Er3+和稀土多元复合肥对蚕豆根尖细胞的微核效应

稀土元素是镧系金属元素的总称,在地壳中含量稀少,约占１５×１０－６．我国对稀土元素的开发利用较早,特别是农业上稀土多元复合肥常与农药一起使用,这对生物和环境的影响为人们所关注,给环境研究带来了新课题．目前对稀土元素的研究主要集中在地球化学、农业化学和...     

粉煤灰综合利用于生产复合肥的探索

随环保事业的迅速发展,固体废物的综合利用越来越被人们重视。本文主要介绍利用粉煤灰生产硅钙镁复合肥的新工艺,从而既可减少固体废物污染,又可使废物综合利用。     

生物炭基缓释肥的制备及其对土壤理化性质的影响

通过淋溶试验分析生物炭热解温度、生物炭与尿素比例、粘结剂含量对生物炭基缓释肥缓释性能的影响,采用土壤培育试验研究生物炭基缓释肥对土壤理化性质的影响。结果表明,600 ℃下热解而成的生物炭缓释性能优于300 ℃下热解形成的生物炭;生物炭添加比例和粘结剂含量的增加能提升生物炭基缓释肥的缓释性能;生物炭基缓释肥的加入可降低培育土壤的容重,增大土壤的饱和导水率,提高土壤pH值和土壤有机质含量。     

ASSESSING GROUND WATER POLLUTION POTENTIAL FROM NITROGEN FERTILIZER USING A GEOGRAPHIC INFORMATION SYSTEM1

ABSTRACT: A geographic information system (GRASS 3.1) was used to correlate the availability of nitrogen fertilizer with the susceptibility of ground water to pollution in Texas to identify potential ground water quality problems. An agricultural pollution susceptibility map, produced by the Texas Water Commission using the DRASTIC methodology, was combined with information on cropped areas, recommended nitrogen fertilizer application rates, and aquifer outcrops. A Nitrogen Fertilizer Pollution Potential Index was generated, identifying 24 percent of Texas within the high pollution potential category An analysis of the susceptibility of major aquifer outcrops to potential pollution from nitrogen fertilizer indicated that 34 percent of the outcrop areas fall in the high pollution potential range. It is proposed that correlating the availability of a pollutant with an assessment of the susceptibility of ground water to pollution yields a more accurate screening tool for identifying potential pollution problems than considering susceptibility alone.     

Estimating the Unknown Components of Nutrient Mass Balances for Forestry Plantations in Mine Rehabilitation, Upper Hunter Valley, New South Wales, Australia

Commercial forestry plantations as a postmining land use in the Upper Hunter Valley of New South Wales, Australia are restricted by both the poor nutrient availability of mining substrates and low regional rainfall. An experiment was conducted to investigate whether municipal waste products and saline groundwater from coal mining operations could improve early tree growth without impacting on the environment through salt accumulation and/or nutrient enrichment and changes in groundwater quality. Potential impacts were investigated by quantifying the nutrient cycling dynamics within the plantation using an input–output mass balance approach for exchangeable calcium (Ca²⁺), exchangeable magnesium (Mg²⁺), exchangeable potassium (K⁺), exchangeable sodium (Na⁺), nitrogen (N), and phosphorus (P). Measured inputs to and outputs from the available nutrient pool in the 0–30 cm of the overburden subsystem were used to estimate the net effect of unmeasured inputs and outputs (termed “residuals”). Residual values in the mass balance of the irrigated treatments demonstrated large leaching losses of exchangeable Ca, Mg, K, and Na. Between 96% and 103% of Na applied in saline mine-water irrigation was leached below the 0–30-cm soil profile zone. The fate of these salts beyond 30 cm is unknown, but results suggest that irrigation with saline mine water had minimal impact on the substrate to 30 cm over the first 2 years since plantation establishment. Accumulations of N and P were detected for the substrate amendments, suggesting that organic amendments (particularly compost) retained the applied nutrients with very little associated losses, particularly through leaching.     

