Soil Nutrient Accumulation Research Articles

Economic and environmental implications of wheat-crop sequences on organic dairy-farm simulations

The market for high-quality organic bread wheat (Triticum aestivum L.) is increasing in New England, USA, providing opportunities for organic dairy farmers to grow this alternative cash crop. Our objective was to determine the sustainability of eight 3-year crop sequences compared with a perennial forage baseline in long-term (25-year), well-managed, medium-sized organic dairy farm simulations. Systems included wheat (spring or winter) preceded by maize (Zea mays L.) silage, a 1-year-old perennial forage grass, or soybean as well as maize silage followed by maize silage or soybean. Farm net return was highest for the entirely grass-based system (US$742.15 cow–1). Higher winter wheat yields for soybean–wheat–grass resulted in 7% more income from feed sales ($1027) than spring wheat. Soybean followed by wheat reduced soil nutrient accumulation by 0.8 kg ha–1 year–1 for phosphorus runoff and leachate losses and for potassium accumulation (–17%); there was also a 4% reduction in water footprint (kg kg–1 fat- and protein-corrected milk). Growing winter wheat provides long-term environmental and economic benefits, although for spring wheat, much of this benefit is lost. Use of maize silage in place of grass, winter or spring wheat, or soybean was less profitable. Most cropping system scenarios were less economically favourable than producing and feeding exclusively grass silage. However, inclusion of soybean increased economic benefits.

시설재배지 염류집적 토양에 대한 추비 저감 처리가 토마토 수량 및 양분함량에 미치는 영향

This study was conducted to evaluate the effects of reduced nitrogen (N) and potassium (K) fertigation as additional fertilizer on tomato yield and nutrient contents in excessively nutrients-accumulated soil. Shoot and root dry weights (DW), dry matter rate for shoot, root and fruit and number of fruit in both AF50 and AF100 (50 and 100% levels of additional fertilizer) treatments were increased in comparison with those in AF0 (0% level of additional fertilizer) treatment. In case of nutrient uptake by tomato, nitrogen, phosphorous (P) and potassium contents in all tomato parts (leaf, stem, root and fruit) in AF50 and AF100 treatment were lower than those in AF0 treatment. On the contrary, soluble sugar and starch contents in all tomato parts in AF50 and AF100 were higher than those in AF0 treatment. There were differences between AF0 and AF50 or AF100 in tomato growth, yield, nutrient level and contents of soluble sugar and starch. In contrast, the level and initiation point of fertigation did not significantly affect the parameters. Based on our results, the application of properly reduced level of additional fertilizer is possible to maintain the productivity of tomato and alleviate the nutrient accumulation in plastic film house soils.

Phosphorus and nitrogen losses from poultry litter stacks and leaching through soils

Stacking poultry litter in fields prior to land application is a common practice that provides important logistical benefits to farmers, but may lead to environmental losses of nutrients. A 2-year field study was conducted to evaluate phosphorus (P) and nitrogen (N) losses from poultry litter stacks with and without a protective cover. Surface runoff from the litter stacks and leachate through two texturally contrasting soils (sand and silt loam) was monitored using a combination of runoff collectors and zero-tension lysimetry. Nutrient losses in surface runoff were small (total P < 3 g m−2; total inorganic N < 7 g m−2), particularly when compared with losses in leachate (total P < 60 g m−2; total inorganic N < 290 g m−2). Covering stacks reduced leachate total P losses by 25–100 times and total inorganic N losses by 25–770 times, such that leachate nutrient losses from covered stacks were similar to that in the controls with no manure stacking. Despite relatively small nutrient losses from litter stacks over the 2-year study, results point to substantial nutrient accumulation in soil after repeated stacking. Water-extractable P concentrations in upper 5-cm soils were similar between covered (120–240 mg kg−1) and uncovered stacks (140–250 mg kg−1), but soil nitrate-N concentrations were much higher under the covered stack (80–140 mg kg−1) than the uncovered stack (<5 mg kg−1). This study clearly points to benefits of covering litter stacks, but highlights long-term concerns with regard to soil nutrient accumulation.

