沿江棉区气候与棉花产量的关系及合理利用

采用正交多项式、灰色系统关联分析等方法，对沿江棉区气候与产量的关系进行了分析，得出沿江棉区棉花产量气候波动的指数ＹＦ值为０．３１７４；气候对棉花产量作用的百分比为３６．６２％；５月１日至入梅前光照，温度，出梅后至早秋连阴雨前的光，热，水，９月中旬至１０月底的光照、大于等于棉纤维沉积的下限温度１５℃的有效积温等３时段７要素，对棉花产量影响最大。并依据１９８７年以来初霜期推迟，９月下旬至１１月底光照、     

罗甸县种植火龙果的气候适应性分析

通过对原产地火龙果生长适宜气候条件和罗甸县气候条件的对比分析,得出罗甸中南部低海拔乡镇的光照、温度、降水等气候条件基本适宜火龙果的生长,但要做好防御罗甸易发气象灾害如低温冻害、大风、洪涝、干旱等的威胁。     

凌云县烤烟种植的气候条件分析

结合广西凌云县烤烟种植的现状,着重分析了烤烟种植所需最适宜的温度、水分、光照等气候条件,并针对影响烤烟优质高产的不利气候因素,提出切实可行的生产建议,以实现凌云县烤烟的优质高产。     

江西省双季水稻生长季气候适宜度评价分析

通过对江西省双季水稻生长季温、光、水的需求及当地气候条件进行分析,建立了双季水稻各生育期光、温、水及气候适宜度评价模型,确定了双季水稻各生育期多年平均日照百分率达50％时的日照时数为适宜的光照状态,根据模型分别计算了1961-2010年江西省早稻和晚稻生长季各气候因子的适宜度.结果表明,双季晚稻的温、光、水及气候适宜度明显高于早稻,双季水稻各生育期以光照适宜度最大,温度次之,降水最小;降水是影响双季水稻生产的重要因素,尤其对晚稻的影响更为显著;温度是双季水稻生长发育的关键气候因子,早稻苗期和分蘖-孕穗期低温,早稻乳熟期高温以及晚稻抽穗扬花期低温是双季水稻温度适宜度偏低的主要原因.     

基于全局变量预测模型的温室环境控制方法

针对传统温室控制系统中存在的控制方案达不到最优化、反应滞后、控制器调节不同步等问题,提出了基于全局变量预测模型的温室环境控制方法。该方法将温室内部温度、湿度、光照等数据,控制器当前状态,温室外部环境的相应数据及当地天气情况进行融合,利用各个全局变量通过数学模型得出温室未来环境状况的短期预测值,通过神经网络实现控制方案,解决了温室控制中的大滞后、大惯性等问题。实验结果证明了该方法的有效性及合理性,并对温室内气候智能控制的发展具有一定的参考价值。     

褐稻虱翅型分化的模拟试验初报

<正> 褐稻虱成虫有长翅型和短翅型之分。据研究,长翅型成虫具迁飞特性,而短翅型成虫繁殖力较强。因此,研究褐稻虱翅型分化,对防治褐稻虱具有重要的现实意义。1981和1982年我们用人工气候箱对影响褐稻虱翅型分化的温度、光照、食料及虫口密度等作了模拟试验。现将试验结果报告如下。材料和方法两年试验都是同时在同一温度、不同光照的两个人工气候箱内进行。1981年是国产S S—400A型人工气候箱,1982年是加拿大产PGW—36和PGV—36型人工气候箱。(一)人工气候箱的温度、光照变化     

人工气候室自动测试专家系统购数据库管理

人工气候室参数自动测试和智能化信息处理是实现人工气候室现代化管理的重要手段。系统的数据库管理是系统设计的关键技术。本文介绍了系统的基本组成，提出系统的数据库管理问题，论述了系统的数据库管理目标、管理内容、管理功能和管理特点。为系统的控制决策奠定了基础。     

