离子交换树脂联合提取土壤有效养分技术

本文详细阐述了离子交换树脂联合提取土壤有效养分的原理和技术方法,提出了一种快速方便的土壤N、P、K联合提取方法,可为离子交换树脂提取土壤养分提供借鉴和参考.     

浅谈推算和预测宏观尺度土壤N_2O释放量的方法

土壤是N2 O的最主要释放源 .本文综述了根据局部地区土壤N2 O释放观察结果 ,推算和预测宏观尺度土壤甚至全球土壤N2 O释放通量变化和年释放量的方法 ,评述了各类方法的优缺点 ;并着重讨论了释放过程机理模型的应用 .     

离子交换树脂在土壤养分测试中的研究进展

概述了在农业领域中应用离子交换树脂获取土壤养分含量的研究进展,探讨了树脂的预处理方法、使用形式以及提取土壤养分的基本操作和影响因素,同时提出该技术在提取土壤养分中的应用前景及需要解决的问题。     

UV—B辐射增强对冬小麦生态系统呼吸速率和N2O排放日变化的影响

通过田间试验,应用静态箱-气相色谱法测定了土壤-冬小麦系统以及土壤的呼吸速率和N2O排放通量,研究了UV—B辐射增强对土壤-冬小麦系统、土壤的呼吸速率和N2O排放日变化的影响。结果表明,土壤-冬小麦系统和土壤的呼吸速率存在着明显的日变化规律,UV—B辐射增强处理并没有改变其日变化规律,但对呼吸速率有抑制作用。在日温差较大的晴天,土壤-冬小麦系统和土壤的N2O排放通量也呈规律性日变化,UV—B辐射增强处理没有改变其日变化规律。在拔节至抽穗期,UV—B辐射增强对土壤-冬小麦系统的日均呼吸速率、N2O排放通量和土壤的日均N2O排放通量均没有显著影响,但显著降低了土壤的日均呼吸速率;在开花期,UV—B辐射增强对土壤-冬小麦系统和土壤的日均呼吸速率、N2O排放通量均没有显著影响;在灌浆期,UV—B辐射增强显著降低了土壤-冬小麦系统的日均呼吸速率、N2O排放通量和土壤的日均N2O排放通量,但对土壤的日均呼吸速率没有显著影响。     

硫膜和树脂膜控释尿素对土壤硝态氮含量及氮素平衡和氮素利用率的影响

【目的】控释尿素已被证明对于提高氮素利用率、减少氮素损失和增产有积极意义,且不同包膜的控释尿素由于包膜材料的不同,对于氮素的释放和供应强度有所不同。本文在黄淮海区域采用玉米田间试验,探讨硫膜和树脂膜控释尿素在氮素供应和减少氮素损失等方面的效应,以期为黄淮海区域夏玉米在高温多雨的种植条件下两种控释尿素的选择和应用提供依据。【方法】以硫膜和树脂膜控释尿素为研究对象,采用田间试验研究0—100 cm土壤剖面中的硝态氮含量,玉米整个生育期的土壤氮素平衡和玉米产量以及氮素利用率。【结果】与相同施氮量的普通尿素相比,硫膜和树脂膜控释尿素均具有"前控后保"的特性,使玉米苗期0—100 cm土层的土壤硝态氮含量降低了11.7%~56.7%和28.8%~68.2%,玉米灌浆期和收获期0—40 cm土层的硝态氮含量分别提高了16.3%~46.7%、0.5%~60.7%;两种控释尿素均能有效降低玉米整个生育期土壤残留的无机氮量、氮素表观损失量和盈余量,降幅分别为12.0%~18.4%、13.2%~66.4%和15.6%~30.9%,使玉米产量提高14.6%~37.5%,氮素利用率提高12.3~20.8个百分点。在N 210 kg/hm2、N 300 kg/hm2两种施氮量条件下,与相同施氮量的硫膜控释尿素相比,树脂膜控释尿素处理的玉米苗期0—60 cm土层的硝态氮含量降低了26.4%~39.1%,灌浆期0—40 cm土层和收获期0—20 cm土层的硝态氮含量分别提高了10%~21.8%和9.6%~16.4%,土壤残留无机氮量、氮素表观损失量和盈余量分别降低了2.3%~6.0%、44.6%~61.3%和17.0%~17.7%,玉米产量提高了6.8%~8.3%,氮素利用率提高了7.1~8.4个百分点,说明树脂膜控释尿素的效果优于硫膜控释尿素。树脂膜控释尿素和硫膜控释尿素在施氮量N 300 kg/hm2时均比N 210 kg/hm2条件下玉米整个生育期不同土层的硝态氮含量提高了1.2%~90.9%和2.0%~56.7%,玉米整个生育期土壤残留无机氮量、氮素表观损失量和盈余量分别提高了42.1%~47.6%、66.2%~137.9%、52.5%~53.8%,玉米产量和氮素利用率分别提高了20.8%和22.5%、6.5和5.2个百分点,施氮量N 300 kg/hm2优于N 210 kg/hm2。【结论】树脂膜控释尿素在减少夏玉米农田土壤剖面硝态氮残留、维持土壤氮素平衡和提高氮素利用率等方面的效果优于硫膜控释尿素和普通尿素。综合考虑保证土壤氮素供应、减少氮素损失、提高玉米产量及氮素利用率等因素,在黄淮海区域高温多雨气候条件下种植夏玉米,以施氮量N 300 kg/hm2的树脂膜控释尿素或者硫膜和树脂膜控释尿素二者配合施用效果最佳。     

