Using shallow saline groundwater for irrigation and regulating for soil salt-water regime

Drought and fresh water shortage are the main limiting factorsfor sustainable development of agriculture in North China Plain.Using saline water for irrigation plays important role forovercoming the constraints and increasing crops yields. Theexploitation and utilization of shallow saline groundwaterenables to regulate the groundwater depth and to promote thetransform of precipitation into available water resources.Thispaper reviews the research and practice on the utilization ofshallow saline groundwater in the part east of South GreatCanal in Haihe River Plain. Findings are presented on the useof saline water, cycling and blending of saline and fresh waterfor irrigation, indexing of crops salt tolerances, regulating forsoil salt-water regime, saline-alkali land reclamation andgroundwater quality freshening. These approaches help therational regulation and utilization of the local water resourcesfor comprehensive control of drought, waterlogging and salinity.     

Incorporation of ridge and furrow method of rainfall harvesting with mulching for crop production under semiarid conditions

A plastic-covered ridge and furrow rainfall harvesting (PRFRH) system combined with mulches was designed to increase water availability to crops for improving and stabilizing agricultural production in the semiarid Loess region of northwest China. The system was built by shaping the soil surface with alternate ridges and furrows along the contour. The plastic-covered ridges served as a rainfall harvesting zone and furrows as a planting zone. Some materials were also used to mulch the furrows to increase the effectiveness of the harvested water. This system can make better utilization of light rain by harvesting rainwater through the plastic-covered ridge. The field experiment (using corn as an indicator crop) showed that grain yields in the PRFRH system with mulches in 1998 and 1999 were significantly higher than the controls, with an increase of 4010–5297 kg per ha (108–143%). In most treatments, the water use efficiencies (WUE) were in excess of 2.0 kg m⁻³. The WUE values of corn in this system were 1.9 times greater than the controls in 1998 and 1.4 times greater than the controls in 1999. The plastic-covered ridge led to a yield increase of 3430 kg per ha (92%) in 1998 and of 1126 kg per ha (21%) in 1999 compared with the uncovered ridge. On average, the additional mulches in the furrow brought about a yield increase of 8–25%. Based on the results of this study and other researches, this technique can increase corn grain yield by 60–95% in drought and average years, 70–90% in wet years, and 20–30% in very wet years. The PRFRH system had the potential to increase crop yield and produced greater economic benefit, therefore it could be used in regions dominated by light rainfall of low intensity where crops generally fail due to water stress.     

黄土丘陵半干旱区枣林露水量研究

利用2012年和2013年叶片湿度传感器(LWS)、温湿度仪、热扩散式探针(TDP)、中子仪实测的露水强度、冠层温湿度、树干径流、土壤水分及气象站监测的气象因子,分析了枣林生育期内露水量的变化规律,探讨了其与水资源输入、输出项的关系。研究结果表明,2012年和2013年枣林露水量随生育期变化呈现递增趋势,果实成熟期达到最大值。露水总量分别为31.31、37.87 mm,分别占同期降水量、蒸腾量和蒸发量的6.87%、10.00%、17.65%和7.90%、15.00%、17.90%,露水量日平均值分别达0.44、0.47 mm。此外,露水量具有发生频率高、稳定性强、重度露水量(大于0.20 mm)比重大的特点。在枣树全生育期内,露水量作为水资源输入项会引起蒸腾量在果实膨大和成熟期显著降低(P0.05),但对蒸发量无显著影响。研究显示露水是该区枣林重要水源,是水量平衡中不可缺少的输入项。     

玉米籽粒内部组分低对比度透射图像精确分割研究

为解决玉米籽粒透射图像由于对比度较低造成内部组分提取不精确的问题,提出一种基于色彩通道非线性变换的多通道重叠区域分割方法,对玉米籽粒图像在灰度、R通道及b通道下得到的二值图像使用重叠区域原理,实现玉米籽粒组分的精确分割。首先,采集不同玉米品种的籽粒透射图像,提取单粒玉米籽粒;其次,采用多通道重叠区域法分割单粒籽粒图像,得到玉米籽粒胚部、角质胚乳和粉质胚乳3部分的图像;最后,以查全率和查准率评价多通道重叠区域法与传统图像分割方法对不同品种玉米籽粒的分割效果。不同品种玉米籽粒的分割试验表明:多通道重叠区域分割方法的查全率、查准率及综合评价指标均达到98%以上,分割效果优于传统的图像分割方法,能够实现不同品种透明角质玉米籽粒透射图像的精确组分分割。     