蔬菜温室垂挂反光幕增效显著

通过对比试验证明，日光温度垂挂反光幕，可有效地改善温室内小气候条件，明显地增强光照，增加温度，减轻病害，提高产量。     

智能温室综合环境因子控制的技术效果及合理的环境参数研究

对自行研制的智能温室环境控制系统的测试表明,温度、湿度、光照、营养液和二氧化碳等各个环境因子控制的技术效果良好,基本达到预期的目的,并明确了各环境参数的合理控制范围。运用该套设施系统和调控指标,采用配套的栽培技术措施,可以实现作物周年高产、优质、高效栽培的目的。     

南亚热带地区重瓣大岩桐的温室栽培技术

文章针对南亚热带地区的特殊气候条件,通过对重瓣大岩桐盆花的品种和基质选择、温度、湿度调控、光照调控、肥水管理、病虫害防治等方面进行了详细的介绍,为南亚热带地区重瓣大岩桐的温室栽培提供技术指导。     

自然光照人工气候室的研究

本文介绍了中国农业科学院植物保护研究所自然光照人工气候室在总体布置、隔热保温的节能措施、全铝合金骨架结构的设计、遮阳防雹、制冷及自动控温、补光等设施方面的特点,既符合了实用、经济、可靠、先进的原则,又创造性地解决了全年利用气候室研究小麦锈病的问题,特别是在炎热的夏季。它的建成将为我国今后各类农用人工气候室的设计提供有益的经验。     

Modelling soil temperature in forest clearcuts using climate station data

A physically based numerical model was developed to estimate the time courses of soil temperature in forest clearcuts from measured solar irradiance, air temperature and wind speed. The model is based upon a finite difference solution of the one-dimensional soil heat flow equation with a surface boundary condition determined from aerodynamic heat transfer and energy balance theory.Modelled soil temperatures were compared with data from two other studies reported in the literature and with temperatures measured in a forest clearcut during 6 and 16 day periods in the summer. The model calculated surface and subsurface soil temperatures accurately over these long intervals. Modelled soil temperatures were relatively insensitive to air temperature, soil thermal properties and the lower boundary soil temperature but quite sensitive to solar irradiance, wind speed and surface roughness.     

Simulating sunflower canopy temperatures to infer root-zone soil water potential

A soil—plant—atmosphere model for sunflower (Helianthus annuus L.), together with clear sky weather data for several days, is used to study the relationship between canopy temperature and root-zone soil water potential. Considering the empirical dependence of stomatal resistance on insolation, air temperature and leaf water potential, a continuity equation for water flux in the soil—plant—atmosphere system is solved for the leaf water potential. The transpirational flux is calculated using Monteith's combination equation, while the canopy temperature is calculated from the energy balance equation. The simulation shows that, at high soil water potentials, canopy temperature is determined primarily by air and dew point temperatures. These results agree with an empirically derived linear regression equation relating canopy-air temperature differential to air vapor pressure deficit. The model predictions of leaf water potential are also in agreement with observations, indicating that measurements of canopy temperature together with a knowledge of air and dew point temperatures can provide a reliable estimate of the root-zone soil water potential.     

高浓度CO2下长白松幼苗土壤和根系呼吸

The objectives of this study were to investigate the effect of higher CO2 concentrations （500 and 700 μmol mol^-1） in atmosphere on total soil respiration and the contribution of root respiration to total soil respiration during seedling growth of Pinus sylvestris vat. sylvestriformis. During the four growing seasons （May-October） from 1999 to 2003, the seedlings were exposed to elevated concentrations of CO2 in open-top chambers. The total soil respiration and contribution of root respiration were measured using an LI-6400-09 soil CO2 flux chamber on June 15 and October 8, 2003. To separate root respiration from total soil respiration, three PVC cylinders were inserted approximately 30 cm deep into the soil in each chamber. There were marked diurnal changes in air and soil temperatures on June 15. Both the total soil respiration and the soil respiration without roots showed a strong diurnal pattern, increasing from before sunrise to about 14：00 in the afternoon and then decreasing before the next sunrise. No increase in the mean total soil respiration and mean soil respiration with roots severed was observed under the elevated CO2 treatments on June 15, 2003, as compared to the open field and control chamber with ambient CO2. However, on October 8, 2003, the total soil respiration and soil respiration with roots severed in the open field were lower than those in the control and elevated CO2 chambers. The mean contribution of root respiration measured on June 15, 2003, ranged from 8.3% to 30.5% and on October 8, 2003, from 20.6% to 48.6%.     

