农田沙漠化演变中土壤质量的生物学特性变化   总被引：9，自引：5，他引：9  

苏永中  赵哈林  张铜会  文海燕 《干旱区研究》2002,19(4):64-68

通过研究处于沙漠化过程中的科尔沁沙地旱作农田土壤酶活性与基础土壤呼吸活性，分析了土壤质量生物学特性的沙漠化演变。结果表明，土壤酶活性与基础土壤呼吸对沙漠过程中环境的变化反应敏感，随着沙漠化程度增加，与土壤物理化学肥力因素有关的过氧化氢酶、脲酶和碱性磷酸酶的活性和土壤呼吸活性随之下降。土壤酶活性和呼吸活性与土壤有机质和养分有极显著的相关，在一定程度上可以用酶活性和呼吸强度表征有机质和养分的状况及其数量的变异，因此，可以作为农田沙漠化演变中土壤质量特征变化的重要辅助指标。  相似文献   

Ranking cows’ methane emissions under commercial conditions with sniffers versus respiration chambers     

G. F. Difford  D. W. Olijhoek  A. L. F. Hellwing  P. Lund  M. A. Bjerring  Y. de Haas 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2018,68(1):25-32

This study assessed the ranking of dairy cows using individual-level correlations for methane (CH₄) emission on-farm using sniffers and in respiration chambers. In total 20 lactating dairy cows, ten Holstein and ten Jerseys were recorded using sniffers installed in milking robots for three weeks of lactation and subsequently in respiration chambers (RC) where they were each recorded on three occasions within the RC. Bivariate linear mixed models were used to determine the individual-level correlations (r_I) between sniffer and RC phenotypes as proxies for genetic correlations. Despite differences in feeding and management, the predicted CH₄ production from sniffers correlated highly with RC CH₄ production r_I?=?0.77?±?0.18 and CH₄ breath concentration correlated nearly as well with RC CH₄ production r_I?=?0.75?±?0.20. These correlations between sniffers on-farm and RC demonstrate the potential of sniffers measurements as large-scale indicator traits for CH₄ emissions in dairy cattle.  相似文献   

Short‐term releases of CO2 from newly mixed biochar and calcareous soil          下载免费PDF全文

R. Cardelli  M. Becagli  F. Marchini  A. Saviozzi 《Soil Use and Management》2016,32(4):543-545

The work aimed to quantify native organic C mobilized in one calcareous soil in the 21 days after addition of biochar at a range of large to very large applications. The experiment was carried out in unplanted microcosms, and CO₂ flux was used as a measure of net mineralization. A rapid methodological approach, which does not require ¹³C as a tracer, was used to assess any priming effects induced by the biochar. The amount of CO₂‐C mobilized was small relative to the amount of biochar C and proportional to the amount of the biochar added. The additional CO₂‐C was similar to the content of the water‐soluble organic carbon in the biochar added with each application. No interaction with native soil C, that is priming effect, was observed.  相似文献   

低温胁迫对蓝莓枝条呼吸作用及生理生化指标的影响   总被引：2，自引：0，他引：2  

张悦  周琳  张会慧  魏殿文 《经济林研究》2016,(2):12-18

为明确蓝莓枝条不同部位的耐低温能力,利用人工模拟低温胁迫的方法研究了蓝莓1年生枝条尖端、1年生枝条基端和2年生枝条对低温胁迫的生理响应。结果表明:低温胁迫下蓝莓不同部位枝条的各生理指标之间虽然具有一定的相关性,但不同生理指标的相关系数差异较大,即蓝莓枝条不同生理过程对低温的敏感性明显不同。其中,0℃时1年生枝条特别是其尖端的呼吸速率明显高于2年生枝条,但其呼吸作用对低温也特别敏感,当温度降低到-10℃时即均发生明显的降低,且1年生枝条尖端的降低幅度最大。另外,低温胁迫下1年生枝条尖端的丙二醛(MDA)含量和相对电导率增加幅度也明显大于1年生枝条基端和2年生枝条,即1年生枝条尖端对低温胁迫更为敏感。低温胁迫下不同部位枝条虽可以通过增加可溶性糖(SS)和可溶性蛋白(SP)等渗透调节物质,以及增强SOD和POD等抗氧化酶活性的方式来提高其抗寒能力,但当温度降低到-40℃时,不但抑制了蓝莓1年生枝条尖端可溶性蛋白的合成,并且1年生枝条尖端和基端的SOD活性较-20℃时也有不同程度的降低,即-40℃时1年生枝条特别是其尖端蛋白质合成的抑制以及抗氧化酶活性的降低可能是导致其蓝莓在我国北方大兴安岭地区易发生冻、干梢现象的主要原因。而1年生枝条基端和2年生枝条具有较强抗低温能力的原因除了其本身代谢活性较低,对低温不敏感外,低温下有效积累渗透调节物质和增强抗氧化酶的活性在降低其膜质过氧化程度和电解质外渗方面发挥了重要的作用。  相似文献   

