河南烟区土壤有机质和氮的含量及施肥技术

根据河南省烟区的自然条件和土壤特点，系统分析了豫中、豫西、豫南、豫东四大烟区土壤有机质和氮素含量及其分布现状。提出了高、中、低肥力水平烟田的有机肥(饼肥)和氮肥用量指标及合理施肥技术措施。     

湖南郴州烟区土壤有机质和全氮时空变异及其影响因素研究

为了探明湖南省郴州烟区土壤有机质和全氮的时空变化规律,从而为烟田有机物料投入和氮素养分管理提供科学依据,采用地统计学技术和地理信息技术相结合的方法,对该区2000年和2015年植烟土壤有机质和全氮时间和空间变异特征进行了研究。结果表明,2个年份有机质和全氮含量均十分丰富,2015年土壤有机质(SOM)和全氮(TN)平均含量较2000年分别增加了2.59 g kg^-1和0.04 g kg^-1,变异系数基本稳定,极差变大,Moran’s I下降,SOM块金效应基本稳定,TN块金效应显著增加;有机质"适宜"和"高"等级面积分别下降了12.07%和17.16%",极高"等级面积增加了29.47%;两个年份全氮含量"适宜"及以下的等级均缺失,2015年土壤全氮"高"等级面积下降了5.51%",极高"等级的面积增加了5.51%。上述结果表明郴州植烟土壤SOM和TN含量增加,极差变大,空间自相关性显著下降,而随机变异性增加。植烟土壤SOM与TN呈显著线性正相关。     

长期不同施肥对稻田土壤有机质和全氮的影响

通过对湖南新化、宁乡、株洲、桃江、武岗5个国家级稻田肥力长期定位试验点18年的田间定位试验,研究了不同施肥方式下0-20 cm土层土壤有机质和全N含量的演变规律。结果显示,中量和高量有机肥与化肥配合处理在提高土壤有机质和全N含量方面效果明显优于单施化肥和秸秆还田处理,且随有机肥用量的增加而增加,表明有机肥与化肥配合施用是提高土壤有机质和N素肥力的重要措施。在不同施肥方式下,稻田土壤有机质总体上呈现出上升或者下降的趋势,但在不同的年份会有波动。     

同时估测土壤全氮、有机质和速效氮含量的光谱指数研究

通过系统分析我国中、东部地区5种不同类型土壤风干样本的有机质、全氮及速效氮含量与近红外(1 000～2 500 nm)光谱反射率之间的关系,进而构建了适合同时估测这3种养分含量的光谱参数及定量估算模型。结果表明,同时与3种养分指标相关较高的波段范围为1 879～1 890与2 050～2 100 nm,其中1 881和2 070 nm两个波段的反射率经多元散射校正及Savitzky-Golay平滑处理并构建而成的差值指数DI(CR1 881,CR2 070)与土壤有机质、全氮及速效氮含量具有良好的线性相关性。独立的观测资料检验显示,基于DI(CR1 881,CR2 070)的估测模型对全氮、有机质和速效氮的预测决定系数R2分别为0.83、0.79和0.72,均方根误差(RMSE)分别为0.20 g kg-1、4.71 g kg-1和23.96 mg kg-1,相对分析误差(RPD)分别为2.56、2.30和2.93。表明DI(CR1 881,CR2 070)是一种可同时估测土壤中3种养分含量的良好光谱指数。     

攀西植烟土壤有机质和全氮空间变异性研究

采用地统计学和GIS技术,研究攀西植烟土壤有机质和全氮空间变异特征及其影响因素,为烤烟种植规划及平衡施肥提供依据。结果表明,研究区植烟土壤有机质和全氮含量变化范围分别为5.00～59.63g.kg-1和0.40～3.16g.kg-1,变异系数分别为38.66%和39.26%,均具有中等程度的空间变异性。半方差分析表明,土壤有机质的块金系数为0.578,具有中等程度的空间相关性,其空间变异性受土壤类型、地形条件等结构因素和施肥、管理水平等随机因素的共同影响;土壤全氮的块金系数为0.221,具有较强的空间相关性,其空间变异性受土壤类型、地形条件等结构因素的影响。空间插值结果得出,北部有机质含量高于南部,东部全氮含量则略高于西部;研究区内有24.57%的区域土壤有机质处于较低水平,39.72%的区域土壤全氮含量属于较丰富水平。不同县域应针对各自不同海拔和土壤类型的养分现状,合理调控有机肥和氮肥的施用。     

