有机肥施用量与蔬菜硝酸盐和重金属关系初探

为控制施肥对蔬菜和土壤的负面影响,探讨蔬菜合理的有机肥施用量,在不同质地土壤上,田间试验小白菜、苦瓜、豇豆三种蔬菜施不同量有机肥,收获时测定其产量、品质、硝酸盐、重金属及试验前后土壤有机质含量。结果表明,(1)在施适量无机NPK的条件下,每造蔬菜的有机肥施用量(禽畜粪便,下同),砂土上小白菜为4500kg/hm2、苦瓜和豇豆为3000kg/hm2;壤土上,小白菜和苦瓜均宜施3000kg/hm2,豇豆则宜施4500kg/hm2;粘土上,小白菜每造只宜施1500~3000kg/hm2的有机肥。(2)有机肥必须与无机肥合理配合施用,才能获得最佳的产量和品质效果,在砂土上有机肥施得越多,蔬菜的硝酸盐含量越高,其它土壤也有类似趋势。(3)施高量(7500kg/hm2)有机肥的小白菜重金属含量最高,其次是施中量(3000kg/hm2)有机肥的,尤其是Cd。(4)施有机肥3000~4500kg/hm2 适量无机肥可使土壤有机质水平保持在种植蔬菜前的含量水平,该施肥量和方式不仅可使蔬菜高产、优质,还有利于保护土壤肥力。     

Methane emissions of differently fed dairy cows and corresponding methane and nitrogen emissions from their manure during storage

This study investigated the effects of supplementing 40 g lauric acid (C₁₂) kg^-1 dry matter (DM) in feed on methane emissions from early-lactating dairy cows and the associated effects on methane, nitrous oxide and ammonia release from the manure during storage. Stearic acid (C₁₈), a fatty acid without assumed methane-suppressing potential in the digestive tract of ruminants, was added at 40 g kg^-1 DM to a control diet. The complete feed consisted of forage and concentrate in a ratio of 1.5:1 (DM basis). The manure was stored for 14 weeks either as complete slurry or, separately, as urine-rich slurry and farmyard manure representing two common storage systems. Methane release of the cows, as measured in respiratory chambers, was lower with C₁₂ by about 20%, but this was mostly resulting from a reduced feed intake and, partly, from a lower rate of fibre digestion. As milk yield declined less than feed intake, methane emission per kg of milk was significantly lower with C₁₂ (11.4 g) than with C₁₈ (14.0 g). Faeces of C₁₂-fed cows had a higher proportion of undigested fibre and accordingly methane release from their manure was higher compared with the manure obtained from the C₁₈-fed cows. Overall, manure-derived methane accounted for8.2% and 15.4% of total methane after 7 and 14 weeks of storage, respectively. The evolution of methane widely differed between manure types and dietary treatments, with a retarded onset of release in complete slurry particularly in the C₁₂ treatment. Emissions of nitrous oxide were lower in the manures from the C₁₂ treatment. This partially compensated for the higher methane release from the C₁₂ manure with respect to the greenhouse gas potential. The total greenhouse gas potential (cow and manure together) accounted for 8.7 and 10.5 kg equivalents of CO₂ cow^-1 d^-1with C₁₂ and C₁₈, respectively. At unaffected urine-N proportion ammonia and total nitrogen losses from stored manure were lower with C₁₂ than with C₁₈ corresponding to the differences in feed and nitrogen intake. The present results suggest that manure storage significantly contributes to total methane emission from dairy husbandry, and that the identification of effective dietary mitigation strategies has to consider both the digestive tract of the animals and the corresponding manure.     

锰尾矿区有机菌肥-速生树种的生态修复效应

在锰尾矿区建立了4.5hm²生态修复工程区，以速生树种泡桐（Paulownia tomentosa）和栾树（Koelreuteriapaniclata）作为建群植物，采用有机菌肥改良其根际环境，利用土壤库存耐性植物种子的自然萌发力来丰富物种多样性.结果表明，工程实施后第6a，有机菌肥处理植物群落干物质生物总量达到33498.7kg/hm²，Mn吸收积累量达到5532.6g/hm²，植物种类数达到51种，分别为无机化肥对照的22.8、2.6和3.4倍；有机菌肥处理的植物群落Pb、Cd、Cu、Zn和Cr的总积累量、根际微生物种类及其数量也显著大于对照.有机菌肥的改良机制可归结于其与植物根系、根际微生物对基质的共同作用.有机菌肥处理区泡桐和栾树的总株数不到该区植物总株数的0.2%，但其干物质生物量、锰吸收量与盖度分别为该区的88%、73%和55.2%.速生树种泡桐和栾树对该区生态修复起到了"主导"作用.     

