基于GIS的土壤肥力质量综合评价——以天然云冷杉针阔混交林为例   总被引：2，自引：1，他引：1  

王璐  王海燕  何丽鸿  刘鑫 《土壤通报》2016,(5):1223-1230

以吉林汪清林业局金沟岭林场中41块天然云冷杉针阔混交林样地为对象,采用主成分-聚类分析,结合GIS技术,对该区域土壤肥力质量进行综合评价。结果表明,按主成分-聚类分析结果将41块样地分为4类:第1类土壤肥力质量综合得分为11.17~18.86(优),包括5块样地;第2类土壤肥力质量综合得分为3.01~7.44(良),包括8块样地;第3类土壤肥力质量综合得分为-6.97~1.27(一般),包括24块样地;第4类土壤肥力质量综合得分为-12.40~-9.63(差),包括4块样地。然后采用Arc GIS软件对综合得分进行普通Kriging插值,其标准均方根预测为0.9544,在1的附近,这基本达到插值精度的要求。从生成的研究区土壤肥力质量综合得分空间分布图来看,森林土壤肥力质量由西向东呈现先降低后升高的趋势;由北向南,森林土壤肥力质量变化幅度逐步减小,表明研究区南部土壤肥力质量变化较北部均匀。就研究区的整体土壤肥力质量而言,土壤肥力质量中等以上(优,良,一般)样地数占所研究区样地总数比例为90.24%,表明所研究区森林土壤肥力质量整体处于良好水平。  相似文献   

Effects of burning on soil macrofauna in a savanna-woodland under different experimental fuel load treatments     

《Applied soil ecology》2014

In West African savanna-woodland, the use of prescribed burning as a management tool has ecological implications for the soil biota. Yet, the effects of fire on soil inhabiting organisms are poorly understood. The aim of this study was to examine the responses of soil macro-invertebrates to early fires in a Sudanian savanna-woodland on a set of experimental plots subject to different fuel load treatments. The abundance of major macro-invertebrate taxa and functional groups, and taxon richness were quantified in soil cores collected from three different soil layers before and immediately after burning. The results indicated that, overall, there was substantial spatial and temporal variation in the composition of macro-invertebrate assemblages. The immediate effects of fire were to reduce total invertebrate numbers and numbers of many invertebrate groups dramatically. This is probably due to the fact that many of the surface-dwelling macrofauna perished as a result of less favorable microclimate due to fire, diminished resources, or migrate to safer environments. Fuel load treatment did not affect the community taxonomic richness or abundance of the soil-dwelling fauna. Furthermore, annual changes in community composition were more pronounced at the burnt site than in the control. This could be related to the inter-annual difference in precipitation pattern recorded during the two-year study period at our site. Since soil macrofauna population declines in fire-disturbed areas, increasing fire prevalence may jeopardize the long-term conservation of fire sensitive macrofauna groups. Special fire management attention is therefore recommended with due consideration to the type of burning and fuel properties to avoid the detrimental effects of intense fire affecting the resilience of savanna soil macrofauna species.  相似文献   

Soil enzyme activities during the 2011 Texas record drought/heat wave and implications to biogeochemical cycling and organic matter dynamics     

《Applied soil ecology》2014

Extreme droughts and heat waves due to climate change may have permanent consequences on soil quality and functioning in agroecosystems. During November 2010 to August 2011, the Southern High Plains (SHP) region of Texas, U.S., a large cotton producing area, received only 39.6 mm of precipitation (vs. the historical avg. of 373 mm) and experienced the hottest summer since record keeping began in 1911. Several enzyme activities (EAs) important in biogeochemical cycling were evaluated in two soils (a loam and a sandy loam at 0–10 cm) with a management history of monoculture (continuous cotton) or rotation (cotton and sorghum or millet). Samplings occurred under the most extreme drought and heat conditions (July 2011), after precipitation resulted in a reduction in a drought severity index (March 2012), and 12 months after the initial sampling (July 2012; loam only). Eight out of ten EAs, were significantly higher in July 2011 compared to March 2012 for some combinations of soil type and management history. Among these eight EAs, enzymes key to C (β-glucosidase, β-glucosaminidase) and P cycling (phosphodiesterase, acid and alkaline phosphatases) were significantly higher (19–79%) in July 2011 than in March 2012 for both management histories regardless of the soil type (P > 0.05). When comparing all sampling times, the activities of alkaline phosphatase, aspartase and urease (rotation only) showed this trend: July 2011 > March 2012 > July 2012. Activities of phosphodiesterase, acid phosphatase, α-galactosidase, β-glucosidase and β-glucosaminidase were higher in July 2011 than July 2012 in at least one of the two management histories. Total C was reduced significantly from July 2011 to March 2012 in the rotation for both soils. Only the activities of arylsulfatase (avg. 36%) and asparaginase showed an increase from July 2011 to March 2012 for both soil types, which may indicate they have a different origin/location than the other enzymes. EAs continued to be a fingerprint of the soil management history (i.e., higher EAs in the rotation than in monoculture) during the drought/heat wave. This study provided some of the first evidence of the adverse effects of a natural, extreme drought and heat wave on soil quality in agroecosystems as indicated by EAs involved in biogeochemical cycling.  相似文献   

