Interspecific Facilitative Root Interactions and Rhizosphere Effects on Phosphorus and Iron Nutrition Between Mixed Grown Chickpea and Barley

A glasshouse study was conducted to investigate the effects of interspecific complementary and competitive root interactions and rhizosphere effects on phosphorus (P) and iron (Fe) nutrition of mixed grown chickpea (Cicer arietinum L.) and barley (Hordeum vulgare L.). In order to provide more physiological evidence on the mechanisms of interspecific facilitation, we determined phosphatase activities in plant and rhizosphere, and root ferric reducing capacity (FR), Fe-solubilizing activity (Fe-SA) and rhizosphere pH. The results of the experiment revealed that biomass yield of barley was significantly increased by associated chickpea as compared to monocultured barley, while mixed cropping caused a slight decreases in the biomass yield of chickpea. The rhizosphere was strongly acidified under chickpea and chickpea/barley mixed cropping and this acidification, in turn, increased the available P, Fe(II) and DTPA-Fe concentrations in the rhizosphere. Fe-solubilizing activity (Fe-SA) and ferric reducing (FR) capacity of the roots were higher in both species grown in mixed culture relative to their monoculture which may improve Fe nutrition of both species. Leaf acid phosphatase (APase, EC 3.1.3.2) activity was higher in both plants under mixed cropping that may improve P nutrition of barley by chickpea.     

不同施肥水平对青稞豌豆混作根际土壤真菌群落结构及多样性的影响

采用真菌ITS区的Illumina MiSeq高通量测序技术，并结合NMDS、RDA和Mantel test分析，探讨青稞单作(Q)、豌豆单作(W)、青稞豌豆混作(Q×W)3种模式在不施肥(0NP)、低氮磷(LNP)、高氮磷(HNP)3种施肥水平下根际土壤真菌群落结构组成及多样性的差异，同时测定其土壤理化性质，并与根际土壤真菌群落结构进行了相关性分析。结果表明：青稞、豌豆在3种种植模式下土壤均呈碱性，且在不同施肥水平下土壤理化性质差异显著。不同试验处理下共检测到18个真菌类群，子囊菌门(Ascomycota，63.5%~78.5%)、被孢霉门(Mortierellomycota，3.6%~14%)、担子菌门(Basidiomycota，1.1%~6.9%)为共有优势类群，在属水平上，Penicillium、Mortierella在青稞豌豆混作根际土壤中相对丰度最高，可能是驱动土壤有机氮、磷转化为无机氮、磷的主要真菌群落。Bipolaris、Blumeria、Fusarium、Cladosporium为土壤真菌群落丰度最高的4种潜在致病菌属，在青稞豌豆混作根际土壤中的相对丰度低于青稞单作和豌豆单作，混作模式在不同施肥水平下4种具有潜在致病性的真菌间相对丰度存在显著差异；在LNP、HNP水平下混作模式根际土壤中的真菌丰富度(ACE、Chao1)和多样性(Shannon、Simpson)指数均低于青稞单作，混作模式在LNP水平下丰富度(ACE、Chao1)指数显著低于0NP水平，但多样性(Shannon、Simpson)指数高于0NP水平；从不同试验处理属水平下真菌群落相对丰度来看，混作模式可显著增加根际土壤中有益菌群的相对丰度，通过根际土壤微生物优势种群及α多样性分析，青稞豌豆混作模式较青稞单作、豌豆单作可增加根际土壤中属水平下Penicillium、Mortierella等具有溶磷、氨化作用菌群的相对丰度，降低Bipolaris、Blumeria、Fusarium、Cladosporium等潜在致病菌群的相对丰度；相关分析表明，速效氮、速效磷、有机质是影响混作模式根际土壤真菌群落结构差异的主要驱动因子。     

Mixed Cropping Effects on Yield,Manganese Influx,and Manganese Depletion in the Rhizosphere of Fodder Crops Grown in Manganese-Deficient Soil

