气相色谱法测定土壤及水中三氯苯残留量

三氯苯是化学工业和合成农药的重要原料。在国外,三氯苯被列为必须监测的土壤污染物之一。国内已有关于测定水体中氯苯系列化合物方法的报道,但尚缺少测定土壤中三氯苯的方法。

核设施退役土壤中氚允许残留量限值推定的一种方法

本文应用美国能源部的软件程序ＲＥＳＲＡＤ ５．０，对我国某氚实验设施场址给出了土壤中残留氚容许限值与年有效剂量目标值的关系。介绍了所用方法。

稻草畏土壤残留的生物测定初报

移栽稻田一次性除草剂稻草畏系由稻无草、乙草胺及一些添加剂混配而成,具有高效、广谱、低毒、经济、对水稻安全、适用地域广等特点,可有效地防除移栽稻田一年生和多年生单、双子叶杂草,一次用药即可控制移栽稻田全季草害。稻草畏推出后,深受广大植保、农资部门和农民的欢迎。

含铬皮革废水污灌和施用含铬污泥时铬在土壤环境中的残留

采样分析了污灌区铬的土壤环境背景值，计算了铬的土壤环境容量以及用含铬皮革废水污灌和施用含铬污泥后铬在土壤中的积累和残留量。

Effects of N, P and K on Output and Nutrient Cycle of Vegetables in Greenhouses

ObjectiveThe aim was to increase farmers’ income and reduce the waste of fertilizer by exploring effects of N, P and K fertilizations on vegetable yields and the accumulation of N, P and K in vegetable and soils. MethodThe fertilization tests were conducted on tomato, cauliflower and celery in greenhouses. ResultWhen N, P and K were not applied in tomato, cauliflower or celery, the yields reduced in 6.0%-13.8% and total annual income reduced by 39 220, 36 902 and 22 023 yuan/hm 2 respectively, suggesting that N, P and K are limiting factors of yield. The absorbed N amounts of tomato and cauliflower were higher compared with celery; the absorbed P amount of cauliflower was higher compared with tomato and celery; the absorbed K amount of tomato was the highest, followed by celery and cauliflower. The absorbed N in tomato fruit was lower than that of cauliflower and the absorbed N amount of other parts of tomato was also lower. Furthermore, the absorbed amounts of P and K by tomato and cauliflower fruits were higher than it absorbed by the other parts, especially the absorbed of K was significantly high. Total absorbed amounts of N, P and K from high to low were cauliflower, tomato and celery. After harvesting of tomato, cauliflower and celery, N, P and K in soils were all higher compared with soils before planting. Influenced by fertilizers, residual N content in soils grown with tomato and residual P content in soils grown with celery both doubled compared with base soils. Cauliflower plants were not applied with organic fertilizer, and residual N and K contents in soils were lower compared with tomato and celery. ConclusionResidual P content in soils is higher, which is a kind of waste and would cause pollution on soils. It is necessary to improve the proportion of organic and inorganic fertilizers in fertilization.

Neural Network Ensemble Residual Kriging Application for Spatial Variability of Soil Properties

High quality, agricultural nutrient distribution maps are necessary for precision management, but depend on initial soil sample analyses and interpolation techniques. To examine the methodologies for and explore the capability of interpolating soil properties based on neural network ensemble residual kriging, a silage field at Hayes, Northern Ireland, UK, was selected for this study with all samples being split into independent training and validation data sets. The training data set, comprised of five soil properties: soil pH, soil available P, soil available K, soil available Mg and soil available S,was modeled for spatial variability using 1) neural network ensemble residual kriging, 2) neural network ensemble and 3) kriging with their accuracies being estimated by means of the validation data sets. Ordinary kriging of the residuals provided accurate local estimates, while final estimates were produced as a sum of the artificial neural network (ANN)ensemble estimates and the ordinary kriging estimates of the residuals. Compared to kriging and neural network ensemble,the neural network ensemble residual kriging achieved better or similar accuracy for predicting and estimating contour maps. Thus, the results demonstrated that ANN ensemble residual kriging was an efficient alternative to the conventional geo-statistical models that were usually used for interpolation of a data set in the soil science area.