Effects of DTPA application on Growth of Red Pepper (Capsicum annuum L.) and Chemical Properties of Nutrient Accumulated Soil in Plastic film House

This study was conducted to evaluate effects of diethylene triamine penta acetic acid (DTPA) treatment on growth of red pepper and nutrient availability to salt accumulated soil in the plastic film house. The treatments were no application (Control), chemical fertilizers (NPK), DTPA (0.06, 0.13, and 0.19 mM) and the half of chemical fertilizers (NPK) with DTPA 0.06 mM. Fruit yield of red pepper showed no significant difference between the treatments (control, NPK, DTPA 0.06 mM, 0.13 mM, except for DTPA 0.19 mM. Red peppers were killed by DTPA 0.19 mM treatment because the high concentration of DTPA was toxic to crop. However, dry mass (stem and leave) and nutrient uptake of red pepper in DTPA 0.06 mM treatment increased significantly compared with those of control. In particular, nutrient uptake of red pepper in DTPA 0.06 mM treatment increased in the order of Fe, Mn, and Zn > Ca and Mg > K, as the magnitude of the stability constants of DTPA. Thus the application of DTPA 0.06 mM was the most effective for the alleviation of nutrient accumulation in the plastic film house soils.

The Changes of Nutrient Content in Soil in Long-term Fertilizer Experiments

&lt;p&gt;The paper describes the influence of long term (more than 30 years) fertilizer application to the changes of soil properties and identifies the influence of different fertilization rates to phosphorus, potassium, calcium and magnesium accumulation in soil.&lt;/p&gt;&lt;p&gt;The research has been carried out at the Research Institute of Agriculture of Latvian University of Agriculture in the long-term subsurface drainage field established in Skrīveri in 1981 under the guidance of professor J. Štikāns. The long-term drainage field was established in the uncultivated gleyic sod-podzolic &lt;em&gt;Hypostagnic&lt;/em&gt; &lt;em&gt;Endogleyic Albeluvisol (Hypereutric), stw-ng-AB(he) &lt;/em&gt;loam that had not been used in agriculture for 20 years before. The experimental field was established with four rates of mineral fertilizers: without fertilizers, N45P30K45; N90P60K90 N135P90K135 calculated in form of P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; and K&lt;sub&gt;2&lt;/sub&gt;O. Since 1994 a seven-year crop rotation has been organized: 1) winter triticale, 2) potatoes, 3) spring wheat, 4) spring oilseed rape, 5) spring barley + perennial grasses (red clover, timothy), 6) perennial grasses, 1st year of using, and 7) perennial grasses 2nd year of using. Mineral fertilizers were applied according to the anticipated rates of plant nutrient elements annually during the cultivation of soil before sowing. For winter cultivars the phosphorus as superphosphate and potassium as potassium chloride fertilizers were cultivated before the sowing in autumn and nitrogen in form of ammonium nitrate was applied the next spring at the beginning of vegetation and at the stage of tillering. During the vegetation period all the required common agro-technical measures were taken – treatment with herbicides, fungicides and insecticides.&lt;/p&gt;&lt;p&gt;After 32 years of trial similar soil parameters showed significantly different content of nutrients related to the different level of fertilizer application. On a low background of fertilizers (N45P30K45) a small increase of mobile phosphorus in soil has only been observed in recent years. At the fertilizer rate N90P60K90 the content of available phosphorus and potassium in soil gradually begins to grow. Fertilization norm N135P90K135 caused a constant accumulation of nutrients in soil. In 30 years’ time the content of exchangeable phosphorus (calcium lactate – extractable) has increased more than 20 times (from 9 till 184 mg P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; kg&lt;sup&gt;-1&lt;/sup&gt;) and exchangeable potassium (calcium lactate – extractable) has increased more than 4 times (from 64 till 223 mg K&lt;sub&gt;2&lt;/sub&gt;O kg&lt;sup&gt;-1&lt;/sup&gt;). There were no relation between different fertilizing rates and calcium and magnesium content in soil observed.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;

Protection Methods to Reduce Nitrogen and Phosphorus Losses from Sloping Citrus Land in the Three Gorges Area of China

The increased application of chemical fertilizers in citrus orchards and the non-point source nitrogen (N) and phosphorus (P) diffusion threaten the fresh water quality of the Three Gorges Reservoir area of China. A 10-year field trial on sloping citrus lands was conducted to evaluate five protection methods for reducing N and P losses: 1) intercropping with perennial white clover (CW); 2) straw mulching of the soil surface (CS); 3) intercropping with yellow daylily contour hedgerows (CH); 4) an impermeable membrane buried in the soil along the contour lines (CM); and 5) intercropping with a rotation of wheat and peanut (CWP). An area of conventional citrus management was also maintained as the control (CK). The results showed that CM and CH were the most effective methods for reducing surface runoff. The sediment yield were reduced at the highest rate by CW and CH and was also significantly reduced by CS. Reduced runoff volume and sediment yield were the crucial mechanism for the reductions in N and P losses. Compared with the control, CW, CS, CH, and CM reduced annual runoff by 9%, 13%, 25%, and 30%, sediment yield by 77%, 55%, 71%, and 28%, N loss by 10%, 23% 36%, and 37%, and P loss by 39%, 31%, 27%, and 25%, respectively. CW, CS, CH, and CM were effective in reducing N and P losses from the sloping citrus land. However, over the long-term, surface soil nutrient accumulation in CW, CS, and CH diminished the benefit of those methods in reducing N and P losses. In addition, CWP increased soil erosion and nutrient loss, which showed that citrus intercropping with other crops was an unsuitable method for citrus sloping land in the Three Gorges area.

