清水河县北堡乡农田耕地土壤养分分析

对清水河县北堡乡14个村主要经济作物的土壤养分状况进行测定,结果表明：全乡农田养分含量整体呈中下等水平;有效磷和速效钾的含量可达到中等等级;碱解氮和有机质含量较低,处于很缺乏状态;pH呈碱性。谷子对磷（P2O5）的需要量最大,玉米对氮（N）的需要量最大,土豆对钾（K2O）的需要量最大。     

Sediment flow behavior in agro-watersheds of the purple soil region in China under different storm types and spatial scales

Conservation tillage has proved to be an effective option to reduce erosion and particulate phosphorus (PP) losses from fields to watercourses. However, it usually leads to the higher losses of P in dissolved reactive (DRP) form if P accumulates into the uppermost soil layer.In this study we investigated the influence of CaCO₃-rich boardmill sludge (BMS, applied 7 years ago) on soil properties and percolate quality with soil samples as well as undisturbed soil columns taken from a long-term conservation-tilled clay field experiment. A short-term laboratory experiment was undertaken to evaluate whether newly added BMS (FS) can be used to improve the quality of percolate waters by reducing turbidity, PP and DRP.The hypothesis was that BMS reduces the risk of dissolved reactive phosphorus (DRP) leaching from conservation-tilled soil. BMS served as a liming agent and counteracted the no-till-induced acidification and accumulation of DRP in the surface soil layer. Surface soil pH was on average 0.3 units higher and soil Ca 500 mg kg⁻¹ higher in the BMS-treated plots than in the plots without BMS. The ability of BMS to enhance the availability of P for plants may prevent the surface accumulation of P in NT cultivation. At the same time, BMS-induced increase in Ca and EC of the surface soil suppress the diffuse double layer by reducing P desorption and leaching risk.In the laboratory experiment, FS reduced percolate turbidity by 80% and PP and DRP concentrations by 62% and 50%, respectively. FS probably improved stability of soil aggregates in the laboratory experiment, obviously through enhanced microbial activity. The covering effect and infiltration of water through the 0–5 cm soil layer seemed to be crucial factors in reducing P losses.BMS proved to be a promising material for the applications to the conservation-tilled fields. The effect of BMS on microbes and immobilization of nutrients, should, however, be studied further in fields under a wider diversity of conditions.     

有机修饰改性对旱地土壤吸附镉离子特性的影响

研究了以不同比例十六烷基三甲基溴化铵(CTMAB)单一修饰和十六烷基三甲基溴化铵 十二烷基磺酸钠(CTMAB SDS)混合修饰土娄土耕层对重金属镉离子吸附的影响,结果表明:吸附量顺序为耕层原土>50%CTMAB>100%CTMAB 20%SDS>100%CTMAB,温度升高,吸附量上升;最佳吸附等温线模型可以用BET模型描述,热力学参数的研究表明,吸附自发性与吸附量具有相同的变化规律,反应的焓变与熵变共同决定了反应的自发性。从热力学角度对修饰改性土娄土对Cd2 吸附的机理进行了探讨。     

模拟污灌条件下土壤碱度和石膏施用对营养元素动态变化的影响

通过室内土柱淋洗试验,研究了污灌条件下土壤碱度和石膏施用对土壤中营养元素动态变化的影响。结果显示,施用石膏可使碱性土壤淋出液的pH值降低至与非碱性土壤的相似,由此引起的土壤盐分增加现象在经过大约15个孔隙体积(PV)水量的淋洗后基本消失。污水中较多的Ca导致在污灌情况下为改良碱土而施用的石膏不能充分发挥作用。土壤中Na离子的存在影响作物对营养元素的利用。污灌条件下Mg、K和P在土壤中累积,灌溉污水中的53.1%￣78.7%的Mg、33.4%￣58.1%的K以及32.7%￣95.5%的P被吸持在土壤中。Mg和P在碱性土壤中的累积程度明显地大于非碱性土壤,施用石膏明显地减小了K和P,但增大了Mg在碱性土壤中的累积程度。B在非碱性土壤中轻微淋溶而在碱性土壤(不论石膏施用与否)中累积。经过19￣23PV的污水淋洗后,碱性土壤中的B含量增大了14倍左右,而在施用石膏后其含量只增大了68.4%,石膏的施用显著地减小了碱性土壤中B的累积程度。B元素在碱性土壤中的累积是影响试验用污水长期灌溉应用的关键因素。     