有机质、全氮和可矿化氮在反映土壤供氮能力方面的意义

用 2 5个表层土壤样品和 6个土壤 3 6个不同层次的土壤样品研究了可矿化氮与有机质、全氮的关系。可矿化氮由通气培养法测定。研究结果表明 ,不论表层土壤或不同层次剖面土壤中的可矿化氮都与有机质、全氮高度正相关。但是由于可矿化氮与有机质、全氮有自相关存在 ,他们之间的相关有一定的不真实性。而且 ,土壤的可矿化氮并不与全氮或有机质成正比 ,可矿化氮与有机质或全氮的比值因土壤而不同 ,差别很大。特别重要的是 ,可矿化氮对有机质或全氮的比率几乎在一条直线上 ,它们之间的相关性明显高于可矿化氮与有机质或全氮的关系。这些结果显示 ,矿化氮的数量取决于有机质和全氮中的可矿化部分 ,而不是其总量。土壤剖面中累积的硝态氮数量低时 ,作物的吸氮量与可矿化氮的关系远较与有机质或全氮的关系密切 ,更证明了测定可矿化氮有其特定意义 ,有机质、全氮的测定并不能代替可矿化氮的测定。     

冀州市土壤有机质和速效氮磷钾的分布状况

冀州市土壤有机质、碱解N、速效K总体上处于中等水平,速效P处于中等偏上水平;土壤有机质大部分含量在6~19g/kg之间,碱解N大部分含量在26~75mg/kg之间,速效P大部分含量在5~52mg/kg之间,速效K大部分含量在50~230mg/kg之间;在集中分布区,土壤有机质和碱解N呈正态分布,速效P和速效K呈偏正态分布;各养分的变异程度以速效P最大,碱解N最小。     

湘西植烟土壤有机质含量分布及其影响因素

为了解湘西州植烟土壤有机质含量分布状况及其影响因素,测试了湘西州7个主要烟区488个土壤样本的有机质含量,采用传统统计学和地统计学方法分析了湘西州植烟土壤有机质含量分布及土壤类型、海拔高度、pH值等影响因素。结果表明:1湘西州植烟土壤有机质含量总体适宜,平均值为21.69g/kg,变幅为3.12~62.97g/kg,变异系数为40.64%,处于适宜范围内的样本占41.48%;2不同县之间的植烟土壤有机质含量差异达极显著水平,永顺县、凤凰县、龙山县植烟土壤有机质含量总体上处于适宜水平,其他各县总体处于较低水平;3湘西州植烟土壤有机质含量在空间分布上是从东北部、西部和西南部向州中部及东南方向减少,在永顺县东南部、保靖县的西部各有一个高值区;4不同植烟类型土壤的有机质含量差异达显著水平,灰黄棕土、水稻土、灰黄泥、浅灰黄泥、黄壤的有机质含量属适宜水平,其他类型土壤的有机质含量偏低;5不同海拔高度的植烟土壤有机质含量差异达极显著水平,湘西州植烟土壤有机质含量有随海拔升高而升高的趋势;6不同pH的植烟土壤有机质含量差异极显著,主要为pH>7.0的植烟土壤有机质含量较高。     

盐渍土改造区土壤养分的时空变异性研究

在第二次全国土壤普查的基础上,于2002年10月对研究区域———河北省曲周县的耕地进行了全面的调查和分析,并将GPS、GIS技术应用到耕地质量调查工作中。研究结果表明:随着盐碱地综合治理的深入、外源物投入数量的增加和质量的改进、作物布局的调整,盐渍土改造区土壤养分在时间和空间上发生了很大的变化。在时间上,耕层土壤有机质平均含量从8.4 g kg-1增加到13.89 g kg-1,全氮平均含量达到0.937 g kg-1,速效磷平均含量从5.45 mg kg-1增加到23 mg kg-1,速效钾含量从34~285 mg kg-1之间逐步变化为67~191 mg kg-1之间的高肥力农业土壤;在空间上,土壤养分的分布与养分的地球化学过程、农业产业结构布局及采用的相应措施有密切关系。主要表现在:土壤有机质、全氮及速效磷含量随着农业集约化程度的提高、外源物质投入的增加而相应增加;土壤速效钾含量则由原来的随地球化学过程而变化,转变为随着农业集约化程度的提高而相应变化。     

