Soil ameliorants alter physicochemical properties and fungal communities in saline-sodic soils of Northeast China

To understand the mechanisms of soil ameliorants affecting microbial communities is important for saline-sodic soils reclamation. High-throughput sequencing was used to characterize the fungal community in soils amended with four types of ameliorants over an 8-year period. Besides a control without any additional ameliorant (CK), other four treatments including 1) amendment with sandy soil (SS), 2) amendment with desulfurization gypsum (DG), 3) amendment with farm manure (FM), and 4) amendment with a mixture of SS, DG, and FM (M) were analyzed. Soil pH and electrical conductivity significantly decreased with the addition of soil ameliorants, whereas the soil organic carbon (SOC), total nitrogen (TN), and SOC/TN ratio (C/N) significantly increased in the FM and M treatments compared with the CK treatment. Fungal richness increased significantly with the mixed ameliorants addition (M). Distinct fungal community structures were observed in the treatments with soil ameliorants. The fungal community composition was significantly associated with the SOC, C/N, aggregate content with a diameter > 0.25 mm and geometric mean diameter. The changes in these soil characteristics were highly correlated with the ameliorants additions, suggesting that the impacts of ameliorants on the soil fungal community occurred indirectly as a result of alterations to soil physiochemical properties.     

秸秆还田和腐熟有机肥对水稻土培肥效果对比分析

为探讨秸秆还田对土壤肥力的影响,该文以18年的定位试验为基础,通过对直接施用秸秆、有机肥以及化肥、有机肥配施等6个处理小区的土壤进行采样,分析了秸秆还田同有机肥培肥方式对土壤理化性质、养分状况与作物产量等方面的影响,着重探讨了秸秆直接还田同传统的施用腐熟有机肥对土壤的培肥效果差异.结果表明直接施用作物秸秆同施用腐熟有机肥对土壤的培肥效果基本相同,均对土壤理化性质有很大的改善,同时可提高作物的产量,因此秸秆直接还田基本可以代替施用腐熟有机肥培肥土壤.     

改良剂对反酸田土壤性质与水稻产量的影响

采用盆栽试验研究了不同改良剂在反酸田土壤上的应用效果。结果表明,土壤pH在3.47~4.90范围内,pH与交换性H+和交换性Al3+呈极显著线性负相关关系,而与土壤有效铁和有效硫含量呈显著正相关。不同改良处理在提高作物产量和改良土壤性质方面较对照处理与NPK处理效果明显,且钙镁磷肥、自研改良剂、石灰及碱渣等无机改良剂改良效果显著高于添加腐植酸、精制有机肥、碱性有机肥处理。其改良效果主要体现在提高土壤pH,显著降低土壤交换性H+和交换性Al3+含量,明显增加土壤有效钙和有效镁的含量,改善根系生长环境,增加水稻地上部养分吸收和水稻籽粒产量。综上,初步认为酸害(包括活性酸和潜在酸)是反酸田土壤最主要的限制因子,钙镁磷肥、自研改良剂和石灰等偏碱性且富含有效钙或磷的无机矿物质是农业生产中改良反酸田的适宜改良剂。     

长期培肥黑土脱氢酶活性动态变化及其影响因素

对东北典型黑土区长期不同培肥黑土脱氢酶活性在作物生长季的动态变化进行研究。结果表明,施用有机肥,生长季黑土总体脱氢酶活性显著高于施用化肥和不施肥,其生长季脱氢酶活性保护容量在5.5 mg TPF/kg土.h以上,黑土总体脱氢酶活性施用高量有机肥>低量有机肥>不施肥>化肥,季节性变化波动性大。长期施用高量有机肥脱氢酶活性最大峰值出现在拔节期,施用低量有机肥、化肥和不施肥最大峰值出现在完熟期;长期施用不同数量和种类肥料所引起的黑土总体脱氢酶活性差异并未因玉米生长影响而改变,说明长期施用高量有机肥黑土微生物氧化活性能力增强,土壤自身调解和维持肥力能力增强。黑土脱氢酶活性的动态变化与绝大多数土壤生物、理化特性指标的动态变化没有显著的相关性;总体脱氢酶活性与多数土壤生物、理化特性因子、植物全磷、钾含量有极显著和显著正相关关系。     

