Zinc Sorption in Sandy Soils from Central Vietnam as a Function of Soil Characteristics

Zinc (Zn) sorption curves were established for 11 cultivated sandy soils from central Vietnam. Soil samples (10 g) were equilibrated with 5 mM calcium chloride (CaCl₂) solutions (50 mL) at five zinc chloride (ZnCl₂) concentrations (0 to 80 mg Zn L^–1). The experimental sorption data were fitted with the Freundlich equation. The amounts of Zn sorbed by soil (Q_Zn) at different Zn concentrations in the equilibrium solution (C_Zn) were closely related to cation exchange capacity (CEC) and pH, that is, to the available exchange sites at given pH values. More specifically, an excellent correlation was found between Zn sorption and exchangeable calcium (Ca_ex), which evidently also depends on CEC and pH. A unique equation was proposed to predict Q_Zn from C_Zn and Ca_ex in the range of Zn loading covered in our research, that is, from traces to Q_Zn ≈ 60 mg Zn kg^–1.     

Effect of Application of Chromium Feedstock Compost on the Growth and Bioavailability of Some Trace Elements in Lettuce

A pot experiment was conducted to investigate the effect of chromium compost (0, 10, 30, and 50%) on the growth and the concentrations of some trace elements in lettuce (Lactuca sativa L.) and in the amended soils. Compost addition to the soil (up to 30%) increased dry matter yield (DMY); more than 30% decreased DMY slightly. The application of compost increased soil pH; nitric acid (HNO₃)–extractable copper (Cu), chromium (Cr), lead (Pb), and zinc (Zn); and diethylenetriaminepentaacetic acid (DTPA)–, Mehlich 3 (M3)–, and ammonium acetate (AAc)–extractable soil Cr and Zn. The addition of Cr compost to the soil increased tissue Cr and Zn but did not alter tissue cadmium (Cd), Cu, iron (Fe), manganese (Mn), nickel (Ni), and Pb. The Cr content in the lettuce tissue reached 5.6 mg kg^?1 in the 50% compost (326 mg kg^?1) treatment, which is less than the toxic level in plants. Our results imply that compost with high Cr could be used safely as a soil conditioner to agricultural crops.     

Soil Properties and Maize Growth in Saline and Nonsaline Soils using Cassava‐Industrial Waste Compost and Vermicompost with or Without Earthworms

The aim of this study was to investigate the effectiveness of compost and vermicompost as soil conditioners in alleviating salt‐affected soils and increasing maize productivity. A greenhouse trial, consisting of seven soil amendment treatments in a completely randomized design with three replications, was carried out at Khon Kaen University, Thailand, during the rainy season of 2011. Plant height and total dry matter of maize increased in treatments with compost and vermicompost application when compared with the control (no fertilizer) in two types of soils (saline and nonsaline) during the growing season. Soil pH and electrical conductivity in saturation paste extracts were decreased by compost and vermicompost amendments with or without earthworms when compared with unamended treatments in the saline soil. Compost and vermicompost amendments improved cation exchange capacity, soil organic carbon, total nitrogen and extractable phosphorus in both soils. These amendments also increased exchangeable K⁺, Ca²⁺ and Mg²⁺ while decreasing exchangeable Na⁺ in the saline soil, which suggested that Ca²⁺ was exchanged for Na⁺, exchangeable Na⁺, then leached out, and soil salinity reduced as a result. Soil microbial activities including microbial C and N and basal soil respiration were improved by the application of compost and vermicompost amendments with or without earthworms when compared with the control in both soils. This experiment showed that the compost and vermicompost were effective in alleviating salinity and improving crop growth. Copyright © 2013 John Wiley & Sons, Ltd.     