Greenhouse Gas Fluxes and Soil Carbon and Nitrogen Following Single Summer Tillage Event

No-till farming results in gradual buildup of soil organic matter (SOM) and re-introduction of tillage can often reverse it. However, tillage in low precipitation regions may be needed to manage weeds and disperse accumulation of immobile soil nutrients. The main objective of this study was to assess the effects of a single summer tillage on carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), soil water filled pore space (WFPS), dissolved organic carbon (DOC) and nitrate (NO3) in winter wheat summer fallow systems that were either tilled for the first time after nine years of no-till (NTT), not-tilled (no-till, NT) or were frequently tilled (conventional, CT; and organic, CF). The study was established in the US Central High Plains region where annual precipitation averaged 332±39 mm. Soil and gas samples were collected before the tillage event (time zero) and at 1hr, 5 hrs, 25 hrs and 50 hrs after. Immediate increases in CO2 and N2O fluxes were observed in all tilled treatments within the first 1 to 5 hours but 50-hr cumulative N2O and CO2 in NTT did not differ from Original Research Article Bista et al.; IJPSS, 6(4): 183-193, 2015; Article no.IJPSS.2015.109 184 the values observed in NT. Tillage however, resulted in a 22% greater 50-hr cumulative CH4 assimilation in NTT compared with NT and was comparable with CH4 in CT suggesting enhanced soil aeration. Soil NO3 did not change in NTT unlike in CT and CF and soil DOC did not increase in NTT until 25 hrs after when, it returned to levels comparable with time zero. In contrast, DOC in CT and CF continued to stay elevated after 50 hrs. In conclusion, single tillage event of a long-term notill performed on dry soil during summer did not negate benefits associated with SOM accrual and may be a viable alternative for farmers to address some of the management-related problems.

