罗梁元 薛欣欣 魏云霞 黄洁 张永发 赵春梅 罗雪华 王文斌

摘  要：木薯种植中的不合理施肥容易引起徒长、产量下降。本研究通过田间试验，设置不施肥、常规施肥、减量施肥、减量同步施肥4个处理，以探明不同施肥量及施肥时期对木薯產量及养分吸收利用的影响，为提高肥料利用效率、增加木薯产量提供依据。结果表明：施肥能够显著增加木薯的株高、茎粗及生物量;减量施肥、减量同步施肥处理木薯块根的产量极显著高于常规施肥与不施肥处理，与不施肥和常规施肥处理相比，减量施肥木薯鲜重依次增加28.15%、32.73%，减量同步施肥依次增加15.46%、19.57%;与常规施肥相比，化肥减量施用能提高木薯块根的收获指数;施肥能够提高木薯的淀粉含量，与常规施肥相比，适当减少化肥用量不会导致木薯块根淀粉含量的下降;化肥减施能够提高肥料的利用率，与常规施肥处理相比较，减量施肥处理氮、磷肥利用率分别提高8.52、5.01个百分点，钾肥利用率两者相近，减量同步施肥处理氮、磷、钾肥利用率分别提高12.65、8.09、6.26个百分点，对肥料利用率的作用更为明显。在本试验条件下，2个化肥减施的处理块根产量分别为44.93 t/hm2及40.08 t/hm2，显著高于常规施肥处理的32.58 t/hm2，肥料利用效率显著提高，达到了“减肥增效”的目的。

关键词：木薯;化肥减施;产量;养分吸收

中图分类号：S533      文献标识码：A

Abstract： Excessive fertilization in cassava planting will cause excessive top growth and reduce tuber root yield. To provide theoretical basis for practices with high yielding and high uptake efficiency of fertilizer， a field experiment was carried out with four treatments i.e. no fertilization （UT）， conventional fertilization （CFT）， 25% reduction in fertilization （RFT） and simultaneous fertilization with 25% reduction （RSFT）. The effects of different fertilizer amounts and split application on cassava yield and nutrient uptake and utilization were studied. The results showed that fertilization could significantly increase plant height， stem diameter and biomass of cassava. The tuber root yields of RFT and RSFT were significantly higher than that in CFT and UT. The fresh weight of cassava in RFT increased by 28.15% and 32.73%， respectively，compared with that in UT and CFT. Yield increments of 15.46% and 19.57% were obtained in RSFT. The starch content in tuber root increased with fertilizer application. The results showed that reducing fertilization in a certain extent would not cause starch content decline in tuber root. Compared with CFT， the uptake rate of N and P increased by 8.52 and 5.01 percent， respectively， in RFT， while similar uptake rate of K was observed in both CFT and RFT. Higher increment of N， P and K uptake rate was observed in RSFT， uptake rate of N， P and K increased by 12.65， 8.09 and 6.26 percent， respectively. Under the conditions of this experiment， significantly higher root tuber yield was obtained in RFT and RSFT， which reached to 44.93 t/hm2 and 40.08 t/ha， while a lower tuber root yield of 32.58 t/ha was found in CFT. The uptake rate of fertilizer was significantly improved， which indicated that higher economic efficiency could be obtained with reduced fertilization.

Keywords： cassava; reduced fertilization; yield; nutrient absorption

DOI： 10.3969/j.issn.1000-2561.2021.11.016

木薯是我国六大热带作物之一，也是重要的淀粉和能源作物[1]，主要分布在广西、广东、福建和海南等熱带、亚热带地区[2]。研究表明，木薯理论产量能达到90 t/hm2[3]，然而2017年来我国木薯平均产量仅为16.5 t/hm2[4]，木薯的种植规模和经济效益不高，主要依靠进口来满足市场需求[5]。……