Effect of Compost and Hydroabsorbent Polymer on Tree Growth and Soil Properties in a Tropical Urban Environment

Horticultural application of hydroabsorbent polymer (HP) has drawn research attention due to its perceived benefits to plant growth. Few studies have compared the use of compost and HP amendments on tree establishment in tropical urban environments. An experiment was conducted to assess the effect of compost (40% v v^–1) and HP (3 and 5 kg m^–3) on the growth of two native tree saplings (Calophyllum soulattri and Syzygium myrtifolium) in loamy and sandy soils. The HP treatments significantly affected soil pH and extractable phosphorus (P) and potassium (K), whereas combined application of compost and HP (5 kg m^–3) resulted in significantly higher nitrogen (N) in both soil types. Plant diameter and height were significantly higher following HP application. This experiment demonstrates the efficacy of HP that can cater the plant requirements at the initial growth stages which are crucial for their successful establishment in tropic urban degraded soils.     

生物降解地膜自然降解过程及其对玉米生长发育和产量的影响

可降解地膜是解决常规塑料地膜引起的白色污染的有效途径。通过试验研究了生物降解膜自然降解过程及其对玉米生长的影响。研究结果表明：（1）生物降解膜降解60和100d后的降解率分别为1.26%和1.91%,而且降解率随着时间的延长而增加;（2）生物地膜在降解前与普通地膜在提高土壤温度方面有着一致的效果,其增温效应与普通膜没有明显的差异;（3）较CK处理,覆盖生物膜时玉米穗上叶、穗位叶和穗下叶叶面积分别增加了10.83%,9.38%和7.94%,可以促进玉米的生长发育进程;（4）生物膜具有极显著的增产作用,比CK处理增产18.7%,但增产效果与普通膜之间差异不显著。     

Effect of Municipal Solid Waste Compost and Compost Tea as Fertility Amendments on Growth and Tissue Element Concentration in Container-Grown Tomato

Evaluation of fertility sources for certified organic greenhouse vegetable production is necessary for further industry growth. Two experiments tested the effects of municipal solid waste compost (MSWC) and water extract tea made from it on potted greenhouse tomatoes. The first used MSWC alone (two levels) and soil tea drench alone (three application frequencies). The second used MSWC and tea in factorial combination at three levels (0, 1×, and 2×). The greatest yield and leaf tissue potassium (K) were obtained using the greatest level combinations of compost and foliar tea spray, and this was significantly greater than conventional nitrogen-phosphorus-potassium (NPK) fertilizer yield. Tissue magnesium (Mg) was affected by compost because of the antagonism from compost K. Tea increased tissue sodium (Na). No significant differences in heavy-metal tissue concentrations were found between treatments. While MSWC is an effective soil fertility amendment, the benefits of using tea may be increased with more frequent application.     

Evaluation of Integrated Nutrient Management Interventions for Cotton (Gossypium hirsutum) on a Vertisol in Central India

Phospho-compost (PC) and poultry manure (PM) were evaluated in field experiments to diversify integrated nutrient management (INM) for rain-fed cotton. Seed cotton yield in the PC (2501–2579 kg ha^?1) was similar to the recommended INM (2673 kg ha^?1) treatment and was significantly better than nitrogen, phosphorus and potassium (100% NPK) (2130 kg ha^?1) and farmers practice (FP) (1886 kg ha^?1). Yield was lower in the PM (2476–2617 kg ha^?1) than in the PC. Nutrient uptake was higher in all INM intervention plots due to an improvement in soil nutrient status compared with those receiving 100% NPK. Soil labile carbon values were higher in the INM treatments (333–452 mg kg^?1), with a greater magnitude in the PC-amended plots (402–452 mg kg^?1). Carbon management index (CMI) values were higher for the INM than treatments NPK and FP. Among INM interventions, PC plots had higher values than the PM.     

Impact of Distillery Effluent on Soil Carbon and Nitrogen Dynamics in a Vertisol of Central India

Distilleries produce a huge quantity of effluents, popularly known as spent wash (SW), which when bio-methanated produce post-methanation effluents (PME). A field experiment on soybean–wheat system was conducted for five consecutive years in a Vertisol of central India to evaluate the effect of distillery effluent (DE) on soil carbon and nitrogen dynamics. Ten treatment combinations consisting of control, 100% NPK + Farmyard Manure (FYM), and graded level of SW and PME were applied. Total carbon content of soil increased significantly with applications of FYM and DE. SW was found superior in enhancing carbon content of soil in comparison to PME. Farmyard Manure contributed more carbon toward the recalcitrant pool, whereas DE contributed more carbon toward the active and slow pool. Nitrogen (N) availability was significantly improved with the application of DE. Balanced application of DE may act as amendment for increasing C and N stocks in Vertisol.     

