云南省植烟土壤理化性状及其相关性研究

为进一步了解云南省植烟土壤理化性状分布特征及其关系,于2014年和2015年对云南省12个州(市)采集2 127份土壤样品进行测定分析.结果表明:1)云南省植烟土壤物理性粘粒质量分数平均50.91%,偏重壤土,pH值以及养分平均质量分数除有机质偏高外,均适宜优质烤烟生产.2)12个州(市)间植烟土壤的物理性粘粒和养分质量分数差异有统计学意义(p0.01),红河和文山物理性粘粒质量分数最高,保山和大理的有机质和速效氮质量分数最丰富,曲靖和昭通速效钾最丰富,昆明、楚雄和临沧有效硼最丰富,德宏和普洱的pH值和养分质量分数较低.3)文山43.08%和红河52.34%的土壤物理性粘粒质量分数大于60%,需适当调节土壤通透性;德宏66.67%,临沧54.78%和普洱53.69%的土壤pH值小于5.5,需调节土壤酸碱度;普洱58.40%和41.61%的土壤速效氮和速效磷质量分数缺乏,需增施氮肥和磷肥;各州(市)均存在35.41%~66.67%土壤速效钾质量分数缺乏,需增施钾肥;红河49.99%土壤有效硼质量分数缺乏,需增施硼肥;大理30.41%,曲靖20.80%和昭通16.66%的植烟土壤水溶性氯质量分数大于30mg/kg,应当适当控制含氯肥料施用.4)云南省植烟土壤有机质、速效氮、速效钾和有效硼质量分数与物理性粘粒质量分数的R2值较高(0.696 2~0.885 9),有机质和速效氮和有效硼质量分数存在随物理性粘粒质量分数升高而先升高再降低趋势,速效钾质量分数存在随物理性粘粒质量分数升高而升高的趋势.     

表面活性剂辅助-凝固-漂浮分散液-液微萃取-高效液相色谱法检测葡萄酒中4种三嗪类除草剂残留

建立了表面活性剂辅助-凝固-漂浮分散液-液微萃取-高效液相色谱(SA-DLLME-SFO-HPLC)法检测葡萄酒中西玛津、莠去津、特丁津和扑草净4种三嗪类除草剂残留的分析方法。考察了萃取剂的类型、萃取剂和表面活性剂的体积、萃取时间和盐效应等对萃取效率的影响,确定最佳萃取条件为:20 μL十一醇作为萃取剂,2 μL 0.25 g/L的Tween-20水溶液作为分散剂,萃取时间10 min,氯化钠的质量浓度为250 g/L。结果表明:西玛津、莠去津、特丁津和扑草净的线性范围为0.008~5 mg/L,检出限分别为2.4、1.8、2.0和2.8 μg/L,富集倍数在24.5~32.4之间。在0.008、0.08和2.4 mg/L添加水平下,西玛津、莠去津、特丁津和扑草净在葡萄酒中的回收率在84%~102%之间,相对标准偏差(n=5)在2.1%~6.9%之间。该方法可用于葡萄酒中西玛津、莠去津、特丁津和扑草净残留量的测定。     

Soil Reserves of Potassium: Release and Availability to Lolium perenne in Relation to Clay Minerals in Six Cropland Soils from Eastern China

An 8‐month greenhouse experiment with ryegrass (Lolium perenne L.) examined the relationship between the dynamics of potassium (K) reserves in soil and changes in clay minerals, using X‐ray diffraction. The capacity of soil to release K was consistent with its ability to supply it and was the highest in the soil samples collected from Laiyang (H₁T₂a), Harbin (H₁T₁) and Beibei (H₂T₄), followed by the sample from Jiangyan (H₁T₂b), and the lowest in the samples from Gao'an (H₂T₃a) and Wangcheng (H₂T₃b). Removal of soil K decreases the intensity of reflections for illite and increases that for interstratified clay minerals. The centre of gravity values of the clay fractions was significantly negatively correlated to the depletion of soil K reserves, as ascertained through chemical extraction or through plant action. The quantitative regression equations between the centre of gravity values and the dynamics of soil reserves of K can be used for predicting the release and plant availability of K even without growing a crop. Copyright © 2017 John Wiley & Sons, Ltd.     