氰在土壤中的吸附与转化

氰(C2N2)是一种具有替代溴甲烷潜力的新熏蒸剂,明确C2N2在土壤中的吸附与转化行为对C2N2的安全应用具有重要的意义.利用静态法研究了C2N2在土壤中的吸附与转化过程,土壤对C2N2的吸附速率与土壤的理化性质有关,受环境温度、土壤含水量和土壤生物的影响较少,与熏蒸浓度无关.采用气相色谱(GC)和流动注射分析仪(FIA)测定了土壤对C2N2的吸附率和C2N2在土壤中的可能转化产物.结果表明,土壤对C2N2的吸附能力很强,熏蒸2h吸附率在75％以上,熏蒸24 h吸附率在98％以上,并可快速转化为HCN、NH4+和NO3-.其中,大约20％的C2N2转化为NH4+和NO3-,13％的C2N2转化为HCN.熏蒸48 h未检测到NO2-.HCN在土壤中不稳定,可进一步转化为其他含氮化合物.     

土壤微生物生物量氮研究综述

简述了土壤微生物生物量N的含量及其影响因素、土壤微生物量N的生物有效性、影响土壤无机氮生物固定的因素及土壤微生物量N的测定，明确了土壤微生物量N在土壤N素循环转化过程中的重要作用。土壤微生物量N是土壤N素转化的重要环节，也是土壤有效氮活性库的主要部分。土壤微生物量N对作物N素的供应起着重要调节作用。土壤无机氮的生物固定对减少N素损失，提高N肥利用效率和保护环境具有积极的作用。     

土壤供氮能力指标研究

本文对国内外土壤供氮能力指标的研究进行了论述 ,作者根据自己的研究结果认为 :在土壤起始NO- 3 N含量较高时 ,用KCl煮沸浸取出的一定深度土壤的NO- 3 N就可作为土壤供氮能力指标 ,反映出当前土壤的供氮能力 .而在土壤起始NO- 3 N含量较低或考虑到起始NO- 3 N的影响后 ,1mol/LNaOH扩散出的NH+ 4 N或KCl煮沸法在酸性土壤上浸取出的NH+ 4 N则是较好的土壤供氮能力指标 ,反映了土壤潜在的供氮能力     

小麦苗期施入氮肥在土壤不同氮库的分配和去向

应用盆栽试验和15N标记技术研究了小麦苗期施入N肥后土壤不同N库的动态。结果表明 ,施肥后 28d ,作物所吸收的土壤N占总吸N量的 58.1% ,吸收的肥料N占 41.9%。作物对肥料N的利用率达到 55.3% ,N肥在土壤中的残留率为 24.3% ,损失率为 20.4%。施肥后短期以NH4+-4 N存在的肥料N占施N量的 50.5% ,随着硝化作用的进行和作物的吸收 ,土壤中的NH4+-N显著下降。NO3--N在第 7d达到高峰 ,表现为先升高后降低的趋势 ,说明施肥后在 7d以前有强烈的硝化作用发生。施肥后 2d ,以固定态铵存在的肥料N占 33.7% ,至 28d ,仅占施入N量的 2.4% ,说明前期固定的铵在作物生长后期又重新释放出来供作物吸收。在施肥后第 7d ,肥料N以微生物N存在的量占施肥量的 15.2% ;至 28d来自肥料N的微生物N也几乎被耗竭 ,仅占施N量的 2.4%。随作物生长 ,肥料N在各个土壤N库中的数量均显著下降。在其它N库几乎被耗竭的情况下 ,至施肥后 28d主要以有机N的形式残留。在不种作物的条件下 ,土壤N素的矿化量很低 ,作物的吸收作用导致土壤有机N库不断矿化 ,施入N肥后 ,土壤N素的矿化量增加 ,表现为明显的正激发效应     