To examine the possibility of managing manganese (Mn) deficiency through mixed cropping, berseem was grown as a monoculture and in mixed cropping with oats, ryegrass, or raya in a Mn-deficient soil under screen-house conditions. In no-Mn berseem monoculture treatment, shoot dry weight (SDW) and root length (RL) were, respectively, 33% and 45% of the maximum recorded values obtained with berseem grown in mixed cropping with ryegrass at 60 days of growth. Corresponding values of SDW and RL of berseem when grown with raya were 78% and 76% of the maximum, respectively. Even though berseem grown in mixed cropping with ryegrass and raya had smaller RL/SDW ratio and greater shoot growth rate than berseem grown as monoculture, it acquired a high shoot Mn concentration because of 3.8 times more Mn influx. A high Mn influx was the result of a high concentration gradient that developed because of depletion of Mn at the root surface.     

滨海盐碱地刺槐白蜡混交林土壤酶与养分相关性研究

研究了刺槐、绒毛白蜡纯林及其混交林中不同土层在不同季节的土壤养分含量、土壤酶活性的变化。结果表明:各林分间的土壤养分含量和土壤酶活性在各个季节和土层均表现出差异。经统计分析,土壤酶活性和土壤养分含量在不同季节呈显著相关关系。土壤酶活性和土壤养分含量在土层中的分布有一定的规律性,总的来说,随着土层逐渐加深,土壤酶活性逐渐减弱,土壤养分含量逐渐下降。混交林中各土层的pH值和含盐量都低于纯林相应值,并且在树木生长、土壤养分和土壤酶活性上,混交林优于纯林。     

Effect of Free Manganese Activity on Yield and Uptake of Micronutrient Cations by Barley and Oat grown in Chelator-buffered Nutrient Solution

The uptake of micronutrient cations in relation to varying activities of Mn²⁺ was studied for barley (Hordeum vulgare L. var. Thule) and oat (Avena sativa L. var. Biri) grown in chelator buffered nutrient solution. Free activities of Mn²⁺ were calculated by using the chemical speciation programme GEOCHEM-PC. Manganese deficient conditions induced elevated concentrations of Zn and Fe in shoots of both species. The corresponding antagonistic relationship between Mn and Cu could only be seen in barley. The observed antagonistic relationships were only valid as long as the plant growth was limited by Mn deficiency. The Mn concentration in both plant species increased significantly with increasing Mn²⁺ activity in the nutrient solution. The concentration of Mn in the shoots of oat was higher than for barley except under severe Mn deficiency where it was found equal for both species. Manganese was accumulated in the roots of barley at high Mn²⁺ activity. The different shoot concentrations of Mn between barley and oat are therefore attributed to the extent of Mn translocation from roots to shoots. Manganese deficiency induced a significant increase in the shoot to root ratio in both species.     

Effects of Ammonium Nitrate and Monosodium Glutamate in Waste Water on the Growth,Antioxidant Activity,and Nitrogen Assimilation of Lettuce (Lactuca sativa L.)

It has been hypothesized that the uptake of organic as opposed to inorganic nitrogen compounds found in wastewater can be properly substituted for plant nutrients. The objective of this study was to compare effects of applying monosodium glutamate wastewater (MGW) and ammonium nitrate (NH₄NO₃) (AN) on nitrogen metabolism and growth of lettuce. The results showed that while NH₄NO₃ (AN), NO₃^-, nitrite content and NR activity increased the protein content of lettuce. Applying MGW with a high concentration of 17 amino acids and macro- and microelements improved the fresh weights of shoot and root as well as the protein content of lettuce. Antioxidant activities were not affected by AN and MGW, and their interaction effects only increased POD after 8 weeks. In conclusion, substituting a portion of the chemical fertilizers with MGW improved lettuce growth, but did not increase NO₃^- accumulation in leaves.     