Winter losses of nitrogen and phosphorus from Italian ryegrass, meadow fescue and white clover in a northern temperate climate

We have studied to what degree Italian ryegrass (Lolium multiflorum Lam.), white clover (Trifolium repens L.) and meadow fescue (Festuca pratensis L.) are able to preserve nitrogen (N) and phosphorous (P) in shoots and roots from one growing season to the next in a northern temperate climate. Field experiments were performed during four consecutive winters in central southeast Norway (60°42′N, 10°51′E), and N and P in plant biomass were measured in the autumn and in the spring. We also measured the contents of total N, total P and organic carbon (C) in seepage water that percolated through the aboveground plant material. Uptake of N and P in Italian ryegrass and white clover was substantially larger than in meadow fescue. The winter losses varied greatly from year to year, depending on the winter climate. On the average for all three of the plant species, the winter losses of N from aboveground biomass were 6, 35, 68 and 10% in the four experimental years, respectively. The corresponding P losses were 11, 36, 60 and 22%. On the average for all plant species and experimental years, 43 (±12)% (S.E., n = 12) of the N, 34 (±9)% of the P and 4 (±1)% of the C that was lost from the aboveground plant biomass during the winter, was recovered in seepage water, basically as a nutrient pulse in melt water in early spring. The very low C recovery rate in seepage water suggested a considerable microbial growth on lost plant C. Assuming that all un-recovered plant C was consumed by microorganisms not included in measurements of the seepage water, modelling showed that microbial immobilisation theoretically might explain the unexpectedly low recovery rates of N and P. The study was not designed to investigate the possible effects of psychrophilic microbes on N and P cycling. Therefore, it is inconclusive and underlines the need for more knowledge on this matter.     

Effect of adding Lactobacillus plantarum and soluble carbohydrates to swine manure on odorous compounds, chemical composition and indigenous flora

Manure odor, which results in the increasing complaints and lawsuits, has increased the tension among swine producers and surrounding residents. The effects of Lactobacillus plantarum and different rates of soluble carbohydrates additions to swine manure on odorous compounds, chemical compounds and indigenous flora were evaluated. Additions were calculated on dried manure weight basis. Variables monitored included ammonia （NH3）, hydrogen sulfide （H2S）, odor offensiveness, pH, ammonium nitrogen（NH4^＋-N）, volatile fatty acids （VFAs）, urease and indigenous flora. The results indicated that the combination of L. plantarum and soluble carbohydrates dramatically reduced manure pH. Lower pH resulted in the reduction of NH3 volatilization （34.6%-92.4%, P〈0.01）, the increases of H2S （P〈 0.05） and NH4^＋-N （5.3%-17.5%, P〈0.05）. In addition, L. plantarum and soluble carbohydrates additions significantly reduced odor offensiveness, those VFAs related to malodor indicators（valeric acids, 12.3%-47.7%, P〈 0.05; iso-valeric, 3.5%-23.8%） and the main microorganisms responsible for odor production, with the number of Eubacteria in swine manure reducing by 4.9%, 11.6%, 17.4%, 34.1% and 32.2% respectively.     

原液补碳模式对猪场厌氧消化液SFSBR处理特性的影响

针对猪场粪尿厌氧消化液在后续生物处理过程中碳源，碱度的严重失衡问题，采用"缺氧（A1）+曝气（O1）+缺氧（A2）+曝气（O2）"的分步进水序批式反应器（SFSBR）处理，以实现碳源，碱度的体系内自平衡利用.通过改变A1，A2段的补碳量（采用定量的猪场粪尿原液，分别以1：1，1：3和3：1的体积比在反应器每个周期的A1，A2阶段启动时补碳，分别简称工况I，Ⅱ，Ⅲ），研究原液补碳模式对处理过程脱氮除磷特性的影响.结果表明，3种补碳模式均实现了短程硝化反硝化脱氮，反应器内pH值均稳定在8.5左右，NH₄⁺-N去除率均达到95%以上.原液补碳直接影响反硝化过程，工况I，Ⅱ条件下A2段反硝化速率分别为2.19和2.15mg/（g·h），均约为工况Ⅲ A2段的1.6倍.不同工况下原液补碳对A段释磷和O段吸磷有显著差异，工况I和Ⅲ条件下SFSBR除磷效果更佳，出水TP浓度分别为7.9和6.4mg/L，去除率分别达到84.4%和87.3%，相较于工况Ⅱ分别提高了9.5%和12.4%.综合考虑脱氮除磷，有机物降解以及碳源/碱度自平衡控制，工况I为最佳补碳模式，系统出水COD，NH₄⁺-N和TP浓度分别为360，10.6和7.9mg/L，相应的去除率分别为74.9%，98.6%和84.4%.研究表明，采用A1/A2段原液添加比为1：1的补碳模式（即工况I）能在碳源/碱度自平衡的基础上实现猪场粪尿厌氧消化液的高效脱氮除磷.     