黄土丘陵区小流域侵蚀环境对土壤微生物量及酶活性的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 黄土丘陵区小流域侵蚀环境对土壤微生物量及酶活性的影响 DOI: 10.5846/stxb201310302611 作者: 作者单位: 西北农林科技大学资源环境学院,西北农林科技大学 资源环境学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金重点基金(41030532); 国家自然科学基金面上项目(41171226); 教育部新世纪优秀人才支持计划(NCET-12-0479) Effect of erosion on soil microbial biomass and enzyme activity in the Loess Hills Author: Affiliation: College of Resources and Environment, Northwest A＆F University,College of Resources and Environment, Northwest A＆F University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土壤侵蚀环境直接影响土壤的特性,对土壤微生物的形成和稳定具有重要的影响。土壤微生物量推动着土壤的物质循环和能量流动,对土壤中各种环境的变化有很强的敏感性。土壤酶活性能表示土壤微生物功能的多样性,与土壤微生物量有着紧密的联系。为了探究不同侵蚀环境对土壤微生物量和酶活性的影响,以黄土丘陵区陈家坬小流域为研究区,选择5种不同侵蚀环境下0-10cm和10-20cm土层的土壤为研究对象,对土壤微生物量及其土壤蔗糖酶、脲酶和碱性磷酸酶活性进行了研究。结果表明:(1)土壤微生物量碳、氮、磷含量均表现为0-10cm大于10-20cm土层;土壤微生物量碳和磷在阴沟坡最大,在阳梁峁坡和峁顶较小,且阴沟坡和峁顶差异显著;土壤微生物量氮在阳沟坡最大,阴阳梁峁坡最小,差异性显著(P < 0.01)。(2)土壤脲酶、蔗糖酶和碱性磷酸酶活性均表现为0-10cm大于10-20cm土层,且在不同侵蚀环境下均表现为阴梁峁坡最大,阳梁峁坡最小。(3)相关性分析表明,土壤微生物量碳、氮、磷与土壤脲酶、蔗糖酶、碱性磷酸酶活性之间均有极显著的正相关。 Abstract:Erosion directly affects soil characteristics and has a significant effect on the formation and stability of the soil microbial community. Soil microbial biomass not only plays a significant role in energy flow and nutrient cycling, but it also shows great sensitivity to changes in soil environment. Soil enzyme activities are indicative of the functional diversity of the soil microbial community, as they are closely associated with soil microbial biomass. To reveal the effect of different erosion environments on soil microbial biomass and soil enzyme activities, soil samples were collected from the Chengjiawa watershed, located in the Yanhe watershed of the hill and gully region of Ansai County, Yan'an, Shaanxi Province, China. Soil samples were collected from five erosion environments in the valley, at depths of 0-10 cm and 10-20 cm. We studied the characteristics of soil microbial biomass including carbon, nitrogen, and phosphorus, soil enzyme activities including soil urease, invertase, and alkaline phosphatase, and correlations between soil microbial biomass and enzyme activities. The results showed that: (1) Soil microbial biomass carbon, nitrogen, and phosphorus were significantly different between the 0-10 cm and 10-20 cm soil layers; soil microbial biomass carbon and phosphorus in the shaded lower slopes were higher than in the other tested environments, whereas in the sunny middle slope and the hill top they were lower than in the other tested soil environments. The difference between the shaded lower slopes and sunny hill top were significant. Soil microbial biomass nitrogen in the sunny lower slope was significantly higher than in the other tested soil environments. Overall, soil microbial biomass of the ditch slope was higher than in the other tested environments. This suggested that the erosion affects the soil microbial properties, and that soil nutrient accumulation and mineralization ability of soils on the downhill slope were higher than in other tested locations. (2) Soil urease, sucrase, and alkaline phosphatase activities were higher in the 0-10 cm layer than in the 10-20 cm layer. In different erosion environments, soil enzyme activities were higher in the shaded middle slope than in any other tested environments, while they were the lowest in the sunny middle slopes. Soil alkaline phosphatase activity did not significantly differ between different soil environments. Soil invertase activity in the shaded middle slopes was significantly different from the other four types of erosion environments. The difference in soil urease activity between the shaded lower slope and other tested environments was significant. Comparisons showed that the environment exposed to erosion affected the properties of soil enzyme activities; the responses of soil invertase and urease were more sensitive to changes in the soil environment. (3) Pearson correlation analysis showed that soil microbial biomass carbon, nitrogen, and phosphorus were significantly positively correlated with each other, as were the soil urease, sucrase, and alkaline phosphatase activities. There was a significant positive correlation between soil microbial biomass and soil enzyme activities, which suggested that these two properties were closely linked and inseparable components of the soil microbial community. Different environments exposed to erosion have diverse levels of soil organic matter content, different physicochemical properties of the soil, diverse forms of soil microbes, and differ in the amount of soil microbial biomass and soil enzyme activities. These differences were reflected in the soil quality, vegetation types, and resistance to soil erosion. 参考文献 相似文献 引证文献