不同灌水量下氮磷钾配施对青稞产量和品质的影响

为探明在不同灌水量下青稞氮磷钾适宜施用量和最佳配比,研究不同灌水量下氮磷钾配施对青稞产量、品质的影响, 2018 — 2019年以春性二棱青稞品种陇青1号为指示品种,在甘肃河西灌区大田栽培条件下采用裂区试验设计,设置灌水为主区、施肥为副区并采用“3414”设计进行田间试验。对青稞产量及其构成因素及品质进行方差分析的结果表明,在各灌水处理下,青稞产量构成因素各项测定指标至少与1个其他指标极显著或显著相关性;在相同氮磷钾配比下青稞平均产量全生育期灌水2次和全生育期灌水1次较全生育期不灌水分别显著增产59.5%、52.8%,灌水2次较全灌水1次增产4.4%;各灌水处理下,13个施肥处理较不施肥处理显著增产,增产率分别为不灌水0.1%～26.2%、灌水1次0.9%～28.3%、灌水2次7.8%～22.7%,且施肥处理N2P2K3、N2P2K0和N3P2K2产量始终较高;各灌水处理下,氮、磷、钾施用量和产量的三元二次回归方程均能反应青稞产量与氮磷钾三要素之间的极显著相关关系。一元二次肥料效应方程下,青稞最高产量施肥量分别为N 189.11 kg/hm2(全生育期不灌水)、186.75 kg/hm2(全生育期灌水1次)和196.50 kg/hm2(全生育期灌水2次);P2O5 61.69 kg/hm2(全生育期不灌水)、48.77 kg/hm2(全生育期灌水1次)和-27.38 kg/hm2(全生育期灌水2次);K2O 61.11 kg/hm2(全生育期不灌水)、60.60 kg/hm2(全生育期灌水1次)和77.44 kg/hm2(全生育期灌水2次)。整体而言,青稞籽粒蛋白质含量随着灌水量增加而降低,籽粒淀粉含量随着灌水量增加而升高。推荐该区春青稞生育期浇水1次,即于拔节期按1 500 m3/hm2灌入。在此水分条件下推荐的N、P2O5、K2O施用量分别为186.75、48.77、60.60 kg/hm2,此时青稞籽粒产量可达到4 355.24 kg/hm2。     

黄河三角洲冲积平原湿地土壤酶活性与养分相关性研究

对黄河三角洲冲积平原湿地酶活性与土壤养分相关性做了研究.结果表明:随着离海距离的增加,土壤有机质及各养分表现出有规律的变化,土壤脲酶、过氧化氢酶活性沿湿地演替的方向活性升高,过氧化物酶活性降低.土壤有机质和各养分与酶活性相关性达极显著和显著水平,不同土壤酶活性之间也有显著的相关性.3种酶可以作为评价黄河三角洲冲积平原湿地土壤肥力的指标.     

Studies on the magnesium metabolism of crops (Part 1) the balance among magnesium,calcium and pot assLum in free and bound forms at the flowering stage of soy-bean plants

In the later nineteenth century, it was established that magnesium is one of the essential elements to plant life. In 1902 Loew¹⁾ and his pupils suggested the necessity of calcium-magnesium- balance in culture solution for the proper growth of the plant. Then, in 1906, it was established that, as first shown by Willstatter, magnesium is one of the constituents of chlorophyll and when this element is lacking, a chlorosis occurs. Dickson²⁾, in 1918, described about the feature of oat plant grown in a magnesium deficient nutrient solution. At that time, it was thought that magnesium was generally contained in the soil more abundantly than the plant required. So this element scarcely received attention. Garner et al.³⁾, in 1923, observed that chlorosis of tobacco plant, so-called sand drown was cured by applying magnesium to the soil. Similar observation was made in 1929 by Jones⁴⁾ on the chlorosis of corn plant. Since that time the magnesium deficiency in all crops was observed everywhere by a great many investigators. In Japan magnesium deficiency in the field has attracted attention from 1951.     

