---

作 者 ：黄巧义 唐拴虎 陈建生 张发宝 解开治 黄旭 蒋瑞萍 李苹

期 刊 ：植物营养与肥料学报 2014年 20卷 4期 页码：947-956

关键词：木薯；ldquo；华南205rdquo；氮；磷；钾；养分吸收累积；施肥；

Keywords:cassava, SC205, N, P, K, nutrient absorption and accumulation, fertilization,

摘 要 ： 【目的】木薯是重要的粮食作物，也是优质的淀粉工业原材料，被认为是非粮生物质能源的最合适原料。氮、 磷、 钾含量水平显著影响木薯产量，但有关木薯养分阶段性累积特征及其对生物量和产量形成影响的相关研究仍较少。本文比较了不同肥料配比情况下，木薯生物量， 氮、 磷、 钾累积量变化趋势，探讨了不同生育期氮、 磷、 钾含量及累积量的重要性及施肥对其影响。【方法】以我国主栽木薯品种“华南205”为材料，2009年在广东省郁南县丘陵坡地开展田间施肥试验，共设CK、 NP、 NK、 PK、 NPK 5个施肥处理。于苗期、 块根形成期、 块根生长早期、 块根快速膨大期和成熟期调查生物量和氮、 磷、 钾含量，得出氮、 磷、 钾累积动态。以各时期氮、 磷、 钾含量及累积量作为原始变量进行主成分分析，判断各时期氮、 磷、 钾含量及累积量的重要性，并分析不同肥料配比对各时期氮、 磷、 钾含量及累积量的影响。【结果】华南205的生物量累积动态呈“S”型曲线, 生物量在苗期较小，进入块根形成期后快速提高，当进入成熟期后增长逐渐减缓。氮肥对生物量影响最大，其次是钾肥，磷肥的影响最小。木薯氮含量的变幅为3.99%~0.93%， 磷含量为0.82%~0.26%， 钾含量为1.39%~0.89%。氮、 磷、 钾含量均在苗期最高，且随着生育期的推进不断降低，尤以氮含量降幅最大。不同氮、 磷、 钾肥料配比显著影响木薯的氮、 磷、 钾含量。PK处理的氮含量较NPK处理降低了32.96%，NK处理的磷含量较NPK处理降低了16.21%，NP处理的钾含量较NPK处理降低了50.37%。氮、 磷、 钾累积量与产量显著相关。主成分分析表明木薯整个生育期的营养状况与块根形成期的氮含量、 苗期的钾含量及块根生长阶段的磷含量相关性最大。氮、 磷、 钾的吸收累积量随着木薯生长不断提高，其中块根形成期、 块根生长早期、 块根快速膨大期的氮累积量较大，块根形成期、 块根快速膨大期的磷累积量较大，块根生长早期、 块根快速膨大期、 成熟期的钾累积量较大。主成分分析表明块根快速膨大期的氮、 磷、 钾累积量对整个生育期养分累积影响显著，同时，苗期及块根生长早期的氮、 钾累积量对养分累积总量影响也较大。【结论】木薯氮、 磷、 钾含量随着植株生长不断下降，而累积量却不断提高。不同氮、 磷、 钾肥料配比显著影响木薯的氮磷钾含量及累积量、 物质累积及产量形成，其中氮肥的影响最大，其次是钾肥，磷肥的影响最小。综合分析表明，苗期、 块根形成期、 块根生长早期为氮、 磷肥的最佳施用时期，块根形成期、 块根生长早期及块根快速膨大期为钾肥的补充阶段。

Abstract:【Objectives】Cassava (Manihot esculenta Crantz) is one of the most important calorie-producing crops in tropics and subtropics, and mainly used for processing industrial food, forage. N, P and K significantly affect Cassava yield, but the study on nutrient accumulation in cassava at different stages and on biomass as well as yield formation is still limited. In this paper，the biomass and accumulation of nitrogen, phosphorus and potassium were investigated under different fertilizers treatments, and we also explored the accumulation characteristic of nitrogen, phosphorus and potassium in cassava at different growth stages.【Methods】“SC205” cultivated widely in south China was used as test material in this experiment. Field fertilization trials with CK (no fertilizer), PK, NK, NP and NPK treatments were carried out at a hilly slope land in Yunan city Guangdong province in 2009. The dry matter and the contents of N, P₂O₅ and K₂O in cassava “SC205” were examined respectively  at the seedling stage (SS), tuber root formative stage (TRF), tuberous root early growing stage (TRG), tuberous root rapidly bulking stage (TRB) and maturity stage (MS), and analysis on cumulative dynamics and principal component of N, P₂O₅ and K₂O were carried out using N, P₂O₅ and K₂O content and accumulations as original variables at each stage to find out the importance of N,  P₂O₅  and K₂O content and accumulations at each growth stage, and to analyze influence of different fertilizer combination on N, P₂O₅ and K₂O content and accumulations at each stage.【Results】The results showed that the biomass accumulation curve of “SC205” is exhibited in “S” shape, and the biomass at SS was relatively low, and increased rapidly after TRF, but the increase trend slowly declined at MS. Nitrogen fertilizer had the  greatest influence on the biomass, the second factor was potash, the influence from phosphate is the least. Data also showed that N content in “SC205” was ranged from 3.99% to 0.93%, and the content of P₂O₅was ranged from 0.82% to 0.26%, and the content of  K₂O  was ranged from 1.39% to 0.89%. The contents of N,  P₂O₅  and  K₂O  at SS reached the highest values, and decreased with the extension of plants growth, especially in N content. Study proved that different fertilizer treatments significantly affect the contents of N,  P₂O₅  and  K₂O  in cassava. Compared with NPK treatment, N content in the PK treatment reduced by 32.96%, and the content of P₂O₅ in the NK treatment reduced by 16.21%, and the content of  K₂O  in the NP treatment reduced by 50.37%. Analysis of principal components showed that the accumulation amounts of N, P₂O₅ and K₂O were significantly associated with cassava production, and that the nutritional status was significantly related to the N content at TRF,  K₂O  content at SS and P₂O₅ content at TRB. Detection on nutrients showed that accumulation of N,  P₂O₅  and  K₂O  increased with cassava growth and development. N accumulation is greater at TRF, TRG and TRB,  P₂O₅  accumulation is greater at TRF and TRB, while  K₂O  accumulation is higher at TRG, TRB and MS, and accumulation of N,  P₂O₅  and K₂O at TRB significantly influenced the total cumulative nutrients . Meanwhile, N and  K₂O  accumulation at SS and at TRF impacted the total cumulative nutrients as well.【Conclusions】Plant growth changed the contents of N, P₂O₅ and K₂O contents at different stages, but the accumulation of N,  P₂O₅  and K₂O increased. Different ratios of N, P, K fertilizers could remarkably affect the cassava biomass, the nutrient contents, the nutrient accumulation, the production and quality of cassava, and the most important factor is nitrogen fertilizer, the second factor is potash, the influence from phosphate is the lowest, showing that SS, TRF and TRG could be the optimum periods for N and P fertilizer application, and TRF, TRG and TRB could be the optimum periods for K fertilizer application.

---