扬州市土壤有机质和速效磷钾的分布研究

研究表明，我市土壤有机质和速效P含量总体上处于中等偏低水平，速效K含量处于中等水平；90％以上的土壤有机质含量在10～40g/kg之间，速效P含量在2～29mg/kg之间，速效K含量在25～125mg/kg之间；在集中分布区，土壤有机质和速效P近似于呈偏正态分布，速效K近似于呈正态分布：各养分的变异程度以速效P最大，速效K最小。各县(市、区)中，以宝应、高邮两地的土壤肥力较高。     

云南植烟土壤有机质与氮含量的研究

2004年在云南省91个烟叶主产县(区)采集683个植烟耕层土壤进行分析。结果表明,云南植烟土壤有机质和全氮含量变幅较大,平均含量分别为33.0 g.kg-1和1.9 g.kg-1,两者处于Ⅰ级和Ⅱ级高水平含量的土壤样本分别占54.3%和68.3%。碱解氮含量平均140.8 mg.kg-1,处于Ⅰ级和Ⅱ级高水平含量的土壤样本占63.1%。不同植烟土壤类型有机质和全氮含量差异较大,其中水稻土含量较高,紫色土次之,红壤及黄壤含量相对较低。     

河南主要植烟土壤养分状况与施肥对策

在河南省不同生态类型区典型地块采集大量土壤和烟叶样品进行分析化验 ,结果表明 :河南省主要植烟土壤的 pH介于中性—微碱性范围 ,有机质和有效氮含量中等偏高 ,大部分土壤有效磷含量偏低 ,有效钾含量较高 ;中量元素钙含量过高 ,最高含量达 4 0 66mg/kg,钾钙关系失调 ;微量元素中锌较缺乏 .烟叶品质突出表现为钾素中等偏低 ,氯离子含量偏高 .为此提出该区烟草施肥中应掌握“稳氮、增磷、补钾、控钙、降氯、配微”的施肥对策     

生物炭对两种植烟土壤活性有机碳的影响

为调查烟秆生物炭对典型植烟土壤根际与非根际活性有机碳组分的影响及其在不同土壤类型中是否具有一致性,选取我国烟草主产区贵州省毕节市黄壤区(东部的黔西林泉科技示范园)和黄棕壤区(西部的威宁黑石科技示范园)两个土壤类型,研究施用不同量烟秆生物炭(0、5、20、40 t·hm-2,分别记为B0、B5、B20、B40)后根际与非根际土壤总有机碳(TOC)、易氧化有机碳(ROOC)、可溶性有机碳(DOC)和微生物量碳(MBC)含量的变化情况。施用生物炭后,根际土壤TOC、ROOC以及非根际土壤DOC在两个土壤中的表现基本一致,而其余则在两种土壤中表现不同。但整体表现为TOC、ROOC及DOC含量在B5处理中没有显著变化,而在B20和B40处理中显著增加,3种有机碳含量与B0相比,增幅最高分别可达305.63%、630.41%及768.48%;不同有机碳及土壤类型的峰值出现在B20或B40处理中。而对MBC来说,非根际土壤中MBC含量在黄壤B5处理中显著降低了20%,在黄棕壤B20和B40处理中分别显著增加了53.98%和145.80%,其余处理与B0之间没有显著差异;而在根际土壤中仅在黄壤B20处理中MBC含量显著增加42.17%,其余处理与B0之间均无显著差异。说明短期施用生物炭对植烟土壤活性有机碳组分(尤其是MBC)的影响与土壤类型、生物炭施用量、根际环境等有关。     

多雨烟区烤烟氮肥优化施用的减氮效应及对烤烟产质量的影响

采用大田试验研究基肥不同施肥方式和基追肥比例对烤烟产质量及减氮效应的影响。结果表明,在多雨条件下,采用挖大穴、施用穴肥(60%基肥条施+40%基肥穴施)的方式能够促进烟株前期吸收更多养分,促进烟株早生快发,提高中部叶质量。当施氮量为127.5 kg·hm~(-2),追肥比例由50%提高到65%时,烤烟上部叶开片度、叶面积、单叶重均有所提高,上部烟叶营养得到改善。在总施氮量比CK(150 kg·hm~(-2))减少15%条件下,通过调整基肥施肥方式和基追肥比例,烟叶产值和烟叶质量均得到提升,既节约了成本,又提高了烟农效益。     