玉米基因型与土壤氮素表观平衡

通过田间试验研究不同基因型玉米产量、N累积量和土壤N素表观平衡.结果表明,3个施N水平处理下不同基因型玉米间的产量、N累积量均存在显著差异.N肥在土壤中的表观残留率平均值由施N112.5kg/hm2水平(Ⅰ)下的36.74%升至施N168.75kg/hm2水平(Ⅱ)下的40.79%和施N225kg/hm2水平(Ⅲ)下的48.36%.应用N累积量较高的玉米基因型可显著减少施用N肥在土壤中的残留率.     

包膜尿素对旱地红壤氮素垂直迁移特征的影响

结合花生田间试验,利用原位土壤溶液取样装置,研究了一次性基施包膜尿素对典型红壤旱地0～100cm深度土壤溶液氮(N)素垂直迁移特征的影响。结果表明,①旱地0～100cm土层红壤溶液N素含量以NO3-N含量最高,且以包膜肥料处理较明显;②对照处理0～100cm土层红壤N素含量变化不大,而普通尿素和包膜尿素处理0～60 c...     

Extraction of phosphorus,potassium, calcium,and magnesium from soils by an ion‐exchange resin procedure

Abstract

A procedure for the simultaneous extraction of phosphorus, potassium, calcium and magnesium from soils, by an ion‐exchange resin procedure applicable to large‐scale advisory soil testing, is described. The important steps are the disaggregation of soil by shaking in water during 15 minutes with a glass marble, the transference of the elements from the soil to a sodium bicarbonate treated mixture of anion and cation exchange resins during a 16‐hour shaking period, the separation of the resin from the soil by sieving and extraction of the elements from the resin.

The results of resin extractable calcium, magnesium and potassium were comparable to the results of these elements extracted with 1M NH₄OAc, to calcium and magnesium extracted with 1M KCl, and to potassium extracted with 0.025M H₂SO₄.

For phosphorus the resin extractable values were not comparable to the results obtained by the former routine method, based on the extraction with 0.025M H₂SO₄. The results of resin extractable P presented closer correlation with cotton response to phosphorus application in 28 field experiments (r = 0.85**) as compared with 0.025M H₂SO₄ extractable P (r = 0.68**), and also with P uptake by flooded rice in a pot experiment with eight lowland soil samples (r = 0.98**), as compared with extraction with 0.0125M H₂SO₄ in 0.050M HCl, for which the correlation was not significant. The reasons for the superiority of the extraction of P with the described procedure are discussed.     

In situ ion exchange resin membrane (IEM) technique to measure soil mineral nitrogen dynamics in grazed pastures

This paper explored the potential of application of in situ ion exchange resin membrane (IEM) technique for assessing soil nitrogen (N) availability and spatial distribution in New Zealand grazed pastures. Field and incubation experiments conducted to test the technique proved IEM technique to be a useful approach to monitoring the continuous changes in soil mineral N in pasture soils. The field testing showed that the IEM technique reflects both differences in pool size and mineral N flux, while 2-M KCl extraction reflects only pool size at the sampling. Testing the effects of residence time, temperature, soil inorganic N content, and soil water content through diffusion modeling offers further support for using IEM to explore the complex dynamics of nitrogen availability in pasture soils.     

离子交换树脂及其在农业和环境科学研究中的应用

离子交换树脂在土壤养分有效性与环境检测等方面的研究日趋增多。离子交换树脂种类繁多,如何选用一个恰当的树脂体系是研究工作者首要考虑的问题。本文叙述了:(一)交换树脂在农业及环境研究方面的简史,(二)离子交换树脂的类型及其性质,(三)二种树脂体系在土壤等方面研究中的应用,(四)选择恰当的离子交换树脂体系的重要性与某些原则,以及小珠型离子交换树脂体系的近期研究进展和其定型产品一交换树脂丸球,作为一种通用土壤养分提取剂及环境枪测方面的商业应用价值。     

Mechanism of reduction of exchangeable aluminum by gypsum application in acid andosols