不同微生物菌肥对滨海盐渍土土壤质量及玉米产量的影响

微生物菌肥改良盐渍土具有高效环保的特点,施用功能性微生物菌肥对滨海地区盐渍障碍绿色消减和土壤质量提升有重要意义. 试验基于河北省滨海地区中度盐渍土,以玉米为指示作物,在常规化肥施用基础上设置施加推荐用量的不同微生物菌肥T1（常规化肥750 kg·hm^-2+复合菌剂75 kg·hm^-2）、T2（常规化肥750 kg·hm^-2+巨大芽孢杆菌300 kg·hm^-2）、T3（常规化肥750 kg·hm^-2+胶冻芽孢杆菌300 kg·hm^-2）、T4（常规化肥750 kg·hm^-2+有机硅肥600 kg·hm^-2）、T5（常规化肥750 kg·hm^-2+生物有机肥600 kg·hm^-2）、T6（常规化肥750 kg·hm^-2+活性微藻15 kg·hm^-2）和仅施化肥750 kg·hm^-2（CK）7个处理,研究玉米两个关键时期（大喇叭口期和成熟期）不同微生物菌肥对土壤养分、盐分、细菌群落和玉米产量与经济效益的影响. 结果表明,相较CK,T1显著提高了全生育期土壤全氮（TN）和有效磷（AP）含量;成熟期土壤有机质（OM）含量较大喇叭口期平均增加10.35%,但各处理间无显著性差异;相较于CK,T5和T6显著降低了全生育期土壤全盐量和Ca²⁺含量,平均降低14.51%~18.48%和24.25%~25.51%. T1显著提高全生育期细菌多样性指数,较CK提高了45.16%;土壤优势菌门为放线菌门、变形菌门、酸杆菌门和绿弯菌门,优势菌属为芽孢杆菌属和Geminicoccaceae. 研究区细菌群落最丰富的功能是化能异养和需氧化能异养,平均相对丰度为28.89%和27.11%,T3和T6显著提高土壤氮循环功能. 冗余分析（RDA）结果表明,Na⁺、SO₄^2-、pH和EC是驱动细菌群落结构的重要因素,相关性热图显示Na⁺、SO₄^2-、pH和EC主要与浮霉菌门呈显著正相关,土壤OM和TN与蓝细菌显著正相关. 相较CK,T6在生育期内增加了蓝细菌的相对丰度,优化了细菌群落结构. 使用推荐用量的菌肥T1和T6分别提高了7.31%~24.83%的玉米产量和9.05%~23.23%的经济效益;土壤化学性质与产量相关性分析结果初步揭示了EC、AP、HCO₃^-和Mg²⁺是限制滨海地区土壤生产力的障碍因子. 综上,推荐用量下使用复合菌剂（T1）和活性微藻（T6）可显著提升土壤养分、降低盐分和改善土壤细菌群落结构多样性,既保证了玉米增产增效,又实现了微生物菌肥高效利用和土壤质量提升.     

秸秆和肥料管理措施对太湖流域水稻种植氮流失的影响

稻田系统的氮流失是农业面源污染的重要组成部分. 当前,氮肥投入量已得到有效控制,针对不同秸秆和肥料管理措施的多途径（径流、侧渗、下渗）氮流失特征研究还较为缺乏. 对此,选取太湖流域种植时长超过20 a且持续秸秆还田超过5 a的稻田,研究秸秆和肥料管理措施对水稻全生育期不同途径氮流失的影响,并基于作物产量、氮利用效率及氮流失强度,对秸秆和肥料管理措施的生产适宜性和环境友好性进行研判. 结果表明,秸秆离田会提升水稻植株对施氮的敏感度. 稻季氮总流失量为9~17 kg·hm^-2,占氮肥施用量的5%~7%. 对秸秆管理而言,秸秆离田的泡田排水具有更高氮流失风险;秸秆还田可降低15%以上的下渗途径氮流失量,但是对侧渗途径的氮流失作用并不明确. 对肥料管理而言,有机肥的适宜替代可较同施氮梯度下的化肥施用减少16%的种植期径流氮流失、26%的下渗氮流失,以及37%的侧渗氮流失. 综合产量数据,实施秸秆还田和肥料类型优化能够有效降低生产单位重量稻米的氮流失量,切实实现对农业生产和环境友好的双向兼顾.     

