施用不同氮肥对盐碱地湖南稷子生产性能以及养分吸收的影响

为探讨盐碱地湖南稷子(Echinochloa frumentacea)高效生产的最佳施氮种类和施氮量,采用单因素随机区组设计,通过在湖南稷子拔节期设置不施肥(CK)、尿素和硫酸铵(N1,N2)轻施肥(F1:50 kg·hm^-2)、中施肥(F2:100 kg·hm^-2)、重施肥处理(F3:150 kg·hm^-2),研究不同氮肥和施氮水平下湖南稷子田间农艺性状、养分吸收及氮肥利用率的变化,探讨盐碱地湖南稷子实现高效生产的适宜氮肥和施氮量。结果表明：与对照相比,施氮量为F2和F3时能够显著提高盐碱地湖南稷子产量及氮磷钾吸收量(P<0.05),植株不同部位氮含量上升,施氮量F3时能够显著提高氮肥利用效率(P<0.05),且同一施氮量下追施硫酸铵后湖南稷子产量、养分吸收及氮肥利用率均高于尿素。综上所述,氮肥追施量在150 kg·hm^-2时,有利于盐碱地湖南稷子的产量的提升和养分的吸收,且同一条件下追施硫酸铵较追施尿素效果显著。     

多梯度氮磷添加对高寒草甸植物群落生物量与氮磷含量的影响

为研究不同梯度氮、磷单独及混合添加对高寒草甸植物群落生物量、植物养分含量及化学计量比的影响,本实验分析了青海省门源县典型高寒草甸植物群落地上总生物量,功能群水平地上生物量,植物全氮、全磷含量及氮磷比对多梯度氮、磷添加的响应情况。结果表明：氮、磷添加均对群落地上生物量影响极显著(P<0.001);氮添加对禾草类和豆科生物量影响极显著(P<0.001);磷添加对禾草类和莎草类生物量影响极显著(P<0.001);氮磷交互作用对豆科和莎草类生物量影响显著(P<0.05)。群落水平上,氮添加显著提高了植物全氮含量,对植物氮磷比(N∶P)有正效应,磷添加显著提高了植物全磷含量,对植物N∶P有负效应,植物全磷对N∶P的负效应大于全氮对N∶P的正效应。本研究表明氮、磷添加可能会使高寒草甸植物群落组成和植物养分含量发生改变,植物群落逐渐向禾草类发展;此外,高寒草甸植物生长趋向于受氮磷共同限制。     

循环流化床中塑料粉与稻壳共燃生成NO的研究

为研究塑料与稻壳共燃的氮氧化物生成规律，在自行设计的循环流化床装置上进行了二者的共燃实验。研究了温度、塑料粉和稻壳的混合比例及过量空气系数对NO生成量的影响。实验结果表明，随温度升高，NO生成量升高；随塑料粉与稻壳混合比例增加，NO生成量呈降低趋势，且NO的生成量低于二者单独焚烧时生成量的线性叠加；随着过量空气系数增加，NO生成量降低。为寻找二者共燃NO生成的一般性规律，采用径向基神经网络建立了NO生成的预测模型，预测结果显示该模型具有很高的精度。     

杂交水稻制种提高结实率的研究

杂交水稻制种不同于水稻栽培、其结实由柱头外露结实和非柱头外露结实两部分构成；空壳中90％以上是由于没有授粉受精造成的：90％以上的受精拉都能正常发育结实。柱头外露率和受精率与结实率呈显著正相关。后期施肥、父本大龄秧和机械授粉能有效地提高柱头外露率、花遇优度和结实率及制种产量。     

北方旱地土壤氮素平衡

北方大部分地区的旱地土壤中,农业氮素一般表现亏损,平衡强度约87%;园田土壤氮素略有盈余,平衡强度约123%.~(15)示踪研究表明,旱地土壤主要作物氮素利用率平均为27.04%,土壤残留24.79%,亏缺损失48.17%.园田主要蔬菜氮素和用率平均为29.11%,土壤残留22.67%,亏缺损失48.23%,其间差异很小.北方旱地施用铵态氮化肥主要损失是氨的挥发.影响氨挥发的因素有风速、温度、土壤水分、土壤质地、化肥品种.氮肥深施是防止氨挥发的有效方法.     