蚯蚓粪配施化肥对玉米根际土壤生物学特征的影响

[目的]探讨蚯蚓粪与化肥配施对玉米根际土壤生物学性状的作用效果,为土壤培肥制度的建立与玉米的合理施肥提供理论依据。[方法]通过大田试验,研究CF(单施化肥)、VC(蚯蚓粪)与VC+CF(蚯蚓粪和化肥各提供50%的氮)等处理对玉米根系分泌物、根际土壤微生物数量、酶活性与腐殖质组成的影响。[结果]同CF处理相比,VC+CF处理显著提高了根系分泌物含量,并明显提高了根际土壤中微生物数量、微生物量碳含量及脲酶、蔗糖酶、过氧化氢酶、中性磷酸酶活性,其中细菌数分别较CK,CF与VC处理提高124.32%,62.99%和15.45%,脲酶活性分别高出44.27%,23.53%和12.50%。此外,VC+CF处理亦显著提高了根际土壤中胡敏酸、富里酸含量和胡/富比。同VC+CF处理相比,VC处理对玉米根际土壤生物学特征的影响较小。[结论]蚯蚓粪与化肥配施能较好地改善玉米根际区域的微生态环境。     

Effects of Conjunctive Use of Organic and Inorganic Sources of Nutrients on Soil Quality Indicators and Soil Quality Index in Sole Maize,Maize + Soybean,and Sole Soybean Cropping Systems in Hot Semi-arid Tropical Vertisol

The soils in the hot semi-arid tropical (SAT) regions generally have low organic matter and nutrient reserves. Soil-management problems in these soils primarily occur because of poor physical conditions and inadequate drainage through excess runoff, finally resulting in poor crop growth. Hence, the present investigation was conducted to study the long-term impact of conjunctive nutrient use treatments on soil quality indicators and soil quality indices under three cropping systems: (i) sole soybean, (ii) soybean + maize, and (iii) sole maize cropping systems at the Indore Centre of the All-India Coordinated Research Project for Dryland Agriculture (AICRPDA) using Navjot and JS-335 as cultivars of maize and soybean, respectively. In 2005, the soil quality assessment study under this experiment was undertaken after 8 years of experimentation. Soil quality assessment was done by identifying the key indicators using principal component analysis (PCA) and linear scoring technique (LST). Soil quality indices (SQI) and relative soil quality indices (RSQI) were also computed. Results revealed that most of the soil quality parameters were significantly influenced by the conjunctive nutrient management treatments. The common key indicators that emerged in all the treatments were pH, organic carbon (OC), exchangeable magnesium (Mg), available zinc (Zn), copper (Cu), manganese (Mn), and boron (B). The soil quality indices across the management treatments under sole maize system varied from 1.70 to 2.40 and application of 20 kg nitrogen (N) (compost) + 20 kg N through urea as top dressing emerged as a one of the most superior treatments with SQI value of 2.40. The soil quality indices in maize + soybean system varied from 1.12 to 1.47 and application of 20 kg N (compost) + 20 kg N through urea + azotobacter at 2 kg ha^?1 proved to be significant with the greatest SQI value of 1.47. In the case of the sole soybean system, the SQI varied from 1.21 to 1.61. After considering all the systems together, the average best performance SQI score (ABP-SQI score) was computed, which varied from 1.14 to 1.56. The greatest value was recorded in the treatment with 20 kg N (compost) + 20 kg N (gliricidia) + 10 kg N (urea). The quantitative relationship developed in this study between mean soybean and maize yields (Y) and RSQI values (X), irrespective of the management treatments, could be quite useful to predict the yield quantitatively with respect to a given change in key indicators for these rainfed Vertisols.     

