基于气候阻力的温室黄瓜蒸腾速率模拟

在北方地区玻璃温室内，观测黄瓜生长期叶温与温室内微气象因子，利用基于能量平衡方程和水汽扩散理论的叶-气温差方程计算植株气孔阻力(ri)，结合同期气候阻力(r^*)和边界层阻力(re)进行分析，结果发现：不同天气条件下ri/re的比值与r^*/re比值之间呈极显著正相关关系，晴天时：ri/re=1.207(r^*/re)-0.326(n=328，r=0.8055)，阴天时：ri/re=0.169(r^*/re)+0.278(n=222，r=0.8076)。根据此拟合方程，以r^*/re代替ri/re代入修正后的P-M公式中计算温室黄瓜的蒸腾速率，与直接代入ri值的计算结果比较，结果晴天与阴天条件下的相对误差均<10%，一致性指数达0.96以上，说明利用拟合方程建立的模型模拟效果很好。此模型能够直接利用气象数据计算温室作物气孔阻力并进而计算蒸腾速率，使温室作物蒸腾速率的计算更简单方便，该文结果对同类温室和作物有参考价值。     

氟 对玉米产量品质及土壤性质的影响

适量氟对动物和人类健康有益, 而过量氟对动物和人类健康有害。为研究氟对玉米产量品质及土壤性质的影响, 采用盆栽试验研究了添加0、100 mg·kg^-1、200 mg·kg^-1、500 mg·kg^-1、1 000 mg·kg^-1 和1 500 mg·kg^-1 氟(NaF)对玉米产量、粗蛋白和淀粉含量及土壤pH、水溶性钙和微生物数量的影响。结果表明: 随氟处理浓度的增加玉米产量显著降低, 减产9.9%~85.4%; 玉米籽粒蛋白质含量显著增加, 从91.8 g·kg^-1 增加到108.8 g·kg^-1。加入氟100 mg·kg^-1 和200 mg·kg^-1 时, 淀粉含量表现为下降趋势,而当加入氟500 mg·kg^-1、1 000 mg·kg^-1 和1 500 mg·kg^-1 时, 淀粉含量表现为上升趋势。玉米不同部位氟含量基本上随氟浓度的增加而增加, 玉米根部和籽粒含氟量与氟添加量的相关性达极显著水平, 相关系数分别为r_根=0.998^**和r_粒=0.915^**; 叶含氟量与氟添加量的相关性达显著水平, r_叶=0.852^*; 玉米不同部位氟含量的大小顺序为根>叶>叶鞘>茎>籽粒。氟浓度在200 mg·kg^-1 时, 籽粒含氟量已超过无公害农产品标准1.0 mg·kg^-1。石灰性土壤添加氟后, 可使土壤pH 增加,从8.05 增加到8.70; 水溶性钙含量显著下降, 由2.71 g·kg^-1 下降到1.02 g·kg^-1。随氟浓度的增加土壤放线菌数量显著降低, 与对照相比, 降低0.92%~65.22%; 低浓度的氟可以促进土壤细菌、真菌的生长, 而高浓度的氟可以抑制细菌、真菌的生长。     

行距配置对冬小麦/白三叶草间作系统小麦群体结构和光合有效辐射的影响

2008~2010 年冬小麦/白三叶草不同栽培方式试验(6 种小麦行距配置, 3 个行距×2 个播种量)研究表明,单作条件下, 小麦群体总茎数、叶面积指数、生物量及产量在行距25 cm 与30 cm 处理间差异不大, 均显著高于行距40 cm 处理。行距30 cm、播种量217.5 kg·hm^-2 处理的籽粒产量和收获系数分别达7 857.8 kg·hm^-2 和0.483。小麦抽穗期和花期, 行距30 cm 与40 cm 处理的冠层底部向上20 cm 处的光合有效辐射(PAR)值差异不大, 行间全天PAR 在50 μmol·m^-2·s^-1 以上的时间至少有8 h, 而单作条件下白三叶草光补偿点在30~50μmol·m^-2·s^-1 之间, 这预示着在行距30 cm 与40 cm 处理的小麦行间间作白三叶草能为白三叶草光合作用提供有效光能。行距30 cm 条件下, “小偃81”与“济麦22”单作以及分别与白三叶草间作处理试验表明, “小偃81”与白三叶草间作系统小麦生物量不受间作影响, 小麦叶面积指数与穗数高于“小偃81”单作。“济麦22”与白三叶草间作系统的3 项指标则低于“济麦22”单作。间作条件下, 白三叶草冠层顶部PAR 日变化呈单峰曲线, 冠层底部PAR 较小, 全天最大仅30 μmol·m^-2·s^-1。与“济麦22”相比, “小偃81”与白三叶草间作冠层底部PAR 全天日变化较小。因此, 行距30 cm 处理小麦行间适合间作白三叶草, 小麦品种“小偃81”比“济麦22”更适合与白三叶草间作。本研究结论可为华北平原发展冬小麦/白三叶草间作种植模式提供参考依据。     

