【作者】 赵政阳；

【导师】 李嘉瑞；

【作者基本信息】 西北农林科技大学 ， 果树学， 2007， 博士

【摘要】 食品及农产品的质量安全是目前国内外关注的热点问题之一,对农产品质量安全影响因素及其控制技术的研究也已引起广泛重视。苹果是世界上最重要的水果种类之一,虽然我国是世界第一苹果生产大国,又是主要的出口国,但在果品质量安全控制方面的研究还十分薄弱。陕西是中国第一苹果生产大省,也是世界著名的优质苹果产区,本文试图通过对陕西苹果质量安全影响因素及其控制技术的研究,为苹果安全生产提供技术依据。2003-2005年,本研究对陕西苹果产区15个以上基地县的果品质量安全和产地环境质量主要技术指标进行了多点位监测分析,对部分重点县的农资(农药、化肥等)市场与农户使用现状进行了跟踪调查,重点研究了果园生产过程中农药、叶面肥、套袋等生产环节以及汽车尾气等对果品质量安全的影响;同时,研究了果园生草对土壤养分和水分的调控效应,对以沼气为纽带的生态果园生产模式的运行效果进行了调查分析。主要结果如下:1.陕西苹果果实中硝酸盐(NaNO3)和亚硝酸盐(NaNO2)含量水平远低于国家规定限量标准,但果实中农药残留检出率和重金属元素含量均较高,是影响苹果质量安全的主要因素,其中有机磷类农药中的乐果、杀菌剂中的多菌灵是目前农药残留控制的重点,铅、氟、砷、镉等是重金属元素残留污染控制的重点。2.陕西苹果产地环境质量主要指标符合国家无公害食品和绿色食品生产的标准要求,其中大气中的SO2和NOx,土壤中的汞、镉、铜、铅元素以及灌溉水中的铅、铬、氟、汞元素含量水平远低于绿色食品苹果的产地环境质量限量标准。按照绿色食品产地环境质量标准,虽然大气中的可悬浮物(TSP)、氟化物以及土壤中的砷、铬元素均未超标,但污染指数较高,是产地环境质量的关键控制因子。3.不同农药种类与使用方法对果实中的农药残留量有重要影响。有机磷(毒死蜱、对硫磷)和拟除虫菊酯类(甲氰菊酯、三氟氯氰菊酯)农药在田间果实上的残留降解规律不同;农药施用浓度加大、施用次数增加,会明显提高果实的残留水平。采收前不同间隔期施用杀菌剂,果实中的农药残留量差异较大,采收前30天用药,未检出残留,采收前20天和10天用药均有残留检出,残留量和检出期限随施药浓度加大而增加和延长。4.果园使用福美胂农药,果树树体各部位和果园土壤中的砷元素含量水平均呈增高趋势,其中果树主干皮部、主枝皮部和主根中砷元素积累较多,果实全果、果肉和果心中的砷含量均明显高于对照,表明砷制剂农药参与树体代谢,对苹果树的污染表现持效期长、范围广的特点。5.果实套袋降低了果实中的铅元素含量,果树喷施叶面肥、公路旁的汽车尾气是造成苹果树重金属污染的重要途径。叶面肥中普遍含有铅、铬等重金属元素,叶面喷肥不同程度地提高了苹果果实和叶片中的铬、铅含量水平,果实污染主要表现为表皮残留,叶片表现为表面吸附和组织吸收的双重污染。国道公路旁200m范围内,果实、叶片和果园土壤不同程度受到了汽车尾气铅尘污染,其中距公路100m范围内是严重污染区,此范围内果实铅含量水平超过了国家无公害水果质量标准。6.苹果果实的果皮是农药和重金属元素残留的主要部位,果肉和果心部位残留较少。7.陕西渭北旱地苹果园生草,对0-40cm土层的土壤养分和水分变化有重要影响。生草果园土壤有机质含量每年可增加0.1%-0.15%,土壤全N、全P、全K含量呈现“S”型年季变化,水解N、速效P和速效K含量水平提高,牧草与果树存在水分竞争,降低了果园土壤总贮水量。以果园生草为基础、以沼气池为纽带的草、畜、沼、窖、果“五配套”生态果园,增加了有机肥源,降低了化肥、农药的使用量,生产效益提高。8.无公害果品是目前陕西苹果安全生产的最低要求,发展绿色食品是今后主要努力的方向和目标;优化区域布局、农资市场监管、农药安全使用、肥料合理使用等是质量安全控制的关键环节;建立以生物防治和物理防治为主的病虫害综合防治技术体系、建立以有机肥为主的施肥制度和以果园生草为基础的土壤管理制度以及果实套袋栽培是陕西苹果安全生产的关键技术措施;建议发展以果园生草覆盖为主的土壤管理制度,以沼气池为纽带的生态果园是保证果品安全的主要生产模式。更多还原