不同耕作方式对砂姜黑土物理性质和玉米生长的影响

砂姜黑土结构不良是影响其生产力的主要限制因子。为改良其土壤结构,基于安徽龙亢农场砂姜黑土耕作定位试验基地,设置免耕、旋耕、深松和深翻四种处理,研究不同耕作方式对砂姜黑土0～40 cm土层土壤物理结构、玉米根系发育及其产量的影响。结果表明:1)在玉米生育期内,免耕处理下0～40cm土壤平均容重和紧实度分别为1.52～1.57g·cm~(–3)和926～1 748 kPa,高于其他耕作处理;0～10 cm土层有效水分库容和饱和导水率低于其他耕作处理,分别仅为0.12 cm~3·cm~(–3)和3.5×10~(–5)mm·min~(–1);根系发育受到明显抑制,根长密度和根干物质的量密度较其他耕作方式分别降低42.5%～117%、35%～73.9%;2016—2017周年作物产量较深松和深翻降低8%～12%。2)与旋耕和深松相比,深翻处理下10～20cm土壤容重和10～30 cm土壤穿透阻力分别降低至1.39～1.51 g·cm~(–3)和725～1 575kPa,0～10 cm土壤饱和导水率显著提高至4.15×10~(–2) mm·min~(–1),0～20 cm土壤有效水分库容提高至17.9%～18.4%,促进了0～10 cm土层根系发育,具有较好的增产效果。3)相关分析表明根长密度与土壤容重(r=–0.74**,P 0.01)和穿透阻力(r=–0.73**,P 0.01)呈极显著负相关关系。综上所述,深翻改良砂姜黑土结构效果明显,有利于作物生长,为该区较适宜的耕作模式。     

玉米秸秆隔离层对西辽河流域盐碱土碱化特征及养分状况的影响

自2008年开始用采自通辽市花吐古拉的盐碱土进行玉米秸秆隔离层处理,并种植大麦,分析4年盐碱土养分及碱化指标变化情况.结果表明:A3 B1处理(玉米秸秆用量6 kg/m2,掩埋深度为10 cm)的改良效果最佳,经过4年的玉米秸秆隔离层生态修复,土壤有机质含量比对照区增加了10.4 g/kg,碱解氮、速效磷、速效钾含量分别比对照区增加了43.2,56.0,102.7 mg/kg,pH值下降了2.19个单位,碱化度下降了37.3％,总盐量降低了2.251 g/kg;阳离子中K+、Na+、Ca2+、Mg2+含量分别下降了78.6％,72.8％,81.5％,75.6％;阴离子中CO32-、HCO3、SO42-、Cl-含量分别下降了60.0％,75.5％,40.0％,65.5％.其他各处理区养分都得到不同程度的增加,碱化特征指标趋于良性改善.     

旱地玉米秸秆地膜二元覆盖的土壤水热效应研究

为了研究不同覆盖方式对旱地农田土壤水温变化规律和降水高效利用的影响,以探求旱地玉米最佳覆盖种植方式,于2013—2015年在山西省寿阳县连续定点定位设置秸秆地膜二元覆盖(MS)、宽膜覆盖(FM)、窄膜覆盖(NM))3个不同覆盖种植方式,以传统露地平作为对照(CK),研究不同覆盖种植模式对旱地玉米土壤温度、水分和产量的影响。结果表明:(1)二元覆盖昼夜温差比宽膜覆盖、窄膜覆盖和露地变化幅度小,二元覆盖昼夜相差8.8℃;在播后25~35天,15cm土层的土壤温度由19.1℃上升到26.5℃,呈现微弱的增温效应。(2)玉米整个生育期秸秆地膜二元覆盖处理(MS)0—160cm土壤贮水量较CK增加68mm;3年平均含水量显示,MS、FM和NM比CK分别提高4.5%,0.4%和1.2%。(3)秸秆地膜二元覆盖(MS)处理,比露地增产17.4%,水分利用效率提高24.8%。因此,秸秆地膜二元覆盖能综合改善田间温度、水分因子,提高了玉米产量和水分利用效率,是山西省旱地玉米最佳的覆盖方式。     

