柑橘园养鸡对土壤肥力和果实品质的影响

Effects of raising chicken on soil fertility and fruit quality in Citrus orchard

【目的】探索柑橘园养鸡对培肥改土及果实产量和品质的影响,为发展柑橘园养殖及其科学管理提供参考。【方法】对柑橘园不同养鸡密度(每hm20、600、1 200和2 400只,分别以CK、T_(600)、T_(1200)和T_(2400)表示)处理5 a后柑橘园土壤肥力(0~40 cm土层)和果实品质指标进行测定,应用隶属函数法对各项指标进行转化并求算土壤肥力综合值(CVFS)和果实品质综合值(CVQS)。【结果】养鸡处理均能降低土壤容重和果实酸度,增加土壤自然含水量、最大持水量、毛管持水量、田间持水量、毛管孔隙、非毛管孔隙、总孔隙、有机碳、全氮、碱解氮、有效磷和速效钾含量、细菌、真菌、放线菌和总微生物数量、蔗糖酶、脲酶和磷酸酶活性、果实产量、单果质量、果实可溶性糖和维生素C含量及糖/酸比。各处理土壤肥力综合值和果实品质综合值均呈现出T_(2400)>T_(1200)>T_(600)>CK的变化规律,且土壤肥力综合值与果实品质综合值之间呈显著正相关。【结论】柑橘园养鸡对土壤肥力和果实品质的提高具有重要促进作用,养鸡密度以每hm^2 2 400只最好,土壤肥力的提高有利于果实品质的改善。

【Objective】Soil structure and fertility improvement are important for high yield and quality of fruits in orchard. Manures contain many nutrients necessary for plant growth and fruit development mand are commonly used for increasing soil fertility. Chicken manure is one of the widely used organic fertilizers. The objective of this study was to evaluate the effect of raising chicken in citrus orchard on soil amendment and enrichment efficiency, fruit yield and quality to select suitable chicken raising density and model through 5 years experiment.【Methods】The experiment included four treatments：（1） CK, raising 0 chicken per hm2;（2） T600, raising 600 chickens per hm2;（3） T1200, raising 1 200 chickens per hm2;（4）T2400, raising 2 400 chickens per hm2. Chickens were raised every year from January to April and September to December, while no chicken was raised from May to August to ensure herb plants growth and grass could cover the orchard ground and prevent soil and water losses. Composite soil samples（0-20 cm and20-40 cm soil layers） for each plot were prepared by mixing 5 soil cores using serpentine five-spot sampling method for soil nutrients content, enzyme activities, microbe counts and soil natural water content determination. Soil cores were collected at depth of 0-20 cm and 20-40 cm to evaluate soil bulk density,soil pore composition and water- holding capacity. Representative fruits were collected for single fruit weight and fruit quality determination. Membership function was used to transform the soil fertility index-es（including soil bulk density, natural water content, maximum water-holding capacity, capillary waterholding capacity and field water-holding capacity, capillary porosity and non-capillary porosity, bacteria,fungi and actynomycete counts, invertase, urease and phosphatase acitivities, soil organic carbon, total-N,hydrolysis- N, available- P and available- K contents） and fruit quality indexes（including single fruit weight, titratable acid, soluble sugar and vitamin C content in fruit, and ratio of soluble sugar to titratable acid）, and to calculate the comprehensive value of soil fertility（CVSF） and fruit quality（CVFQ）. Statistical analysis was completed using the SPSS19.0 software package for Windows. Statistically significant differences were identified using analysis of variance ANOVA and Duncan’s multiple range test. Relationships among single fruit weight, yield, CVSF and CVFQ were examined by calculating the Pearson correlation coefficient.【Results】Soil bulk density decreased by 2.0%-9.1%, natural water content increased by4.0%-16.6%, maximum water-holding capacity increased by 6.6%-23.0%, capillary water-holding capacity increased by 4.1%-14.8%, field water-holding capacity increased by 5.1%-18.5%, non-capillary porosity increased by 13.7%-39.8% capillary porosity increased by 2.0%-4.2%, total porosity increased by 4.5%- 11.9%; bacteria counts increased by 57.2%- 167.8%, fungi counts increased by 42.4%-200.6%, actynomycete counts increased by 71.3%-155.3%, total microbe counts increased by 57.5%-167.6%, invertase activity increased by 87.3%-214.6%, urease activity increased by 32.0%-102.7%,phosphatase activity increased by 165.9%- 421.5%; soil organic carbon content increased by 20.0%-62.8%, total-N content increased by 10.8%-31.0%, hydrolysis-N content increased by 46.7%-108.1%,available- P content increased by 1 480.6%- 2 914.3%, available- K content increased by 120.1%-292.4%; single fruit weight increased by 17.8%-37.4%, fruit yield increased by 10.6%-32.3%, soluble sugar content increased by 7.6%-69.4%, titratable acid content decreased by 6.5%-18.3%, ratio of soluble sugar to titratable acid increased by 15.2%-107.4%, vitamin C content increased by 12.1%-40.5%under raising chicken treatments（ including T600, T1200 and T2400） compared with the CK. The CVSF and CVFQ significantly increased by raising chicken treatments, and the values of both were ranked as T2400〉T1200〉T600〉CK. The CVSF was significantly related to single fruit weight（r = 0.941, P〈0.01）, fruit yield（r = 0.941, P〈0.01） and CVFQ（r = 0.978, P〈0.01）.【Conclusion】Raising chicken in citrus orchard is valuable for improving soil porosity, water-holding capacity, microbe number, nutrients content, enzymes activity, fruit yield and quality, and the effects of the improvement were increased as the increase of the density of chicken raised.