宁夏回族自治区平罗县主要农作物碳足迹研究

农田碳足迹可以全面地反映农作物生产过程中各种因素引起的碳排放效应,是指导农业生产节能减排的重要指标。为探明农作物生产的碳足迹,基于宁夏回族自治区平罗县农田生产的实地调查数据,利用碳足迹的基本理论和方法,测算了该县农作物碳足迹。结果表明,水稻、玉米和小麦的碳足迹分别为1 487.56±164.59,913.03±142.99和809.75±144.99kg Ce/(hm2.a);碳成本分别为0.17±0.05,0.08±0.02g和0.12±0.03kg Ce/kg;化肥的施用量是影响碳足迹的主要因素,而水稻生产过程中灌溉水及育秧过程也是其碳足迹较高的主要原因。为了提高农田固碳减排增汇效益,应压缩水稻种植面积,扩大玉米和小麦种植,同时,建立节肥低碳高效的种植模式是实现平罗县农田节能减排的有效途径。     

北京市怀柔区设施种植业废弃物处理现状及发展

针对北京市怀柔区设施种植业废弃物处理的现状,分析废弃物处理过程中存在的问题,并提出相应的解决措施。     

Can sieving size affect the determination of soil available micronutrients?

<正>Dear Editor,Globally, approximately two billion people suffer from micronutrient deficiencies(Tulchinsky, 2010; Myers et al.,2014).Soil micronutrient availability is of great importance for the evaluation of soil fertility and the determination of appropriate measures for improving crop quality and human health.The diethylenetriamine-penta-acetic(DTPA)     

集对分析法在区域雨水资源开发利用潜力综合评价中的应用

探讨了区域雨水资源开发利用潜力的综合评价方法,并将集对分析理论应用于该研究,建立了区域雨水资源开发利用潜力综合评价模型。实例分析表明,该方法用于评价区域雨水资源开发利用潜力,方法简单,评价结果符合实际情况。     

马尾松人工林施肥试验初报

本文通过对马尾松人工林施肥试验，表明在Ⅲ类地，适量施尿素和过磷酸钙可促进幼林树高、胸径生长。     

夏玉米田作物蒸腾与棵间土壤蒸发模拟计算方法研究

本文依据能量平衡原理和质量守恒定律，提出了作物蒸腾与棵间土壤蒸发的估算模式，并对参数的估算做了详细的分析和讨论。最后利用试验区实测资料，通过田间水热耦合运移的数值模拟，对夏玉米田作物蒸腾棵间土壤蒸发模型及其模拟计算方法进行了验证，结果表明，本文提出的模型和模拟计算方法是有效而实用的。     

马关县草果种植地的施肥效果试验

在马关县仁和镇的4年生草果种植地开展了施用不同量的农家肥、钾肥、普钙和复合肥促进草果植株开花结实效果的试验。结果表明:对该地的草果种植地进行合理的施肥能有效促进草果植株叶芽、花芽的分化,提高其结实率及结实量。各施肥处理的草果植株在叶芽数量、花芽数量、结实率及结实量等4个指标上均优于不施肥的对照,分别比对照提高了24.4%~204.9%、22%~97.6%、5.4%~36.9%和72.4%~442.3%。各施肥处理的草果植株在叶芽数量及结实量2个指标上存在极显著的差异,而在花芽数量及结实率2个指标上无显著差异。综合各施肥处理的草果植株结实量及结实率,在马关县及其土壤状况相似的草果种植地较佳的施肥肥种为钾肥或复合肥,其施肥量为钾肥200 g/株(丛)或复合肥400 g/株(丛),前者草果植株单株(丛)的结实量达8.46 kg,比不施肥的对照高442.3%,后者草果植株单株(丛)结实量达7.82 kg,比不施肥对照高401.3%。     

零通量面法用于农田蒸发蒸腾量的研究

应用土壤水分零通量面的原理方法,对北京房山节水灌溉区进行了研究。通过土壤水势监测分析,显示了灌区在研究时段内零通量面的性质及其出现的空间位置。用数值方法处理了零通量面随时间变化的情况,计算了监测时段的蒸发蒸腾量,并与大田水量平衡模型法、作物系数-参考作物需水量法进行了比较。     

Effects of isorhapontigenin on cell cycle arrest and down-regulation of cyclin D1 expression in bladder cancer cells

AIM：To explore the inhibitory mechanism of isorhapontigenin (ISO) on the proliferation, migration and invasion of UMUC3 bladder cancer cells. METHODS：Human UMUC3 bladder cancer cells were pretreated with ISO, and the proliferation of the cells was observed under phase-contrast microscope and by ATPase assay. The expression of cyclin D1 was determined by RT-PCR and Western blotting. The cell cycle alteration was detected by flow cytometry, and the cell migration was examined by wound-healing assay. RESULTS：Over 20 μmol/L of ISO significantly inhibited the proliferation of UMUC3 cells with the IC50 of (22.5±2.8) μmol/L. The mRNA and protein levels of cyclin D1 in UMUC3 cells were markedly decreased after treatment with ISO. Exposure of UMUC3 cells to low dose (5 μmol/L) of ISO led to significant induction of G0/G1 growth arrest at both 12 h (58.82%) and 24 h (63.94%), compared with the negative control cells (47.33%) without inducing obvious apoptosis. ISO at dose of 5 μmol/L also markedly inhibited the cell migration. CONCLUSION：ISO significantly exhibits inhibitory effects on the proliferation and migration of human bladder cancer cells by down-regulation of cyclin D1 expression accompanying with G0/G1 cell cycle arrest.