旱作春玉米冠层及叶片瞬态气体交换及水分利用效率日变化特征

旱作作物不同尺度瞬态气体交换和水分利用效率同步观测的研究，对于节水高效农业理论研究和生产实践均具有及其重要的意义。该文采用涡度相关技术和LI-COR6400便携式光合作用测定仪测定旱作春玉米灌浆期冠层、叶片瞬时CO₂和H₂O汽交换速率，并分析其瞬态水分利用效率日变化特征。结果表明，旱作春玉米灌浆期0～100 cm根层土壤相对湿度为40%时，日变化过程中晴日中上部位叶片的光合速率高峰值为1.3 mg·m^-2·s^-1(29.82 μmol·m^-2·s^-1)，与同纬度地区灌溉玉米的光合速率高峰值相近；而群体下光合速率高峰值为0.9 mg·m^-2·s^-1(20.65 μmol·m^-2·s^-1)，只及同纬度地区灌溉玉米灌浆期光合速率高峰值的54.5%；群体和叶片水分利用效率高峰值分别为0.16 g(CO₂)/g(H₂O)和0.06 g(CO₂)/g(H₂O)，正午前后分别维持在0.0055～0.0123 g(CO₂)/g(H₂O)和0.0113～0.0197 g(CO₂)/g(H₂O)，叶片尺度的光合速率和水分利用效率在10∶00以后的时段内明显高于群体水平。     

波浪冠层群体微生态环境对高油大豆产量和品质的影响

探讨波浪冠层群体对高油大豆产量和品质的影响，为其推广应用提供理论依据。2005-2006年，以高油大豆品种鲁豆9号为试验材料，采用田间试验和室内分析相结合的方法，研究波浪冠层对鲁豆9号群体结构、微生态环境、光合特性、产量、产量构成因素、蛋白质、脂肪及脂肪酸组分的影响，以及它们之间相互作用的关系。结果表明，波浪冠层群体与CK相比，株高平均降低1.41 cm、分枝减少0.08个，分别降低和减少1.38%和5.30%；群体光照度、CO₂浓度和湿度分别增加67.68 μmol/(m²·s)和8.31 μL/L和0.33 mbar，分别增加5.06%、2.45%和4.47%；低温生育期时温度提高0.06℃，高温生育期时温度平均降低0.17℃；植株中部透光率提高1.57%,光合速率提高4.04%；密度平均增加3.0万株/hm²，单产平均增加253.65 kg/hm²，增产11.76%，差异达极显著水平。在籽粒脂肪总量提高1.52%基础上，亚油酸含量提高1.60%，亚麻酸和硬脂酸含量分别降低0.14%和7.20%。波浪冠层群体密度与脂肪和棕榈酸含量呈极显著和显著负相关(r=-1.00^**和-0.90^*)；脂肪与亚油酸呈正相关(r=0.79)，而与硬脂酸呈负相关(r=-0.55)；油酸与亚油酸和亚麻酸均呈负相关(r=-0.74和-0.50)，亚油酸和亚麻酸呈显著正相关(r=－0.95^*)。因此，波浪冠层群体调节了大豆生长发育的微生态环境，更利于高油大豆产量形成和品质改良，不仅能增产，而且提高高油大豆脂肪含量、优化脂肪酸组分、提高了营养价值，在生产上有较广阔的应用前景。     