土壤中植物有效硫的评价

本文综述了土壤硫素形态及有效性、土壤有效硫的测定方法以及不同方法测定的土壤有效硫与植物生长的相关性。土壤有效硫的测定主要考虑表层土壤可溶性和部分吸附态硫酸盐,但土壤有机质含量、有机硫含量和组成、土壤机械组成、pH值以及下层土壤硫素状况也是不可忽略的重要因素。目前还没有一种行之有效的统一方法能够合理评价土壤有效硫状况。今后应进一步研究不同土壤的供硫特性,并对不同有效硫评价方法进行筛选,找出适合我国土壤和气候条件下的土壤有效硫评价方法和指标,以期为合理施用含硫肥料提供依据。     

室内淋洗条件下脱硫石膏对滨海吹填土理化性质的影响

为改善吹填土的理化性质,实现吹填土在城市生态建设方面的充分利用,通过室内土柱淋洗试验,研究在不同施用量下脱硫石膏对吹填土各种离子动态变化的影响。结果表明:脱硫石膏可以显著改善滨海吹填土的理化性质,脱硫石膏施用量分别为0.7%,1.4%,2.1%,3种处理下土柱的饱和导水率分别是6.21,7.41,9.51mm/h;淋洗后土壤电导率、Na+和Cl-浓度、钠吸附比(SAR)和碱化度(ESP)等指标较淋洗前均有90%以上的降幅程度;且在前20h的淋洗过程中,各种化学指标的下降效果最为明显,而在将近150h的剩余时间内虽有下降,但下降速率很缓慢。     

Impact of long-term application of fertilizer, manure and lime under intensive cropping on physical properties and organic carbon content of an Alfisol

Intensive cropping with conventional tillage results in a decline of soil organic carbon (SOC) with consequent deterioration of soil physical properties. Some studies indicate that this decline in SOC can be arrested by way of organic manure application and improved nutrient management practices. This study was conducted to find out the long-term effects of inorganic fertilizer, manure and lime application on organic carbon content and physical properties of an acidic Alfisol (Typic Haplustalf) under an annual soybean-wheat crop rotation. Six treatments namely, control (CON), nitrogen fertilization (NIT), nitrogen and phosphorus (NP), nitrogen, phosphorus and potassium (NPK), NPK plus manure (NPKM) and NPK plus lime (NPKL) from a long-term fertilizer experiment continuing at Ranchi, India, were chosen for this study. Soil samples were collected from the selected treatments after 29 crop cycles and analyzed for physical and chemical properties. The results indicated that SOC content in all the treatments decreased from initial levels, but the decrease was considerably less in NPKM (8.7%) and NPKL (10.9%) treatments than that in NIT (28.3%) treatment. The SOC at 0-15 and 15-30 cm depth was lowest in NIT and CON. The NPKM, NPKL and NPK treatments up to 30 cm soil depth recorded significantly higher SOC than NIT and CON. Application of balanced fertilizer along with manure (NPKM) or lime (NPKL) improved soil aggregation, soil water retention, microporosity and available water capacity and reduced bulk density of the soil in 0-30 cm depth over CON. In contrast, soil aggregate stability, microporosity and available water capacity were significantly lower in the NIT plots than that in CON. The study thus suggests that soil management practices in acidic Alfisols should include integrated use of mineral fertilizer and organic manure or lime to maintain the organic carbon status and physical environment of soil.     