Soil aggregate formation and stability induced by starch and cellulose     

《Soil biology & biochemistry》2015

Soil aggregate (SA) can be formed and stabilized when soil organic matter (SOM) is decomposed in the soil. However, the relationships between the SA dynamics and SOM with different decomposition rates have not been clarified. Therefore, this study examined the effects of the addition of polysaccharides to soil on SA formation and stability. A Japanese tropical soil was incubated for 99 d at 30 °C in a dark environment following the addition of 0.5% (w/w) starch or cellulose. The decomposition rates of the amendments, and SA formation and stability were evaluated by measuring soil respiration rates, and distribution fractions of soil aggregate sizes and mean weight diameter (MWD) of SA, respectively. The cumulative soil respirations with all treatments rapidly increased until Day 12 of the incubation. The initial slope of the cumulative soil respiration in the soil with starch was significantly higher than that in the soil with cellulose. In either soil with starch or cellulose, the fractions of macro-aggregates (>1000 μm in diameter) significantly increased, respectively, compared with control soil. However, the fractions of meso-aggregates (250–1000 μm) and nano-aggregate (<20 μm) in the soil with starch significantly decreased, while those fractions in the soil with cellulose fluctuated until Day 6. The MWDs reached the maximum on Day 6, indicating the SA formation in the soils with starch or cellulose. The increasing rate of the SA formation in the starch-amended soil was greatly higher than that in the cellulose-amended soil. After Day 6, the MWDs in the soils with either polysaccharide decreased with similar trends with no significant differences between treatments, indicating similar stability of the SA in both treatments. This study showed that the different decomposability of the organic amendments might influence the SA formation differently, but not the SA stability.  相似文献   

印楝素对中华稻蝗若虫呼吸作用的影响   总被引：5，自引：0，他引：5  

崔志新  林进添等 《华中农业大学学报》2001,20(6):544-546

呼吸测定试验表明，以每头印楝素5.0μg点滴3龄中华稻蝗蝗蝻前胞背板，4hCO2释放量减少，抑制率达到33％。对6龄蝗蝻测定，处理后试虫CO2释出量降低，呼吸受到抑制，而且随着时间的推移，呼吸失去了节律，图线变得近于直线。点滴法与注射法，在前期呼吸影响有所不同，点滴法随着经过的时间，呼吸抑制率提高；而注射法48h呼吸抑制率才提高，到72h达到最高，其图形为U形。  相似文献   

Reduced tillage with residue retention improves soil labile carbon pools and carbon lability and management indices in a seven-year trial with wheat-mung bean-rice rotation     

Rafeza BEGUM  Mohammad M. R. JAHANGIR  Mohammad JAHIRUDDIN  Mohammad Rafiqul ISLAM  Shaikh M. BOKHTIAR  Khandakar R. ISLAM 《土壤圈》2022,32(6):916-927

Soil total organic carbon (TOC) is a composite indicator of soil quality with implications for crop production and the regulation of soil ecosystem services. Research reports on the dynamics of TOC as a consequence of soil management practices in subtropical climatic conditions, where microbial carbon(C) loss is high, are very limited. The objective of our study was to evaluate the impact of seven years of continuous tillage and residue management on soil TOC dynamics (quantitative and qualitati...  相似文献   

