Combined effect of fertilizer and herbicide applications on the abundance, community structure and performance of the soil methanotrophic community

The use of agrochemicals, such as mineral fertilizers and herbicides in agricultural systems, may affect the potential of soils to act as a sink for methane. Typically, the effect of each agrochemical on soil methane oxidation is investigated separately whereas in the field these agrochemicals are used together to form one comprehensive land management system. Here we report the results of field experiments that assessed the combined effect of multiple fertilizer and herbicide (nicosulfuron, dimethenamide and atrazine) applications on the soil methanotrophic community. Soils treated with organic fertilizer had three times higher methane oxidation rates compared to soils receiving mineral fertilizers. These higher oxidation rates were positively reflected in a significantly enhanced abundance of methanotrophs for the organic fertilized soils. In contrast, herbicide application did not alter significantly the soil methane oxidation rate or the methane-oxidizing population abundance. Subsequently, the methanotrophic community structure was analyzed with group-specific DGGE of 16S rRNA genes. Cluster analysis of the methanotrophic patterns clearly separated the mineral from organically fertilized soils. Less pronounced clustering differentiated between chemical and manual weed control. Furthermore, cluster analysis of the methanotrophic community revealed that soil type was the primary determinant of the community structure. Our results indicate that fertilizer type had the greatest influence on methane oxidizer activity and abundance. Soil type had the most pronounced effect on the microbial community structure.     

几种粉煤灰的特性及其硅、磷的农业化学行为研究

 对采自湖南省的几种粉煤灰特性及其硅、磷农业化学行为的研究结果表明，粉煤灰颗粒组成以砂粒（1～0.05 mm）和粗粉粒（0.05～0.01 mm）为主，平均分别占34.37 % 和38.56 %。容重较小，仅为土壤的1/2~1/3，除采自长沙电厂的粉煤灰外，pH一般大于10.0，可以用作粘质酸性土壤改良剂。粉煤灰水溶性硅和有效硅含量与土壤相差不明显，不能把粉煤灰直接作硅肥使用。粉煤灰的全钾含量和土壤大致相同，但其游离态铁比土壤低3 ~ 4倍。粉煤灰中硅的释放量随时间变化的关系可以用Elovich方程和Freundlich方程进行较好的描述，其相应的参数b和k反映了硅的释放能力，b、k值越大，硅释放能力越强。不同来源粉煤灰的b、k值不同，其大小顺序为：湘潭电厂(1539.3，2139.3)、岳阳纸厂(1602.4，1274.0)＞华能电厂(1325.7，1181.6)＞长沙电厂(1250.6，915.9)＞洞庭氮肥厂(751.9，565.6)＞株洲电厂(555.5，454.4)；粉煤灰中硅在100 h内释放量比土壤高3.0~25.0倍，能为作物提供一定数量的硅营养，故可把粉煤灰作为一种硅肥添加剂，其中以湘潭电厂和岳阳纸厂的粉煤灰为好。粉煤灰的全磷含量和有效磷含量一般比土壤高，它对磷的吸附量随着加入溶液磷的浓度的增加而增加，但其吸附率随着加入溶液磷的浓度的增加而减少；粉煤灰的吸磷率比土壤高，但其解吸率低。Langmuir方程、Freundlich方程和Temkin方程都能很好地拟合粉煤灰对磷的吸附，其相应的参数Xm、a和k2都可以表征粉煤灰对磷的吸附能力。粉煤灰对磷的吸附主要是专性吸附和化学沉淀反应，所以在施用粉煤灰改良土壤或利用粉煤灰作添加剂制造复混肥时，必须考虑粉煤灰对磷的固定作用。     

Prof. Dr. Dr. h.c. Heinz Peschke zum 65. Geburtstag

The materials of article had been reported at the International Symposium "Nutritional and environmental Research in the 21st Century - The value of long-term field experiments", 5-7 June 2002, Bad Lauchstädt and Halle upon Saale. Agrochemical monitoring of the basic landscape components was launched in order to assess human impacts of land-use on the site of Barybino Experimental Station (Moscow Region, clay loam soddy-podzolic soils. 55°30'N, 37° 36' E). The climate is moderate continental, mean annual temperature of 3.8 °C and mean precipitation of 567 mm (1965-1998) at an elevation of 185 m above sea level. A typical soil cover pattern is represented as a complex of soddy-podzolic soils (podzo-luvisols) with excessive surface moistening features manifested differently according to the influence of the micro relief. The study was carried out from 1991 to 2001 in a crop rotation of silo maize, barley, perennial grasses (clover with timothy) and winter wheat, under different systems of fertilization (application of organic as well as mineral fertilizers, plant remedies and their combinations). Agrochemical monitoring let to establish the anthropogenic impacts on the system "soil-nutrients-plant"-environment. Alterations of the landscape components affected by human activities and climate change were estimated. At the site it could be shown that the amount of precipitation, soil properties and type of cultivated crop had mainly influenced migration of the nutrient elements.     

