有机肥全量替代化肥对茶叶产量和品质、土壤养分及氮素利用的影响

Effects of Total Replacement of Chemical Fertilizer with Organic Fertilizer on Yield and Quality of Tea,Soil Nutrients and Nitrogen Utilization

为促进区域茶园科学合理施肥,以当地茶园推荐的化肥施用量为对照(CK),设置了6个梯度有机肥施用量作为处理,即:3000(FQ1),4500(FQ2),6000(FQ3),7500(FQ4),9000(FQ5),12000 kg/hm^(2)(FQ6),分析了有机肥施用量对茶叶产量和品质、土壤养分及氮素利用的影响。结果表明:不同处理对茶叶产量及产量性状存在极显著影响(P<0.01);与CK相比,养分投入量相当(或更少)条件下施用有机肥造成了茶园产量及产量性状不同程度地下降(降幅为4.32%~32.28%),进一步增加有机肥施用量才可获得较好的产量及产量性状。与CK相比,有机肥施用量≥4500 kg/hm^(2)时提高了茶叶水浸出物含量,其中FQ6处理茶叶水浸出物含量得到显著提高(P<0.05);施用有机肥对茶叶茶多酚和氨基酸含量的影响相对较小,仅2019年FQ5和FQ6处理显著提高了茶叶氨基酸含量及2020年FQ1处理显著降低了茶叶茶多酚含量(P<0.05);有机肥施用量对茶叶咖啡碱及酚氨比不存在显著影响(P>0.05),但一定程度提高了茶叶咖啡碱含量并降低了茶叶的酚氨比。与CK相比,不同有机肥施用量均可缓解茶园土壤酸化状况并显著提高茶园土壤碱解氮含量(P<0.05);除FQ1处理,施用有机肥处理显著提高了茶园土壤有机质和速效钾含量(P<0.05);FQ1显著降低了茶园土壤有效磷含量(P<0.05),而FQ5(2019年)和FQ6处理显著提高了土壤有效磷含量(P<0.05)。氮素盈余量和氮肥偏生产力随着氮肥施用量的增加分别表现出极显著增加和下降趋势(P<0.01),其中:CK与养分投入量相当条件下施用有机肥(FQ3处理)的氮素盈余量和氮肥偏生产力差异不显著(P>0.05);氮素盈余量、氮肥偏生产力与氮肥施用量的关系分别呈线性(y=0.786x-115.04,P<0.01)和幂函数关系(y=635.28x-0.605,P<0.01),即随着肥料氮投入的增加,氮素盈余量和氮肥偏生产力分别呈增加和下降趋势。基于2019,2020年的茶叶产量反应,应用线性加平台模型拟合每年有机肥最佳施用量为8739.55~9169.95 kg/hm^(2),但造成氮素盈余量过大和氮肥偏生产力较低,并增加了环境污染的风险。综上,茶园施用有机肥虽然降低了产量,但提高了茶叶品质,改善了茶园土壤养分状况;同时,从氮素利用角度考虑,茶园施用有机肥时不应过分追求茶叶产量,可适当降低有机肥施用量以控制氮的投入。

In order to promote the scientific and rational fertilization of regional tea garden,this study took the recommended fertilizer application rate of local tea garden as the control(CK),and six gradient organic fertilizer application rates were used as treatments:3000(FQ1),4500(FQ2),6000(FQ3),7500(FQ4),9000(FQ5),12000 kg/ha(FQ6),the effects organic fertilizer application rate on yield and quality of tea,soil nutrients and nitrogen utilization were analyzed.The results showed that:Different treatments had extremely significant effects on tea yield and yield traits(P<0.01);Compared with CK,the application of organic fertilizer under the condition of the same(or less)nutrient input reduced the yield and yield characters of tea garden in different degrees(the decrease range was 4.32%-32.28%).Further increasing the application amount of organic fertilizer could obtain better yield and yield characters.Compared with CK,the content of tea water extract was increased when the application rate of organic fertilizer was more than 4500 kg/ha,and the content of tea water extract was significantly increased in FQ6 treatment(P<0.05);The effects of organic fertilizer application on tea polyphenols and amino acids content were relatively small,only FQ5 and FQ6 treatment significantly increased tea amino acid content in 2019,and FQ1 treatment significantly reduced tea polyphenols content in 2020(P<0.05).There was no significant effect of organic fertilizer on caffeine and phenol ammonia ratio of tea(P>0.05),but it increased caffeine content and decreased phenol ammonia ratio of tea to a certain extent.Compared with CK,different application rates of organic fertilizer could alleviate soil acidification and significantly increase the content of alkali hydrolyzable nitrogen in tea garden soil(P<0.05);Except for FQ1 treatment,organic fertilizer application significantly increased the contents of soil organic matter and available potassium(P<0.05);FQ1 treatment significantly decreased the content of soil available phosphorus(P<0.05),while FQ5(2019)and FQ6 significantly increased the content of soil available phosphorus(P<0.05).Nitrogen surplus and nitrogen partial productivity increased and decreased extremely significantly with the increase of nitrogen application rate respectively(P<0.01).There was no significant difference in nitrogen surplus and nitrogen partial productivity between CK and organic fertilizer(FQ3)under the same nutrient input rate(P>0.05);The relationship between nitrogen surplus,nitrogen partial productivity and nitrogen application rate was linear(y=0.786x-115.04,P<0.01)and power function(y=635.28x-0.605,P<0.01),that is,with the increase of fertilizer nitrogen input,nitrogen surplus and nitrogen partial production increased and decreased respectively.Based on the response of tea yield in 2019 and 2020,the linear plus platform model was used to fit the optimal application rate of organic fertilizer every year,which was 8739.55-9169.95 kg/ha,but caused excessive nitrogen surplus and low nitrogen partial productivity,and increased the risk of environmental pollution.In conclusion,the application of organic fertilizer in tea garden reduced the yield,but improved the quality of tea and improved the soil nutrient status;In addition,from the perspective of nitrogen utilization,the yield should not be excessively pursued when applying organic fertilizer in tea garden,and the amount of organic fertilizer should be appropriately reduced to control nitrogen input.