不同CO2浓度下鸡蛋呼吸仿真分析及验证   总被引：2，自引：2，他引：0  

王娇娇  王巧华  曹芮  谢娟娟 《农业工程学报》2021,37(6):302-308

贮存环境中CO_2浓度对鸡蛋呼吸作用及新鲜度变化具有重要影响,为了进一步考察在不同CO_2浓度下鸡蛋呼吸释放CO_2的扩散及新鲜度变化情况,该研究测定贮存在温度为25℃、相对湿度为65%、CO_2体积分数分别为1.5%、3.0%、4.5%及空气(对照组)环境下鸡蛋呼吸和新鲜度,利用FLUENT软件完成不同CO_2浓度下鸡蛋第1天呼吸释放CO_2的扩散过程仿真。结果表明,利用Fluent软件计算所得气体速度值和试验值基本一致,模拟值与实测值相对误差在4%～9%。不同CO_2浓度下鸡蛋释放CO_2的扩散过程符合重气扩散的特点,其扩散方向受到CO_2浓度的影响,且随着贮存环境中CO_2浓度的增加,鸡蛋呼吸释放CO_2的扩散量和扩散速度逐渐变小,呼吸得到抑制。再通过分析贮存过程中不同CO_2体积分数下鸡蛋呼吸强度和新鲜度变化得出,对照组1.5%CO_2与3.0%CO_2下的鸡蛋呼吸强度和新鲜度具有显著差异(P0.05),当贮存环境中CO_2体积分数达到3.0%时,对鸡蛋呼吸强度的抑制效果不再明显,且新鲜度变化保持不变。3.0%CO_2和4.5%CO_2体积分数下贮存鸡蛋20 d,其新鲜度等级仍在AA级以上,综合经济因素,3.0%CO_2保鲜鸡蛋效果较优。该研究可为鸡蛋呼吸和气调保鲜技术提供理论及数据基础。  相似文献   

华北南部低丘山地刺槐林地非主要生长季土壤微生物的呼吸特征     

吕海燕  李玉灵  孟平  张劲松  陆森  王平 《中国农业气象》2011,32(2):174-178

采用树木环割法,于2009-11—2010-03,利用Li-8100土壤呼吸自动观测系统,观测研究了位于河南省济源市的华北山区南部低丘山地40a生刺槐林土壤微生物呼吸速率（Rh）的时间变化特征及其与土壤温度和湿度的关系。结果表明：（1）在非主要生长季,Rh日变化不明显,但呈现出明显的日际变化特征;Rh平均值为0.426μmol.m-2.s-1。（2）林地5cm深处土壤温度与Rh之间存在显著的指数相关关系（P〈0.01）,且Rh随5cm深处土壤温度的升高而增大,表示二者关系的参数Q10值是1.86,说明非主要生长季Rh对温度的变化十分敏感;Rh与土壤含水量呈显著的线性相关关系（P〈0.01）,且Rh与5cm深处的土壤温度和土壤体积含水量均有很好的复相关关系（P〈0.01）。比较偏相关系数表明,影响Rh的主要土壤物理因子是土壤水分。  相似文献   

Soil microbial communities resistant to changes in plant functional group composition     

Carolyn B. Marshall  Roy Turkington 《Soil biology & biochemistry》2011,43(1):78-85

The soil community is an often ignored part of research which links plant biodiversity and ecosystem functioning despite their influence on numerous functions such as decomposition and nutrient cycling. Few consistent patterns have been detected that link plant and soil community composition. We used a removal experiment in a northern Canadian grassland to examine the effects of plant functional group identity on soil microbial community structure and function. Plant functional groups (graminoids, legumes and forbs) were removed independently from plots for five growing seasons (2003-2007) and in the fifth year effects on the soil microbial community were examined using substrate-induced respiration (SIR - a measure of metabolic diversity) and phospholipid fatty acid analysis (PLFA - a measure of microbial community composition). Removal treatments were also crossed with both a fertilizer treatment and a fungicide treatment to determine if effects of functional group identity on the soil community were context dependent. Plant functional group identity had almost no effect on the soil microbial community as measured by either SIR or PLFA. Likewise, soil properties including total carbon, pH, moisture and nutrients showed a limited response to plant removals in the fifth year after removals. We found a direct effect of fertilizer on the soil community, with fertilized plots having decreased metabolic diversity, with a decreased ability to metabolize amino acids and a phenolic acid, but there was no direct soil microbial response to fungicide. We show that in this northern Canadian grassland the soil microbial community is relatively insensitive to changes in plant functional group composition, and suggest that in northern ecosystems, where plant material is only slowly incorporated into the soil, five growing seasons may be insufficient to detect the impact of a changing plant community on the soil microbes.  相似文献