Recultivation of Agricultural Land Impaired by Construction of a Hydropower Plant on the Sava River,Slovenia

Hydropower plants on the lower river Sava, Slovenia, were developed without sealing the underground upstream. As a consequence, without the countermeasures of elevating and recultivating, the agricultural land on the river banks would be inundated because of the water‐table increase of the river. To remedy this, the fields were elevated and recultivated. The goal of this study was to assess soil quality and production potential after land raising and recultivation and to answer the question whether it is possible to recover soil quality and crop yield after large‐scale mass manipulation, such as land raising. After recultivation and after the second year of land reuse for the two cultures grass–clover mixture and corn on two sites, Middle Pijavsko and Lower Pijavsko, soil physical and chemical characteristics and crop yields were evaluated. Mixing of topsoil with the second horizon during removal and during backfill with filling material resulted in uneven soil fertility, plant growth and decreased yield. Driving on the refilled second layer with heavy machinery caused soil compaction in the Middle Pijavsko in spite of favourable soil texture (loam, 38·7% sand). On the areas with very high sand content (over 55%) and low clay content (10%), soil compaction was not as severe or persistent. Recultivation measures restored the agricultural land almost to the production potential prior to powerplant construction. Immediate intensive land use (corn) showed less favourable effect on soil characteristics. Copyright © 2015 John Wiley & Sons, Ltd.     

江浦胡桥老栗园低产原因的分析及其改造措施

经土壤分析和实地调查,江浦胡桥板栗低产有如下几个原因:①土壤缺硼,9个样点的含硼量平均仅0.32μg/g。缺硼有碍板栗受精结实,严重的可导致70％左右的空苞率;②多年不施肥,土壤养份只耗不补,肥力低下,缺磷现象尤其严重。9个样点的P_2O_5含量仅2.41μg/g,其中2个点属低级水平,7个点属极低水平;而板栗需要大量磷素,尤以花期需磷更多;③坡地栽培,缺乏水土保持措施,引起水土流失;④未整形修剪,密度不合理,树体高大,枝条拥挤,相互遮荫,形成冠顶平面结果;⑤不除灌木杂草,使其与板栗争光争肥。今后的改造措施:①挖鱼鳞坑,保水保肥;②增施肥料,特别要增施氮、磷、硼等肥料,花期试行喷硼;③重视整形修剪,逐步回缩树冠;④高枝嫁接换种,结合安排授粉树。     

一种新型水质改良剂对池塘水质的影响

一种新型水质改良剂对池塘水质的影响研究结果表明,施用新型水质改良剂对水化因子有很大影响,使池塘DO升高,COD、NH4+-N、NO2--N降低,pH值变化平稳;1次施用的效果持续时间约为15 d,在池塘中施用这种新型水质改良剂可达到改良水质的目的。     

坝上地区尚义县农业可持续发展的途径分析

在分析尚义县复杂的生态环境的基础上,针对如何发展尚义农业并实现可持续发展,提出了因地制宜的布局策略,阐述了水土保持工作是南部地区可持续发展的核心问题、关键所在,改良利用是北部地区可持续发展的有效途径。同时,对一些传统生产观念及模式进行了异议。     

三种水质改良剂对水中三态氮降解效果初步测试

对水质改良剂对降低养殖水体中的三态氮浓度及有机物耗氧量进行了探讨,选出效果显著的,并找出水质改良剂加入水体中的最适浓度,以便在生产中改善水质,促进渔业生产。     

改良微气调沙藏法贮藏板栗的研究

在传统沙藏法基础上,运用介质散热装置和PE薄膜覆罩研制出改良微气调沙藏法,并对板栗贮藏介质温度、呼吸强度、气体成分、品质变化及贮藏效果进行试验。结果表明,利用介质散热装置与0.04mmPE覆膜处理作用的改良微气调沙藏法,有效地改善了板栗贮藏环境,能使其保持适宜的温度、湿度、O2与CO2浓度比例,其贮藏品质得到改善,经120天常温贮藏,商品果率达93.4%。     

