Potassium is responsible for salinity in soils amended with poultry manure

Abstract

Soil salinity increases when heavy rates of poultry manure are applied to sandy coastal plain soils. Analysis of soils involved in a poultry manure study during 1970, 1971 and 1972 has shown that soil salinity is primarily associated with a high concentration of ? in the soil solution. Although concentrations of other elements increased with the application of poultry manure also, the increases were not sufficient to account for the salinity in these soils.     

Evaluation of fly ash as a soil amendment for the Atlantic Coastal Plain: I. Soil hydraulic properties and elemental leaching

A major limitation to crop yields in the Atlantic Coastal Plain is drought stress caused by the low moisture-holding capacities of the coarse-textured soils common to the area. Because coal fly ash is comprised primarily of silt and clay-sized particles, it has the potential, if applied at high enough rates, to permanently change soil texture and increase moisture holding capacity. A series of soil column studies were conducted to evaluate the effects of high rates of fly ash on soil hydraulic properties and elemental leaching of trace metals and boron. Fly ash from two Delaware power plants (EM=Edgemoor and IR=Indian River) was incorporated in a Hammonton loamy sand (fine-loamy, siliceous, mesic, Typic Hapludults) at six rates (0, 5, 10, 20, 30, and 40%, by weight). The effect of fly ash on soil moisture holding capacity, hydraulic conductivity, and wetting front velocity was determined. Leachates from columns amended with 30% fly ash were analyzed for B, Cd, Ni, Pb, Cu, and Zn. Soil moisture holding capacity was increased from 12% in the soil alone to 25% in the soil amended with 30% fly ash. Boron and soluble salts leached rapidly from ash amended soils while only trace quantities of Cd, Ni, Pb, Cu, and Zn were detected in column leachates.     

基于钾平衡和氮淋失风险的红壤猪粪安全用量

我国红壤区土壤普遍缺钾。通过8 a猪粪施用试验,研究了长期不施肥,长期施低量有机肥钾（59?kg/(hm2·a)）,高量有机肥钾（237?kg/(hm2·a)）,高量有机肥钾+石灰（有机肥钾237?kg/(hm2·a)＋石灰1?000?kg/(hm2·a)）对红壤旱地钾平衡的影响,并结合氮淋失风险制定有机肥钾安全用量。研究表明,红壤旱地长期有机肥施用提高了土壤供钾能力,而不会增加钾淋失。施入土壤的有机肥钾超过69%被作物吸收,但低量有机肥处理导致土壤钾库不断耗竭,而高量有机肥和高量有机肥+石灰处理每年可向土壤补充钾48～57?kg/hm2。针对单作玉米系统,保障作物钾需求和土壤钾库平衡的有机肥施钾量为180?kg/hm2。若考虑有机肥施用的硝酸盐淋失风险,有机肥施钾量不能高于155?kg/hm2,同时需补施25?kg/hm2化肥钾满足作物生长、预防土壤钾库耗竭。     

Evaluation of nitrate leaching from mine tailings amended with biosolids under Mediterranean type climate conditions

Mine tailings are difficult to revegetate due to the lack of organic matter, severe nutrient limitations, and potential metal toxicity. Biosolids has been shown to be favorable for improving properties of mine tailings. The rates of biosolids required to reclaim mine tailings (up to ) may produce conditions where significant amounts of nitrates can leach into groundwater. Leaching column experiments were conducted to determine the influences of biosolids placement and plant cover on nitrate leaching from biosolids-amended mine tailings. PVC columns packed with 7.7 kg of tailings were treated with 168 g of biosolids (approximately 270 kg mineral ). Biosolids were either placed on the surface or mixed with the tailings and half of the columns were seeded with perennial ryegrass (Lolium perenne, L.). Columns were drip irrigated at a rate of 758 mm of water y^-1. This rate was twice the average precipitation for Central Chile. All leachates were collected weekly for up to 21 weeks and analyzed for nitrate, pH, electrical conductivity, and chemical oxygen demand. The electrical conductivity and nitrate concentration of percolates decreased with time, while the pH remained constant. In some cases the percolate had nitrate concentrations greater than the maximum amount allowed for human consumption (10 mg ). Vegetation cover and mixing the biosolids with tailings reduced NO₃-N concentrations in the percolate.     

