Comparison of modeling approaches to quantify residue architecture effects on soil temperature and water

RZ-SHAW is a hybrid model, comprised of modules from the Simultaneous Heat and Water (SHAW) model integrated into the Root Zone Water Quality Model (RZWQM) that allows more detailed simulation of different residue types and architectures that affect heat and water transfer at the soil surface. RZ-SHAW allows different methods of surface energy flux evaluation to be used: (1) the SHAW module, where evapotranspiration (ET) and soil heat flux are computed in concert with a detailed surface energy balance; (2) the Shuttleworth–Wallace (S–W) module for ET in which soil surface temperature is assumed equal air temperature; and (3) the PENFLUX module, which uses a Penman transformation for a soil slab under incomplete residue cover. The objective of this study was to compare the predictive accuracy of the three RZ-SHAW modules to simulate effects of residue architecture on net radiation, soil temperature, and water dynamics near the soil surface. The model was tested in Akron, Colorado in a wheat residue-covered (both standing and flat) no-till (NT) plot, and a reduced till (RT) plot where wheat residue was incorporated into the soil. Temperature difference between the soil surface and ambient air frequently exceeded 17 °C under RT and NT conditions, invalidating the isothermal assumption employed in the S–W module. The S–W module overestimated net radiation (R_n) by an average of 69 Wm⁻² and underestimated the 3-cm soil temperature (T_s3) by 2.7 °C for the RT plot, attributed to consequences of the isothermal assumption. Both SHAW and PENFLUX modules overestimated midday T_s3 for RT conditions but underestimated T_s3 for NT conditions. Better performances of the SHAW and PENFLUX surface energy evaluations are to be expected as both approaches are more detailed and consider a more discretized domain than the S–W module. PENFLUX simulated net radiation slightly better than the SHAW module for both plots, while T_s3 was simulated the best by SHAW, with a mean bias error of +0.1 °C for NT and +2.7 °C for RT. Simulation results for soil water content in the surface 30 cm (θ_v30) were mixed. The NT conditions were simulated best by SHAW, with mean bias error for θ_v30 within 0.006 m³ m⁻³; RT conditions were simulated best by the PENFLUX module, which was within 0.010 m³ m⁻³.     

Enhancing the Simplified Surface Energy Balance (SSEB) approach for estimating landscape ET: Validation with the METRIC model

Evapotranspiration (ET) can be derived from satellite data using surface energy balance principles. METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is one of the most widely used models available in the literature to estimate ET from satellite imagery. The Simplified Surface Energy Balance (SSEB) model is much easier and less expensive to implement. The main purpose of this research was to present an enhanced version of the Simplified Surface Energy Balance (SSEB) model and to evaluate its performance using the established METRIC model. In this study, SSEB and METRIC ET fractions were compared using 7 Landsat images acquired for south central Idaho during the 2003 growing season. The enhanced SSEB model compared well with the METRIC model output exhibiting an r² improvement from 0.83 to 0.90 in less complex topography (elevation less than 2000 m) and with an improvement of r² from 0.27 to 0.38 in more complex (mountain) areas with elevation greater than 2000 m. Independent evaluation showed that both models exhibited higher variation in complex topographic regions, although more with SSEB than with METRIC. The higher ET fraction variation in the complex mountainous regions highlighted the difficulty of capturing the radiation and heat transfer physics on steep slopes having variable aspect with the simple index model, and the need to conduct more research. However, the temporal consistency of the results suggests that the SSEB model can be used on a wide range of elevation (more successfully up 2000 m) to detect anomalies in space and time for water resources management and monitoring such as for drought early warning systems in data scarce regions. SSEB has a potential for operational agro-hydrologic applications to estimate ET with inputs of surface temperature, NDVI, DEM and reference ET.     

木本能源植物黄连木研究进展

介绍了前人对黄连木生物生态与生理学特性、繁殖与栽培技术、病虫害防治等的研究工作;概述了黄连木的药用价值、用作工艺良材及阿月浑子砧木等用途;并对进一步的研究方向进行了论述.     

能量饲料发芽处理后酶活性变化的研究

本文对三种能量饲料（玉米、大麦、小麦）经发芽处理后，α－淀粉酶，（α＋β）一淀粉酶、蛋白酶、纤维素酶活性变化进行分析研究。结果表明：禾谷类籽实荫发后，酶活性迅速上升，随发芽时间的增长，大麦中纤维素酶活性显著降低，自然晒制后，并不影响酶活性大小，仅幼芽中的酶活性低于发芽后的整粒籽实。     

安徽省粮食作物全素平衡施肥研究

运用土壤养分系统诊断技术对长江流域的小麦，江淮丘陵区域的水稻和淮北平原的玉米进行了全素平衡施肥田间试验。结果表明：采用新的施肥技术与目前通用施肥模式相比，小麦、玉米和水稻分别增产９％～２０％，７％～１６％和６％～１１％。还证实硫肥对淮北玉米有增产效果。采用能量——经济学评价方法对肥料效应进行了系统评估，认为土壤养分系统诊断技术可在安徽省“二高一优”农业中广泛应用     