L-茶氨酸改善慢性应激大鼠抑郁行为作用研究

研究L-茶氨酸对慢性不可预见性温和应激模型大鼠的抗抑郁作用及其机制。建立慢性不可预见性温和应激（CUMS）抑郁大鼠模型,通过糖水偏好实验,旷场实验,明暗箱实验评估L-茶氨酸的抗抑郁作用效果;为了阐释其相关机理,本研究通过酶联免疫法测定了各组大鼠海马和皮层组织中5-羟色胺（5-HT）、去甲肾上腺素（NA）、促肾上腺皮质激素（ACTH）和皮质酮（CORT）的含量,同时也检测了大鼠血清和海马组织中超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）的活性。结果表明,与空白对照组相比,模型组大鼠糖水偏好度、横穿格数和直立次数、进入明箱中的大鼠数量以及停留的时间极显著降低,显示大鼠抑郁模型构建成功;而与模型组相比,灌胃低高两个剂量L-茶氨酸的大鼠抑郁症状有不同程度改善,尤其高剂量都达到显著水平。同时,L-茶氨酸能显著提升大鼠海马和皮层中5-HT、NA的含量,降低ACTH,CORT的含量,上调大鼠血清和皮层中SOD和GSH-Px的活性,进一步表明了其抗抑郁的功效,其机制可能主要与促进单胺类递质分泌有关。     

新型底质改良剂对池塘水质和底质的影响

利用膨润土、腐植酸钠、黄腐酸吸附光合细菌制成一种新型底质改良剂,通过对池塘水质指标和底质有机质的测定,研究该底质改良剂对池塘水质和底质的影响。结果显示,该底质改良剂可以改善养殖水体水质,水体中溶解氧(DO)含量能够得到有效提高,化学需氧量(CODMn)明显下降,氨氮(NH4+-N)和亚硝酸盐氮(NO2--N)的去除效果显著,水体pH值稳定在渔业水质标准范围(淡水6.5~8.5);且可在一定程度上减少池塘底质有机质的积累。     

PID Control for Multivariable System Based on Ameliorative RBF Neural Networks

Aiming at systems which are of characteristics of multi-input and multi-output, nonlinearity and time-variation in the industrial control fields, this paper presents a intelligent PID control method based on ameliorative RBF neural networks, which constructs RBF neural networks identifier on-line and identifies a controlled object on-line by means of adopting the nearest neighbor-clustering algorithm, and adjusts parameters of PID controller on-line and realizes decoupiing control of multivariable, nonlinear and time-variation system. The simulation result indicates that the controller can get parameters which are optimal under some control law, it makes the decoupled system, compared to the PID control method based on the conventional RBF neural networks, has perfect dynamic and static performances, possesses the advantages of high precision, quick response speed and is of great adaptability and robustness.     

Curtailment of muddy floods in the Sompting catchment, South Downs, West Sussex, southern England

Abstract. Muddy floods due to runoff are a widespread problem on the South Downs of southern England and are associated with increased growing of autumn-sown cereals over the last two decades. The 10.6 km² Sompting catchment has been monitored over the 12-year period 1990/91–2001/02. A housing estate at the lower end of the catchment that was frequently inundated by muddy floods in the late 1980s and early 1990s has not been flooded since the winter of 1993/94, even during the heavy rainfall events of October and November 2000. This is a result of the ameliorative measures put in place in the early 1990s, primarily the reversion of some winter cereal fields to permanent grassland (set-aside). Other land management changes helped, for example, some parts of the catchment were put down to short-term grass leys and small dams were constructed to impound runoff. Flooding of the housing estate occurred when more than 30% of the catchment was covered by eroded fields, which contributed runoff to the valley floors leading down to the housing estate. The length of continuous down-valley flow was greater in the early 1990s compared with later years. The introduction of grassland reduced the risk of flooding not only by reducing the area contributing to runoff, but also by stopping valley floor flows linking up. Such measures to alleviate runoff, erosion and flooding fit well with policies proposed in the recent report by the UK Policy Commission on the Future of Farming and Food.