长期施用化肥和农家肥对土壤化学性质和作物产量的影响

A long-term fertiliztion experiment was carried out in an experimental field in Lyczyn near Warsaw,Poland.Application ofmineral fertilizers ,especially Nfertilizer with and without farmyard manure accel-erated the eacidification process of the soil.Application of 1.6 t CaO ha^-1 every four years was essential to maintenance of the soil pHKCl at 5.5-6.6 and base saturation degree above 60% Application of 50 t farmyard manur ha^-1 every 4 years,whih contained 46 kg P and 240 kg K,was sufficient to maintain boh the K and P fertility of the soil.Besides,it was beneficial to alleviating soil acidifcation. As a result of long-term unbalanced fertilization,yield responses to N,P and K fertilizers incereased significantly with time.the efficiency of N from farmyard manure was found to be comparable to that of N fertilizer during 1988-1991.     

日粮中添加黄芪多糖对锦江黄牛瘤胃体外发酵及养分降解率的影响

[目的]试验旨在探究不同水平黄芪多糖(astragalus polysaccharides, APS)对锦江黄牛瘤胃体外发酵指标及养分降解率的影响。[方法]选取4头健康并安装永久瘤胃瘘管的锦江黄牛公牛,采集瘤胃液。采用单因素试验设计,试验分为6组,每组4个重复,在基础日粮中分别添加0、0.25%、0.5%、1.0%、2.0%和4.0%的黄芪多糖,体外发酵24 h后测定发酵参数、养分降解率,并评定多项指标综合指数(MFAEI)。[结果]结果表明,与对照组相比,1.0%和2.0%添加组的瘤胃液菌体蛋白(MCP)含量均显著升高(P<0.05);2.0%添加组的氨态氮(NH3-N)含量显著降低(P<0.05);1.0%添加组的丙酸含量显著升高(P<0.05),乙丙酸比值显著下降(P<0.05);0.5%、2.0%和4.0%添加组的粗蛋白(CP)降解率极显著高于对照组(P<0.01);各添加组的总产气量、pH、乙酸含量、干物质(DM)降解率、酸性洗涤纤维(ADF)降解率及中性洗涤纤维(NDF)降解率与对照组相比均无显著变化(P>0.05)。MFAEI指数评定结...     

夏玉米田作物蒸腾与棵间土壤蒸发模拟计算方法研究

本文依据能量平衡原理和质量守恒定律，提出了作物蒸腾与棵间土壤蒸发的估算模式，并对参数的估算做了详细的分析和讨论。最后利用试验区实测资料，通过田间水热耦合运移的数值模拟，对夏玉米田作物蒸腾棵间土壤蒸发模型及其模拟计算方法进行了验证，结果表明，本文提出的模型和模拟计算方法是有效而实用的。     

Lithic soils in the semi-arid region of Brazil: edaphic characterization and susceptibility to erosion

Soils(Leptosols or Epileptic Regosols)with lithic contact at a depth of 50 cm occupy almost 20%of the Brazilian semi-arid region.These lithic soils are susceptible to erosion due to faster saturation of water-holding capacity during rainfall,which accelerates the beginning of runoff.However,erosion traits of lithic soils in the semi-arid region of Brazil are less studied.The aim of this study was to characterize the soil and landscape attributes in areas with Neossolos Litólicos(Entisols)in the Caatinga biome to identify region of high susceptibility to erosion.Results showed that the soils were characterized by a sandy texture,soil structure with poor development and low content of organic carbon.These attributes increase susceptibility to erosion and reduce water storage capacity,especially in the states of Cearáand Sergipe.In these states,the content of rock fragments in the soil reaches 790 g/kg.High contents of silt and fine sand,high silt/clay ratio,predominance of Leptosols and strong rainfall erosivity were observed in Piauíand northwestern Ceará.A very high degree of water erosion was observed in the states of Pernambuco and Paraíba.Despite the low degree of erosion observed in the state of Bahia,it is highly susceptible to erosion due to the predominance of very shallow soils,rugged relief and high values of rainfall erosivity.Lower vulnerability was observed in the state of Alagoas because of its more smoothed relief,greater effective soil depth,thicker A horizon of soil and lower rainfall erosivity.In general,the characteristics that intensify the susceptibility to erosion in the Caatinga biome are those soil structures with poor development or without aggregation,low contents of organic carbon,high contents of silt and fine sand,high values of silt/clay ratio and rugged relief in some regions.This study collected information contributing to a better characterization of soils with lithic contact in the semi-arid region of Brazil.In addition,regions with a higher susceptibility to erosion were identified,revealing insights that could help develop strategies for environmental risk mitigation.     

耕作与施肥模式对渭北旱塬春玉米田蓄水保墒与玉米产量的影响

为揭示渭北旱塬春玉米田休闲期不同保护性耕作模式的蓄水保墒与增产增收效应,寻找适合渭北旱塬春玉米田水肥高效利用的耕作方式和施肥水平,于2013—2014年度在陕西省合阳县甘井镇春玉米田分别设置传统农户模式(翻耕+低肥,S1)、现有高效模式(免耕+高肥,S2)、创新高效模式(深松+平衡施肥,S3)等模式处理,研究各类耕作与施肥相结合保护性耕作模式下春玉米水分利用率、产量和经济效益差异。结果表明,创新模式S3和现有模式S2较农户模式S1播前增加了土壤贮水量;创新模式S3和现有模式S2处理在玉米主要生育期0~200 cm土层平均土壤贮水量分别比农户模式S1增加23.3 mm和18.1 mm,水分利用效率分别提高12.3%和10%,产量增加11.1%、9.2%。创新模式和现有模式均较农户模式能够增加土壤贮水量,提高水分利用效率,增加产量和经济效益,但创新模式蓄水保墒,增产增收优势明显,是适合渭北旱塬地区春玉米生产的水肥管理模式。     