Soil affects on the cadmium and zinc contents of Chinese cabbage in Yunnan Province,China

Chinese cabbage and surface soil samples (0–20 cm) from a periurban market garden in Yunnan Province (P.R. China) were collected to determine variations of cadmium (Cd) and zinc (Zn) contents in Chinese cabbage and the influence of soil factors. Mean Cd content was 0.49 mg kg^?1 dry materials (DM) in Chinese cabbage, ranging between 0.23 and 1.34 mg kg^?1 DM (n = 21 samples). Mean Zn content was 51.2 mg kg^?1 DM, ranging from 34.9 to 157.5 mg kg^?1 DM (n = 21 samples). The soil factors best predicting Chinese cabbage Cd and Zn contents were total and available Cd and Zn contents and cation exchange capacity (CEC). Soil samples and corresponding Chinese cabbage samples were divided into two groups: soils with low pH (<6.5, n = 10) and soils with high pH (>6.5, n = 11). Positive correlation between CEC with pH > 6.5 and Cd and Zn contents in Chinese cabbage were observed. Available trace element contents and CEC explained 77% and 69% of variation of Cd and Zn contents in Chinese cabbage, respectively. AEC (enrichment coefficient related to trace element availability) and BCF (bioaccumulation factors) could be used to understand Cd and Zn accumulation in Chinese cabbage.     

转基因玉米双抗12-5对根际土壤酶活性及 微生物多样性的影响

采用田间试验研究了转基因玉米瑞丰1号-双抗-12-5(RF1-12-5)种植对根际土壤酶活性、微生物群落的影响,可为RF1-12-5的环境释放和商业化应用提供科学的安全性评价数据支持。研究结果表明:①在5个生育期内,RF1-12-5与其非转基因对照品种瑞丰1号(RF1)根际土壤碱性蛋白酶、脲酶和酸性转化酶活性均没有显著性差异;RF1-12-5根际土壤过氧化氢酶活性在收获期、碱性磷酸酶活性在乳熟期显著低于RF1,其他生育期差异不显著。②在5个生育期内,RF1-12-5与RF1根际土壤微生物群落的Shannon多样性指数、McIntosh均匀度指数和Simpson优势度指数均不存在显著性差异,主成分分析未发现RF1-12-5与RF1根际微生物功能多样性存在规律性差异。     

水分胁迫对巴西香蕉幼苗水分状况、质膜透性和根系活力的影响

在盆栽试验条件下,以巴西香蕉幼苗为试材,设置7个水平土壤含水量处理,分别为100％～91％、90％～81％、80％～71％、70％～61％、60％～51％、50％～41％和40％～0,测定叶片相对含水量、组织含水量、自由水、束缚水含量、质膜透性和根系活力。研究结果表明,随着水分胁迫的加剧,叶片相对含水量、组织含水量、自由水含量和根系活力均随土壤相对含水量的下降而减少;而水分饱和亏缺、束缚水含量和质膜透性则随土壤相对含水量的下降而升高。综合不同处理下巴西香蕉幼苗水分状况、质膜透性和根系活力可知,香蕉幼苗生长最适宜的土壤水分含量是田间持水量的71％～80％。     

亮菌多糖的分离纯化及体内抗肿瘤活性研究

本文建立高效的亮菌多糖分离纯化工艺,并研究其体内抗肿瘤活性。以市售亮菌粗粉为原料,采用水提醇沉、Sevag法脱蛋白、DEAE纤维素离子交换层析、SephadexG-100凝胶过滤层析等方法得到亮菌多糖ATPSⅡ和ATPSⅡ-2;建立小鼠S180实体瘤模型,以生理盐水和环磷酰胺为阴性和阳性对照,观察ATPSⅡ和ATPSⅡ-2在不同剂量（10mg／kg40mg／kg80mg／kg）给药10d后,对小鼠肿瘤抑制的作用。结果表明：亮菌粗粉中多糖含量为22．7g／100g;紫外光谱分析显示纯化得到的ATPSⅡ纯度接近100％;ATPSⅡ和ATPSⅡ-2对肿瘤的抑瘤率随着多糖浓度的增大而增大,其高剂量组对S180的抑瘤率分别为46．7％和51．7％,与阳性对照组相比,亮菌精制多糖ATPSⅡ和ATPSⅡ-2高剂量组抗s180效果接近于临床化疗药环磷酰胺,具有显著的抗肿瘤活性。     