Evaluation of industrial by-products as soil acidity amendments: chemical and mineralogical implications

Lime, mined gypsum and some gypsum-like by-products have been frequently applied to soil to counter acidity. We have examined the changes in the chemical and mineralogical properties of three acid soils resulting from the application of three industrial by-products (phosphogypsum, red gypsum and sugar foam). We did so in laboratory experiments on suspensions of soil in saturated solutions of the by-products. A sizeable fraction of the Al released by exchange with Ca of the amendments remained on the mineral surfaces as Al polymers, as suggested by changes in the CuCl₂-, oxalic–oxalate- and DTPA-extractable Al contents. Polymerization of Al was promoted by corresponding neutral and basic pH of red gypsum and sugar foam saturated solutions, respectively. Sorption of these Al polymers was particularly favourable in those horizons with more clay fraction and variable-charge clay minerals. On the other hand, in most cases there was little or no detectable sorption of sulphate, thus excluding precipitation of crystalline or amorphous basic Al sulphates to alleviate Al toxicity. Based on the reduction of the Al saturation of the exchange complex in the soils, as well as on the small contents of heavy metals and natural radionuclides of the three by-products, these can be considered effective alternatives to mined gypsum and lime for alleviating soil acidity and reducing toxic concentrations of Al in agricultural, acid soils.     

Characterization of ester sulphate in a gypsum-amended podzol using an immobilized sulphatase reactor

An immobilized sulphatase reactor column was successfully used to determine the biochemical stability of ester sulphate in soil organic matter extracted from a podzol amended with gypsum. The sulphatase from Helix pomatia was covalently attached to controlled-porosity glass beads, and the immobilized enzyme was packed into a small glass column. The optimum pH, the time required to reach equilibrium, and the percentage of substrate consumed for the enzymatic hydrolysis of soil ester sulphate (pH 7.7, 90 min, 23–59%) were substantially different from those of p-nitrophenyl sulphate at similar concentrations of substrate (pH 7.0, 40 min, 99%). The striking difference in the biochemical stability and kinetic behaviour between soil ester sulphate and the simple synthetic substrate reflected their different chemical nature and structural features. The amounts of enzymatically hydrolysable (labile) ester sulphate in soil organic matter extracted from the podzol amended with gypsum at rates of 0, 50, and 200 kg S ha^-1 were significantly different (P=0.0004), being 0.5, 1.1, and 1.4 g S ml^-1 soil extract (or 5, 11, and 14 g S g^-1 soil), respectively. The labile ester sulphate was not correlated with the total hydriodic acid-reducible organic sulphate with the soil organic matter extracts but with the hydriodic acid-reducible organic sulphate: organic C ratio, which increased as a result of gypsum amendment. This study revealed that input of inorganic sulphate as gypsum substantially increased the accumulation of labile ester sulphate in a podzol.     

绿萍的增产和改土作用

扩大有机肥源是夺取当季作物高产和改良土壤的重要一环.绿萍是一种水生绿肥,具有固氮(通过体内共生蓝藻的作用)及繁殖力强的特性.我国稻田养萍的历史相传已有两个世纪(浙江省农科院土壤肥料研究所编,1976),浙江、福建、四川、广东、广西部分地区早有利用绿萍作为肥料的习惯.     

不同施肥处理对黄泥土微生物生物量碳氮和酶活性的影响

通过室内培育实验,研究了不同施肥处理对黄泥土微生物生物量C、N和脲酶、酸性磷酸酶、蔗糖酶活性的影响。培养过程中,单施化肥处理土壤微生物生物量C、N均呈下降趋势,施用有机肥处理的土壤微生物量C前期升高至一定水平后或保持稳定、或呈下降趋势,而微生物生物量N总体均呈下降趋势;不同施肥处理的脲酶活性呈前期上升后期下降趋势,而酸性磷酸酶和蔗糖酶则单施化肥处理呈上升趋势、配施有机肥处理呈下降趋势。与对照处理相比,单施化肥处理显著降低土壤微生物生物量C、N,高量施用化肥处理还显著降低土壤脲酶活性,但对酸性磷酸酶和蔗糖酶活性的影响并不明显。秸秆施用可显著提高土壤微生物生物量C、N和酶活性,特别是高量施用秸秆的效果更明显。施用猪粪由于同时带入了大量的活性养分,对土壤微生物生物量C、 N和酶活性的影响尚难评价。在高度集约农业利用下,继续保持较高的化肥施用量并不利于土壤生物质量的维护和提高,而秸秆直接还田才是保持土壤健康状态的有效措施。     

