correlation with the commodity rate, a significantly positive correlation with the number of potatoes per plant, and an extremely and significantly negative correlation with the fresh weight of shoots and leaves and shoot-to-root ratio. The commodity rate had an extremely and significantly positive correlation with the fresh weight of stems and leaves, the fresh weight of roots, the fresh weight of commodity tubers, the number of commodity tubers, the fresh weight of single commodity tuber and the number of tubers per plant, respectively, and an extremely and significantly negative correlation with the shoot-to-root ratio. The yield of 30,000 plants/hm ²was the lowest, followed by 75,000 plants/hm², and the yield of 45,000 plants/hm² was the highest, followed by 52,500 plants/hm². Although the commodity rate gradually declined with the increase of density, it could reach more than 90% at a density level of 45,000 to 52,500plants/hm². Different ratios of nitrogen, phosphorus and potassium had extremely significant effects on yield and the commodity rate, N:P:K=1:1:2 had both the highest output and commodity rate, followed by N:P:K=0.8:0.8:2. A two-year experimental study showed that when the planting density of sweet potato was 45,000 -52,500 plants/hm², and the ratio of nitrogen, phosphorus and potassium was N(0.8-1):P(0.8-1):K(2), the yield was the highest, reaching 22611.41 -22933.57 kg/hm², and the commodity rate was 90.40%-92.30%. Therefore, with the above density and nitrogen, phosphorus and potassium fertilizer ratio, sweet potato planting could obtain high yield and better commodity rate.