铜和维生素A 及其互作效应对肉鸡免疫功能的影响

采用4×2(铜×维生素A)完全随机试验设计, 研究了日粮添加不同水平的铜(0 mg·kg^-1、8 mg·kg^-1、150 mg·kg^-1、225 mg·kg^-1)和维生素A(1 500 IU·kg^-1、5 000 IU·kg^-1)对肉仔鸡不同生长阶段(0~4 周龄和5~7 周龄)免疫功能的影响。结果表明: 添加铜为8 mg·kg^-1 时, 肉鸡生长前期(0~4 周龄)可显著(P<0.05)或极显著(P<0.01)提高肉鸡脾脏活化T 淋巴细胞百分率和血清抗体效价, 生长后期(5~7 周龄)可极显著(P<0.01)或显著(P<0.05)提高脾脏、胸腺、盲肠扁桃体活化T 淋巴细胞百分率和外周血液中活化T、B 淋巴细胞百分率; 整个试验期添加高铜(150 mg·kg^-1、225 mg·kg^-1)时, 活化T、B 淋巴细胞百分率均不同程度下降。添加维生素A 5 000 IU·kg^-1 时, 肉鸡生长前期可显著(P<0.05)提高其外周血液中活化T 淋巴细胞百分率, 生长后期可极显著(P<0.01)或显著(P<0.05)提高脾脏、盲肠扁桃体活化T 淋巴细胞百分率和血清抗体效价。铜和维生素A 互作效应对肉鸡生长前期的活化T、B 淋巴细胞百分率和血清抗体效价影响不显著, 对生长后期的外周血液、胸腺、盲肠扁桃体活化T 淋巴细胞百分率影响显著(P<0.05), 以8 mg·kg^-1 铜× 5 000 IU·kg^-1 维生素A 处理最高; 以上结果提示铜和维生素A 对肉鸡免疫功能的影响存在互作效应。     

不同水分供应对甘薯叶片光合与荧光特性的影响及其光响应模型比较

水分供应对甘薯生长发育、产量形成具有重要影响。为探讨不同水分处理对甘薯光合与荧光特性的影响,本研究以鲜食型甘薯‘烟薯25号’为试验材料,研究不同水分处理下甘薯叶片的光合-光响应过程及其荧光特性,并利用不同模型对光响应过程进行拟合。研究结果表明：干旱和淹水处理显著降低了甘薯叶片净光合速率（P_n）、气孔导度（G_s）和蒸腾速率（T_r）;当PAR≤1 000 μmol·m^-2·s^-1时,干旱及淹水处理P_n的降低主要受气孔限制,当PAR>1 000 μmol·m^-2·s^-1时,P_n的降低主要受非气孔限制。荧光参数表明,干旱及淹水处理下甘薯叶片光系统Ⅱ（PSⅡ）对光的捕获及吸收能力下降,热耗散增加。光响应模型以直角双曲线修正模型拟合精度最高,且能拟合出饱和光强,适用于不同的土壤水分环境。模型拟合参数显示,所有处理甘薯叶片初始量子效率（α）为0.039~0.055,位于0~0.125的理论范围值内,干旱、淹水处理下甘薯叶片表现出显著的光饱和、光抑制现象,光能利用减弱,且淹水处理的光利用能力小于干旱处理。综合分析认为,直角双曲线修正模型是甘薯不同水分条件下光响应变化最佳模型。干旱及淹水处理均会对甘薯光系统造成损伤,使甘薯光合能力下降,淹水比干旱更易于降低甘薯叶片对光的利用能力,高光强会加重甘薯水分的胁迫程度。     

基于鱼类保护目标的椒江环境流量研究

以鱼类为保护目标, 通过建立概念模型将鱼类保护目标与流量之间的关系相联系, 识别了与椒江鱼类保护目标相关的环境流量组成要素。采用FLOWS 方法, 计算了椒江2 个断面的环境流量, 柏枝岙断面的低流量为6.8~17.3 m³·s^-1、高流量为22.2 m³·s^-1, 低流量脉冲为74 m³·s^-1, 高流量脉冲为110 m³·s^-1, 齐岸流量为948 m³·s^-1; 灵海断面的低流量为16.0~31.8 m³·s^-1, 高流量为46.0 m³·s^-1, 齐岸流量为2 488~3 184 m³·s^-1。并得出每组环境流量出现时间、持续时间和出现频率等的推荐结果。与Tennant 方法的计算结果比较, 采用FLOWS 计算方法能够反映环境流量的季节性变化特点, 同时体现了环境流量与自然流量过程的一致性。此研究结果可为椒江的水资源合理利用与河流生态系统保护提供理论依据。     