Small lateral air pressure gradients generated by a large chamber system have a strong effect on CO2 transport in soil

Gas transport in soils is usually assumed to be purely diffusive, although several studies have shown that non-diffusive processes can significantly enhance soil gas transport. These processes include barometric air pressure changes, wind-induced pressure pumping and static air pressure fields generated by wind interacting with obstacles. The associated pressure gradients in the soil can cause advective gas fluxes that are much larger than diffusive fluxes. However, the contributions of the respective transport processes are difficult to separate. We developed a large chamber system to simulate pressure fields and investigate their influence on soil gas transport. The chamber consists of four subspaces in which pressure is regulated by fans that blow air in or out of the chamber. With this setup, we conducted experiments with oscillating and static pressure fields. CO₂ concentrations were measured along two soil profiles beneath the chamber. We found a significant relationship between static lateral pressure gradients and the change in the CO₂ profiles (R² = 0.53; p-value <2e-16). Even small pressure gradients between −1 and 1 Pa relative to ambient pressure resulted in an increase or decrease in CO₂ concentrations of 8% on average in the upper soil, indicating advective flow of air in the pore space. Positive pressure gradients resulted in decreasing, negative pressure gradients in increasing CO₂ concentrations. The concentration changes were probably caused by an advective flow field in the soil beneath the chamber generated by the pressure gradients. No effect of oscillating pressure fields was observed in this study. The results indicate that static lateral pressure gradients have a substantial impact on soil gas transport and therefore are an important driver of gas exchange between soil and atmosphere. Lateral pressure gradients in a comparable range can be induced under windy conditions when wind interacts with terrain features. They can also be caused by chambers used for flux measurements at high wind speed or by fans used for head-space mixing within the chambers, which yields biased flux estimates.     

An explanation of linear increases in gas concentration under closed chambers used to measure gas exchange between soil and the atmosphere

Earlier models describing the accumulation of gases under closed chambers are based on the assumption of a constant concentration source that does not change during the time of chamber deployment. A new model is proposed which is based on the assumption of a constant production source, and takes into account possible changes in gas concentrations at the source during chamber deployment. Using N₂O as an example, simulations have been carried out for different source strength and depth, diffusivities and air porosities. The main finding was a chamber‐induced increase in gas concentrations in the upper part of the soil profile, including the depth where the N₂O source is located. The increase started immediately after chamber closure. Nevertheless, fluxes calculated from increasing concentrations within the chamber's headspace were always less than those expected under undisturbed conditions, i.e. in the absence of a chamber. This was due to a proportion of the gas produced being stored within the soil profile while the chamber was in place. The discrepancy caused by this effect increased with increasing air‐filled porosity and decreasing height of the chamber, and a procedure for correcting chamber flux measurements accordingly is proposed. The increase in soil gas concentrations after chamber closure was confirmed in a laboratory experiment.     

Effects of light and temperature on seed germination of Poa pratensis from high latitudes

One‐to‐three‐year‐old seed of Poa pratensis "Lavang”;, “Leikra”; and “Ryss”; was germinated under various temperature and light regimes on a thermogradient plate and on paper or in soil in phytotron compartments. While the optimal constant temperature for germination of Lavang and Leikra in 12 h light/12 h dark cycles was around 16°C, Ryss germinated nearly 100% over the 10–28°C temperature range. Compared with constant temperatures, daily fluctuations, even at the small amplitude 18/15°C, stimulated germination of Lavang and Leikra. Dark germination was inferior to germination in light/ dark cycles at constant temperatures of 15°C and higher, but light showed no advantage at alternating temperature. Continuous light inhibited germination regardless of light source (fluorescent, incandescent or natural). The stimulating effect of daily light/dark cycles increased, but the inhibiting effect of continuous light decreased with increasing seed age. It is concluded that seed of Poa pratensis ought to be covered by a 0.5–1.0 cm soil layer when sown in a northern environment involving continuous light and low soil temperatures.     