Reclamation and salt leaching efficiency for tile drained saline‐sodic soil using marginal quality water for irrigating rice and wheat crops

Due to increased population and urbanization, freshwater demand for domestic purposes has increased resulting in a smaller proportion for irrigation of crops. We carried out a 3‐year field experiment in the Indus Plains of Pakistan on salt‐affected soil (EC_e 15·67–23·96 dS m⁻¹, pH_s 8·35–8·93, SAR 70–120, infiltration rate 0·72–0·78 cm h⁻¹, ρ _b 1·70–1·80 Mg m⁻³) having tile drainage in place. The 3‐year cropping sequence consisted of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) crops in rotation. These crops were irrigated with groundwater having electrical conductivity (EC) 2·7 dS m⁻¹, sodium adsorption ratio (SAR) 8·0 (mmol L⁻¹)^1/2 and residual sodium carbonate (RSC) 1·3 mmol_c L⁻¹. Treatments were: (1) irrigation with brackish water without amendment (control); (2) Sesbania (Sesbania aculeata) green manure each year before rice (SM); (3) applied gypsum at 100 per cent soil gypsum requirement (SGR) and (4) applied gypsum as in treatment 3 plus sesbania green manure each year (GSM). A decrease in soil salinity and sodicity and favourable infiltration rate and bulk density over pre‐experiment levels are recorded. GSM resulted in the largest decrease in soil salinity and sodicity. There was a positive relationship between crop yield and economic benefits and improvement in soil physical and chemical properties. On the basis of six crops, the greatest net benefit was obtained from GSM. Based on this long‐term study, combined use of gypsum at 100 per cent soil gypsum requirement along with sesbania each year is recommended for soil amelioration and crop production. Copyright © 2010 John Wiley & Sons, Ltd.     

3种固沙材料与风沙土复配后土壤改良效应及其质量评价

揭示风沙土复配其他固沙材料后的土壤质量变化及改良效应对研发防沙固沙新材料具有重要的指导意义。以乌兰布和沙漠风沙土为对照(CK),采用粉煤灰、脱硫石膏、牛粪3种固沙材料按干质量比15%,25%与风沙土进行复配,研究了不同材料与配比复配土壤对机械组成、养分含量、金属含量的改良效应,运用最小数据集构建、隶属度计算与土壤质量指数计算等方法评价了复配土壤质量。结果表明：(1)不同复配土壤的机械组成均发生了改变,粉粒、粗砂等难蚀、较难蚀颗粒体积分数增加,易蚀的细砂体积分数降低。(2)除石膏复配土壤各养分指标与CK相近外,其余复配土壤有机碳含量较对照提高1.2～10.4倍,牛粪复配土壤在提高养分含量方面显著高于其他材料;以牛粪和石膏为材料的复配土则分别增加或降低了沙土中的金属含量,而粉煤灰复配土的Cr, As较CK下降。(3)不同复配土对土壤理化性质作用影响各异,粉煤灰在粒径改良方面较优,牛粪在养分提升方面效果显著,石膏在重金属含量降低方面作用明显,粉煤灰石膏混合复配则综合了二者的优势。(4) 3种固沙材料均在不同程度上提高了复配土壤的质量,但复配土壤质量仍处于较低水平。综上,不同复配比例组合中,1...     

The Effects of Fresh and Composted Chicken Manures on Some Soil Characteristics

The effects of fresh and composted chicken manures on some soil characteristics were investigated. Fresh and composted chicken manures were mixed with the soil at the rates of 0%, 1%, 2%, 3%, and 4%, and then were incubated for 90 days. At the end of this incubation period, some soil physical properties closely related to soil aggregation (such as hydraulic conductivity, water stable aggregates, aeration porosity, and available water) and some soil chemical characteristics (such as organic carbon, total nitrogen, pH, and electrical conductivity, EC) were determined. As doses of both manures in the soil mixtures increase, the amounts of water stable aggregates, hydraulic conductivity, and aeration porosity increased, whereas the available water content decreased. Increasing doses of both manures increased the amount of the soil organic carbon and total nitrogen. Application of both manures to the soil increased the EC values, but it was limited in the composted chicken manure.     