磁化水处理对镉胁迫下欧美杨幼苗光合及生长特性的影响

为探讨磁化水灌溉处理在促进植物生长、提高植株重金属耐受性方面的作用机制,本研究采用随机区组试验设计,研究了镉胁迫（0 μmol·L^-1、50 μmol·L^-1、100 μmol·L^-1）下磁化水灌溉处理对1 a生欧美杨''I-107''光合特性、叶绿素荧光动力学参数及生长特性的影响。结果表明：1）镉胁迫会显著降低植株高生长和根茎叶干物质量;低浓度（50 μmol·L^-1）镉处理促进根系直径及体积增大（P<0.05）,高浓度（100 μmol·L^-1）则会抑制根系各形态参数;镉胁迫下欧美杨叶绿素b和类胡萝卜素含量分别降低12.50%、43.24%和19.27%、46.37%（P<0.05）,净光合速率（P_n）、蒸腾速率（T_r）、胞间二氧化碳（C_i）分别降低13.68%和33.68%、8.07%和27.81%、5.00%和14.99%（P<0.05）,同时,PSⅡ潜在活性（F_v/F_m）、最大光化学速率（F_v/F_o）、光合性能指数（PIabs）和量子产额（φ_Eo）均有不同程度降低。2）磁化水灌溉提高镉胁迫植株高生长及根茎叶干物质量,增加植株根系长度及表面积;同时,叶绿素a、叶绿素b和类胡萝卜素含量在0 μmol·L^-1和100 μmol·L^-1镉胁迫下分别提高16.99%、40.20%,8.67%、39.10%和17.32%、50.52%（P<0.05）;G_s、C_i及WUE显著升高,T_r则降低24.20%、23.33%、12.06%（P<0.05）;另外,F_v/F_m、F_v/F_o、PIabs显著升高（P<0.05）。综上所述,磁化水灌溉处理有助于提高镉胁迫下欧美杨幼苗光合色素含量,维持光合机构功能,增强光合碳同化速率,减轻镉胁迫对植株生长发育的抑制。     

浙中三个桔园土壤的水分性质及结构改良剂的应用效果

在实验室条件下研究了浙中金衢盆地三个桔园土壤的持水特性、饱和导水率、蒸发强度及三种土壤结构改良剂对土壤团聚作用和蒸发强度的影响.结果表明,持水量与<0.01mm物理性粘粒含量呈正相关(r=0.933^*);饱和导水率与团聚体平均重量直径呈正相关(r=0.956^**),而与结构破坏率呈负相关(r=-0.996^**).当土壤吸力在50-100kPa时,桔园就需灌溉.加入三种土壤结构改良剂后能明显改善土壤水稳性团聚体,其效果为聚乙烯醇>聚丙烯酰胺>水解聚丙烯腈;使土壤的日平均蒸发强度减少,其减少的顺序为黄筋泥>紫砂土>红砂土.土壤饱和导水率K₁₀值紫砂土>黄筋泥>红砂土,主要取决于土壤水稳性团聚体的平均重量直径,二者呈正相关(r=0.956^**).     

Studies on the maturing process of newly reclaimed soils under cultivation (Part 5) Change of the methoxyl content and the heat of combustion of soil humus under cultivation

It has been considered by investigators, no matter whether they stand by the lignin-protein complex theory or not, that lignin plays an important role in the humus formation of plant residues. When plant residues are added to the soil, though almost all the plant constituents are decomposed, only lignin accumulates in the soil as a component of humus, as it is resistant to the microbial decomposition. However, lignin does not remain unchanged in this case and is thought to be modified, either through chemical agencies or as a result of specific microbial action. Though it is not yet fully clarified what changes it undergoes in the humification process, at least it is indicated that the methoxyl, as a characteristic radical of lignin, is attacked during the process.     

Better Laws = Better Environment the Role of the Environmental Lawyer in the Reconstruction and Modernisation of the Water Sector in Private Sector Participation

In order to secure a better environment, it is essential to ensure that the right and appropriate laws exist and are enforced. Before any major change is made to the physical environment, careful consideration should be given to the existence of the appropriate legal and organisational structure to ensure that the desired changes and improvements can be satisfactorily accomplished. Private sector participation is often seen as a catalyst for change and improvement in the economic and environmental situation, but, of itself, that will not create the desired cure. As water is a natural monopoly, it is essential to secure and maintain an effective, efficient and independent regulator. Environmental law should be kept under constant review to ensure that it is relevant and that it meets the challenges of the future, as well as securing the victories of the past.     