云南省玉米间作蔬菜和牧草对坡地土壤侵蚀的影响

2005—2006年在云南农业大学试验农场10°坡地上研究了玉米间作蔬菜和牧草对径流、土壤侵蚀的影响。结果表明,间作的水土保持效果优于玉米单作。2005年径流和土壤侵蚀,间作比玉米单作分别减少24.4%～34.1%和13.0%～50.9%;2006年间作比玉米单作分别减少8.5%～55.3%和32.5%～85.3%。其中玉米间作牧草水土保持效果最好,其次是玉米间作马铃薯及间作甘蓝。2005年径流量与降雨量、降雨强度和降雨侵蚀力呈极显著正相关;土壤侵蚀量与降雨强度和降雨侵蚀力呈极显著正相关关系。     

自然降雨下玉米秸秆堆沤还田对滇中小流域坡耕地氮素流失的影响

为探究自然降雨下不同堆沤方式秸秆还田对小流域坡耕地径流泥沙及氮素流失的影响,以滇中二龙潭流域坡耕地为研究对象,设置9种不同玉米秸秆堆沤方式,分别为CK及8种处理,各处理包括2种秸秆还田量(0.75,1.5 kg/m^2)、2种秸秆粒度(1,5 cm)、2种秸秆堆沤方式(水或水与尿素堆沤),研究烤烟坡耕地产流产沙及氮素流失特征。结果表明:(1)在4场具有典型产流的降雨中,施用较高秸秆还田量(1.5 kg/m^2)和粗颗粒秸秆(5 cm),均可有效减少坡耕地产流产沙量(10.06%~38.60%和10.07%~38.60%);(2)施用较低秸秆还田量(0.75 kg/m^2)、粗颗粒秸秆(5 cm)及未添加尿素堆沤的秸秆径流TN、NO3--N浓度低于施用高秸秆还田量(1.5 kg/m^2)、细颗粒秸秆(1 cm)及添加尿素堆沤的处理(1.96%~32.79%和3.97%~40.89%);(3)各处理下NO3--N/TN、NH4+-N/TN、PN/TN分别为63.64%~86.18%,5.31%~13.86%和5.33%~25.80%,表明坡耕地地表径流氮素主要流失形式为NO3--N,溶解态氮是径流中的主要氮素污染物;(4)施用较低秸秆还田量(0.75 kg/m^2)、粗颗粒(5 cm)秸秆、未加尿素堆沤的秸秆,泥沙TN流失浓度降低(16.87%~48.15%);(5)施用较高秸秆还田量、粗颗粒秸秆及未添加尿素堆沤可有效降低滇中坡耕地氮素的流失风险(0.32%~35.05%和54.52%~77.23%)。TN径流和泥沙流失中,以径流输出为主,占TN流失量的50.09%~71.67%。为了减少该流域氮素流失量,可选择施用较高秸秆还田量(1.5 kg/m^2)和粗颗粒(5 cm)秸秆,并依据烤烟不同生长期的吸收情况和土壤养分情况等选择少量或不添加尿素堆沤进行秸秆还田。     

玉米季坡耕地地表糙度的变化特征及其对土壤侵蚀的影响

通过野外模拟降雨试验,研究玉米种植下紫色土坡耕地地表糙度的变化特征,并分析地表糙度对产流产沙的影响.结果表明:随生育时期的推进,地表糙度逐渐衰退,在抽雄期时达到最小,地表糙度平均变幅大小为横坡垄作＞顺坡垄作＞平作,苗期时变化幅度最小,拔节期或抽雄期时最大;玉米长势越好地表产流时间越晚,各生育时期地表产流时间均为顺坡垄作最早,横坡垄作最晚;全生育期内地表径流量呈现先降低后增高的变化趋势,除苗期外横坡垄作产流量均低于平作,总体而言地表糙度对地表径流的影响未达到显著水平;苗期时土壤侵蚀量随地表糙度的增大呈指数递减,而其余3个生长时期均是随地表糙度的增大土壤侵蚀量呈指数或者幂函数递增.     