思茅市主要植烟土壤养分特征及推荐施肥技术

对思茅市的主要植烟土壤调查取样分析结果表明,全市植烟土壤有机质、速效磷、碱解氮、pH值、速效钾和速效锌含量比较适宜;土壤交换性镁含量丰富;土壤速效硼和水溶性氯供应明显不足,大部分烟区处在缺乏与潜在性缺乏之间。根据测土配方施肥指标,思茅市的施肥技术是控氮、增磷、补钾、增施硼和氯肥,对部分土壤补充镁和锌,部分偏酸的土壤施用碱性肥料来调节酸碱度。     

Content of organic carbon and total nitrogen inStagnic Albeluvisols depending on fertilization

Abstract

The content of soil organic carbon (SOC) and total nitrogen (N_tot) was studied in a long-term field experiment with a three-field crop rotation (potato – spring wheat – spring barley) set up on arable sandy loam Stagnic Albeluvisol at Eerika, Tartu, Estonia. The studied factors were: (A) organic fertilizers with three treatments: (i) without organic fertilizer, (ii) farmyard manure (60 t ha^?1) used in every third year, and (iii) different organic (alternative) fertilizers (beet leaves + straw; pure beet leaves; slurry + straw; cereal straw) and (B) mineral nitrogen fertilizer with the rates: N-0; N-40; N-80; N-120 and N-160 kg ha^?1. The study years were 1993, 1996 and 1999. The average content of SOC (1.03%) was significantly influenced by the use of organic fertilizers. Only N_tot (mean value 0.110%) was influenced also by fertilization with mineral nitrogen. The C/N ratio (mean value 9.5) reflected changes in the content of SOC and N_tot     

有机肥施用模式对环水有机蔬菜种植氮磷径流的影响

在水环境敏感区域以有机生产代替常规集约化农业,对保护生态环境、提高水库水质和保障居民饮用水安全具有重要意义。实际生产中,如果为追求产量盲目施用有机肥会增加氮磷径流流失风险。为在保障产量的前提下减少氮磷流失,本研究于昆明松华坝水库集水区,以不施肥(CK)和常规施用化肥(CF)为对照,在有机生产方式下设置不同类型有机肥[牛粪(DMC)、鸡粪(CMC)以及二者与豆饼的混合有机肥(HH)]及用量(与CF处理等氮素投入100%、80%和60%)的有机肥施用模式,共计11个处理(CK、CF、0.6DMC、0.8DMC、DMC、0.6CMC、0.8CMC、CMC、0.6HH、0.8HH、HH),分析其对土壤径流氮磷流失阻控效果和作物产量的影响。研究结果表明,在有机种植方式下,施用有机肥可使施肥初期(0～25d)总氮径流浓度比常规施化肥降低26.3%～73.9%,生育期总氮累积浓度降低32.8%～67.0%。单施牛粪和鸡粪导致径流水总磷浓度比CF提高49.1%和12.3%,施用混合有机肥或减氮施用牛粪和鸡粪总磷浓度则比CF处理降低15.8%～52.5%。氮素投入水平和施肥类型对径流水氮磷浓度、土壤硝态氮和速效磷含量有显著影响。等氮素投入下不同肥料类型的径流水总氮浓度为化肥牛粪混合有机肥鸡粪,总磷浓度为牛粪鸡粪混合有机肥化肥;土壤硝态氮含量为化肥牛粪、鸡粪混合有机肥,速效磷含量为鸡粪牛粪混合有机肥化肥。以60%氮素水平施用有机肥对径流水氮磷累积浓度和土壤硝态氮含量削减效果最佳,但土壤速效磷仍有累积风险。混合有机肥处理的青花菜产量最高,而单施牛粪或鸡粪存在减产风险。综合来看,与常规施用化肥相比, 60%氮素投入加牛粪、鸡粪和豆饼混合有机肥的施肥模式可在产量提高16.7%的前提下,使径流水总氮、硝态氮、氨态氮浓度分别降低66.5%(18.94mg·L~(–1))、67.2%(11.11 mg·L~(–1))和66.2%(6.57 mg·L~(–1)),总磷降低52.5%(0.5 mg·L~(–1)),可作为推荐施肥类型和用量在松华坝流域有机蔬菜生产进行推广。     

Sterols in soil organic matter in relation to nitrogen mineralization in sandy arable soils