五大连池火山熔岩地貌苔藓植物对土壤养分积累作用的研究

PDF HTML阅读 XML下载 导出引用 引用提醒 五大连池火山熔岩地貌苔藓植物对土壤养分积累的作用 DOI: 10.5846/stxb201306221758 作者: 作者单位: 内蒙古大学生命科学学院,内蒙古大学生命科学学院,内蒙古大学生命科学学院,内蒙古大学生命科学学院,内蒙古大学生命科学学院,内蒙古大学生命科学学院,内蒙古大学生命科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目(31170497) The effect of bryophytes on nutrient accumulation in surface soil in the Wudalianchi volcanic area Author: Affiliation: College of life science,Inner Mongolia University,College of life science,Inner Mongolia University,College of life science,Inner Mongolia University,College of life science,Inner Mongolia University,College of life science,Inner Mongolia University,College of life science,Inner Mongolia University,College of life science,Inner Mongolia University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了解五大连池火山熔岩地貌土壤主要矿质养分含量及其特点,同时探讨苔藓植物对土壤养分积累的影响,选取了6座形成年代不同的火山,对其进行了苔藓植物生境分布、盖度调查及土壤养分含量的测定。结果表明:(1)西焦得布山、卧虎山、南格拉球山、莫拉布山等老期火山阔叶林下苔藓种类匮乏,其盖度<1%;老期火山石塘林苔藓种类较丰富,盖度可达10%-15%,主要分布有毛尖紫萼藓、山羽藓、美灰藓、虎尾藓等石生藓类,同时还有石缝藓、卷叶凤尾藓等生于石缝内。(2)新期火山中老黑山的林下以垂枝藓为优势种,盖度可达50%-80%,常见伴生种有山羽藓、狭叶小羽藓、金灰藓、毛尖紫萼藓等。老黑山火山砾生境以砂藓为优势种,盖度可达45%;常见伴生种有垂枝藓、美灰藓、真藓、桧叶金发藓等。(3)新期火山中的火烧山上分布的苔藓以毛尖紫萼藓、垂枝藓、美灰藓等干燥石生藓类为主,盖度为10%左右,峭壁背阴处和石缝等小生境中分布有密叶三瓣苔、毛尖金发藓、桧叶金发藓等。(4)土壤N、P、K三大营养元素含量在老期火山土壤中基本上都为丰;全N、S、有机质含量在新期火山土壤中的含量最低,有随火山形成年代的增加而升高的趋势;全K、Ca、Mg、Fe、Zn、B含量在新期火山土壤中都最高,有随年代的增加而减少的趋势;全Mn和Cl含量在新期火山土壤中较高,也随年代的增加而有下降的趋势;全P的量在各火山土壤中的含量都较高,没有明显的变化趋势;新期火山土壤pH值高于老期火山,土壤酸碱反应总体上呈中性。(5)土壤全N、S含量与有机质含量,全K含量与全Mg、Fe含量,全Mg含量与全Fe含量呈极显著正相关(P < 0.01);全S含量和有机质含量具有显著正相关性(P < 0.05);全N含量与全K含量呈极显著负相关(P < 0.01);全N与全Zn,全K、S与有机质,全Ca与Cl,全S与全Zn,全Zn与有机质含量间具有显著的负相关性(P < 0.05)。(6)表面有苔藓植物覆盖的火烧山土壤所含N、S、P、有机质等的含量高于火山砾;老黑山路边土壤养分含量几乎都低于林下样品,老黑山表面覆盖有垂枝藓、山羽藓、砂藓和桧叶金发藓的火山砾所含N、S、有机质的含量高于只有砂藓覆盖的火山砾。 Abstract:Studying the content and characteristics of soil nutrients and the bryophytes community is crucial to revealing the soil nutrition conditions and the effect of bryophytes on soil nutrient accumulation. In our study we selected Laoheishan, Huoshaoshan, Xijiaodebushan, Wohushan, Nangelaqiushan and Molaushan volcanoes as sampling plots. Laoheishan and Huoshaoshan are new-period volcanoes and the rest are old volcanoes. We arranged 15 quadrats to investigate the habitat distribution and coverage of bryophytes; and tested for total N, P, K, Ca, Mg, S, Fe, Mn, Zn, B, Cl, soil organic matter and pH values in ten surface soil/lapilli samples (0-20cm) collected from those sampling plots.The research results showed that: (1) Bryophyte species were deficient under broadleaf forest on old volcanoes,with coverage of under 1%. There were some common species like Entodon compressus C. Muell., Myuroclada maximowiczii (Borszcz.) Steer et Schof., Taxiphyllum taxirameum (Mitt.) Fleisch. distributed in humid habitats. Bryophyte species were abundant in old stone forests. There, not only distributed epilithic mosses like Grimmia pilifera P.Beauv., Abietinella abietina (Hedw.) Fleisch., Hedwigia ciliata (Hedw.) Ehrh. ex P. Beauv., Eurohypnum leptothallum (C.Muell.) Ando; but also many distributed geophilous mosses like Saelania glaucescens (Hedw.) Broth. ex. Bom. et Broth., Fissidens cristatus Wils. ex Mitt. and so on. (2) Rhytidium rugosum (Hedw.) Kindb. was the dominant species under Laoheishan volcano forest with coverage of 50%-80%. Abietinella abietina, Weissia edentula Mitt., Haplocladium angustifolium (Hamp.et C.Muell.) Broth., Haplocladium microphyllum (Hedw.) Broth., Pylaisiella polyantha (Hedw.) Grout, Grimmia pilifera, were common accompanying species in this habitat. Racomitrium canescens (Hedw.) Brid. was the dominant species of lapilli habitat on Laoheishan volcano with coverage of 45%. Eurohypnum leptothallum, Rytidium rugosum, Polytrichum juniperinum Hedw., Bryum argenteum Hedw., Bryum uliginosum (Brid.) B.S.G. were common accompanying species in this habitat. (3) The dominant species on Huoshaoshan volcano were Rytidium rugosum, Grimmia pilifera, Eurohypnum leptothallum, Polytrichum piliferum Hedw. and Tritomaria quinquedentata (Huds.) Buch, which were distributed in shady spots in cliffs or rock crevices. (4) The total N, S, and organic matter were lowest in the soil collected from new-period volcanoes; while in contrast, the total K, Ca, Mg, Fe, Zn, B, Mn and Cl were highest in new-period volcanic soil. The pH value of new-period volcanic soil was also higher than old volcanic soil. Total P in the different soil samples had no significant differences. The total N, P, S, Cl, and organic matter in volcanic soil were higher than in lapilli. (5) The total N had a significantly positive correlation with total S and soil organic matter; total K with total Mg and total Fe, and total Mg with total Fe also had significantly positive correlations (P < 0.01). Total S has a positive correlation with soil organic matter (P < 0.05). Total N has a significantly negative correlation with total K. Total N with total Zn; total K, S, and soil organic matter; total Ca with Cl; total S with total Zn; total Zn with soil organic matter also had negative correlations (P < 0.05). (6) The N, S, P and organic matter from Huoshaoshan which were covered by bryophytes are higher than those of lapilli. The nutrient contents of roadside soil were less than values obtained from samples from Laoheishan forest, except for Ca and Zn. The N, S and organic matter of samples from Laoheishan which were covered by Rytidium rugosum, Abietinella abietina, Racomitrium canescens, Polytrichum juniperinum, are all higher than the sample which was only covered by Racomitrium canescens. 参考文献 相似文献 引证文献