Effects of Different Organic Residues on Rice Yield and Soil Quality

Calcaric regosols are a valuable land resource, distributed widely across western China. Soil quality has deteriorated considerably in recent years owing to the blind pursuit of economic benefits. A 2-year field experiment was carried out to evaluate the effects of using spent mushroom compost, leguminous plant (Vicia sepium L.) compost, and a combination of the two (at a 1:1 and 2:1 ratio), on rice yield and soil quality in a suburb of China. Vicia sepium L. composted with spent mushroom compost at a 1:1 ratio produced the highest grain and stover yield, grain and stover phosphorus concentration, and phosphorus uptake of rice; they were 56.5%, 93.2%, 89.3%, 198.6% and 22.2% greater than control soil, respectively. The 2:1 ratio (Vicia sepium L.: spent mushroom compost) produced the highest grain N concentration, stover N concentration, and N uptake; they were 31.6%, 31.4%, and 40.7% higher than control, respectively. Soil physical, chemical, and environmental properties were improved with the application of Vicia sepium L. composted with spent mushroom compost at a 2:1 ratio. In particular, soil water-stable aggregates, organic carbon, particulate organic carbon, total nitrogen, available potassium, and cation exchange capacity increased, whereas bulk density, pH, and phytoavailable heavy metals decreased. This organic treatment is beneficial to improve soil quality indicators, and contribute to soil restoration.

Impact of Intensive Greenhouse Production System on Soil Quality

Composite top- and subsoil samples were collected from the greenhouses in the Al-Balawneh area,Jordan,where intensive greenhouse production system(IGPS) has been practiced since 1998,to study the impact of IGPS on soil quality as measured by the chemical and biological properties to develop a sustainable production system.The study showed that IGPS led to higher electrical conductivity in top- and subsoils compared to an uncultivated soil(control).Quality and amount of irrigation water,lack of efficient drainage,and quantity and types of applied fertilizers were major factors resulting in salt buildup.IGPS resulted in lower total N(TN) and NO_3-N in the soil compared to the control.The lower TN was due to crop uptake,microbial immobilization,volatilization,and irregular application of composted animal manure or poultry manure.In contrast,higher residual Olsen-P content was detected in both soil layers of greenhouses than in the control.Residual P was classified as very high in the topsoil layers and sufficient to high in the subsoil layers.Residual available K in the soils of greenhouses was relatively lower than that in the control and it was,however,classified as high to very high.A large increase of Cl and a considerable decrease in the bacterial count were observed in both soil layers of IGPS compared to the control treatment.Economically sustainable soil management practices need to be adopted by farmers to achieve a sustainable and profitable production.This can be accomplished through education,targeted towards the farming community in the central Jordan Valley.

Assessment, Composition and Possible Source of Organochlorine Pesticides in Surface Soils from rmqi, China

Twenty-eight surface soil samples from 5 functional zones （park, traffic roadside, business/residential area, rural area, and industrial area） of Uruimqi, China were collected and analyzed for the concentrations of 14 organochlorine pesticides （OCPs）, such as 3 isomers of hexachlorocyclohexane （HCHs） （α-HCH, β-HCH, and γ-HCH）, 4 dichlorodiphenyltrichloroethanes （DDTs） （p,p′-DDT and its metabolites p, p′-DDD （1,1-dichloro-2,2-bis（p-chlorophenyl）ethane） and p,p′-DDE （1,1-dichloro-2,2-bis（4-chorophenyl）ethylene）, and o, p′-DDT）, and methoxychlor, aiming to survey the residue levels and compositions of these 14 OCPs, to identify possible sources of the OCPs, and to assess their potential risks to human health and the environment in surface soils of Ur/imqi. The concentrations ranged from non-detected to 30.86μg kg^-1 for HCHs （sum of α-, β-, and γ-HCH）, from non-detected to 40.03 μg kg^-1 for DDTs （sum of p, p′-DDT, p, p′-DDD, p, p′-DDE, and o, p′-DDT）, and from non-detected to 11.95 μg kg^-1 for methoxychlor. The total concentrations of the OCPs ranged from 16.40 to 84.86 μg kg^-1, with a mean of 41.89 ± 16.25 μg kg^-1. According to the measured concentrations and occurrence rates of the 14 OCPs, DDTs, HCHs, and methoxychlor were the most dominant compounds. Among the 5 functional zones, the total concentration of OCPs was in the order of rural area 〉 traffic roadside 〉 park 〉 business/residential area 〉 industrial area. The different compositions of DDTs and HCHs indicated that the residues of these compounds in most soil samples originated from historical application, besides slight recent introduction at some sampling sites. The results of Pearson correlation analysis showed that soil total organic carbon played an important role in the residue levels of HCHs, but such relationships were not found with DDTs or other OCPs. The soil quality of Uriimqi was classified as Class I based on the guidelines of the Chinese Environmental Quality Standard for Soil （GB15618-1995）, indicating that the residue levels of OCPs have little risks to the environment and human health in the study area.