Urea hydrolysis in wetland soil amended with Sesbania aculeata green manure and rice straw

Summary The effect of incorporating sesbania and rice straw and of period of decomposition on urea hydrolysis was studied in a wetland soil under laboratory conditions. Urea hydrolysis proceeded more rapidly in the crop residue-amended soil than in the control soil, and increased with increases in the rate of addition of crop residues and with longer periods of decomposition. Irrespective of amendment treatment, urea hydrolysis followed first-order reaction kinetics, and rate constants in the unamended soil ranged from 0.021 to 0.024 h^-1 after urea application of 200 g N g^-1 soil. In the amended soil, hydrolysis rates ranged from 0.033 to 0.149 h^-1 with sesbania and 0.071 and 0.250 h^-1 with rice straw, depending on the length of decomposition period.     

Influence of surface‐applied poultry manure on topsoil and subsoil acidity and salinity: A leaching column study

It has been suggested that surface applications of animal manure can ameliorate both top and subsoil acidity. For that reason, the effects of surface incorporation (0–5 cm) of a high rate of poultry manure to an acid soil on pH and exchangeable and soluble Al in the top‐ and subsoil were investigated in a leaching column study. During the experimental period of 108 d, columns received a total of 875 mm with leaching events occurring after 9, 37, 58, and 86 d. Incorporation of poultry manure into the surface 5 cm resulted in a large rise in pH measured in both 1M KCl and in soil solution. This liming effect was attributed primarily to the substantial CaCO₃ content of poultry manure. In the 15–45 cm layer, pH_KCl was not significantly different between poultry manure and control treatments but surprisingly, soil‐solution pH was substantially less in the poultry‐manure treatments. Exchangeable Al was significantly less in poultry manure than in control in all soil layers although the effect was most marked in the 0–5 cm layer. However, although concentrations and activities of monomeric Al (Al_mono), and the proportion of total Al present as Al_mono, in soil solution were lower under poultry manure than in control in the 0–5 cm layer, the reverse was, in fact, the case in lower soil horizons. This was attributed to a soluble‐salt effect, originating from the large cation content of poultry manure, displacing exchangeable Al³⁺ and H⁺ back into soil solution. Indeed, electrical conductivity and concentrations of Ca²⁺, Mg²⁺_, K⁺, and Na⁺ in soil solution were substantially higher in the poultry‐manure than in the control treatments at all soil depths. Poultry‐manure applications also resulted in substantial increases in the concentrations of Ca²⁺_, Mg²⁺_, K⁺, Na⁺, Al_mono, NH , and NO in leachates, particularly at the fourth leaching. It was concluded that although surface application of poultry manure can raise soil pH in the topsoil, increases in soluble‐salt concentrations in soil solution can greatly modify this effect in the subsoil.     

Influence of farm yard manure,poultry manure and forest litter on copper solubility in soil and uptake by Phaseolus vulgaris

Long term and intensive use of copper‐based fungicides on coffee farms may contaminate soils with copper. The legacy of copper pollution may pose the risk of contaminating food crops cultivated on these soils. A randomized block design field experiment at Kilimanjaro, Tanzania was designed to investigate the effects of different application rates of cattle manure, poultry manure and forest litter on aqua regia, EDTA and CaCl₂ extractable copper in soils and copper uptake by bean plants grown on this long‐term copper‐contaminated soil (more than 50 yr of copper application). It was important to examine the potential of the organic amendments in mobilizing or immobilizing copper and assess the risks of contaminating bean crops at a farm, where the application of organic amendments was common practice. At harvest, rhizosphere soils were collected and analysed. The soils were found to have large concentrations of copper, greatly exceeding international standard levels. Poultry manure applied at 40 tons/ha significantly increased CaCl₂ extractable copper compared with the control treatment. Organic carbon, cation exchange capacity, EDTA extractable copper, aqua regia extractable copper and copper concentrations in bean seeds or leaves were not significantly changed by the organic matter treatments. The concentration of copper was significantly less in bean seeds than in bean leaves (P < 0.01). The bean plants did not take up excessive quantities of copper, and therefore, the risk of copper contamination of bean crops in this farm appears to be small.     