南方温室内空气循环式蓄热除湿系统的保温效果

为探索南方温室内空气循环式蓄热除湿系统的保温效果,设置了空气循环式冷凝除湿（冷凝处理）、土壤地面地膜覆盖降湿（覆盖处理）和普通换气除湿（对照）三种处理,观测了不同条件下温室内的气温和地温变化数据。结果表明：在晴天除湿系统运行期间,冷凝处理温室内下层气温明显比对照和覆盖处理的高,分别高0．9—2．7℃和0．2～1．7℃;在阴雨天（不启动除湿系统）,冷凝处理温室内各层的气温均高于或等于对照和覆盖。典型晴天,冷凝处理的5cm、10cm、15cm、20cm地温比对照分别高1．0～2．1℃、1．0～1．5℃、1．2～1．5℃、1．4～1．6℃。全年气温最低的1月份,冷凝处理温室下层的日平均气温均高于对照和覆盖,分别高0．1～2．3℃和0．1～1．5℃,其中高于0．5℃以上的天数分别为17d和18d。说明在南方地区冬季,空气循环式冷凝除湿系统具有明显的保温效果。     

不同孔隙度土壤气体扩散系数测定

土壤气体扩散系数是研究土壤气体传输过程的一个重要参数,它随土壤质地、容重和孔隙的改变而变化,难以估算,为准确测定和研究其特征,依据气体扩散原理设计并研制了土壤气体扩散系数测定装置。以石英砂和砂质壤土为试验材料,利用该装置研究了气体扩散系数与不同含水量和容重下的充气孔隙度间的关系。结果表明:砂质壤土原状土和装填土的气体扩散系数差别很小;土壤相对扩散系数随土壤总孔隙度减小而变小,且粒径较小的土壤具有相对较小的气体扩散系数;原状和装填砂质壤土的相对扩散系数与充气孔隙度之间的关系均可以用幂函数方程来拟合,方程中的参数与土壤质地密切相关,原状土非活性孔隙度为0。Buckingham模型的预测值与实测结果基本一致(均方根误差=0.008),但Millington and Quirk模型(均方根误差=0.032)和SWLR模型(均方根误差=0.023)的预测结果偏差较大。     

西藏高原地温对气温变化的响应

选取1971-2013年西藏西部、中部和东部8个气象站的浅层（5、10、20cm）地温和较深层（40、80cm）地温以及气温逐月的观测资料,采用气候倾向率法、Mann-Kendall（M-K）检验等方法,分析近43a西藏年、季平均气温,年、季平均地温,年平均地气温差的变化趋势以及地温与气温的气候突变关系,并对21世纪地温的变化趋势进行预估。结果表明：（1）各研究站点年平均浅层地温均呈显著上升趋势（P＜0.05）,其中藏西部和藏中部比藏东部增温显著;各季节几乎地温上升显著,其中冬、春季升幅显著高于夏、秋季。（2）年、季深层地温除昌都无显著变化外,其余站点几乎均呈显著上升趋势（P＜0.05）,其中狮泉河、日喀则、拉萨各季深层地温升幅显著高于同期浅层地温,而泽当和昌都各季深层地温升幅低于同期浅层地温。（3）研究地温对气温的响应发现,研究期内藏西部的狮泉河浅层年地气温差小于深层,藏中部的日喀则和拉萨浅层年地气温差20世纪90年代前大于深层,90年代后接近或小于深层;藏东部的昌都浅层年地气温差在80年代中期前小于深层,80年代中期后大于深层。各土层年平均地温与年平均气温均呈极显著正相关,不同土层年地温间也呈极显著正相关（P＜0.01）。（4）西藏21世纪地温随着气温显著升高,藏西部和藏中部增温幅度整体高于藏东部。年均地温高于气温,且其升温幅度大于气温,气温升高,地温增加,预估至21世纪末,昌都、拉萨、波密地温水平将分别达到偏南的八宿、泽当和察隅现有地温水平,相当于所有站点南移近1个纬度。