南水北调东线工程泵站技术管理模式研究

以南水北调东线工程准市场化运作为背景 ,以合理性、经济性和可靠性为目标 ,以江苏省江水北调工程泵站技术管理为基础 ,从管理体制、运行管理、日常管理、维护检修等方面研究南水北调东线工程大型梯级泵站的技术管理模式与方法。研究结果对提高工程调水可靠性、经济性和工程的可持续发展有一定意义。     

秸秆覆盖对季节性冻融期土壤水分特征的影响

以北方高寒区典型城市哈尔滨市为研究区域,通过冬季大田试验(试验周期2013-11-01—2014-04-30),设置自然无覆盖、覆盖秸秆厚度5、10、15 cm 4个处理,分别测定不同处理下20、40、60、100、140、180 cm深度土壤液态含水率以及气象数据,分析季节性冻融期秸秆覆盖对土壤水分变化特征的影响。研究结果表明:秸秆覆盖使0~60cm土层内液态含水率增加或减小的时间拐点发生延迟,随着秸秆覆盖厚度的增加其延迟效果越明显,但土壤冻结期的延迟效果比冻土融化期明显;秸秆覆盖阻碍了冻土融化初期融雪水入渗,使自然无覆盖处理液态含水率在20、40、60 cm土壤深度出现短暂的峰值,而在冻土融化末期秸秆覆盖抑制了土壤水蒸发,使各秸秆覆盖处理液态含水率在20、40、60 cm土壤深度又高于自然无覆盖。秸秆覆盖可有效平抑冻融期0~60 cm土层土壤液态含水率的变化幅度,且随着土壤深度的增加其平抑效果具有减弱趋势;积雪融水和秸秆覆盖的双重作用能够有效增加土壤墒情,但其增墒能力随着土壤深度的增加而降低,不同秸秆覆盖处理对0~60 cm土层的平均增墒能力由大到小排序依次为:15、10、5 cm。     

基于K均值聚类的厚壁组织区域自动提取

桉树是我国南方的速生丰产林,区域提取是定量分析各种组织抑制桉树茎生根原因的重要前提。为此,介绍了基于K均值聚类的在桉树茎切片图像中自适应提取厚壁组织区域的图像处理技术。将桉树茎切片彩色图像转换为CIEL*a*b*彩色空间,用K均值聚类分析算法对描述颜色的a*和b*通道进行聚类分析,提取细胞厚壁,然后填充其中白色的细胞腔,构成完整的厚壁组织区域。实验结果表明,在CIEL*a*b*空间使用该算法可以获得较准确的实验结果。     

半干旱黄土丘陵区沙棘优良品种引种栽培试验研究

1994-2003年在黄土高原半干旱区的陕西吴旗县、安塞县进行中国沙棘优良类型和俄罗斯优良沙棘品种引种试验,采用家系选择法初步筛选出5个中国沙棘生态经济型优良单株,对3个俄罗斯良种沙棘的生长适应性经济性状进行了评价。前者生长迅速、树冠好、根系发达、郁闭快、水土保持效益好,果实较大、单株产量较高、Vc和含油量较高,适于在黄土丘陵区种植;后者经济性状较好,果实大、无刺或少刺,但适应性较中国沙棘差。     

京津冀地区市域及县域蔬菜生产特征分析

利用区位熵指数和K均值聚类算法(K-means)分析了京津冀地区13个市域单元和184个县域单元的蔬菜生产空间分布、集聚程度及分类。结果表明:京津冀地区市域蔬菜生产大致分为紧缩型、发展型和平衡型三类;县域蔬菜生产呈现一定的专业聚集度,区位熵两极分化趋势明显,可根据县域蔬菜生产特征将京津冀地区划分为4个蔬菜生产区。     

九江市休闲旅游产品体系构建与开发研究

通过实地调研的方法分析了九江市休闲旅游产品开发的优势条件和存在的问题,并对产品体系的构建进行了初步探讨,认为应着重从加强资源整合和实施品牌战略、做好＂水＂的文章和彰显产品特色、优化产品结构和加快产品创新等方面入手,科学开发休闲旅游产品。