Improvement of degraded physical attributes of a saline-sodic soil as influenced by phytoremediation and soil conditioners

This study aimed to evaluate the use of phytoremediation and soil conditioners in the recovery of physical attributes of a saline-sodic Fluvic Neossol in Brazil Northeast. The applied treatments were: Atriplex nummularia L., as phytoremediation plant, due to its ability to extract salts from the soil; organic conditioners, such as bovine and sheep manure; gypsum and polymer, as chemical conditioners. Samples with preserved structure were collected at the time of the experiment installation and 18 months after in the layers 0–10 cm and 10–30 cm. The analyzed attributes were: water dispersed clay, dispersion index, bulk density, penetration resistance, soil porosity, and saturated hydraulic conductivity. The use of sheep manure, gypsum and polymer promoted an increase in saturated hydraulic conductivity in the 0–10 cm layer from 4.51 to 16.37 cm day^?1, 11.26 to 23.95 cm day^?1 and 7.24 to 22.77 cm day^?1, respectively. Gypsum increased the macroporosity in the superficial layer by 42.6%. Atriplex and polymer were more efficient at reducing soil penetration resistance. The polymer was more efficient at improving the physical properties. However, it is necessary to consider phytoremediation with Atriplex as a more sustainable alternative that can still be used as complementary fodder in animal feed.     

不同改良措施对设施蔬菜土壤肥力和番茄品质的影响

为探明不同改良措施对设施蔬菜土壤及番茄果实品质的影响,该研究以陕西省太白县秦西蔬菜种植示范园大棚为研究试点,选取草木灰、生物炭、EM菌(Effective Microorganisms)3种改良剂,设置了EM菌(E)、生物炭(S)、生物炭+EM菌(SE)、草木灰(C)、草木灰+生物炭(CS)、草木灰+生物炭+EM菌(CSE)和不施加任何改良剂的空白对照(CK)7个处理。结果表明:各处理均能改善土壤理化性质,其中草木灰+生物炭+EM菌(CSE)处理在提高土壤pH值、有机质、全氮、碱解氮、全磷、速效磷、全钾及速效钾含量方面效果最显著,与CK处理相比,分别提高了23.06%、130.94%、44.34%、52.78%、67.72%、126.71%、16.24%、119.48%;与CK处理相比,各种配施改良剂处理的植株全氮含量显著高于单施改良剂处理,草木灰+生物炭+EM菌(CSE)处理最显著,提高了25.17%;各处理的植株全磷含量较CK处理均显著增加,草木灰+生物炭+EM菌(CSE)处理效果最明显,且草木灰+生物炭+EM菌(CSE)处理是CK处理的2.09倍;除EM菌(E)处理外,其他5个处理均能显著提高植株全钾含量,草木灰+生物炭+EM菌(CSE)处理效果最显著,且草木灰+生物炭+EM菌(CSE)处理是CK处理的1.44倍;但6个处理均对植株灰分无显著影响;与CK处理相比,草木灰+生物炭+EM菌(CSE)处理的糖酸比最高,达69.23%;与CK处理相比,各处理的土壤综合肥力指数均显著提高,而草木灰+生物炭+EM菌(CSE)处理效果最显著;通过对各处理的综合得分均值进行比较,草木灰+生物炭+EM菌(CSE)处理得分最高。综合分析得出,施加草木灰+生物炭+EM菌能有效改善太白县高山设施蔬菜种植土壤的酸化、肥力等,提高西红柿的品质。     

Improving the physical properties of soil from the Biancana Badlands, Tuscany, Italy, by use of amendment materials

Abstract. Weakly weathered clay bedrock and samples of A horizon of a developed Biancana soil were incubated with compost or green manure in the presence of two physical forms of gypsum: one mined and ground and the other from flue-gas desulphurization (FGDG). The gypsum efficiency was evaluated in combination with two organic polymers: polyvinyl alcohol (PVA) and polyacrylamide. Compost and green manure increased permeability only in the presence of gypsum. The FGDG was more effective than the mined gypsum, alone or in combination with PVA.     