Investigation of environmental and land use impacts in forested permafrost headwaters of the Selenga-Baikal river system,Mongolia - Effects on discharge,water quality and macroinvertebrate diversity

Headwater streams play a major role for provision of ecosystem services, e.g. drinking water. We investigated a high-altitude headwater catchment of the Kharaa River (including 41 1st-order rivers) to understand the impact of land cover (especially forest cover), environment and human usage on runoff, chemical water quality and macroinvertebrate fauna in a river basin under discontinuous permafrost conditions in an arid, sparsely populated region of Mongolia. To verify our hypotheses that different landuses and environmental impacts in permafrost headwaters influence water quality, we investigated 105 sampling sites, 37 of them at intermittent stream sections without water flow. Discharge was positively impacted by land cover types steppe, grassland and forest and negatively by shrubland, forest burnt by wild fires (indicating a reduction of permafrost) and slope. Water quality was affected by altitude, longitude and latitude, shrub growth and water temperature. Shannon diversity of macroinvertebrates was driven by water temperature, iron content of the water, flow velocity, and subbasin size (adjusted R² = 0.54). Sample plots clustered in three groups that differed in water chemistry, macroinvertebrate diversity, species composition and bio-indicators. Our study confirms that steppes and grasslands have a higher contribution to runoff than forests, forest cover has a positive impact on water quality, and diversity of macroinvertebrates is higher in sites with less nutrients and pollutants. The excellent ecological status of the upper reaches of the Kharaa is severely threatened by forest fires and human-induced climate change and urgently needs to be conserved.     

三种水牛奶碱性磷酸酶（ALP）及乳酸脱氢酶（LDH）同工酶的研究

用聚丙烯酰胺凝胶圆盘电泳法，对摩拉（Ｍｕｒｒａ）、尼里（Ｎｉｌｉ－Ｒａｖｉ）和三品系杂交种［Ｎｉ♂×（Ｍｕ♂×Ｎａｒｍｉｎｇ♀）♀）的水牛奶ＡＬＰ及ＬＤＨ同工酶进行了研究．结果表明：三种水牛奶ＡＬＰ及ＬＤＨ都有三种同工酶，只有ＡＬＰ３和ＬＤＨ１出现的比例为１００％，其余的均小于１００％．ＡＬＰ同工酶相对总活力在种间及尼里内与产奶量呈正相关趋势，而在三品杂和摩拉内则相反．ＡＬＰ三种同工酶的相对活力均表现出杂种优势，且ＡＬＰ１和ＡＬＰ２与品种的产奶量呈正相关趋势；尼里的三种酶、三品杂的ＡＬＰ３、摩拉的ＡＬＰ２和ＡＬＰ３与产奶量呈正相关趋势，其余的则相反，三种奶的ＡｓＰ是ＡＬＰ３＞＞ＡＬＰ２（或ＡＬＰ１）＞ＡＬＰ１（或ＡＬＰ２）。两性载体电解质是水牛奶ＡＬＰ的较强抑制剂．ＬＤＨ１酶活力相对百分含量，在种间表现出杂种优势，且与产奶量呈正相关趋势，而ＬＤＨ２和ＬＤＨ３则否；尼里三种酶活力的大小排列与酶的序号一致，三品杂和摩拉则否；在各品种内，ＬＤＨ３与产奶量呈正相关趋势，ＬＤＨ１和ＬＤＨ２则相反。     