Synergistic suppression effects of flame retardant,porous minerals and nitrogen on premixed methane/air explosion

A novel composite inhibitor based on porous mineral materials and conventional flame retardant of ammonium polyphosphate (APP) is prepared to suppress the premixed methane/air explosion. Taking advantages of gas and powder inhibitor, N₂ and the prepared composite inhibitor are combined to use. The suppression performance of N₂-composite inhibitor on methane explosion is investigated on a 20-L spherical experimental explosion apparatus and the characteristic pressure data are obtained. The combined inhibition effects of N₂ and the prepared composite inhibitor are greater than either acting alone. Thermal decomposition behavior and gaseous products of composite inhibitor are analyzed with thermogravimetric analysis and thermogravimetric-mass spectrometry, respectively. Based on physical and chemical actions, the inhibition mechanisms of N₂-composite inhibitor system are proposed. This work provides a reference to prepare high-performance gas explosion inhibitor based on the synergism of binary or multiple components.     

Assessing the Impacts of Long-Range Sulfur and Nitrogen Deposition on Arctic and Sub-Arctic Ecosystems

For more than a decade, anthropogenic sulfur (S) and nitrogen (N) deposition has been identified as a key pollutant in the Arctic. In this study new critical loads of acidity (S and N) were estimated for terrestrial ecosystems north of 60° latitude by applying the Simple Mass Balance (SMB) model using two critical chemical criteria (Al/Bc = 1 and ANC_le = 0). Critical loads were exceeded in large areas of northern Europe and the Norilsk region in western Siberia during the 1990s, with the more stringent criterion (ANC_le = 0) showing the larger area of exceedance. However, modeled deposition estimates indicate that mean concentrations of sulfur oxides and total S deposition within the Arctic almost halved between 1990 and 2000. The modeled exceeded area is much reduced when currently agreed emission reductions are applied, and almost disappears under the implementation of maximum technically feasible reductions by 2020. In northern North America there was no exceedance under any of the deposition scenarios applied. Modeled N deposition was less than 5 kg ha⁻¹ y⁻¹ almost across the entire study area for all scenarios; and therefore empirical critical loads for the eutrophying impact of nitrogen are unlikely to be exceeded. The reduction in critical load exceedances is supported by observed improvements in surface water quality, whereas the observed extensive damage of terrestrial vegetation around the mining and smelter complexes in the area is mainly caused by direct impacts of air pollution and metals.     

Agricultural ammonia emissions inventory and spatial distribution in the North China Plain

An agricultural ammonia (NH₃) emission inventory in the North China Plain (NCP) on a prefecture level for the year 2004, and a 5 × 5 km² resolution spatial distribution map, has been calculated for the first time. The census database from China's statistics datasets, and emission factors re-calculated by the RAINS model supported total emissions of 3071 kt NH₃-N yr⁻¹ for the NCP, accounting for 27% of the total emissions in China. NH₃ emission from mineral fertilizer application contributed 1620 kt NH₃-N yr⁻¹, 54% of the total emission, while livestock emissions accounted for the remaining 46% of the total emissions, including 7%, 27%, 7% and 5% from cattle, pigs, sheep and goats, and poultry, respectively. A high-resolution spatial NH₃ emissions map was developed based on 1 × 1 km land use database and aggregated to a 5 × 5 km grid resolution. The highest emission density value was 198 kg N ha⁻¹ yr⁻¹.