基于二污普数据果菜茶畜禽粪污氮承载评估

为评估我国各省份果菜茶种植对当地畜禽粪污承载消纳能力,基于各省份果菜茶产量数据与第二次全国污染源普查结果分别核算了畜禽粪肥氮需求量和供给量,以粪肥替代化肥比率为0.4和0.5两种情景评估了各省份果菜茶种植粪肥氮承载消纳情况.结果表明:①全国果菜茶种植氮素平均需求量为358.7 kg/hm2,畜禽养殖业粪肥氮素产生量为463.3×104 t,供给量为277.97×104 t.果菜茶单位种植面积粪肥氮素供给量全国平均值为126.37 kg/hm2.②粪肥替代化肥比率为0.4时,全国果菜茶单位种植面积粪肥氮养分需求量为143.5 kg/hm2,各省份粪肥氮养分承载压力系数在0.21~2.99之间,平均值为0.78.③粪肥替代化肥比率为0.5时,全国果菜茶单位种植面积粪肥氮养分需求量为179 kg/hm2,各省份粪肥氮养分承载压力系数在0.17~2.39之间,平均值为0.63.研究显示,粪肥替代化肥比率在0.4和0.5条件下,全国大部分省份畜禽粪肥氮养分提供量未超过本区域果菜茶种植的肥料所需.各省份畜禽养殖业可提供的粪污全部用于区域内果菜茶作物施肥,全国有22个省份粪肥替代化肥的比率在0.4之内.      

超高温预处理对猪粪堆肥过程碳氮素转化与损失的影响

以猪粪、砻糠为原料,利用自行设计的超高温预处理装置,开展了为期56d的模拟堆肥试验,比较了超高温预处理好氧堆肥（HPC）和常规高温好氧堆肥（CK）过程中碳、氮素转化及损失.结果表明,CK有机质最大降解度（42.58%）比HPC堆体（49.29%）小,但降解速率常数（0.1d^-1）高于HPC（0.07d^-1）,两种堆肥工艺碳素降解率差异不显著.HPC堆体NH₄⁺-N、TN质量分数平均比CK高143.9%、11.2%,而NO₃^--N质量分数则比CK低58.8%.HPC堆肥后期胡敏酸含量及腐殖质聚合程度分别比CK高45.2%~56.8%、59.1%~65.3%.在预处理阶段以及后续堆肥阶段,HPC、CK有机碳损失率分别为48%、51%,氮损失率分别为18%、27%.说明超高温预处理不仅有利于堆肥过程的保氮,而且促进富里酸向胡敏酸的转化,提高了堆肥产品腐殖化水平.     

禽畜粪便减量化处理技术初探

随着中国养殖业的迅速发展,禽畜粪便的排放数量逐年增加。据统计,禽畜粪尿排放量每头牛为55kg/d~65 kg/d,每头猪为3.5 kg/d~11.0 kg/d,每只鸡为0.10 kg/d~0.15 kg/d,每只羊为2.66 kg/d。大量的禽畜粪便不经处理而排入环境,将会对地表水、地下水、土壤和空气造成严重的污染,并危及禽畜本身及人体健康。因此,实现禽畜粪便的减量化、无害化及资源化,防止和消除养殖场粪便的污染及其利用问题的研究,对于生态环境的保护、实施可持续发展战略都具有十分重要的意义。本试验利用日本JST赠送的生态厕所反应装置为试验设备,分别以木屑和木屑与秸秆混合物为微生物载体,对牛粪便进行减量化处理技术研究。旨在为研究中国农业的玉米作物秸秆是否可以替代木屑作为反应过程中的调理剂,达到对禽畜养殖业粪便良好的减量化处理效果,减轻对环境的污染,同时也为中国大量的农作物秸秆寻找另一条资源化利用途径。     

Denitrification on Andosols in an intensive dairy farming region of central Japan

Evaluation of denitrification capacities is necessary to develop a sustainable manure management system in order to reduce NO₃⁻ leaching and N₂O emissions from agricultural soils. Denitrification rates were measured using the acetylene inhibition technique on intact soil cores from eight Andosols under three different cropping systems in an intensive livestock catchment of central Japan. The N application rates ranged from 200 to 800 kg N ha⁻¹ yr⁻¹. The denitrification rates were highly variable across fields, and were influenced significantly by land uses and manure forms. Compared with upland fields, paddy rice fields had a greater denitrification rate up to 1380 and 85 mg N m⁻² day⁻¹ in the top 30-cm soil layer during flooding and non-flooding periods, respectively. In upland fields, the maximum value for the top 30-cm soils was 44 mg N m⁻² day⁻¹ and most of the rates were less than 10 mg N m⁻² day⁻¹. The greater denitrification rates were often associated with slurry application rather than composted dry manure. Overall, denitrification from Andosols in this study displayed a lower capacity than that of non-Andosols.