Physiological processes associated with salinity tolerance in an alfalfa half‐sib family          下载免费PDF全文

M. Rokebul Anower  M. D. Peel  I. W. Mott  Y. Wu 《Journal of Agronomy and Crop Science》2017,203(6):506-518

We previously reported an alfalfa half‐sib family, HS‐B, with improved salt tolerance, compared to parental plants, P‐B. In this study, we conducted additional experiments to address potential physiological mechanisms that may contribute to salt tolerance in HS‐B. Vegetatively propagated HS‐B and P‐B plants were treated with a nutrient solution (control) or a nutrient solution containing NaCl (EC = 12 dS/m). Shoots and roots were harvested at various time points after treatment for quantification of proline, soluble sugar, and H₂O₂ using spectrophotometers. Subcellular localization and quantification of Na in roots were conducted using a Na⁺‐specific dye under a confocal microscope. HS‐B produced 86 and 89% greater shoot and root dry biomass, respectively, compared to parental plants, P‐B, under salinity in the greenhouse. Under saline conditions the HS‐B shoots accumulated 115% and roots 55% more soluble sugars than P‐B counterparts. The non‐saline HS‐B shoots, however, showed 72% less soluble sugars than the non‐saline P‐B plants. Under saline conditions HS‐B accumulated 39% less proline in shoots, while roots accumulated 56% more proline, compared to their P‐B parents. HS‐B plants also showed a greater reduction of stomatal conductance under mild saline stress. HS‐B shoots and roots contained 3–4 times less reactive oxygen species (H₂O₂) after salt treatment compared to P‐B plants. Sodium localization and distribution analysis using Na⁺‐specific dye revealed HS‐B plants accumulated 88% and 48% less Na⁺ in stele and xylem vessels compared to P‐B. The study provides insights into the potential mechanisms that may contribute to salt tolerance in HS‐B: maintaining RWC by accumulating soluble sugars while reducing transpiration, maintaining healthy status by reducing oxidative stresses, and preventing salt toxicity by reducing accumulation of Na⁺ inside root cells and xylem.  相似文献   

The installation of underground pipelines: effects on soil properties          下载免费PDF全文

T. Batey 《Soil Use and Management》2015,31(1):60-66

Since the 1970s a network of underground pipes, up to 1200 mm diameter, has been installed in the UK to transmit crude oil to refineries and gas from onshore terminals for distribution. Chosen routes are subject to significant constraints. Current techniques for pipe installation involve topsoil removal and storage. Trench depth is set to allow a cover of 1200 mm overburden after pipes have been installed. The heavy machinery involved results in severe compaction of exposed subsoil. Subsoil is loosened comprehensively and topsoil replaced. Existing field drains are reconnected, and, if necessary, new drains with gravel backfill installed. Pipe installation usually takes place between April and October. Preventative measures to limit compaction during installation are not a practical option. If subsequent arable crops or grass are poorer or drainage more defective than before disturbance, the loss is assessed and compensation paid. To determine the cause of the loss >60, investigations have been made throughout the UK. Soil physical properties were assessed in an open trench using visual and tactile methods. Consistently, severe compaction in the subsoil was identified as the cause of poor crop growth or drainage; it was not observed in the topsoil. Specific recommendations for remedial action were made based on location, depth and severity of the compaction. These included the installation of additional land drains, increasing the amount of gravel above the drains, or further subsoil loosening orientated to cross gravel backfill. After appropriate remedial action, net compensation for crop losses was frequently small or negligible.  相似文献   

基于GIS的不同种植模式下凉州区日光温室土壤养分分析   总被引：3，自引：3，他引：0  

张生瑞  韩梅  袁政祥  张正鹏  王祎 《甘肃农业科技》2015,(1):21-24

采用GPS定位取样测试、ACIGIS软件数据分析和地统计分析方法,对凉州区日光温室土壤养分状况进行了分析评价。结果表明,在0~20 cm表层土壤中,不同种植模式的氮、磷、钾养分分布趋势基本一致。种植番茄—架豆、番茄—辣椒电导率最大,为1.97 ms/cm;种植番茄—架豆盐分最高,为11.9 g/kg;种植人参果CEC最大,为16.87%。在20~40 cm土壤中,种植番茄—辣椒电导率最高,为2.59 ms/cm;种植小乳瓜盐分最大,其值为17.9 g/kg;种植人参果CEC最大,为19.94%。  相似文献   