密度对凡纳滨对虾存活、生长和能量收支的影响

研究了密度(12.04、24.08、48.16、144.49、240.81、337.13、433.46、529.78、626.11尾/m2)对凡纳滨对虾(平均初始湿重0.026±0.006g)存活、生长和能量收支的影响。实验周期45d。结果表明:I.12.04、24.08和48.16尾/m2密度水平对虾的存活率显著高于626.11尾/m2密度水平,但与其它处理差异不显著;II.12.04和24.08尾/m2密度水平对虾的特定生长率显著高于其它处理,特定生长率(SGRd)与密度(D)的回归方程为:SGRd=-0.3911Ln(D) 10.068(R2=0.8745)。     

小麦灌浆期中光能供求关系模拟与南京地区合理株型的探讨

提出了一个数学模型,对南京地区(32.04°N,118.5°E)小麦籽粒灌浆期中光能供求关系作模拟,以消光系数的日变化为反映株型的指标,从叶水平角随灌浆日进程所应具有的动态表现探讨本地区辐射条件下的合理株型。利用模型对不同基因型的光能利用率作了具体分析。分析表明,在辐射资源不足的南京地区,小麦叶片的水平角随灌浆进程以有一个由直立而水平再至倒垂的动态过程为宜。     

基于小气候模型的温室能耗预测系统研究

【目的】建立一个基于温室小气候模型的温室冬季加温所需基础能耗计算机预测系统，为进一步研究中国温室环境的优化调控提供依据。【方法】根据能量平衡原理，综合考虑作物蒸腾对温室运行能耗的影响，建立了温室加温所需基础能耗预测系统。利用温室作物蒸腾和小气候观测试验资料确定了温室小气候模型中的作物参数，并用上海两个Venlo型自控温室2001年～2003年3个冬季的实际耗煤量对系统预测结果进行了检验。【结果】对两个温室冬季加温能耗预测结果与实际耗煤量统计分析回归方程分别为（x和y分别为实际值和预测值）y＝0.8526x和y＝0.8321x；决定系数R2分别为0.85和0.90；相对误差分别为27%和29%。结果表明，系统对能耗预测结果与实际耗煤量趋势一致。【结论】本研究建立的温室加温能耗预测系统是建立在温室小气候模型的基础上，其原理具有普适性，因此具有通用性强的特点。     

Effects of pioglitazone on myocardial energy metabolism and hemodynamics in rats with myocardial infarction

AIM: To observe the effects of pioglitazone on myocardial energy metabolism and hemodynamics in rats with heart failure after myocardial infarction (MI). METHODS: The model of MI was established by ligation of left anterior descending artery. The 20 surviving rats were randomly divided into MI group (n=10) and pioglitazone intervention group (P group,n=10, pioglitazone 3 mg·kg^-1·d^-1 orally). The sham-operated rats (SH, n=10) served as controls. Hemodynamic parameters were measured. The ratio of left ventricular weight to body weight (LVW/BW) and the ratio of right ventricular weight to body weight (RVW/BW) were calculated after 8-week treatment. The expression of PPARγ was examined by Western blotting. Mitochondrial respiratory function was determined by Clark oxygen electrodes. The size of adenine acid pool (ATP, ADP and AMP) in mitochondria was measured by HPLC. The adenine nucleotide translocator(ANT) activity was detected by the atractyloside-inhibitor stop technique. RESULTS: Compared with SH group, the protein expression of PPARγ was significantly decreased in MI group (P<0.01). The mitochondrial respiratory activity, the transport activity of ANT and the high-energy phosphate content were decreased in MI group (P<0.01), and the hemodynamic parameters were in disorder (P<0.01). Compared with MI group, the protein expression of PPARγ in P group was significantly increased. The mitochondrial respiratory activity, the high-energy phosphate content, the transport activity of ANT were improved (P<0.01). However, the hemodynamic parameters were not significantly changed.CONCLUSION: Pioglitazone increases the protein expression of PPARγ and improves myocardial energy metabolism in the development of heart failure in the rat model of myocardial infarction, but dose not change the hemodynamic parameters significantly.     

Presence and dispersal of infective Frankia in peat and meadow soils in Sweden

Summary Use of the N₂-fixing grey alder, Alnus incana (L.) Moench, as a short-rotation crop for energy production is currently being explored. To evaluate the need for inoculation of alders, the distribution of infective propagules of Frankia in the soil at potential sites for alder plantations was examined. Uninoculated grey alder seedlings were grown in three types of soil. Frequent nodulation was found in a meadow soil which had been free from actinorhizal plants for nearly 60 years, but the alder seedlings failed to nodulate in peat soil from two different bog sites. One of these bogs had been exploited for peat and the surface layer of the peat had been removed, so that the soil samples were taken from deep layers of the peat. At the other site, an area of cultivated peat, there were no infective propagules of Frankia in plots without alders; the infective Frankia was present in plots only where it had been introduced by inoculated alders. There was no detectable air-borne dispersal of Frankia. Instead, water movement might account for the dispersal of Frankia in peat. Although the apparent absence of Frankia in these peat soils necessitates inoculation of alder seedlings before planting out, this makes it possible to introduce and maintain Frankia strains with selected beneficial characteristics, since there is no competition from an indigenous Frankia flora.