【Abstract】 Food and agricultural product safety is one of the key problems paid more attention by foreign and domestic people nowadays. Studies on the factors affecting agricultural product safety and their control techniques have also caught wide attention. Apple is one of the most important fruits in the world. Few researches on fruit safety are conducted even though China ranks first in the world for apple production and exportation. Shaanxi, as one of the good quality apple production regions in the world, ranks first in China for its apple production. The objective in this research was to supply with technical basis for apple safety production through studies on the factors affecting apple safety and their control techniques. From 2003 to 2005, the main technical indexes of fruit safety and environmental quality in the apple production bases distributed in more than 15 counties in Shaanxi were monitored and analyzed. The agricultural material (pesticide, fertilizer, etc.) market and reality utilization by family hold were traced and investigated in some of the key counties. The effects of the production links including pesticide and foliage fertilizer application, bagging, etc. and the tail gas of the car, etc. on fruit safety were studied crucially. At the mean time, the regulating and controlling effect of orchard grass on soil nutrition and water were researched and the circulating effect of the ecological orchard production mode linked by marsh gas was also investigated in this paper. The main results were as follows:1. Even though the contents of nitrate and nitrite in apple fruit were far less than the limited standard provided by the national government in Shaanxi, the rate of pesticide residual found in the test and the content of heavy mental in fruit were relatively high, which were main factors affecting apple safety in which dimethoate, a kind of organic phosphorus pesticides, and carbendazim, a kind of fungicides, were key objects for controlling pesticide residual nowadays. Lead, fluorin, arsenic and cadmium, etc. were key objects for controlling pollution caused by the elements of heavy metals.2. The main indexes of environmental quality in Shaanxi apple production base tally with the standard required by the state no harmful food and green food production, in which the content level of SO2 and NOx in air, the contents of mercury, cadmium, copper and lead in soil and the contents of lead, chromium, fluorin, mercury in irrigation water were far less than the limited standard of environmental quality for green food - apple production in Shaanxi apple production base. According to the standard of environmental quality for green food production in the production base, even though the contents of suspending polluters (TSP) and fluoride in atmosphere as well as arsenic and chromium in soil did not exceed the standard, the pollution indexes were relatively high, which were key factors for controlling environmental quality in the production base.3. Different kinds of pesticides and application methods produced great effect on the content of pesticide residual in fruit. The decomposing rules of the organic phosphorus (chlorpyrifos and parathion) and pyrethroid (fenpropathrin and cyhalothrin) pesticide residuals were different. The residual level in fruit increased significantly as the pesticide application concentration and the spray time increased. The contents of fungicide residuals in fruit varied greatly when the fungicide was sprayed in different intervals between spray time and fruit harvest time before fruit harvest. There was no residual found in the test when the interval was 30 days, but the residuals were found in the test respectively when the intervals were 20 and 10 days respectively. The amount of pesticide residual increased and the interval of the days between spray time and fruit harvest time when pesticide residual was found in the test prolonged as the pesticide application concentration increased.4. The arsenic contents in soil and all organs of the fruit tree showed an increased trend after asomate was sprayed in the orchard. In which arsenic contents in trunk barks, bough barks, and taproots accumulated more compared with the other organs. The arsenic contents in whole fruit, fruit flesh and fruit core were higher than control, which showed that the arsenical pesticide took part in the metabolism in tree, arsenic pollution manifested permanently and extensively in apple orchards.5. Fruit bagging reduced the lead contents of fruits. Spraying fertilizer on the fruit tree leaves and the bus tail gas beside the roads were main approaches to contaminate apple trees by heavy metal. The leaf fertilizers generally had heavy metal elements, such as chromium and lead, etc. which increased the level of chromium and lead contents in apple fruit and leaves to different extent. The phenomenon of fruit contamination showed that the residual was in the pericarp. The phenomenon of leaf contamination showed that the heavy metals were absorbed on the surface and in the tissue, i.e. double pollution. Fruits, leaves and orchard soil were contaminated by bus tail gas which contained lead particles to different extent within 200 meter scope beside the national roads. Especially, the most contaminated area was within 100 meter away from national roads. In this range, the contents of lead in apple fruit were beyond the national standard of non-harmful fruit quality.6. The pericarp of apple fruit was the main residual part of pesticide and heavy metal. The flesh and core parts had less residual.7. To grow forage grass in the apple orchard in dry land of Weibei, Shaanxi had important effect on soil nutrient and water change in 0-40cm soil layer. The organic matter contents in soil of apple orchard growing grass could increase 0.1 percent to 0.15 percent every year. The contents of whole nitrogen, whole phosphorous and whole potassium in soil showed the changes of“S”curve in the seasons of a year. The contents of hydrolyzed nitrogen, quick-acting phosphorous and potassium increased. The total water storage capacity in the orchard was reduced due to the water competition between the forage grass and fruit trees. The ecological orchards based on growing forage grass and linked by marsh gas pool, formed“five sets together”including forage grass, livestock, marsh gas, cellar and fruit, which increased organic fertilizer source and reduced the amount of chemical fertilizer and pesticide. The efficiency of production was improved.8. To develop green food is the main effort direction and objective in future. Area layouts are optimized on the basis of investigation and study. Monitoring Agricultural material market, utilizing pesticide safely and using fertilizer properly are the key links for controlling quality safety. The integrative pest and disease prevention and control technical system characterized mainly by biological and physical control should be built and completed step by step. The fertilizer application system mainly using organic fertilizer and soil manage system based on growing forage grass are established. The fruit culture through fruit bagging is the key measure for apple safety production in Shannxi. Developing ecological orchards based on growing forage grass in orchard and linked by the marsh gas pool is a leading production mode to ensure fruit quality safety.更多还原