Clay Addition to Sandy Soil——Influence of Clay Type and Size on Nutrient Availability in Sandy Soils Amended with Residues Differing in C/N ratio

Addition of clay-rich subsoil to sandy soil results in heterogeneous soil with clay peds(2-mm) or finely ground( 2 mm) clay soil(FG), which may affect the nutrient availability. The aim of this study was to assess the effect of clay soil particle size(FG or peds)and properties on nutrient availability and organic C binding in sandy soil after addition of residues with low(young kikuyu grass,KG) or high(faba bean, FB) C/N ratio. Two clay soils with high and low smectite percentage, clay and exchangeable Fe and Al were added to a sandy soil at a rate of 20%(weight/weight) either as FG or peds. Over 45 d, available N and P as well as microbial biomass N and P concentrations and cumulative respiration were greater in soils with residues of KG than FB. For soils with KG residues,clay addition increased available N and initial microbial biomass C and N concentrations, but decreased cumulative respiration and P availability compared to sandy soil without clay. Differences in measured parameters between clay type and size were inconsistent and varied with time except the increase in total organic C in the 53 μm fraction during the experiment, which was greater for soils with FG than with peds. We concluded that the high exchangeable Fe and Al concentrations in the low-smectite clay soil can compensate a lower clay concentration and proportion of smectite with respect to binding of organic matter and nutrients.     

黏土和沙壤土对烟叶发育过程中栅栏细胞超微结构的影响

采用大田试验,比较研究了黏土和沙壤土烟叶发育过程中栅栏细胞超微结构变化,结果表明:1)叶长5 cm之前,黏土和沙壤土烟叶细胞超微结构变化差异不大.2) 5 cm之后沙壤土烟叶细胞发育较为迅速,叶长10～15 cm时叶绿体开始贴壁排列,功能开始全面发挥,叶长20 cm时基粒垛叠明显增厚,叶长30 cm时液泡发育成熟,叶绿体进入旺盛功能期;而黏土烟叶细胞发育相对迟缓,叶长20 cm时叶绿体功能才开始全面发挥,叶长40~50 cm时进入旺盛功能期.3)定长时黏土烟叶细胞内叶绿体积累的淀粉粒和嗜锇颗粒不及沙壤土烟叶充实.     

长期不同施肥方式对南方黄泥田水稻产量及基础地力贡献率的影响

对连续27年施肥的南方黄泥田水稻产量、基础地力贡献率变化进行了分析,结果表明,连续施用化肥(NPK)、化肥+牛粪(NPKM)、化肥+稻草(NPKS)处理的水稻平均产量比不施肥(CK)分别提高74.9%、96.6%、91.7%,NPKM与NPKS处理产量分别比NPK处理提高12.4%与9.6%,均达到极显著差异,但NPKM与NPKS产量相当。双季稻年份(1983-2004年),NPK、NPKM、NPKS处理的水稻每5～7年年际增产率随试验年份的延长呈递增的趋势。早稻与晚稻的基础地力贡献率均呈波浪式下降趋势,其平均贡献率分别为47.1%与60.0%。不同施肥处理产量与基础地力呈显著或极显著正相关。     

Effects of light,macronutrients, and sucrose on germination and development of the endangered fern Adiantum reniforme var. sinense (Adiantaceae)

Effects of light, macronutrients strength of Murashige and Skoog (MS) (1962), and sucrose in the culture medium on spore germination and gametophyte development of the endangered fern Adiantum reniforme var. sinense were investigated. The presence of light was found to be essential for both spore germination and gametophyte growth. Moreover, a medium consisting of 1/4 MS with 15 g/l sucrose was optimal for spore germination and early gametophyte development; whereas, MS medium with 30 g/l sucrose was optimal for further gametophyte development. Increasing amounts of sucrose (45–60 g/l) in the medium delayed gametophyte growth and development. Additionally, sporophyte formation and early growth of gametophytes in a medium consisting of clay and peat (v/v = 1:2) was higher than those in a medium consisting of pure river sand. These findings indicated that requirements for nutrients for spore germination and early gametophyte development of A. reniforme var. sinese were relatively low, but these increased with further gametophyte development, formation and growth of sporophytes.     

反射光谱估算滨海土壤黏粒含量

探明反射光谱估算土壤黏粒含量的成因是实现黏粒含量测定、提高估算精度的基础。该文以江苏省滨海平原的150个土壤样品为研究对象,将测得的原始光谱数据进行平滑、一阶导数、连续统去除和倒数等数据变换,采用逐步多元线性回归(stepwise multiple linear regression,SMLR)和偏最小二乘回归(partial least squares regression,PLSR)方法估算黏粒含量,并在此基础上分析建模的影响波段,探讨反射光谱估算土壤黏粒含量的成因。结果表明,连续统去除光谱数据的SMLR分析估算精度最高,建模集和验证集决定系数分别为0.941和0.750。360~900、1 800~2 490 nm是黏粒含量的重要建模影响波段,该建模影响波段主要包括铁离子(410 nm附近)、土壤有机质(500~800 nm)、层状硅酸盐中的结晶水(1 900 nm附近)、绿泥石和蛭石等黏土矿物(2 325 nm)的吸收特征波段;PLSR分析表明,1 400 nm附近回归系数出现的双峰特征源于高岭石的双峰吸收。黏粒中的黏土矿物、黏粒对铁离子的吸附特性以及黏粒与有机质的高度相关性是实现反射光谱估算滨海土壤黏粒含量的原因。     