不同耕作方式玉米地下部生长发育及土壤水分状况的研究

通过对不同耕作方式玉米地下部生长发育及土壤水分状况进行分析,结果表明,不同耕作方式下,玉米的根系生物量、根系体积在不同生育期存在差异;不同耕作方式间玉米根系性状存在差异,翻耕覆膜根系生长状况好于其它耕作方式。三种耕作方式中,土壤含水量的变化趋势表现出低-高-低的倒"V"字型变化,这种规律性变化与根系的生长发育特性和灌溉有关。     

石灰性土壤施用不同磷肥对玉米苗期生长和土壤无机磷组分的影响

研究旨在探讨不同磷肥品种对玉米生长发育和土壤无机磷组分的影响,以期为磷肥高效利用提供参考.采用盆栽试验,设置6个处理:磷酸一铵(MAP)、过磷酸钙(SSP)、聚磷酸铵(APP)、氮磷复合肥硝酸磷肥(NiP)、硫酸铵+过磷酸钙混施(SA+P),试验60天后测定了玉米的生物学指标和玉米植株磷素含量,同时测定了土壤有效磷与土...     

Effect of soybean inoculation with Bradyrhizobium and wheat inoculation with Azotobacter on their productivity and N turnover in a Vertisol

A long-term field experiment was conducted for 8 years on a Vertisol in central India to assess quantitatively the direct and residual N effects of soybean inoculation with Bradyrhizobium and wheat inoculation with Azotobacter in a soybean–wheat rotation. After cultivation of soybean each year, its aerial residues were removed before growing wheat in the same plots using four N levels (120, 90, 60 and 30 kg ha^?1) and Azotobacter inoculation. Inoculation of soybean increased grain yield by 10.1% (180 kg ha^?1), but the increase in wheat yields with inoculation was only marginal (5.6%; 278 kg ha^?1). There was always a positive balance of soil N after soybean harvest; an average of +28 kg N ha^?1 yr^?1 in control (nodulated by native rhizobia) plots compared with +41 kg N ha^?1 yr^?1 in Rhizobium-inoculated plots. Residual and direct effects of Rhizobium and Azotobacter inoculants caused a fertilizer N credit of 30 kg ha^?1 in wheat. Application of fertilizers or microbial inoculation favoured the proliferation of rhizobia in crop rhizosphere due to better plant growth. Additional N uptake by inoculation was 14.9 kg N ha^?1 by soybean and 20.9 kg N ha^?1 by wheat crop, and a gain of +38.0 kg N ha^?1 yr^?1 to the 0–15 cm soil layer was measured after harvest of wheat. So, total N contribution to crops and soil due to the inoculants was 73.8 kg N ha^?1 yr^?1 after one soybean–wheat rotation. There was a total N benefit of 13.8 kg N ha^?1 yr^?1 to the soil due to regular long-term use of microbial inoculants in soybean–wheat rotation.     

Influence of Plant Growth Promoting Rhizobacteria,Compost, and Biochar of Azolla on Rosemary (Rosmarinus Officinalis L.) Growth and Some Soil Quality Indicators in a Calcareous Soil

In order to study the effect of plant growth promoting rhizobacteria (PGPR), Azolla compost and Azolla biochar on some soil quality indicators and rosemary growth, a greenhouse experiment was conducted in a completely randomized design with six replications. Treatments consisted of T₁ (control), T₂ (1% Azolla compost), T₃ (1% Azolla biochar), T₄ (PGPR (P. fluorescens), T₅ (1% compost + PGPR) and T₆ (1% biochar + PGPR). Rosemary growth parameters and nutrients concentration increased in all treatments compared to control. Treatments increased soil nutrient concentrations, soil microbial respiration (SMR) and microbial biomass C (MBC) but decreased soil metabolic quotient (qCO₂) compared to control treatment. A significant enhancement in rosemary growth occurred due to the improved soil quality as a result of organic fertilizers application, particularly by co-application of P. fluorescens and compost or biochar of Azolla.