Cadmium bioavailability to Nicotiana tabacum L., Nicotiana rustica L., and Zea mays L. grown in soil amended or not amended with cadmium nitrate

Summary Mature (flowering) tobacco (Nicotiana tabacum cv. PBD6, Nicotiana rustica cv. Brasilia) and maize (Zea mays cv. INRA 260) plants were grown in an acid sandy-clay soil, enriched to 5.4 mg Cd kg^–1 dry weight soil with cadmium nitrate. The plants were grown in containers in the open air. No visible symptoms of Cd toxicity developed on plant shoots over the 2-month growing period. Dry-matter yields showed that while the Nicotiana spp. were unaffected by the Cd application the yield of Z. mays decreased by 21%. Cd accumulation and distribution in leaves, stems and roots were examined. In the control treatment (0.44 mg Cd kg^–1 dry weight soil), plant Cd levels ranged from 0.4 to 6.8 mg kg^–1 dry weight depending on plant species and plant parts. Soil Cd enrichment invariably increased the Cd concentrations in plant parts, which varied from 10.1 to 164 mg kg^–1 dry weight. The maximum Cd concentrations occurred in the leaves of N. tabacum. In N. rustica 75% of the total Cd taken up by the plant was transported to the leaves, and 81% for N. tabacum irrespective of the Cd level in the soil. In contrast, the Cd concentrations in maize roots were almost five times higher than those in the leaves. More than 50% of the total Cd taken up by maize was retained in the roots at both soil Cd levels. The Cd level in N. tabacum leaves was 1.5 and 2 times higher at the low and high Cd soil level, respectively, than that in N. rustica leaves, but no significant difference was found in root Cd concentrations between the two Nicotiana spp.Cd bioavailability was calculated as the ratio of the Cd level in the control plants to that in the soil or as the ratio of the additional Cd taken up from cadmium nitrate to the amount of Cd applied. The results showed that the plant species used can be ranked in a decreasing order as follows: N. tabacum > N. rustica > Z. mays.     

Nitrate leaching in an organic dairy/crop rotationas affected by organic manure type, livestock densityand crop

Abstract. In dairy farming systems the risk of nitrate leaching is increased by mixed rotations (pasture/arable) and the use of organic manure. We investigated the effect of four organic farming systems with different livestock densities and different types of organic manure on crop yields, nitrate leaching and N balance in an organic dairy/crop rotation (barley–grass-clover–grass-clover–barley/pea–winter wheat–fodder beet) from 1994 to 1998. Nitrate concentrations in soil water extracted by ceramic suction cups ranged from below 1 mg NO₃-N l^?1 in 1^st year grass-clover to 20–50 mg NO₃-N l^?1 in the winter following barley/pea and winter wheat. Peaks of high nitrate concentrations were observed in 2^nd year grass-clover, probably due to urination by grazing cattle. Nitrate leaching was affected by climatic conditions (drainage volume), livestock density and time since ploughing in of grass-clover. No difference in nitrate leaching was observed between the use of slurry alone and farmyard manure from deep litter housing in combination with slurry. Increasing the total-N input to the rotation by 40 kg N ha^?1 year^?1 (from 0.9 to 1.4 livestock units ha^?1) only increased leaching by 6 kg NO₃-N ha^?1. Nitrate leaching was highest in the second winter (after winter wheat) following ploughing in of the grass-clover (61 kg NO₃-N ha^?1). Leaching losses were lowest in 1^st year grass-clover (20 kg NO₃-N ha^?1). Averaged over the four years, nitrate concentration in drainage water was 57 mg l^?1. Minimizing leaching losses requires improved utilization of organic N accumulated in grazed grass-clover pastures. The N balance for the crop rotation as a whole indicated that accumulation of N in soil organic matter in the fields of these systems was small.     

华北山前平原农田土壤硝态氮淋失与调控研究

本文依托中国科学院栾城农业生态系统试验站小麦-玉米一年两熟长期定位试验, 应用土钻取土和土壤溶液取样器取水的方法, 研究了不同农田管理措施下土壤硝态氮的累积变化, 计算了不同氮肥处理通过根系吸收层的硝态氮淋失通量。结果表明, 小麦-玉米生长季土壤硝态氮累积量和淋失量随着施氮量的增加显著增加, 相同氮肥水平下增施磷、钾肥增加了作物的收获氮量, 施磷肥增加的作物收获氮量最高可达123kg·hm^-2·a^-1, 施钾肥增加的作物收获氮量最高为31 kg·hm^-2·a^-1。不同灌溉水平下0~400 cm 土体累积硝态氮随着灌溉量的增加而降低, 控制灌溉(小麦季不灌水, 玉米季灌溉1 水)、非充分灌溉(小麦季灌溉2~3 水, 玉米季按需灌溉)、充分灌溉(小麦季灌溉4~5 水, 玉米季按需灌溉)各处理剖面累积硝态氮量分别为1 698 kg·hm^-2、1148 kg·hm^-2 和961 kg·hm^-2。与非充分灌溉和充分灌溉处理相比, 控制灌溉在100~200 cm 土层硝态氮累积量显著高于其他层次, 2003~2005 年间控制灌溉剖面增加的硝态氮量占施肥总量的23%; 非充分灌溉处理剖面增加的硝态氮量占施肥总量的22%; 充分灌溉处理剖面增加的硝态氮量占施肥总量的47%。免耕措施降低了作物产量, 影响土壤水的运移, 增加了硝态氮的淋失风险。根据作物所需降低氮素投入(N 200 kg·hm^-2·a^-1), 增施磷、钾肥, 控制灌溉量是减少华北山前平原地区硝态氮淋失, 保护地下水的有效措施。     