基于多维分形的铜陵地区土壤中Pb元素空间分布

克里格插值法的平滑作用使其无法反应空间分布的奇异性。该文将多维分形地统计学方法应用于铜陵地区土壤中Pb元素的空间分布研究中。通过将克里格插值法与多维分形方法的结果进行对比发现,该地区土壤中Pb元素有较强的空间自相似性,多维分形方法合理地强化了局部区域的估值结果,可以较好的表达土壤元素空间分布的局部奇异性。多维分形方法可以广泛应用于土壤元素空间分布的研究,尤其是矿区土壤重金属元素空间分布的研究。     

辐照杀菌对鸡蛋蛋白液特性的影响

为了探明液态蛋蛋白液经辐照处理后有关特性的变化情况,为液态蛋的辐照杀菌技术应用提供试验依据。试验研究了不同辐照条件下鸡蛋蛋白液的pH值、色度、黏度、热变性、起泡性和乳化性的变化。试验表明,在辐照剂量0～3.0 kGy范围内随辐照剂量增大,蛋白液的pH值有所下降,但变化相对不大;蛋白液的黏度在辐照剂量0～0.4 kGy范围内随辐照剂量增大有较大下降,但剂量大于0.4 kGy 以后蛋白黏度随辐照剂量增大变化较小;蛋白液的色度随剂量增大无变化,但蛋液经加热凝固后,2.0 kGy以上剂量辐照组蛋白胶体颜色出现褐色,且随辐照剂量增大而加深;随辐照剂量增大,蛋白液起泡性能增强,但泡沫稳定性下降;随辐照剂量增大辐照后蛋白液的乳化性、乳化稳定性均下降。     

Effect of Catch Cropping on Phosphorus Bioavailability in Comparison to Organic and Inorganic Fertilization

ABSTRACT

Phosphorus (P) is a limited resource and its efficient use is a main task in sustainable agriculture. In a 3-year field experiment the effects of catch cropping [oil radish (Raphanus sativus), buckwheat (Fagopyrum esculentum), serradella (Ornithopus sativus), ryegrass (Lolium westerwoldicum), and phacelia (Phacelia tanacetifolia)] of organic fertilization (cattle manure and biowaste compost) and of inorganic fertilization (Triple-Superphosphate) on plant and soil parameters were investigated on a P-poor loamy sand in Northeast Germany. The catch crops were sown in September and remained on the plots until next spring. Then the main crops oilseed rape (Brassica napus), spring barley (Hordeum vulgare), or spring wheat (Triticum aestivum) were cultivated. The yield and P uptake of the main crops were determined. Furthermore, in the soil the organic matter content, pH, phosphorus (P) in soil solution (Psol), double-lactate and oxalate P content, P sorption capacity, and degree of P saturation were measured. All applied forms of fertilizer affected the P contents in soil and the yields and P uptakes of main crops. For green fertilization especially phacelia was found to contribute to the P supply of the main crops, since it increased the P uptake as well as the P contents in soil significantly. The cultivation of ryegrass led to a reduction of the P availability in soil. For example, in average of the three years the Psol content was 0.35 mg L^{? 1}when phacelia was cultivated and 0.22 mg L^{? 1} when ryegrass was cultivated. The cultivation of phacelia had a comparable effect on soil and plant parameters as the organic and mineral fertilization. An improved P availability and P utilization by catch cropping can reduce the need for external P input which may help to save the limited P resources worldwide.     

天津市滨海新区小区园林绿化的设计构思

针对天津地区土质为盐碱性土壤这一特点,选择合理树种,合理配置,从绿化作用出发,使居住环境更好的适应现代化建筑,创造清新宜人的生活、休息场所。