转Bt-cry1Ab玉米花粉对意大利蜜蜂生长发育及体内酶活性的影响

自10年前首次种植转基因植物以来,转基因作物已在全球得到大面积推广。这些转基因作物中绝大多数品种具有抗虫基因能够增强作物对靶标昆虫的抗性。同时转抗虫基因植物可能带来的生态安全和环境问题也引起了国际社会广泛的关注。鉴于此,本实验开展了转Bt-cry1Ab基因抗虫玉米花粉     

Effects of the nitrification inhibitor dicyandiamide on soil mineral N, pasture yield, nutrient uptake and pasture quality in a grazed pasture system

Recent lysimeter studies have demonstrated that the nitrification inhibitor, dicyandiamide (DCD), can reduce nitrate (NO) leaching losses from cow urine patches in grazed pasture systems. The objective of this study was to quantify the effects of fine particle suspension (FPS) DCD on soil mineral N components, pasture yield, nutrient uptake and pasture quality under grazed pasture conditions. A field study was conducted on the Lincoln University dairy farm, Canterbury, New Zealand, from 2002 to 2006. FPS DCD was applied to grazed pasture plots at 10 kg ha^?1 in early May in addition to applied cow urine patches at a nitrogen (N) loading rate of 1000 kg N ha^?1, with DCD reapplied in early August. Soil mineral N levels in the urine patches were monitored. Pasture yield, N and cation concentrations and uptake were measured in treatment urine patches and inter‐urine areas of the pasture. Comparisons were made with control plots which did not receive DCD. NO levels under the DCD‐treated urine patches (0–7.5 cm) were in the order of 10 kg N ha^?1 compared with 40–80 kg N ha^?1 under untreated patches, and soil ammonium (NH) levels were consistently higher under the DCD‐treated patches. The DCD significantly and consistently increased pasture yield in both the urine patches, and inter‐urine areas of the pasture in all 4 years of the trial. Mean annual dry matter (DM) yields over 4 years were inter‐urine areas, 10.3; inter‐urine + DCD, 12.4; urine, 12.4 and urine +DCD 16.0 t DM ha^?1, representing an average DM yield increase of 20 and 29% in inter‐urine and urine patch areas, respectively. On a whole paddock basis, the increase in annual DM yield resulting from DCD application was estimated to be 21%. N, calcium (Ca), magnesium (Mg) and potassium (K) concentrations in pasture were unaffected by treatment with DCD; however, total annual uptake of these nutrients by pasture was significantly higher in all years where DCD had been applied. Pasture DM, protein, carbohydrate, metabolizable energy and fibre levels and sward clover content were not affected by treatment with DCD. The results demonstrate the agronomic value of the DCD treatment in addition to the environmental benefits in a grazed pasture system.     

The influence of time, storage temperature, and substrate age on potential soil enzyme activity in acidic forest soils using MUB-linked substrates and l-DOPA

The purpose of this experiment was to evaluate whether soil storage and processing methods significantly influence measurements of potential in situ enzyme activity in acidic forest soils. More specifically, the objectives were to determine if: (1) duration and temperature of soil storage; (2) duration of soil slurry in buffer; and (3) age of model substrates significantly influence the activity of six commonly measured soil extracellular enzymes using methylumbelliferone (MUB)-linked substrates and l-dihydroxyphenylalanine (l-DOPA). Soil collected and analyzed for enzyme activity within 2 h was considered the best measure of potential in situ enzyme activity and the benchmark for all statistical comparisons. Sub-samples of the same soil were stored at either 4 °C or −20 °C. In addition to the temperature manipulation, soils experienced two more experimental treatments. First, enzyme activity was analyzed 2, 7, 14, and 21 days after collection. Second, MUB-linked substrate was added immediately (i.e. <20 min) or 2 h after mixing soil with buffer. Enzyme activity of soil stored at 4 °C was not significantly different from soil stored at −20 °C. The duration of soil storage was minimal for β-glucosidase, β-xylosidase, and peroxidase activity. N-acetyl-glucosaminidase (NAGase), phosphatase, and phenol oxidase activity appeared to change the most when compared to fresh soils, but the direction of change varied. Likewise, the activities of these enzymes were most sensitive to extended time in buffer. Fluorometric MUB and MUB-linked substrates generally had a 3-day shelf life before they start to significantly suppress reported activities when kept at 4 °C. These findings suggest that the manner in which acidic forest soils are stored and processed are site and enzyme specific and should not initially be trivialized when conducting enzyme assays focusing on NAGase, phosphatase, and phenol oxidase. The activities of β-glucosidase, β-xylosidase, and peroxidase are insensitive to storage and processing methods.     

