长期施钾对双季玉米钾素吸收利用和土壤钾素平衡的影响

柳开楼; 黄晶; 叶会财; 韩苗; 韩天富; 宋惠洁; 胡志华; 胡丹丹; 李大明; 余喜初; 黄庆海; 李文军; 陈国钧

doi:10.11674/zwyf.20383

长期施钾对双季玉米钾素吸收利用和土壤钾素平衡的影响

Effects of long-term potassium fertilization on potassium uptake, utilization and soil potassium balance in double maize cropping system

摘要

摘要:
目的玉米 (Zea mays L.) 生产需要投入大量的钾素营养。研究长期大量投入钾素对玉米钾素吸收利用以及土壤钾素平衡的影响，旨在保障该地区双季玉米的高产高效和土壤钾库平衡。
方法红壤钾肥长期定位试验位于江西省进贤县，始于1986年，种植制度为一年两季玉米。试验处理包括不施肥对照 (CK)，氮磷化肥处理(NP)，氮磷钾化肥处理(NPK)，2倍量的氮磷钾化肥处理 (DNPK)，氮磷钾化肥+有机肥处理 (NPKM) 和单施有机肥处理 (OM)。每季收获后，调查分析玉米产量和钾素含量，以及耕层土壤有效钾含量，计算玉米钾素吸收量、钾肥利用率、钾肥收获指数、钾肥农学效率和土壤钾素表观平衡；并以每10年为一个阶段，分析玉米产量、钾素吸收利用等指标及耕层土壤速效钾含量、钾素表观平衡等的变化规律。
结果在试验的33年（1986—2018）间，NPK、DNPK、NPKM和OM处理的玉米年均产量和年均吸钾量均显著高于NP处理。在试验的第一个10年 (1986—1995年) 间，各钾肥处理间玉米产量和吸钾量无显著差异；而在第3个10年 (2006—2015) 和后3年 (2016—2018年) 间，NPKM处理的玉米年产量和年吸钾量分别比NPK处理提高了129.9%～246.7%和55.2%～62.1%。33年玉米的年均钾肥利用率以OM处理最高，而DNPK处理显著低于其他处理。在2006—2015和2016—2018年，NPKM处理的钾肥利用率显著高于DNPK处理，在2016—2018年间分别比NPK和DNPK处理显著增加了56.0%和119.2%。与NPK处理相比，1996—2005、2006—2015和2016—2018年间NPKM处理的年钾肥收获指数分别提高了61.6%、53.5%和35.8%，年钾肥农学效率分别增加了23.3%、227.8%和445.5%。除了1986—1995年间OM处理土壤钾素为亏缺外，其他施钾处理的土壤钾素均为盈余，NPKM处理的钾盈余量比NPK处理增加了53.2%～211.6%。钾素盈余量与耕层土壤速效钾含量显著相关 (P < 0.001)，钾素盈余量每增加1 kg/hm²，2016—2018年间耕层土壤速效钾含量增加2.60 mg/kg，明显高于1996—2005和2006—2015年的1.40和1.18 mg/kg。
结论除前10年的单施有机肥处理外，其他施用钾肥处理在试验期间土壤钾素均处于盈余状态，钾肥施用量和钾肥来源对玉米钾素的吸收量没有显著影响。试验20年之后，有机无机肥配施对玉米产量、吸钾量和钾肥利用率的提升优势逐渐凸显。同时，长期施用钾肥导致的钾素盈余量增加会进一步提升耕层土壤速效钾含量，且随着试验年限的延长，钾素盈余量对耕层土壤速效钾的提升作用逐渐增加。

Abstract:
Objectives Potassium (K) nutrition is fundamental to maize ( Zea mays L.) productivity. The effect of long-term, large-scale exogenous K input on the K absorption and utilization of maize and the soil K balance were studied to determine the corresponding optimum yield of maize and efficiency of K fertilizer.
Methods The long-term fertilization experiment was established in 1986 on a red soil of Jinxian County of Jiangxi Province, the planting system is annually double maize cropping. Test treatments included no fertilizer control (CK), chemical N and P fertilizer (NP), chemical NPK fertilizer (NPK), double amount of chemical NPK fertilizer (DNPK), chemical NPK fertilizer with manure (NPKM) and manure alone (OM). The maize grain yield and biomass, and the K contents in plants and soil were measured at each harvest; K uptake and K use efficiency (KUE) were as well calculated.
Results The annual average grain yield and K uptake of maize in NPK, DNPK, NPKM and OM treatments were higher than NP treatment during the 33 years. There was no significant difference in grain yield and K uptake of maize among NPKM, DNPK, OM and NPK treatments during 1986‒1995. However, during 2006‒2015 and 2016‒2018, the grain yield and K uptake of maize in NPKM were increased by 129.9%‒246.7% and 55.2%‒62.1% than NPK treatment, respectively. During the 33 years of observation, OM treatment gave the highest KUE while DNPK had the least. During 2016‒2018, the KUE of NPKM treatment was 56.0% and 119.2% higher than NPK and DNPK treatments, respectively. Compared with NPK in 1996‒2005, 2006‒2015 and 2016‒2018, the K harvest index of NPKM treatment was increased by 61.6%, 53.5% and 35.8% and the K agronomic efficiency increased by 23.3%, 227.8% and 445.5% respectively. The soil K was in excess throughout the 33 years in all K fertilization treatments, except for OM and NPKM treatments during 1986‒1995, which had 53.2%‒211.6% higher residual K than NPK treatment. Every 1 kg/hm²increase of residual K resulted to a respective increase in available K content by 1.40, 1.18 and 2.60 mg/kg in 1996‒2005, 2006‒2015 and 2016‒2018.
Conclusions Under the tested K fertilization program for double maize cropping system of south China, the K budget was surplus, except for the single manure application during the first 10 years of the study. However, the amount of potassium fertilizer and the source of potassium fertilizer had no significant effect on the uptake of potassium in maize. Combining application of chemical N‒P‒K of 100‒26‒100 kg/hm² and 15000 kg/hm² of fresh pig manure in long-term are effective in keeping maize yield optimum, enhancing K uptake and K-use efficiency. K surplus increase available K content in acid soil, and with the extension of experiment years, the increasing effect of K surplus on soil available potassium increased gradually.

HTML全文

参考文献(33)

施引文献

资源附件(0)