黄振瑞 周文灵 敖俊华 陈迪文 黄莹 江永 李奇伟

摘  要：以甘蔗品種‘粤糖03-393（‘粤糖60号）为试验材料，采用随机区组设计，通过4 a（造）钾肥水平（0、225、450、675、900 kg/hm²）定位试验，研究长期施用钾肥对甘蔗产量、农学效应、植株吸钾量、钾肥利用率、土壤钾素含量、土壤钾素平衡和钾肥经济效益的影响。结果表明：随着钾肥施用量的增加，甘蔗农学效应、产量、钾肥利用率呈先增后降的趋势，产投比逐渐减小，450 kg/hm²处理的产量和钾肥利用率最高，225 kg/hm²处理的农学效应和产投比最高;甘蔗植株的吸钾量、土壤钾素含量、钾素平衡系数呈升高的趋势，出现植株奢侈吸收、土壤钾素含量过高、表观盈余过多、钾素资源浪费现象。合理施用钾肥能增加农学效应和产量，而过量施钾会降低农学效应和钾肥利用率，还造成资源浪费和养分流失。考虑农学效应、肥料利用率、土壤钾素表观平衡、综合效益等因素，甘蔗钾肥施用量建议为225～450 kg/hm² K₂O。

关键词：钾肥;甘蔗;产量;土壤钾素平衡中图分类号：S566.1      文献标识码：A

Sugarcane Yield and Soil Potassium Balance in Potassium Application of Four Consecutive Years

HUANG Zhenrui¹， ZHOU Wenling²， AO Junhua^2*， CHEN Diwen²， HUANG Ying²， JIANG Yong²， LI Qiwei²

1. Crops Research Institute， Guangdong Academy of Agricultural Sciences / Guangdong Provincial Key Laboratory of Crop Genetics and Improvement， Guangzhou， Guangdong 510640， China; 2. Guangdong Provincial Bioengineering Institute （Guangzhou Sugarcane Industry Research Institute） / Guangdong Key Lab of Sugarcane Improvement & Biorefinery， Guangzhou， Guangdong 510316， China

Abstract： A four-year （2014 to 2017） potassium fertilizer field experiment designed by a random block with cultivar ‘Yuetang 03-393 （‘Yuetang 60） and five K₂O levels of 0， 225， 450， 675 and 900 kg/hm² respectively was conducted to evaluate the effects of the long-term application of potassium fertilizers on sugarcane yield， agronomy efficiency， plant potassium （K） uptake， potassium use efficiency and soil potassium content. Under a certain K₂O application range， with the increase of potassium application rate， the agronomy efficiency， yield and potassium use efficiency of sugarcane increased and then decreased， while the output-input ratio was down. The yield and potassium use efficiency of the treatment with 450 kg/hm²K₂O were the highest， and the agronomy efficiency and output-input ratio of the treatment with 225 kg/hm²K₂O were the best. With the increase of potassium fertilizer dosage， the potassium uptake， soil potassium content and potassium equilibrium coefficient of sugarcane plants increased， resulting in luxury absorption of plants， excessive soil potassium content， excessive apparent surplus and waste of potassium resources. The reasonable application of potassium fertilizers could increase the agronomic benefit and yield. However， the excessive application of potassium fertilizers could reduce the agricultural effect and potassium use efficiency， and also result in the waste of resources and loss of K nutrients. Considering agronomy efficiency， fertilizer use efficiency， apparent balance of soil potassium and comprehensive benefits， the recommended amount of potassium fertilizers for sugarcane is K₂O 225– 450 kg/hm².

Keywords： potassium fertilizer; sugarcane; yield; soil potassium balance

DOI： 10.3969/j.issn.1000-2561.2020.07.009

甘蔗作为我国乃至全世界最重要的糖料作物，全国种植面积常年保持在140万hm²左右，占全国常年糖料种植面积的85%以上^[1]。甘蔗产业健康绿色发展对国家食糖安全具有重要战略意义。甘蔗对钾的吸收大于氮和磷，是典型的喜钾作物，存在奢侈吸收的现象。钾素是实现甘蔗稳产增产和品质形成的重要元素，合理施用钾肥是实现甘蔗持续高产的重要措施。由于甘蔗种植区域地力条件较差，加之受价格波动较大，生产上往往只重视氮磷肥而忽视钾肥的施用，钾肥的应用在甘蔗生产上一直未得到充分重视。……