Pollution of intensively managed greenhouse soils by nutrients and heavy metals in the Yellow River Irrigation Region, Northwest China.

The present study aimed to assess the potential ecological risk of heavy metals and nutrient accumulation in polytunnel greenhouse soils in the Yellow River irrigation region (YRIR), Northwest China, and to identify the potential sources of these heavy metals using principal component analysis. Contents of available nitrogen (AN), phosphorus (AP), and potassium (AK) in the surface polytunnel greenhouse soils (0-20cm) varied from 13.42 to 486.78, from 39.10 to 566.97, and from 21.64 to 1,156.40mgkg(-1), respectively, as well as AP, soil organic matter (SOM) and AK contents tended to increase significantly at the 0-20- and 20-40-cm soil layers. Heavy metal accumulations occurred in the polytunnel greenhouse soils as compared to arable soils, especially at a depth of 20cm where Cd, Zn and Cu contents were significantly higher than arable soil. Cd and As were found to be the two main polluting elements in the greenhouse soils because their contents exceeded the thresholds established for greenhouse vegetable production HJ333-2006 in China and the background of Gansu province. It has been shown that Cd, Cu, Pb and Zn at the 0-20-cm soil layer were derived mainly from agricultural production activities, whereas contents of Cr and Ni at the same soil layer were determined by 'natural' factors and As originated from natural sources, deposition and irrigation water.

Effect of Biosolid Amendments on the Metal and Nutrient Uptake and Spectral Characteristics of Five Vegetable Plants

The accumulation of metals and nutrients in biosolid-amended soils and the risk of their excess uptake by plants is a topic of great concern. This study examines the elemental uptake and accumulation in five vegetable plants grown on biosolid-applied soils and the use of spectral reflectance to monitor the resulting plant stress. Soil, shoot, root, and fruit samples were collected and analyzed for several elemental concentrations. The chemical concentrations in soils and all the plant parts increased with increase in applied biosolid concentrations. The Cu and Zn concentrations in the plant shoots increased in the order of collard<radish<lettuce<tomato<pepper. The Cu and Zn concentrations accumulated significantly in the fruits of the tomato plants compared to other plants. Among all the plants, the shoot concentration factor (SCF) of Zn was significantly higher for pepper plants, indicating increase in uptake of Zn. The shoot relative uptake index (SRUI) of Cu and Zn increased in the order of collard<radish<lettuce<tomato<pepper. The shoot dry weight and spectral reflectance of the radish plants in the near-infrared (NIR) region (800-1,300 nm) decreased significantly with increase in biosolid concentration compared to other plants. Increase in plant stress with increase in biosolid dose was evident in radish plants through significant reduction in Normalized Difference Vegetative Index (NDVI). This study indicates the potential use of spectral reflectance as a tool for the screening and monitoring of stress-sensitive plant species and their physiology and as a result, indirectly assesses the chemical concentrations in soils and plants.

