小麦种质资源耐深播性评价体系研究

为建立准确、简单易行的种质资源耐深播评价体系,以15份耐深播能力存在不同程度差异的小麦种质为材料,在大田环境下,研究6个播种深度(5 cm、7 cm、9 cm、11 cm、13 cm、15 cm)下小麦出苗率、出苗时间、苗高、地中茎长、胚芽鞘长、胚芽鞘横截面积及初生根长的差异,筛选小麦耐深播评价的最佳播种深度及其密切相...     

天山北坡蒸发观测误差对比分析

本文以天山北坡阜北农场和哈地坡站为例，以Φ２０ｃｍ蒸发皿加水深２０ｍｍ为基础，对蒸发皿内加水深度不同，含盐浓度不同的蒸发量观测误差进行分析，揭示加水深度不同，含盐浓度不同，蒸发观测结果不同相互间的不同。     

Predicting soil organic matter stability in agricultural fields through carbon and nitrogen stable isotopes

In order to evaluate the sustainability and efficiency of soil carbon sequestration measures and the impact of different management and environmental factors, information on soil organic matter (SOM) stability and mean residence time (MRT) is required. However, this information on SOM stability and MRT is expensive to determine via radiocarbon dating, precluding a wide spread use of stability measurements in soil science. In this paper, we test an alternative method, first developed by Conen et al. (2008) for undisturbed Alpine grassland systems, using C and N stable isotope ratios in more frequently disturbed agricultural soils. Since only information on carbon and nitrogen concentrations and their stable isotope ratios is required, it is possible to estimate the SOM stability at greatly reduced costs compared to radiocarbon dating. Using four different experimental sites located in various climates and soil types, this research proved the effectiveness of using the C/N ratio and δ¹⁵N signature to determine the stability of mOM (mineral associated organic matter) relative to POM (particulate organic matter) in an intensively managed agro-ecological setting. Combining this approach with δ¹³C measurements allowed discriminating between different management (grassland vs cropland) and land use (till vs no till) systems. With increasing depth the stability of mOM relative to POM increases, but less so under tillage compared to no-till practises. Applying this approach to investigate SOM stability in different soil aggregate fractions, it corroborates the aggregate hierarchy theory as proposed by Six et al. (2004) and Segoli et al. (2013). The organic matter in the occluded micro-aggregate and silt & clay fractions is less degraded than the SOM in the free micro-aggregate and silt & clay fractions. The stable isotope approach can be particularly useful for soils with a history of burning and thus containing old charcoal particles, preventing the use of ¹⁴C to determine the SOM stability.     

PIANT WATER REQUIREMENT AND SUITABLE DEPTH OF GROUND WATER LEVEL IN WEST RANGELAND OF INNER MONGOLIA

<正> Ejina rangeland is located in Alashan Laegue, west part of Innermongolian Autono-mous Region with a area of 1.22×10~4 square Km of which the available area is 6940 squareKm, Because the varieties of reasons, such as natural, human, historic and present, therunoff of Ejina River is decreased year by year, the irrigated area of the rangeland is de-creased. The deterioration of the ecologic environment is caused by the degeneration of the     

不同覆水深度对莲藕腐败病菌越冬种群动态的影响

莲藕腐败病菌所引起的腐败病是制约莲藕生产的重要因子,土壤带菌是该病害主要初侵染源。为探明该病菌在土壤中越冬数量的变化动态,研究了不同覆水深度下,病原菌在土壤中越冬存活数量。研究结果表明,不同水层下莲藕腐败病菌的存活数量存在差异,但种群变化动态趋势较为相似,6 cm覆水深度下的病菌数量大于2 cm覆水深度的;此外,温度、降水量等气候因子对该菌的种群变化也有一定的影响。     

栽培深度对百合子球繁育的影响

[目的]为百合的种球生产提供指导。[方法]以2个东方百合品种和2个亚洲百合品种为材料,设栽植深度51、01、5 cm,研究栽植深度对百合子球繁育的影响。[结果]栽植深度对亚洲百合直径膨大倍数和重量膨大倍数的影响差异不显著,对2个东方百合品种子球膨大的影响差异较大。东方百合分生小子球的能力一般都比较弱,亚洲百合仅"白天使"分生子球的能力比较弱,但子球系数均随栽植深度的增加而增加。栽植深度对百合子球地上部分生长的影响比较大,5 cm栽植深度的子球的地上部分起始时间显著高于其他栽植深度,但后期高度基本一致。[结论]10 cm的栽植深度比较适宜于东方百合。相对较深的栽培深度,可以大大提高百合子球的生成率。     

A study to determine an equation of enveloping curve for regional flood peaks by maximum rainfall data

In this paper, Creagers equation and Groups equation are algebraically examined to determine an equation of an enveloping curve for regional flood peaks from the viewpoint of the curve profile. The applicability of a small drainage area with little observed data on flood peak discharge was examined in comparison to specific flood peak discharge calculated by a rational formula using data of maximum rainfall. In the algebraical consideration, the Creagers equation had an extreme value at a drainage area A=1.0 km², and the specific flood peak discharge became a maximum. Flood peak discharge calculated by Groups equation had an extreme value at a drainage area A=6,568 km², and it became a maximum. Except for Hokkaido, in catchment areas not exceeding 1,178 km², Groups curve q _K was closer to the curve q _DAD of specific flood discharge than Creagers curve qc. From the above research results, the Groups equation is applicability better than the Creagers equation, as the drainage area A is 1,178 km² or less.     

耕作深度对加工专用型花生赣花92-01的抗旱效果研究

为了应对南方红壤旱地经常出现的伏旱对花生生产造成的不利影响,选择示范推广中的加工专用型花生赣花92-01为供试品种,研究了不同耕作深度对赣花92-01的抗旱效果对比。结果表明,该品种在生长过程中的各项生理指标及产量和产量因子的表现均以耕作深度为20cm的效果最好,耕深30cm的效果次之,耕深10cm的效果最差。     

中国土壤中钙积层深度与年降水量关系的定量研究

在国内外相关研究的基础上,总结了土壤中钙积层深度与年均降水量存在函数关系的前提条件,并对中国区域内不同钙质土壤进行了广泛深入的研究,筛选出48个土壤剖面,建立了适用于我国区域的新的土壤钙积层深度x（cm）与年均降水量y（mm）的函数关系式：y=-0.069 3x2＋12.063 0x＋68.499 0,其中相关系数R2=0.725 4（n=48）。利用这一关系式可根据古土壤推算古降水量,为研究古土壤与古气候定量重建提供更为精确、可靠的数据。     

梭梭种子育苗技术试验

以播种日期和播种深度为主要因子,研究其种子育苗的关键技术。结果表明,早春（4月5日）播种,土壤保墒好,梭梭种子在田间出苗率在50％以上,占种子有胚率（68％）的74％,苗齐而壮;播种覆土0cm、1cm和2cm三处理差异小,出苗较多,平均出苗率为13．85％;4cm、6cm和8cm三处理差异大,出苗少,平均出苗率仅为1．14％,两者相差12．15倍。覆土4cm以上已失去了播种价值。