摘要
【目的】明确乌龙茶产区镁肥投入对茶叶产量、品质、养分吸收及土壤镁素平衡的影响,旨在为茶园科学施用镁肥及提高茶树镁营养提供科学依据。【方法】在福建省乌龙茶代表产区安溪县和武夷山市茶园设置不同镁肥用量试验,两个试验地均以不施镁肥为对照(Mg0),安溪县镁肥(MgO,下同)用量处理为17.5、35.0、52.5和70.0 kg/ha,武夷山市镁肥用量处理为17.5、35.0、70.0和140.0 kg/ha,镁肥用量由低到高均依次记作Mg1、Mg2、Mg3和Mg4,收获期测定茶叶产量、养分吸收量、茶叶品质及土壤交换性镁浓度,并分析镁肥肥效反应。【结果】施用镁肥可提高茶叶产量及茶芽密度,安溪县春季和秋季茶芽密度增幅分别为2.2%~10.6%和8.5%~19.4%,武夷山市春季和秋季茶芽密度增幅分别为3.6%~15.3%和17.3%~22.9%。施镁对茶多酚含量影响不显著(P>0.05,下同),各镁肥处理的春茶游离氨基酸总量也与对照差异不显著,但安溪县秋茶Mg4处理、武夷山市秋茶Mg2处理的游离氨基酸总量较对照显著提高(P<0.05,下同)。施镁可提高氮、磷、钾肥料偏生产力及茶叶纯收益,安溪县春茶和秋茶纯收益分别增加2846~5127和2636~6282元/ha;武夷山市春茶和秋茶纯收益分别增加5676~37659和9171~14347元/ha。施镁后新梢氮、磷、钾浓度及秋茶镁浓度无显著变化,但春茶新梢镁浓度增加,安溪县Mg4处理较对照显著提高7.8%,武夷山市Mg2处理较对照显著提升7.4%;各镁肥处理的新梢氮、磷、钾和镁带走量较对照有不同程度提高。两个试验地0~20 cm及武夷山市20~40 cm土壤交换性镁浓度均随施镁量增加而增加,且土壤交换性镁浓度和镁素盈余量均呈极显著正相关关系(P<0.01);而安溪县20~40 cm土壤交换性镁浓度变化不显著,土壤交换性镁浓度与镁素盈余量相关性不显著。【结论】施用镁肥在改善土壤交换性镁浓度的同时,提高了茶叶产量及茶芽密度,其中以武夷山茶区的增产潜力高于安溪茶区。施肥还可提高新梢氮、磷、钾和镁带走量,以及氮、磷、钾肥料偏生产力和茶叶纯收益,但对茶叶品质(茶多酚、游离氨基酸)的改善作用相对有限。
【Objective】To clarify the effects of magnesium fertilizer input on tea leaf yield,quality,nutrient utilization efficiency,and magnesium balance in oolong tea intensive production system,thereby providing a theoretical reference for the scientific application of magnesium fertilizer in tea gardens,and improving the magnesium nutrition of tea trees.【Method】Magnesium gradient experiments were conducted in Anxi County and Wuyishan City tea gardens in Fujian.Five magnesium levels were set in the present study,including no magnesium application as control(Mg0),17.5,35.0,52.5,70.0 kg/ha in Anxi,and no magnesium application as control(Mg0),17.5,35.0,70.0,140.0 kg/ha in Wuyishan,respectively.The amounts of magnesium fertilizer used were Mg1,Mg2,Mg3,and Mg4 in order from low to high.The yield,nutrient absorption,tea quality,and soil exchangeable magnesium concentration were measured during the harvest period,and the fertilizer efficiency after the application of magnesium fertilizer was analyzed.【Result】Magnesium fertilizer application increased tea yield and tea bud density,which increased by 2.2%-10.6%and 8.5%-19.4%in spring and autumn tea bud densities in Anxi County test,and 3.6%-15.3%and 17.3%-22.9%in spring and autumn tea bud densities in Wuyishan City test,respectively.Magnesium fertilizer application had no significant effect on tea polyphenol content(P>0.05,the same below),and total free amino acid content of spring tea under magnesium treatments had no significant difference with control.But the total free amino acid contents in Mg4 treatment in Anxi County,and Mg2 treatment in Wuyishan City in autumn tea both were significantly higher than control(P<0.05,the same below).The partial productivity of nitrogen,phosphorus and potassium fertilizers with magnesium treatments showed an increasing trend.Magnesium fertilizer application also increased the income of tea.The income of Anxi County spring tea and autumn tea increased by 2846-5127 yuan/ha and 2636-6282 yuan/ha respectively,and Wuyishan City spring tea and autumn teaincreased by 5676-37659 yuan/ha and 9171-14347 yuan/ha respectively.The concentrations of nitrogen,phosphorus and potassium in young shoots and magnesium concentrations in autumn tea had no significant variation,but the concentrations of magnesium in spring tea shoots increased with magnesium treatment.Among which,Mg4 treatment in Anxi County increased by 7.8%and Mg2 treatment increased by 7.4%in Wuyishan City compared with control.Magnesium treatments improved the take-away amount of nitrogen,phosphorus and potassium compared with control at various extents.The exchangeable magnesium concentration in the surface soil(0-20 cm)increased with the increase of magnesium application for both places.Moreover,the exchangeable magnesium concentration in sub surface layer(20-40 cm)of Wuyishan City test site also showed a increased trend.In addition,there was extremely significant positive correlation between exchangeable magnesium concentration and magnesium surplus(P<0.01),but the exchangeable magnesium concentration in the sub surface layer(20-40 cm)of Anxi County test site did not change significantly,and there was also no significant correlation between exchangeable magnesium concentration and magnesium surplus.【Conclusion】Magnesium fertilizer application increases exchangeable magnesium concentration of soil,and increases the tea yield and tea bud density,which is more prominent for Wuyishan City tea garden.Magnesium input also increases the amount of nitrogen,phosphorus and potassium and magnesium contents carried away by shoots,increases partial productivity of nitrogen,phosphorus and potassium fertilizers and net income of tea.However,the effects on tea quality(tea polyphenols and free amino acids)is relatively limited.
作者
黄梓璨
尹家旭
黄永鑫
苏达
吴良泉
HUANG Zi-can;YIN Jia-xu;HUANG Yong-xin;SU Da;WU Liang-quan(College of Resources and Environmental Sciences/Fujian Agriculture and Forestry University,Fuzhou 350002,China;International Magnesium Institute,Fujian Agriculture and Forestry University,Fuzhou 350002,China;College of Agriculture,Fujian Agriculture and Forestry University,Fuzhou 350002,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2020年第9期2120-2129,共10页
Journal of Southern Agriculture
基金
国家自然科学基金青年项目(31501832)。
关键词
乌龙茶
交换性镁
养分吸收
镁肥
oolong tea
exchangeable magnesium
nutrient absorption
magnesium fertilizer