Analysis of the uncertainty associated with the estimation of nitrogen losses from farming systems

This work describes the analysis of the uncertainty linked to the annual direct and indirect losses of different nitrogenous compounds at the scale of a group of farms. The nitrogen (N) forms taken into account are: ammonia (NH₃), nitric oxide (NO), nitrous oxide (N₂O), dinitrogen (N₂) and nitrate (NO₃). The gaseous N emissions for the different components of the farms are estimated with a selection of adapted emission factors. The NO₃ losses at the farm scale are calculated as the difference between the surplus of the farm-gate N balance and the gaseous N emissions.     

不同生育期干旱对冬小麦产量及水分利用效率的影响

用盆栽对冬小麦不同生育阶段进行不同程度水分调亏试验结果表明 :拔节—孕穗期、抽穗—扬花期和灌浆—成熟 3个阶段内 RW上限为 4 0 %、5 0 %、60 %的水分亏缺均引起了产量的极显著下降 ,而且水分亏缺越严重 ,产量降低越大。在 3个生育阶段内进行 RW上限为 4 0 %的水分调亏减产幅度都很大 ,而且 3个生育阶段之间差异不明显 ;进行 5 0 %、60 %水分调亏 ,其减产程度则与生育期有关。灌浆—成熟期的减产程度大于前二个时期 ,这可能与前二个阶段复水后作物的补偿生长有关。不同生育期水分亏缺对冬小麦产量构成因素的影响也不同 ,拔节—扬花期水分亏缺主要减少了穗粒数 ,灌浆—成熟阶段的水分亏缺主要减少了千粒重     

Evaluation of the RZWQM-CERES-Maize hybrid model for maize production

The root zone water quality model (RZWQM) was developed primarily for water quality research with a generic plant growth module primarily serving as a sink for plant nitrogen and water uptake. In this study, we coupled the CERES-Maize Version 3.5 crop growth model with RZWQM to provide RZWQM users with the option for selecting a more comprehensive plant growth model. In the hybrid model, RZWQM supplied CERES with daily soil water and nitrogen contents, soil temperature, and potential evapotranspiration, in addition to daily weather data. CERES-Maize supplied RZWQM with daily water and nitrogen uptake, and other plant growth variables (e.g., root distribution and leaf area index). The RZWQM-CERES hybrid model was evaluated with two well-documented experimental datasets distributed with DSSAT (Decision Support System for Agrotechnology Transfer) Version 3.5, which had various nitrogen and irrigation treatments. Simulation results were compared to the original DSSAT-CERES-Maize model. Both models used the same plant cultivar coefficients and the same soil parameters as distributed with DSSAT Version 3.5. The hybrid model provided similar maize prediction in terms of yield, biomass and leaf area index, as the DSSAT-CERES model when the same soil and crop parameters were used. No overall differences were found between the two models based on the paired t test, suggesting successful coupling of the two models. The hybrid model offers RZWQM users access to a rigorous new plant growth model and provides CERES-Maize users with a tool to address soil and water quality issues under different cropping systems.     

水稻旱作覆膜节水增产试验研究

通过水稻旱作全程覆膜与半程覆膜、旱作不覆膜及水栽对比试验，研究其耗水规律，计算其节水量与增产量，并进行经济效益分析，提出了适合本地区的栽培模式。     

水稻灌溉效益分摊系数试验研究

通过试验方法，选择不同的降雨年型，系统地分析了淠史杭灌区不同降雨年型的灌溉增产率，灌溉效益扮摊系数；找出了水稻灌溉效益分摊系数与水稻生育期降雨量，灌水量之间的经验公式，对本地区及气候条件相似地区具有一定的参考价值。