Dissolution of alkaline earth sulfates in the presence of montmorillonite

In a study of the effect of montmorillonite on the dissolution of BaSO₄ (barite), SrSO₄ (celestite), and²²⁶Ra from U mill tailings, it was found that: (1) More of these substances dissolve in an aqueous system that contains montmorillonite than dissolve in a similar system without clay, due to the ion exchange properties of the clay; (2) Na-montmorillonite is more effective in aiding dissolution than is Ca-montmorillonite; (3) the amount of Ra that moves from mill tailings to an exchanger increases as solution sulfate activity decreases. Leaching experiments suggest that²²⁶Ra from H₂SO₄-Circuit U mill tailings from Edgemont, South Dakota, is not present as pure Ra sulfate or as an impurity in anhydrite or gypsum; it is less soluble, and probably occurs as a trace constituent in barite.     

基于全球导航卫星系统的智能化精细平地系统优化与试验

农田土地精细平整是中国现代地面精细灌溉的重要基础,能提高农田灌溉均匀度,改良土壤水盐分布,控制杂草,达到节水增产的效果。应用GNSS(global navigation satellite system,全球导航卫星系统)技术进行土地精细平整具有不受天气影响、测量速度快、工作效率高等优点,具有广泛应用前景。该文结合中国土地平整的实际情况和前期的研究成果,开发了适合国内应用的GNSS控制平地系统,降低了研发的设备成本,优化完善了平地系统的功能。为减少分立设备数量,提高系统集成度,设计了集成控制终端,集成GNSS接收模块、差分电台模块、核心处理平台和阀控制模块,并设计了集成控制终端的外壳,通过可旋转调整支架固定在拖拉机驾驶室内,具有良好的防尘、降温和牢固等优点;为完善地形测量功能,增加了测量轨迹的实时显示,以及农田面积等地势信息的计算,便于指导后续平整作业;优化了基准设计,建立了坡面平整的数学模型,实现了任意坡度坡面平整。优化后的系统主要由集成控制终端、自主差分GNSS接收设备、液压系统以及平地铲运设备几部分构成;以Visual Studio2008为系统软件开发环境,GNSS精细平整集成软件能够实现农田地势测量、基准设计及平整作业等功能。该智能平地系统在中国农业大学上庄试验站进行了长时间平整实验,平面平整后最大高程差从20.9降到10.5 cm,高程标准差从10.6降到5.5 cm,平地误差小于5 cm的测点累积百分比从77%上升到90%左右,平整效果良好。坡面平整的坡度从0.239%降到0.120%,符合设计要求。结果表明,系统工作稳定可靠,作业精度满足土地精细平整要求,适用于在中国推广应用。     

基于优化点匹配模式的农作区遥感影像融合分类

利用遥感影像进行农作物长势监测及估产中,对所用多源影像进行恰当的影像融合是正确解译的重要前提,在传统的基于灰度的影像匹配融合模式中,存在着高运算量和精度不高的问题,该文使用一种基于优化点匹配模式进行农作区遥感影像融合方法,对不同传感器的两景西北农作区遥感影像进行了融合分析验证。所用两景ASTER和SPOT图像匹配总体误差RMS=0.8965,融合后的影像总体分类精度提高到89.67%。     

The giant squid Architeuthis: An emblematic invertebrate that can represent concern for the conservation of marine biodiversity

The current public perception is that there is little reason for concern for the conservation of marine invertebrates, in part due to the scarcity of emblematic species to represent that diverse group. This paper shows that giant squid can be considered an emblematic species to represent concern for the conservation of marine invertebrate biodiversity because it satisfies all the requirements of an emblematic species. It shows that Architeuthis attracts public interest and attention and can serve as an indicator of oceanographic conditions and ocean climate change. It asserts that Architeuthis can represent concerns for vulnerable marine ecosystems associated with submarine canyons and that it belongs to a broad diverse phylogenetic group of organisms associated with these canyons, sharing common concerns with that group with respect to vulnerability and conservation. This study also advocates that the giant squid can serve as an indicator of effects of ecosystem stress resulting from anthropogenic effects including ocean acidification and warming. It is also shown to be vulnerable to such anthropogenic effects as fishing, acoustic seismic exploration and, possibly, pollutants.     