Effect of carbon rate and type amended with ammonium or nitrate on nitrous oxide emissions in a strong ammonia oxidation soil

Journal of Soils and Sediments - The work aimed to (1) better understand how C rate and type affecting N2O emissions when combined application with different N forms in a strong ammonia oxidation...     

Bioavailability of zinc and lead from a contaminated soil amended with pine bark-goat manure compost

The distribution in soil and plant uptake of zinc (Zn) and lead (Pb) as influenced by pine bark-goat manure (PBG) compost additions were investigated from the soils artificially contaminated with Zn or Pb ions using maize (Zea mays L.) as a test crop. Soils were amended with four rates of pine bark-goat manure compost (0, 50, 100, and 200 tons ha^?1) and four rates (0, 300, 600 and 1200 mg kg^?1) of Zn or Pb. Maize was planted and grown for 42 days. At harvest, plants samples were analyzed for Zn and Pb concentration. Soils samples were analyzed for pH, extractable and diethylene triamine pentaacetic acid (DTPA) extractable Zn and Pb. Extractable Zn and Pb was lower in PBG compost amended soils than in unamended soils and steadily declined with increasing amount of compost applied. The extractable fraction for Zn dropped by 62.2, 65.0 and 44.6% for 300, 600 and 1200 mg Zn kg^?1, respectively when 200 t ha^?1 of PBG compost was applied. Metal uptake by maize plants were directly related to the rate of applied heavy metal ions with greater concentrations of metals ions found where metal ions were added to non-amended soils.     

华北平原农田裂缝对硝态氮淋溶的影响

土壤干缩开裂是常见的自然现象。目前关于土壤干缩开裂的研究主要集中于裂缝的最终形态特征,并且以室内试验为主。本研究通过室外大田试验,结合动态计算机图像分析及水氮运移模拟软件WHCNS,研究土壤干缩开裂的动力学过程、特征及其对农田水氮运移的影响。利用原位熔化石蜡浇筑得到了裂缝三维结构形态,借助三维激光扫描仪量化裂缝的几何特征,发现每平米裂缝平均长度为4.58m,裂缝上表面平均宽度为5.72 mm,平均深度为9.06 cm。基于三维扫描仪提取得到的裂缝几何参数,通过WHCNS仿真模拟,发现相较于无裂隙情况,裂隙的存在分别增加了传统施肥和优化施肥情况下97.40%和256.43%的硝态氮淋失量;与优化施肥模式相比,传统施肥模式更容易造成硝态氮的淋失风险。在模拟灌溉模式对硝态氮淋洗情况的影响时,其差异不明显;强降雨的设置同样增加了硝态氮的淋失风险,导致硝态氮的年均淋洗量增加83.61%。裂缝的存在严重影响农田作物对肥料的吸收和利用,通过优化施肥量、更改灌溉模式以及避免强降雨前施肥都可以减少肥料的损失。     

Nitrate leaching from organic arable crop rotations: effects of location, manure and catch crop

Abstract. Nitrate leaching from crop rotations supporting organic grain production was investigated from 1997 to 2000 in a field experiment at three locations in Denmark on different soil types. Three experimental factors were included in the experiment in a factorial design: (1) proportion of N₂-fixing crops in the rotation (crop rotation), (2) catch crop (with and without), and (3) manure (with and without). Three, four-course rotations were compared, two at each location. The nitrate leaching was measured using ceramic suction cells. Leaching losses from the crop rotation with grass–clover green manure and without catch crops were 104, 54 and 35 kg N ha⁻¹ yr⁻¹ on the coarse sand, the loamy sand, and the sandy loam, respectively. There was no effect of manure application or time of ploughing-in the grass–clover green manure crop on the accumulated nitrate leaching from the entire rotation. Catch crops reduced nitrate leaching significantly, by 30–38%, on the sandy soils. At all locations catch crops reduced the annual averaged nitrate concentration to meet drinking water quality standards in the crop rotation with green manure. On the coarse sand there was a time lag between the onset of drainage and the start of N-uptake by the catch crop.     