Bewirtschaftungsmassnahmen nach überhöhten Güllegaben zur Verminderung des Nitratverlust-potentials und deren Ertragseffekte bei unterschiedlichen Bodenformen: Management measures after excessive slurry rates for reduction of nitrate leaching risk and their yield effects at different typological soil units

The effects of different organic nutrient amounts and cover crops on yield, simplified N balance, soil parameters and groundwater protection were estimated on the basis of 3-year studies (2000?–?2002) carried out on two sites, which were overdressed by pig slurry application rates previously. The typological soil units were a Calcic Gleysol with a high humus and total N content and a Dystric Cambisol on cumulic material. According to the anaerobic incubation method a very high and a high potential for N-mineralization was indicated at these sites. Without any application of manure only at the Cambisol with wheat small yield losses of 5 dt.ha^???1 occurred during the 3 years period of experiments. When maize and sugar-beet were cultivated the yield potential could be achieved mostly. That and a well established cover crop too, resulted in a distinct reduction of the potential for nitrogen losses to the aquifer of about 100 to 150?kg.ha^???1. At eutrophic sites a balanced nitrogen in- and output is neither an ecological management procedure nor an economic use of nutrient resources. For relevant reduction of nitrate losses adequate soil testing methods are proposed on field scale level. Therefore the best is the laborious N_min-method, but also parameters, which characterize the nitrogen mineralization potential, give valuable information for the estimation of N demand.     

A New Technique to Rapidly Test Agrochemical Residues in Fruits and Vegetables

Extraction of AchE, relationship between substrate and enzyme concentration, and inhibition effects of the agrochemicals to AchE are discussed in this paper. Through the re-search, the proper AchE concentration for hydrolysis of 1 ml 1mmol/L substrate and I50 val-ues of the agrochemicals to AchE are decided. It is proved that Asch-DTNB method is a rapid test tool for agrochemical residues in fruits and vegetables.A rapid test card has been developed with sensitivity of 0.05mg/L.     

RFID tags for identifying and verifying agrochemicals in food traceability systems

The objective of this paper is to identify what data should be stored in an automatic recording system to trace the use of agrochemicals. RFID tags are proposed as the most appropriate storage systems. The essential information to store on an RFID tag is as follows: country of registration, chemical type, unique registration number of an agrochemical, container size, specific gravity, unit of measure, and a digital signature. Digital signatures address issues of verification of data integrity and security—a major concern of the agrochemical industry. Detailed data will be drawn from publicly available databases of approved pesticides. Encoding schemes have been designed which can record all of the essential information on commonly available cheap RFID labels. A prototype system to record and transfer data in a traceability system is developed, including hardware and software aspects. The user interface of the system is presented with a sample sequence of user screens to assist the loading of a full pack of agrochemical tagged with an RFID transponder. An experimental trial with practicing agrochemical professionals was undertaken. The user interface proved effective and acceptable. During the trial, more than 250 product identification cycles with RFID were carried out without failure.     

论农药对环境的危害

我国是世界农药生产和使用大国,且以使用杀虫剂为主,致使不少地区土壤、水体及粮食、蔬菜、水果中农药的残留量大大超过国家安全标准,对环境、生物及人体健康构成了严重威胁。     

温室黄瓜病害对靶施药机器人设计

以温室黄瓜为对靶施药对象,结合温室环境和黄瓜种植模式设计了移动悬挂式精准对靶施药机器人系统。利用机器视觉获取黄瓜病情信息,实现基于颜色和纹理信息的病情判断和定量分析。研究光照、土壤温度、气温和湿度等环境要素的周期数据与黄瓜病害有效特征信息表达之间相互关系,预警温室黄瓜病害发生和变化趋势。病害信息和环境要素拟合信息为喷雾机运动控制提供决策依据,以病灶分布作为轨迹规划和对靶施药依据,实现PLC控制三自由度喷雾机械臂和独立喷嘴作业。室内试验表明机器人具有较好的稳定性和实用性。     

防空洞农业化利用的研究进展

防空洞作为我国城市建设中留下的城市内部空间,利用率较低,随着城市扩张和环境恶化问题的出现,其利用问题得到关注。防空洞具有一定微气候环境,光照不足,但其在冬季和夏季,温度和湿度相对较稳定,可以避免冬寒和夏伏的季节性影响进行农业生产,该文概述了近年来防空洞进行农业化利用方面的进展,可为我国防空洞的有效再利用提供参考。     

对重视和加速我国和我省无公害蔬菜生产的思考和建议

本文概述了无公害蔬菜的基本概念,以及在我国实施和推广无公害蔬菜的重要性和可行性。并指出要加强我国,特别是我省无公害蔬菜生产建设必须注意提高思想认识,建立并完善无公害生产标准化体系,搞好无公害蔬菜生产等问题。同时指出应针对我省具体情况,加大我省在无公害蔬菜生产方面的植保科研力度。