Cutting frequency and stubble height of reed canary grass (Phalaris arundinacea L.): influence on quality and quantity of biomass for biogas production

Abstract Reed canary grass (RCG) used for land treatment of waste water can serve as a substrate for biogas production. The aim of this experiment was to study the effects of two, three or four cuts per year to stubble heights of 5, 12·5 or 20 cm on the digestibility and yield of digestible organic matter (DOM) of RCG. Both dry‐matter yield and the yield of DOM decreased with more than two cuts per year. Height of cutting had no effect on the digestibility of the regrowth harvested from the different cutting regimes. Increased height of cutting resulted in increased dry‐matter production and therefore also of increased DOM yield in the regrowth harvested from the four‐cut regime. The total DOM yield from the four‐cut regime was, however, only 0·84 of the DOM yield from the two‐cut regime.     

棉花芦管育苗新技术研究 Ⅰ.芦管育苗对棉苗素质的影响

试验于１９９６～１９９８年在扬州大学农学院内进行，供试棉花品种为苏棉８号。春、夏播棉芦管育苗和传统营养钵育苗对比试验结果指出，芦管育苗棉花出苗率和生育进程与对照无明显区别；但是，幼苗期阶段根、茎、叶生长均处弱势地位；而大苗期后，长势逐渐增强，到了现蕾期，棉株长势和根、茎、叶干物质积累量均接近或超过对照。这种前弱后强的苗情发展特点，是其特有的双层根阶段性影响的结果。芦管苗双层根的形成，引根大量深扎，对棉花蕾期稳发和防后期早衰均具有重要意义     

Relations between soil heterogeneity and common reed(Phragmites australis Trin.ex Steud.) colonization in the Keriya River Basin,Xinjiang of China

How common reed （Phragmites australis Trin. ex Steud.） colonization correlates to soil heterogeneity and environmental determinants remains unclear in arid areas. We conducted a field investigation and soil sampling in 100 plots along Keriya River Basin to uncover the relationship between common reed and heterogeneous soils. Reed colonization variables and its soil properties were measured and recorded for the analysis of their relationship using Pearson correlation and redundancy analysis methods. The comparison results of common reed characteris- tics among 100 plots showed that common reeds performed strong tolerance and ecophysiological plasticity to edaphic stresses. Common reed colonization was tightly connected to soil heterogeneity according to the correla- tion analysis between its colonization characteristics and soil properties. Common reed colonization got feedbacks on soil properties as well, including the increase of soil organic matter and the alleviation of salt uplifting. The main limiting environmental determinant of common reed colonization was soil salt, followed by pH and soil water content.     

芦苇微咸水适宜灌溉模式研究

以湿地芦苇生产区为研究背景,设置单因素和双因素交互作用试验。基于数理统计方法讨论了不同灌溉水盐度和水位深度对芦苇植株高度、基茎粗和产量的影响。单因素试验表明:芦苇基茎粗呈平缓降低趋势,低盐度范围内芦苇株高变化趋势不明显,高盐度抑制芦苇生长,采用小于0.9%盐度的水灌溉芦苇对其产量影响不显著;芦苇的株高和基茎粗随水位升高而增加,高水位范围内株高增长不明显,灌溉水层保持在20~25 cm芦苇长势较好。因此,从双因素交互作用分析结果中可以得出结论:盐度和水深均是制约芦苇生长和产量的重要因子。采用盐度上限0.9%,水层深度20~25 cm咸淡水混合灌溉模式比较理想。     

湿地芦苇动态水分生产函数研究

以芦苇主产区盘锦双台子河口湿地为研究背景,在分析芦苇干物质生长规律的基础上,经回归分析得出了芦苇干物质随时间累积的数学模型.依据旱作物动态产量模型,运用分阶段线性函数形式构造了水分亏缺影响函数并对参数进行了拟合,建立了盘锦双台子河口湿地芦苇生产区芦苇水分生产函数动态产量模型.     

控制性间歇灌溉模式下湿地芦苇节水潜力分析

通过充分灌溉和控制性间歇灌溉方式对芦苇需水进行了研究.研究结果表明:两种灌溉模式对芦苇蒸腾影响不显著,对芦苇棵间水分蒸发和田间渗漏影响明显,棵间蒸发和田间渗漏是水分损失的主要因素,控制田间蒸发和田间渗漏量具有明显的节水潜力.     

芦苇缺乏某种主要矿质元素表现症状的试验

土壤肥力是芦苇产量高低的先决条件,施肥是提高苇田单产的必要手段。配制不同成分的生长液对芦苇进行水培,根据芦苇生长情况,分析各营养素对芦苇生长的作用,以期为苇田科学合理施肥提供依据。     

麦田芦苇空间分布型及抽样技术初报

对麦田中芦苇的空间分布型及抽样技术进行了调查,结果表明,芦苇的空间分布为聚集分布,分布的基本成分是个体群,且聚集强度随着杂草密度的增加而增强.     

Light competition for invasive species control: A model of cover crop–weed competition and implications for Phalaris arundinacea control in sedge meadow wetlands

Summary Since resource competition plays a critical role in many plant invasions, controlling invasive vegetation may require managing the supply of limiting resources. For example, lowering light availability with a cover crop might prevent invasions during community establishment in light-limited restored ecosystems. However, most cover crops evaluated for invasive species control either do not adequately suppress invasives or equally suppress desired species. To improve our ability to predict cover crop effectiveness, we use a theoretical model of plant competition to identify potential mechanisms by which cover crops might favor desired species over invasives. In addition, we consider the model's implications for controlling an invasive forage, Phalaris arundinacea, in restored sedge meadows. The model suggests that cover crops will improve the outcome of competition between desired and invasive species only when (1) desired species have lower minimum light requirements than invasive species and (2) invasive species dominance results from rapid establishment and resource preemption. Cover crops in the model favor desired species over faster-growing invasives because faster-growing invasives are positioned higher in the canopy. Invasive species higher in the canopy shade desired species more than desired species shade invasives. Consequently, by reducing invasive species biomass, cover crops give desired species a competitive advantage. The simple requirements for cover crop success in the model suggest that cover crops may be effective for invasive species control in light-limited restored ecosystems. The available information on P. arundinacea responses to shade suggests, however, that cover crops are unlikely to favor sedge meadow species over P. arundinacea.     

苇浆抄造性能的研究

本文研究了硫酸盐法苇浆和亚硫酸镁盐法苇浆的抄造性能，在某一打浆度下，两种苇浆具有较好的抄造性能，两种苇浆的湿纸页干度与粘附力的关系有很大的差异；适当地提高打浆度和控制好湿纸干度，硫酸盐法苇浆能够获得较好的抄造性能。