解钾细菌与黏土矿物协同促进玉米生长提高土壤养分有效性

为了揭示解钾细菌在西北矿区浅埋古河道土壤中对植物生长和土壤养分利用的影响,通过日光温室短期盆栽的方式,以不同黏土矿物配比的人工培土为基质模拟古河道不同质地土壤,以西北地区常见农作物玉米为宿主,研究解钾细菌在人工培土基质中的微生物数量变化规律,以及二者协同作用对玉米生长和矿质养分吸收的影响。结果表明:1)土壤黏土矿物含量增大有利于提高土壤解钾细菌数量,促进微生物活性。当黏土矿物质量分数为68%,速效钾质量分数约170 mg/kg时,解钾细菌数量最大;2)玉米地上部分干质量、根冠比、根系活力随黏土矿物含量增大而增大,以解钾细菌作用下黏土矿物质量分数68%的玉米生长效果最佳;3)在解钾细菌作用下,植物氮磷钾积累量和土壤养分利用的最佳土壤黏土矿物质量分数为45%、68%和75%,土壤钾素、氮素和磷素最大利用率分别达到65%、53%和17%;4)解钾细菌在土壤钾素含量低时促进土壤磷素吸收,土壤钾素过量时,促进土壤氮磷钾的吸收,提高土壤养分利用率。因此,土壤黏土矿物与解钾细菌相互作用,而且积极影响植物生长和土壤养分的吸收利用,这对进一步探寻适合矿区浅埋古河道土壤的微生物复垦技术,深入改良和开发矿区退化土壤具有重要意义。     

Clay dispersion and its relation to surface charge in a paddy soil of the Red River Delta,Vietnam

Dispersion is an important issue for clay leaching in soils. In paddy soils of the Red River Delta (RRD), flooding with fresh water and relatively high leaching rates can accelerate dispersion and the translocation of clay. For the clay fraction of the puddled horizon of a typical paddy soil of the RRD, the effect of various cations and anions as well as humic acid (HA) at different pH values on the surface charge (SC) were quantified and the dispersion properties were determined in test tubes and described by the C₅₀ value. In the <2 µm fraction, dominated by illite, the proportion of 2:1 vs. 1:1 clay minerals is 5:1. The organic‐C content of the clay fraction is 2.2%. Surface charge was found to be highly pH‐dependent. At pH 8 values of –32 and at pH 1 of –8 mmol_c kg^–1 were obtained. Complete dispersion was observed at pH > 4, where SC is > –18 mmol_c kg^–1. The flocculation efficiency of Ca strongly depends on the pH. At pH 4, the C₅₀ value is 0.33, 0.66 at pH 5, and 0.90 mmol L^–1 at pH 6. At pH 6, close to realistic conditions of paddy soils, the effect of divalent cations on the SC and flocculation decreases in the order: Pb > Cu > Cd > Fe^II > Zn > Ca > Mn^II > Mg; Fe^II was found to have a slightly stronger effect on flocculation than Ca. An increase in concentrations of Ca, Mn^II, and Mg from 0 to 1 mmol L^–1 resulted in a change in SC from –25 to approx. –15 mmol_c kg^–1. In comparison, the divalent heavy‐metal cations Pb, Cu, Cd, and Zn were found to neutralize the SC more effectively. At a Pb concentration of 1 mmol L^–1, the SC is –2 mmol_c kg^–1. From pH 3 to 5, the dispersion of the clay fraction is facilitated rather by SO than by Cl^–, which can be explained by the higher affinity of SO to the positively charged sites. With an increase of the amount of HA added, the SC continuously shifts to more negative values, and higher concentrations of cations are needed for flocculation. At pH 3, where flocculation is usually observed, the presence of HA at a concentration of 40 mg L^–1 resulted in a dispersion of the clay fraction. While high anion concentrations and the presence of HA counteract flocculation by making the SC more negative, Fe^II and Ca (C₅₀ at pH 6 = 0.8 and 0.9 mmol L^–1, respectively) are the main factors for the flocculation of the clay fraction. For Fe^II and Ca, the most common cations in soil solution, the C₅₀ values were found to be relatively close together at pH 4, 5, and 6, respectively. Depending on the specific mineralogical composition of the clay fraction, SC is a suitable measure for the determination of dispersion properties and for the development of methods to keep clay particles in the soil in the flocculated state.