连作及轮作土壤微生物菌群对黄瓜幼苗生长及土壤酶活性的影响     

刘杰  吴凤芝  周新刚 《中国蔬菜》2015,1(5):38

通过植物-土壤反馈试验,研究连作及轮作土壤微生物菌群对黄瓜幼苗生长和土壤酶活性的影响。结果表明,轮作土壤微生物处理黄瓜植株鲜质量、叶绿素含量、土壤中性磷酸酶、蔗糖酶活性显著高于连作土壤微生物处理;连作及轮作土壤微生物处理增加了黄瓜幼苗干质量、鲜质量、叶绿素含量及总叶面积,显著提高了土壤中性磷酸酶、蔗糖酶、脲酶活性。综上,连作及轮作土壤微生物菌群对黄瓜幼苗生长均产生正反馈作用,并且轮作土壤微生物的正反馈作用大于连作土壤微生物。  相似文献   

Comparative soil distribution and dissipation of phoxim and thiamethoxam and their efficacy in controlling Bradysia odoriphaga Yang and Zhang in Chinese chive ecosystems     

《Crop Protection》2016

Bradysia odoriphaga Yang and Zhang (the chive gnat) is the major insect pest affecting Chinese chives (Allium tuberosum Rottl. ex Spreng.) in Northern China. Only three insecticide products are registered for its control. In the present study, we compared the persistence and distribution of thiamethoxam and phoxim in soil and determined their long-acting control effects against B. odoriphaga and two other secondary pests, Thrips alliorum Priesner and the Asiatic onion leaf miner Acrolepia alliella Semenov and Kuznetsov (Lepidoptera: Acrolepiidae), after a single soil application using the directional spray-washing method during the early Chinese chive root-rearing period. Under the same applied dosage, the rhizosphere soil at a depth of 4.0–10.0 cm had concentrations of thiamethoxam and phoxim ranging from 2.21 to 7.44 mg/kg and 0.09–0.44 mg/kg, respectively, at the 7th day after application. The half-lives of thiamethoxam and phoxim in the soil were 27.5 and 6.7 days, respectively. Thiamethoxam persisted for 210 days, whereas phoxim only persisted for 45 days in the soil and plants. In addition, thiamethoxam applied at 6.0 kg a.i./ha maintained a low population density of B. odoriphaga, T. alliorum and A. alliella for nine months longer than phoxim. In conclusion, thiamethoxam may help farmers more effectively manage B. odoriphaga and other secondary pests on Chinese chive and reduce the costs of insecticide use while sustaining protection.  相似文献   

Phosphorus availability and farm structural factors: examining scarcity and oversupply in north‐east Germany          下载免费PDF全文

T. F. H. Theobald  K. Daedlow  J. Kern 《Soil Use and Management》2015,31(3):350-357

Assessing factors influencing phosphorus (P) availability in soils is important in preventing its overexploitation and excessive application in agricultural systems. Despite high historical P applications in the federal state of Brandenburg (Germany), county data on soil test P (STP) reveal considerable disparities in soil available P. In addition, negative soil balances as a result of small mineral P and manure inputs have been observed, raising questions about the factors leading to this situation. Our work focused on identifying possible causes operating at the farm management level by conducting a letter survey in two administrative districts of Brandenburg, the counties Barnim and Uckermark, linking farm management factors (ownership type, farm size, land tenure, animal husbandry with or without grassland and its intensity, presence of a biogas plant and organic production) to farmers’ self‐indicated levels of STP. Small‐ to medium‐sized individual farms tended to have (very) high STP, while large partnership farms and companies/cooperatives were sensitive to factors resulting in low STP. Farms with low shares of land ownership, the presence of grassland, extensive cattle farming and stockless organic farming had lower STP. On the other hand, biogas plants, partly in combination with intensive livestock (cattle) farming, were associated with larger STP. It was concluded that more care should be devoted to the design of agricultural policies and that further (inter‐ and transdisciplinary) research on this topic is needed.  相似文献   

Organic input quality is more important than its quantity: C turnover coefficients in different cropping systems     

《European Journal of Agronomy》2016

Annual C input to soil is a major factor affecting soil organic carbon (SOC) dynamics. However different types of C-sources can have different behaviour, in relation to their chemical characteristics and how they interact with soil. Root-derived C, in particular, should be more efficient than other organic materials as a result of the physicochemical and biological characteristics of the surrounding environment, leading to a reduction in the C decomposition rate.To test this hypothesis, we considered a long-term experiment underway in Northern Italy since 1962, comparing permanent meadow and 6 different crop rotations over a wide range of nutrient inputs, in both organic and inorganic forms. C inputs from amendments were measured and those from crops were calculated using allometric functions and crop and residues yields. The time evolution of SOC was studied through a single-pool, first-order kinetic model, allowing the estimation of humification coefficients for residues, roots, farmyard manure and cattle slurries.The highest value of the humification coefficient was estimated for farmyard manure, which confirmed its high efficiency in stabilising SOC content. Root C presented a humification coefficient 1.9 times higher than above-ground plant materials while slurries were intermediate, with a humification coefficient roughly half that of farmyard manure and even lower that of roots.The quality of C input thus seems of fundamental importance for evaluating the sustainability of different cropping systems in terms of SOC dynamics.  相似文献