高海拔冻土层地区不同土壤温度对花叶海棠光合特性的影响

为促进花叶海棠在高海拔冻土层地区的生长,通过使用自控温电热带土壤增温措施对土壤进行增温试验,分别设置2.0 (S₁)、3.0 (S₂)、4.0 (S₃)、5.0 (S₄) ℃ 4种增温梯度和1个CK对照组,测量不同梯度下花叶海棠的净光合速率、蒸腾速率、气孔导度及胞间CO₂浓度。结果表明：在4种处理中,S₄的花叶海棠叶片净光合速率、蒸腾速率、胞间CO₂浓度最大,与对照相比,其增长率分别为13.88%、58.55%、18.42%;S₃的花叶海棠叶片气孔导度最大,增长率为8.68%。土壤温度与花叶海棠叶片的净光合速率、气孔导度、胞间CO₂浓度呈极显著相关,与蒸腾速率呈显著相关。与对照组相比S₄与S₃能明显提高净光合速率、蒸腾速率,与对照组相比S₄、S₃、S₂能明显地提高气孔导度、胞间CO₂浓度。综合各项指标分析,在试验范围内土壤温度增加4.0~5.0 ℃最适宜花叶海棠的生长。     

风沙土玉米钾肥适宜用量的研究

田间试验结果表明:在吉林省西部风沙土上,施用钾肥对玉米有明显的增产效果。施用K2O 75kg/hm2,相对增产值为23.6%,化肥利用率达31.7%,千粒重和穗粒数最高,为最佳用量。     

Is the Period of 18 Years Sufficient for an Evaluation of Changes in Soil Organic Carbon under a Variety of Different Soil Management Practices?

The influence of differing soil management practices on changes seen in soil organic carbon (SOC) content of loamy Haplic Luvisol was evaluated. The field experiment included two types of soil tillage: 1. conventional tillage (CT) and 2. reduced tillage (RT) and two treatments of fertilization: 1. crop residues with nitrogen, phosphorus, and potassium (NPK) fertilizers (PR+NPK) and 2. NPK fertilizers (NPK). The results of SOC fluctuated from 9.8 to 14.5 g kg^?1 and the tillage systems employed and fertilization status did not have a statistically significant influence on SOC. The SOC content was higher in RT (12.4 ± 0.86 g kg^?1) than in CT (12.2 ± 0.90 g kg^?1). On average, there was a smaller higher value of SOC in PR+NPK (12.4 ± 1.02 g kg^?1) than in NPK (12.3 ± 0.88 g kg^?1). During a period of 18 years, reduced tillage and application of NPK fertilizers together with crop residues build up a SOC at an average speed of 7 and 16 mg kg^?1 year^?1, respectively, however conventional tillage and NPK fertilizer applications caused a SOC decline at an average speed of 104 and 40 mg kg^?1 year^?1, respectively.     

郭岩山不同海拔天然栲树林土壤硅形态特征

目的 探究郭岩山不同海拔天然栲树林土壤硅形态的变化特征及其与土壤理化性质的相关关系,进一步揭示亚热带地区土壤硅形态含量对环境变化的响应机制。 方法 本研究以郭岩山自然保护区不同海拔天然栲树林土壤为研究对象,在郭岩山自然保护区海拔600、700、800、900 m分别设置标准地,采集不同海拔各土层（0～20、20～40、40～60 cm）的土样,测定土壤不同硅形态含量,分析环境变化对土壤中硅形态的影响。 结果 （1）高海拔土壤有效硅（258.26 mg·kg−1）、水溶性硅（155.69 mg·kg−1）、活性硅（388.97 mg·kg−1）及无定形硅（1 561.97 mg·kg−1）含量均显著高于低海拔土壤有效硅（93.16 mg·kg−1）、水溶性硅（78.38 mg·kg−1）、活性硅（231.84 mg·kg−1）及无定形硅（832.24 mg·kg−1）。深土层（40～60 cm）的土壤有效硅含量（227.53 mg·kg−1）显著高于0～20 cm（120.79 mg·kg−1）及20～40 cm（171.37 mg·kg−1）土层;（2）土壤有效硅含量与活性硅及水溶性硅含量呈极显著正相关,其中,活性硅是有效硅增加最重要的直接贡献形态,而水溶性硅是土壤硅转化过程中重要的过渡性形态;（3）土壤有机质和土壤pH值对各土壤硅形态含量的影响最显著,解释率分别达14.1%和9.2%,其中,土壤有机质与无定形硅及水溶性硅呈正相关,与土壤活性硅及有效硅呈负相关,而土壤pH值与有效硅、活性硅呈正相关,与无定形硅呈负相关。 结论 海拔引起的环境及土壤理化性质变化可改变土壤硅形态含量。研究结果为天然栲树林有效利用土壤硅及调控土壤硅形态提供了参考依据,对天然栲树林的保护具有重要的科学指导意义。     

江西水土流失对防洪的影响及防治对策

江西省水土流失面积 3 5 2万km2 ,严重破坏了生态环境。水土流失导致河床和水库淤积 ,加剧了洪涝灾害程度。鄱阳湖承担着长江巨大超额洪水的调蓄 ,但湖区面积已由 2 0世纪 5 0年代初期的 5 10 0多km2 萎缩到现在的 3 95 0多km2 ,容积缩小了 72亿m3。本省境内的“五河”流入鄱阳湖内的水量达 14 0 0多亿m3,是该湖容积的 4倍多 ,可见搞好水土保持对长江防洪的重要意义。水土保持措施已在防洪减灾中发挥了重大作用 ,应把水土保持生态环境建设作为长江和本省新世纪水利发展战略的重要内容