Nitrate leaching from an organic dairy crop rotation: the effects of manure type, nitrogen input and improved crop rotation

Abstract. Four management systems combining high and low livestock densities (0.7 and 1.4 livestock units ha⁻¹) and different types of organic manure (slurry and straw based FYM) were applied to an organic dairy crop rotation (undersown barley – grass–clover – grass–clover – barley/pea – oats – fodder beet) between 1998 and 2001. The effects of the management systems on crop yields and nitrate leaching were measured. In all four years, nitrate leaching, as determined using ceramic suction cups, was higher in the three crops following ploughing of grass–clover than under the barley or grass–clover. Overall, no significant differences in nitrate leaching were observed between the management systems. However, the replacement of the winter wheat crop used in the earlier experimental period (1994–97) by spring oats with catch crops in both the preceding and succeeding winters reduced nitrate leaching compared with the earlier rotation. Increasing the livestock density, which increased manure application by c. 60 kg total N ha⁻¹, increased crop yields by 7 and 9% on average for FYM and slurry, respectively. Yields were 3–5% lower where FYM was used instead of slurry. The experiment confirmed the overriding importance of grassland N management, particularly the cultivation of the ley, in organic dairy crop rotations.     

Soil aggregation and water holding capacity of soil amended with agro-industrial byproducts and poultry litter

Journal of Soils and Sediments - Soil organic matter (SOM) addition has been shown to be effective for improving physicochemical and hydrological properties, but its effectiveness may be improved...     

Heterogeneity of O2 dynamics in soil amended with animal manure and implications for greenhouse gas emissions

Soil oxygen (O₂) availability influences nitrification and denitrification, the major biological processes responsible for nitrous oxide (N₂O) production and emissions from soil. In this study O₂-specific planar optodes were used to visualise O₂ distribution with high spatial and temporal resolution in soils in which the same amount of solid fraction of pig manure had been distributed in three different ways (mixed, layered, single patch) and which were maintained at a water potential of −5 kPa (corresponding to 91% of water-filled pore space). In parallel, the greenhouse gas emissions (N₂O, CO₂ and CH₄) from soil at high temporal resolution were monitored. At the end of the incubations, vertical profiles of mineral nitrogen (ammonium and nitrate) in the soil matrix were quantified. The optode results revealed that anoxia rapidly developed in zones with manure addition and gradually expanded to the entire soil during the 66-h experimental period. The anoxia in the soil developed more quickly as the heterogeneity of manure distribution decreased (from single patch to layered to mixed). The single patch distribution of manure solids delayed peak emission rates of both N₂O and CO₂, but stimulated the cumulative N₂O emissions and reduced the cumulative CO₂ fluxes. The faster the anoxia developed, the less the nitrification process appeared to contribute to N₂O emissions. No treatment effects on CH₄ emissions were observed. Combined high resolution imaging of O₂ dynamics and measurements of N₂O emission rates are essential to get a detailed understanding of how O₂ availability regulates the distribution and coupling of denitrification and nitrification activity in soil. Such unique information on soil O₂ dynamics could be used for further modelling and quantification of processes producing greenhouse gases from soil ecosystems.     

Effect of sodium chloride on denitrification in glucose amended soil treated with ammonium and nitrate nitrogen

Laboratory incubations were conducted to study the effect of sodium chloride (NaCl) on denitrification and respiratory gases (CO₂, O₂) from soil treated with ammonium or nitrate and incubated at 20 % moisture. The same samples were assayed for denitrifying enzyme activity (DEA) after incubation at 40 % moisture with glucose and NO₃^–. Under aerobic conditions (20 % water content), a flush of activity was observed at 6 hours after start of incubation and subsided to negligible levels at 12 hours. Sodium chloride significantly depressed N₂O and CO₂ emissions and O₂ consumption. Significantly more loss of N₂O occurred from NH₄⁺‐ than NO₃^–‐treated soil at all NaCl levels and was attributed to higher microbial activity. A highly significant positive correlation was obtained between N₂O emission and respiratory gases. The respiratory quotient (CO₂ evolved/O₂) was higher for NH₄⁺‐treated soil and decreased with the amount of NaCl. At 40 % moisture, N₂O emissions were higher than at 20 % and peaked at 37 hours followed by a sharp decrease. Short‐term incubations of soil with NH₄⁺ or NO₃^– did not have an effect on denitrifying enzyme activity (DEA) while NaCl had a positive effect, particularly in previously NO₃^–‐treated soil.