The adverse effects of soil salinization on the growth of Trifolium alexandrinum L. and associated microbial and biochemical properties in a soil from Iran

The aim of this study was to determine the effects of increasing concentrations of salt solutions (including 0.12, 2, 6, and 10 dS m⁻¹) on the growth of berseem clover (Trifolium alexandrinum L.) and related soil microbial activity, biomass and enzyme activities. Results showed that the dry weights of root and shoot decreased with an increase in the concentrations of salt solutions. Soil salinization depressed the microbiological activities including soil respiration and enzyme activities. Substrate-induced respiration was consistently lower in salinized soils, whereas microbial biomass C did not vary among salinity levels. Higher metabolic quotients (qCO₂) and unaffected microbial biomass C at high EC values may indicate that salinity is a stressful factor, inducing either a shift in the microbial community with less catabolic activity or reduced efficiency of substrate utilization. Acid phosphatase and alkaline phosphatase activities decreased with increasing soil salinity. We found significant, positive correlations between the activities of phosphatase enzymes and plant's root mass, suggesting that any decrease in the activities of the two enzymes could be attributed to the reduced root biomass under saline conditions.     

Fluxes of CO2, CH4, and N2O in an alpine meadow affected by yak excreta on the Qinghai-Tibetan plateau during summer grazing periods

To assess the impacts of yak excreta patches on greenhouse gas (GHG) fluxes in the alpine meadow of the Qinghai-Tibetan plateau, methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) fluxes were measured for the first time from experimental excreta patches placed on the meadow during the summer grazing seasons in 2005 and 2006. Dung patches were CH₄ sources (average 586 μg m⁻² h⁻¹ in 2005 and 199 μg m⁻² h⁻¹ in 2006) during the investigation period of two years, while urine patches (average −31 μg m⁻² h⁻¹ in 2005 and −33 μg m⁻² h⁻¹ in 2006) and control plots (average −28 μg m⁻² h⁻¹ in 2005 and −30 μg m⁻² h⁻¹ in 2006) consumed CH₄. The cumulative CO₂ emission for dung patches was about 36-50% higher than control plots during the experimental period in 2005 and 2006. The cumulative N₂O emissions for both urine and dung patches were 2.1-3.7 and 1.8-3.5 times greater than control plots in 2005 and 2006, respectively. Soil water-filled pore space (WFPS) explained 35% and 36% of CH₄ flux variation for urine patches and control plots, respectively. Soil temperature explained 40-75% of temporal variation of CO₂ emissions for all treatments. Temporal N₂O flux variation in urine patches (34%), dung patches (48%), and control (56%) plots was mainly driven by the simultaneous effect of soil temperature and WFPS. Although yak excreta patches significantly affected GHG fluxes, their contributions to the whole grazing alpine meadow in terms of CO₂ equivalents are limited under the moderate grazing intensity (1.45 yak ha⁻¹). However, the contributions of excreta patches to N₂O emissions are not negligible when estimating N₂O emissions in the grazing meadow. In this study, the N₂O emission factor of yak excreta patches varied with year (about 0.9-1.0%, and 0.1-0.2% in 2005 and 2006, respectively), which was lower than IPCC default value of 2%.