Unusually low net N mineralization in soils relatively rich in total organic C and N was repeatedly reported for sandy arable soils in NW Europe. In order to adequately account for it in simulation models, it is necessary to know the involved substances and processes. Therefore, 9 arable top soils (< 6% clay) with a wide range of total organic C (1.1%–5.2%) and C : N ratios (12–35) were studied. The soils varied strongly in the mineralizability of soil organic N which was determined via long‐term laboratory incubations (> 200 d). It was hypothesized that mineralization was controlled by antioxidants, and the Trolox equivalent antioxidant capacity (TEAC) of the soils was measured. In addition, pyrolysis–field ionization mass spectrometry (Py‐FIMS) was applied to investigate the influence of the molecular‐chemical composition of soil organic matter. In these soils, the compound class of sterols from Py‐FIMS analysis was most closely, negatively correlated with the mineralizability of soil organic N (r² = 0.75, p = 0.003). This was probably not an antioxidative effect, because the TEAC values did not correlate sufficiently with the mineralizability and the sterol intensities. However, the negative relation with sterols could be causal, since the correlation was about as close with other components of the compound class of sterols and even closer with the main plant sterol beta‐sitosterol (r² = 0.84, p = 0.001). In addition, the variability among samples was strongly governed by the proportions of sterols, and sterols also had a high discriminating power in discriminant analysis. Furthermore, the proportions of sterols were extraordinary in those arable podzol soils that developed under previous heath‐ or woodland (up to 10.2% of total ion intensity from Py‐FIMS). In conclusion, the inhibitory effect of these compounds needs to be investigated in more detail in order to optimize parameterization of N as well as C simulation models especially for podzolized, sandy arable soils with former heath‐ or woodland vegetation.     

Influence of tillage, crop rotation and nitrogen fertilization on soil organic matter and nitrogen under rain-fed Mediterranean conditions

The long-term effects of cropping systems and management practices on soil properties provide essential information for assessing sustainability and environmental impact. Field experiments were undertaken in southern Spain to evaluate the long-term effects of tillage, crop rotation and nitrogen (N) fertilization on the organic matter (OM) and mineral nitrogen (N_min) contents of soil in a rain-fed Mediterranean agricultural system over a 6-year period. Tillage treatments included no tillage (NT) and conventional tillage (CT), crop rotations were of 2 yr with wheat (Triticum aestivum L.)-sunflower (Helianthus annuus L.) (WS), wheat-chickpea (Cicer arietinum L.) (WP), wheat-faba bean (Vicia faba L.) (WB), wheat-fallow (WF), and in addition, continuous wheat (CW). Nitrogen fertilizer rates were 50, 100, and 150 kg N ha⁻¹. A split-split plot design with four replications was used. Soil samples were collected from a depth of 90 cm at the beginning of the experiment and 6 yr later. Soil samples were also collected from a depth of 30 cm after 4 yr. These samples, like those obtained at the beginning of the experiment, were subjected to comprehensive physico-chemical analyses. The soil samples that were collected 6 yr later were analyzed for OM, NH₄⁺---N and NO₃⁻---N at the 0–30, 30–60 and 60–90 cm soil depths. The tillage method did not influence the OM or N_min contents of the soil, nor did legume rotations increase the OM content of soil relative to CW. A longer period may have been required for differences between treatments to be observed owing to the small amount of crop residue that is returned to soil under rain-fed conditions of semi-arid climates. The WF rotation did not raise the N_min content of the soil relative to the other rotations. The consistent significant interaction between tillage and crop rotation testifies to the differential effect of the management system on the OM content and N status of the soil. The ammonium levels clearly exceeded those of NO₃⁻---N throughout the soil profile. The high N_min content of the soils reveals the presence of abundant N resources that should be borne in mind in establishing N fertilization schemes for crops under highly variable climatic conditions including scant rainfall such as those of the Mediterranean region.     

Soluble organic nitrogen in agricultural soils

 The existence of soluble organic forms of N in rain and drainage waters has been known for many years, but these have not been generally regarded as significant pools of N in agricultural soils. We review the size and function of both soluble organic N extracted from soils (SON) and dissolved organic N present in soil solution and drainage waters (DON) in arable agricultural soils. SON is of the same order of magnitude as mineral N and of equal size in many cases; 20–30 kg SON-N ha^–1 is present in a wide range of arable agricultural soils from England. Its dynamics are affected by mineralisation, immobilisation, leaching and plant uptake in the same way as those of mineral N, but its pool size is more constant than that of mineral N. DON can be sampled from soil solution using suction cups and collected in drainage waters. Significant amounts of DON are leached, but this comprises only about one-tenth of the SON extracted from the same soil. Leached DON may take with it nutrients, chelated or complexed metals and pesticides. SON/DON is clearly an important pool in N transformations and plant uptake, but there are still many gaps in our understanding. Received: 10 June 1999