Salt composition of groundwater and reclaimed solonetzes in the Baraba Lowland

Solonetzes of experimental trials established in 1981 and 1986 in the Baraba Lowland were examined. It was found that gypsum-based ameliorants improve the soil and lead to a decrease in the content of soluble salts in the soil profile. Exchange processes between cations of the soil adsorption complex and calcium of gypsum were particularly intensive in the first years after gypsum application. This resulted in a sharp rise in the content of soluble salts that migrated down the soil profile to the groundwater. In the following years, the reclaimed solonetzes were desalinized under the conditions of relatively stable groundwater level. On the 30th year after single gypsum application, the groundwater level sharply rose (to 50 cm), and the soil was subjected to the secondary salinization; the contents of bicarbonates, carbonates, and sodium in the soils increased. Spring leaching caused some desalinization, but the content of soluble salts in the upper soil meter increased again in the fall. A close correlation between the salt compositions of the groundwater and the reclaimed solonetzes was revealed.     

Field application of industrial by-products as Al toxicity amendments: chemical and mineralogical implications

Lime, gypsum and various gypsum‐like by‐products have long been applied to soil surfaces as ameliorants of soil acidity and aluminium and manganese toxicity. We examined changes in chemical and mineralogical properties at two different depths in two acid soils one year after the application of gypsum, phosphogypsum + dolomitic residue, red gypsum + dolomitic residue, sugar foam, and sugar foam + mined gypsum. All treatments were found to increase the proportion of Ca²⁺ and decrease those of Al³⁺ and Mn²⁺ in the exchange complex of the surface and subsurface horizons, thus reducing its effective Al and Mn saturation. However, the mined gypsum treatment resulted in losses of Mg²⁺ from the Ap horizon of the soils, and the sugar foam treatment was not so effective with the AB horizons as the other treatments. The combined application of both gypsum‐like by‐products and the dolomitic residue proved the most effective choice with a view to reducing the effective Al and Mn saturation of the exchange complex in the Ap and AB horizons. In addition, both treatments reduced Mg²⁺ losses at both depths. Finally, all treatments resulted in the formation and retention on mineral and organic surfaces of a large fraction of the Al³⁺ released by exchange with Ca²⁺ as Al polymers. This is quite consistent with the observed changes in the CuCl₂‐, oxalate‐ and DTPA‐extractable Al contents as well as by SEM and EDS analyses. Based on these results, the use of the appropriate mixtures of these by‐products is an effective alternative to that of mined gypsum and lime to alleviate soil acidity and reduce toxic concentrations of Al³⁺ and Mn²⁺ in agricultural acid soils.     

宁夏红寺堡扬黄灌区次生盐渍化土壤改良成效研究

系统分析了利用脱硫废弃物和次生盐渍化土壤专用改良剂对宁夏红寺堡扬黄灌区次生盐渍化土壤的改良效应,结果表明:施用脱硫废弃物可以改善土壤理化性状,但改良效果不理想,同时施用脱硫废弃物和专用改良剂后土壤砂粒含量减少,粉粒、黏粒含量普遍增加;土壤体积质量平均增加5.34%、孔隙度降低5.61%,土壤pH和全盐均有不同程度的下降;施用脱硫废弃物和专用改良剂后土壤有机质和养分含量、枸杞产量都有较大幅度的增加,其中施用改良剂Ⅱ的增幅最大,但考虑改良剂原料成本后施用改良剂II当年最终经济效益最大。相同改良剂秋施改良效果明显优于春施;施用量越大对土壤理化性状的改良效果越好,枸杞干果产量和直接经济效益也越高,但最终经济效益以施用量为11.25 t/hm2的处理最佳。