Swine effluent treatment using anaerobic digestion at different loading rates

The industrial swine production is characterized by generation of significant effluent amounts that require treatment. The most adopted practices by Brazilian swine farmers have been wastewater storage in lagoons and its subsequent use as a biofertilizer. Nutrient accumulation in soil and water creates the need for an effective management of these residues. The anaerobic digestion process is an important alternative and low-cost treatment for organic matter reduction. However, its efficiency is limited by the digester capacity of solid degradation, especially at low hydraulic retention times. Thus, the present study aimed to verify the behavior of an upflow anaerobic digester by increasing the organic loading rate. This was accomplished in three stages using, as a parameter, volatile solids at 0.5; 1.0 and 1.5 kgVS m-3 d-1, respectively. This digester model proved to be quite robust and effective in swine manure treatment, achieving high efficiency of volatile solid removal at all stages of the study (stage 1: 61.38%; stage 2: 55.18%; and stage 3: 43.18%). Biogas production was directly related to the increasing organic load, reaching 0.14, 0.85, and 0.86 Nm³ kgVS-1add., respectively, with no significant difference (p&lt;0.05) of biogas methane concentration among the studied stages (73.7, 75.0, and 77.9%).

Soil Characteristics in Relation to Vegetation Communities in the Wetlands of Poyang Lake, China

Poyang Lake is an important wetland with global ecological functions. Impact of plant species composition on soil physicochemical characteristics is potentially critical but is as yet poorly understood in this great, shallow and water passing lake wetland. Five dominant plant communities, Phragmites communis community (Phragmites), Polygonum hydropiper community (P. hydropiper), Artemisia selengensis community (A. selengensis), Carex cinerascens community (C. cinerascens) and Phalaris ayuyldinacea community (Phalaris) were surveyed to identify the influences of plant species composition on soil properties. Results show great heterogeneity in soil characters among studied vegetation communities. The lowest average values of pH and soil bulk density are presented in soil with Phragmites, while the highest ones are determined in C. cinerascens and A. selengensis, respectively. Moreover, C. cinerascens is determined with the highest average contents of total organic carbon (TOC) and total nitrogen (TN), whereas Phalaris community presents the lowest soil carbon and nutrient accumulation in surface soil. Plots of C. cinerascens, Phragmites and Phalaris are identified with obvious convergence patterns, while dispersive patterns are identified in A. selengensis and P. hydropiper, suggesting great heterogeneity in soil properties among typical communities in Poyang Lake.

Functional relationships with N deposition differ according to stand maturity in Calluna-dominated heathland.

Plant and soil bio(chemical) indicators are increasingly used to provide information on N deposition inputs and effects in a wide range of ecosystem types. However, many factors, including climate and site management history, have the potential to influence bioindicator relationships with N due to nutrient export and changing vegetation nutrient demands. We surveyed 33 heathlands in England, along a gradient of background N deposition (7.2-24.5 kg ha(-1) year(-1)), using Calluna vulgaris growth phase as a proxy for time since last management. Our survey confirmed soil nutrient accumulation with increasing time since management. Foliar N and phosphorus (P) concentrations in pioneer- and mature-phase vegetation significantly increased with N deposition. Significant interactions between climate and N deposition were also evident with, for example, higher foliar P concentrations in pioneer-phase vegetation at sites with higher temperatures and N deposition rates. Although oxidized N appeared more significant than reduced N, overall there were more, stronger relationships with total N deposition; suggesting efforts to control all emissions of N (i.e., both oxidized and reduced forms) will have ecological benefits.

Effect of saline water irrigation on soil development and plant growth in the Taklimakan Desert Highway shelterbelt

Water scarcity is a world-wide problem, especially in desert ecosystems. To overcome this shortage, saline groundwater is increasingly being used, although it has risks of increasing soil salinity and causing plant salt toxicity. In this study, we investigated the effects of saline water irrigation on soil properties and plant growth along the Taklimakan Desert Highway shelterbelt. The results showed that soil salts (about 8mScm−1) and nutrients significantly accumulated at the soil surface (crust and 0–10cm soil layers) with saline irrigation, but the soil salinization did not increase (<1.0mScm−1) within the 40–60cm soil depth where abundant lateral roots also germinated and extended horizontally. While the deepest main root system was 200cm for Tamarix, it extended to about 150cm for other two species studied (Haloxylon and Calligonum). More than 87% of the biomass of the lateral roots was present in the 20–80cm soil depths for the three species; although no active absorbing roots were found within the 0–10cm soil depths where the salts had accumulated. These findings indicated that saline water irrigation within artificial shelterbelts may be beneficial for soil nutrient accumulation and accentuates the potential uses of these sandy soils. After 7-yrs irrigation with nutrient accumulation, structured soil under shelterbelt has progressively formed, as indicated by increased soil aggregate size and stability. Saline water irrigation did not influence the normal growth of adaptive plants, which may be attributed to the plant adaptability to salt stress through root morphology adjustment. In summary, saline groundwater irrigation offers potential advantages and opportunities for plant growth on sandy soils evolution in a desert environment where saline groundwater is the sole water resource for plants.