Sequential effects of spent coffee grounds on soil physical properties

Spent coffee grounds are a bio-residue studied as soil organic amendment and it has been proven that it has short-term effects on soil physical properties. However, its sequential effects on the cultivation of clayey soils are little studied. Therefore, an in vitro experiment was carried out to evaluate the effect of increasing doses (1%, 2%, 2.5%, 5%, 7.5%, 10%, 12.5% and 15%) of spent coffee grounds on the physical properties of a clayey soil in the Spanish Mediterranean area which is rich in smectites. The addition of spent coffee grounds increased water retention at −33 and −1500 kPa proportionally to the added amounts, but the increase in the wilting point was much larger than the field water capacity, decreasing the plant available water content. A non-linear influence on the aggregate size is demonstrated. It increased total porosity and consequently reduced soil bulk density. This fact was reflected in the stereomicroscopy images where an increase in the pores analysed with image analysis was observed. Furthermore, SEM images corroborate that spent coffee grounds act intensely in the short-term due to the interaction between their particles and those of clay. The 5% dose acted as a threshold dose from which the greatest effects on soil physical properties occur. In general, the use of SCG as an organic amendment is a good sustainable solution because it supposes a reuse of this bio-residue (15 million tons per year), an increase in soil organic carbon (SCG contains ≈ 50% carbon) and an improvement of the soil physical and chemical properties.     

Can Uganda's gorillas survive?—A survey of the Bwindi Forest Reserve

The most detailed survey yet made of the numbers, distribution and conservation status of gorilla in the Bwindi Forest Reserve indicates a total population of 95–135 animals and a breeding population of only about 75. Within the Reserve the local people use an area more than twice as large as that used by the gorillas, and it is clear that gorillas avoid areas of human use. Conflict exists therefore between present human use of the reserve and gorilla conservation in Uganda. Small populations are especially vulnerable to extinction and since one of the primary aims of the Reserve is to provide a sanctuary for the gorilla, together with the other species of this immensely rich forest community, steps should be taken now to lessen the conflict. In particular it is recommended that the extent of all human use be reduced from the present 35–40% of the Reserve area to less than 20% as long as such use can be adequately controlled; if it cannot, National Park status should be considered; that no further access roads be built; that mechanised felling never be allowed; and that the Reserve be extended in the northwest to include extra gorilla habitat and to protect an important watershed in the region.     

Use of ammonium bicarbonate DTPA soil test to evaluate elemental availability and toxicity

Abstract

The literature published on the use of the Soltanpour and Schwab Ammonium Bicarbonate‐DTPA (AB‐DTPA) soil test shows that it can be used to determine availability and toxicity indices for many elements. It has been shown to be an effective test for measuring the availability indices of P, K, Zn, Fe, Mn, Mo, Pb, Ni, Cd and Se. Theoretically, it can also be used to determine the availability indices for S, Cu and As. The AB‐DTPA test can predict toxicity of B as well as the standard hot water rest, although within the non‐toxic range of B, it is not as effective as the hot water test. The hot water test alone predicts B availability well, but the AB‐DTPA B test result requires inclusion of soil water pH, organic matter and clay contents in a regression equation for predicting B availability. This test is not suitable for determination of exchangeable plus soluble Ca and Mg (high levels), as these precipitate as carbonates during extraction. The AB‐DTPA test procedure with analysis by an inductively‐coupled plasma spectrometer for simultaneous determination of elements, makes soil and overburden testing very efficient.     

高密度水产养殖自控生态型大棚的水质净化技术

集约化水产养殖条件下,如何净化和循环利用大量的养殖污水,已成为限制淡水渔业发展的瓶颈。该研究通过创新的工程设计,在自控生态大棚内实现多种水生动物和植物的高密度、集约化、节水化养殖。养鱼水经过红萍、蔬菜等植物的吸收以及水净化综合技术处理,可以循环使用。该大棚不向外排泄养殖废水,不仅大大节约用水,而且养殖密度成倍增加,并不构成任何环境污染