施氮对香梨园土壤养分、根系生物量及产量品质的影响

Effect of nitrogen fertilization on soil nutrients,root biomass,yield and quality in Korla Fragrant Pear orchard

[目的]研究库尔勒香梨树体根系生物量及产量、品质如何响应土壤养分的变化。[方法]以5-7年生库尔勒香梨为试验对象,研究0、150、300和450 N kg·hm^(-2)(分别表示为N0、N1、N2和N3)4个氮肥施用量处理下库尔勒香梨土壤养分与根系生物量及产量、品质的相关性。[结果]随着施氮量的增加,土壤养分、根系生物量、果实产量及果实中可溶性固形物、Vc含量和糖酸比均表现为先增加后降低的趋势,在N2处理达最大值。果实中石细胞含量则表现为先降低后增加的趋势,在N2处理达最小值。果实中总酸含量随着施氮量的增加而不断降低,在N3处理达最小值。果实产量与土壤中生物氮极显著正相关(P <0.01),与生物碳、碱解氮、无机碳、全碳显著正相关(P <0.05);果实中可溶性固形物、Vc含量、糖酸比与土壤中生物氮、生物碳和碱解氮均表现为极显著正相关(P <0.01);果实糖酸比与土壤全碳间存在显著正相关关系(P <0.05);果实中总酸与土壤全氮、硝态氮、铵态氮、碱解氮、全碳间显著负相关(P <0.05)。果实产量、糖酸比与根系生物量间极显著正相关(P <0.01);果实总酸与根系生物量表现为极显著负相关(P <0.01);可溶性固形物及Vc均与根系生物量表现出显著正相关(P <0.05)。在合理的施氮范围内随着库尔勒香梨园土壤养分的提高,香梨树体根系生物量及产量、品质均呈上升态势,产量和品质与树体根系生物量之间同样存在着动态依存关系。[结论]在5-7年树龄库尔勒香梨的经营管理过程中,可通过提高土壤养分,增加根系生物量来促进香梨增产提质。N2处理(300kg·hm^(-2))施肥量可作为最佳施氮量。

【Objective】The response of root biomass,yield and quality to soil nutrient changes in Korla Fragrant Pear orchard was studied.【Method】The 5-7 year old Korla Fragrant Pear was taken as the test object.And the correlation between soil nutrients and root biomass,yield and quality of Korla Fragrant Pear was studied under four nitrogen-2 fertilizer application rates of 0,150,300 and 450 N kg·hm(named as N0,N1,N2 and N3,respectively).【Result】With the increase of nitrogen application rate,soil nutrients,root biomass,fruit yield,soluble solids,VC content and sugar-acid ratio in fruit all increased firstly and then decreased,and reached its maximum value under N2 treatment.The content of stone cells in fruits decreased firstly and then increased,and reached its minimum value under N2 treatment.The total acid content in fruit decreased with the increase of nitrogen application rate,and reached its minimum value under N3 treatment.There was an extremely significant positive alkali-hydrolyzed nitrogen,inorganic carbon and total carbon(P<0.05).Soluble solids,VC content and sugar-acid ratio in fruits were correlated between fruit yield and soil biological nitrogen(P<0.01),and it was positively correlated with biological carbon,significantly positively correlated with biological nitrogen,biological carbon and alkali-hydrolyzable nitrogen in soil(P<0.01).There was a significant positive correlation between fruit sugar-acid ratio and soil total carbon(P<0.05).There were significant negative correlations between total acid and soil total nitrogen,nitrate nitrogen,ammonium nitrogen,available nitrogen and total carbon(P<0.05).Fruit yield and sugar-acid ratio were significantly positively correlated with root biomass(P<0.01).Fruit total acid was significantly negatively correlated with root biomass(P<0.01);Soluble solids and VC showed a significant positive correlation with root biomass(P<0.05).with the increase of soil nutrients,the root biomass,yield and quality of fruits showed an increasing trend in a reasonable range of nitrogen application,and there were also dynamic dependency relationships between yield and quality and root biomass.【Conclusion】In the management process of 5-7 years old Korla Fragrant Pear,the yield and quality of fruits can be promoted by improving soil nutrients and increasing root biomass.The N2 treatment(300 kg·hm-2)was recommended as the best nitrogen application rate.