Mechanism of reduction of exchangeable aluminum in acid Andosols treated with gypsum was studied by using cation exchange resin methods to determine the amount of polymerized aluminum. Two types of acid Andosols were used as test soils: Kitakami light colored Andosol (fine, mixed, mesic, Andic Dystrochrept) and Kawatabi thick high humic Andosol (medial, mesic mixed Alic Pachic Melanudand). Polymerization of aluminum in the soil solution of both Kitakami and Kawatabi Andosols treated with gypsum was suggested based on an analysis using cation exchange resin methods, whereas that in monomer aluminum solution was not detected. Accumulation of polymerized aluminum in both Kitakami and Kawatabi Andosols was determined by using cation exchange resin, and the amounts of polymer aluminum trapped by the resin and the ratio of polymer aluminum to monomer aluminum were increased with the incubation time. The values of CEC which decreased in the Kitakami Andosol after gypsum treatment were almost equivalent to the amounts of cation exchange sites occupied by polymer aluminum ions which were calculated based on the decrease of the values of Y _l. We conclude that the mechanism of reduction of exchangeable aluminum in strongly acid Andosols treated with gypsum is as follows: firstly, exchangeable aluminum adsorbed on the cation exchange sites of soils may be released into the soil solution due to the increase in the ion strength caused by gypsum application, and then monomer aluminum in soil solution may be polymerized in the presence of soil colloidal materials. Consequently, the polymer aluminum formed in the soil solution may be selectively and irreversibly fixed on the cation exchange sites of 2 : 1 clay minerals.     

A proposed use of ion exchange resins to measure nitrogen mineralization and nitrification in intact soil cores

Abstract

A procedure is proposed for measuring nitrogen mineralization and nitrification in intact soil cores. The method relies on ion exchange resins to trap ammonium and nitrate entering and leaving cores of soil otherwise open at the top and bottom. Changes in soil concentrations plus an accounting of ions trapped by the lower resin after field incubations, indicate rates of nitrogen reactions. Using this technique, we estimated net ammonification rates from 0–36 mg N/kg/mo and nitrification rates from 0–16 mg N/kg/mo for the surface of a sandy, low nutrient soil under pine cultivation in north Florida; higher rates occurred after urea fertilization. The procedure has potential advantages over others, but must be more fully evaluated under a variety of conditions.     

稠油降解菌的筛选及其对胶质和沥青质生物降解

以稠油为唯一碳源,从辽河油田石油污染土壤、渣油中,经富集培养,分离筛选出细菌菌株11株、真菌23株和放线菌10株。将在含油培养基上长势良好的菌株进行室内摇瓶实验,发现真菌的降解效果好于细菌,F2006的降解效果最好,14d去除率达到39.8%。在胶质和沥青质污染土壤中,观察真菌F4、F2008、F9902、F2006、F2017、F6和F9904在14d、28d和42d对胶质和沥青质的去除率,测试结果表明,菌株F2006和F2008降解效果较好,在42d时去除率分别达到55.73%和57.62%。两次实验说明,菌株F2006为降解胶质和沥青质的优势菌株,在生物修复中具有较好的应用前景。     

An examination of potential extraction methods to assess plant-available organic phosphorus in soil

The role of soil organic phosphorus (P) in plant nutrition was assessed using data from a glasshouse pot experiment carried out on seven soil types using two contrasting plant species (Lolium perenne, Pinus radiata) and 12 different extractants (five salts (0.025 M ethylenediaminetetraacetic acid (EDTA), 0.025 M EDTA pH 7, Olsen, Mehlich-III, and 6% NaOCl pH 7.5) and seven exchange resins (Hampton chelating resin, Bio-Rad Chelex-100, Dow MAC-3, Amberlite IRC76, Diaion WT01S, Lewatit MP500A, Diaion WA30)). The contribution from mineralization of soil organic P was inferred by consistent increases in correlation coefficients between extractable P and plant P uptake when organic P was considered in addition to inorganic P. The best correlated extractants for combined inorganic and organic P were NaOCl (r = 0.84), Hampton chelating resin (r = 0.78), and MP500A resin (r = 0.73), which compared favorably with Olsen P (r = 0.66) and EDTA (r = 0.72). ³¹P nuclear magnetic resonance analysis of selected extracts from two soils confirmed that the Hampton-chelating-resin-extractable P was mainly monoester and diester forms of organic P, while there was no monoester or diester organic P in the IRC76 resin extract—poorly correlated with plant uptake. The findings of this study suggest that readily extractable forms of organic P in soil contribute to short-term plant P uptake, and this P should be considered for inclusion in routine tests for soil P availability.