Altered N, P and C dynamics with absence of fire in Eucalyptus forests affected by premature decline

AbstractAbsence of fire is increasingly recognized as an important driver of soil nutrient budgets in Eucalyptus forest, especially in forests affected by premature Eucalyptus decline, due to the effects of soil nutrient accumulation on nutrient balances and forest community dynamics. In this study, we present a dataset of soil and foliar nutrient analyses, and vegetation measurements from a fire chronosequence survey in native E. delegatensis forest. Measured indices include total soil and extractable soil nitrogen (N), or phosphorus (P), soil organic carbon (C), soil acid‐phosphatase (PME) activity, foliar N and foliar P, and understorey and overstorey vegetation canopy height. We show that in some cases indices are strongly linked to time since fire (2–46 years). Time since fire correlated positively with foliar N, total and extractable soil N, soil organic C, and also soil PME activity; the latter an indicator of biotic P demand. Differences in the strength of these relationships were apparent between two geology types, with stronger relationships on the potentially less‐fertile geology. The strong positive correlation with time since fire and understorey canopy height reflected increasing shrub biomass and thickening of the shrub layer. The strong positive correlation for soil or foliar N, but not P, with time since fire, indicates that P does not increase relative to N over time. P may, therefore, become limiting to growth in this plant community. Similarly, the significantly higher concentrations of soil N but not P, also found in both older and long‐unburnt forest stands (&gt;100 years since management), may exacerbate a situation of soil nutrient limitation over several decades. A characteristic feature of long unmanaged stands is a developing tea tree (Leptospermum sp.) understorey, which may benefit from elevated soil N availability and increasing organic C accumulation with prolonged fire absence. This increased shrub biomass would outcompete Eucalyptus for resources, including soil nutrients and water.

Fallow Cover Crop Species and Nitrogen Rate of Fertigated Solution on Cucumber Yield and Soil Sustainability in Greenhouse Condition

Nutrient accumulation in surface soil has become a serious problem for cucumber production in greenhouse. However, still in many cases, soil management practices are only focused on maintaining crop yield, regardless of sustainability related with soil chemical properties. This study was conducted to propose a sustainable soil management practice by investigating the impact of cover crop species and nitrogen rate of fertigated solution on cucumber yield and soil chemical properties in greenhouse condition. Rye and hairy vetch were tested as a fallow cover crop, and each amount of urea (1/2, 3/4, 1 times of N fertilizer recommendations), determined by soil testing result, was supplied in fertigation plots as an additional nitrogen source. The result showed that the yield of cucumber was higher in rye treatment than control and hairy vetch treatment. In addition, rye effectively reduced EC and accumulated nutrients from the soil. Meanwhile, N concentration of fertigated solution showed no significant effect on the growth and yield of cucumber. Consequently, these results suggest that it is desirable to choose rye as a fallow catch crop for sustainable cucumber production in greenhouse.

不同植被恢复类型的土壤肥力质量评价

PDF HTML阅读 XML下载 导出引用 引用提醒 不同植被恢复类型的土壤肥力质量评价 DOI: 10.5846/stxb201306111672 作者: 作者单位: 华南农业大学林学院,华南农业大学林学院,华南农业大学林学院,华南农业大学林学院,华南农业大学林学院 作者简介: 通讯作者: 中图分类号: S714.8 基金项目: 广东省林业科技创新专项（2010KJCX012-02，2011KJCX031-02） Soil fertility quality assessment under different vegetation restoration patterns Author: Affiliation: College of Forestry, South China Agricultural University,College of Forestry, South China Agricultural University,College of Forestry, South China Agricultural University,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:科学确定森林土壤肥力指标并进行肥力质量的评价，对立地生产力和多目标森林经营的研究有着重要意义。以采伐（径级12 cm择伐）迹地上发育来的稀树灌丛、针叶林、针阔混交林和常绿阔叶林为研究对象，进行每木调查与群落分析，并比较各群落土壤因子间的差异，用典范对应分析（CCA）和因子分析对土壤肥力质量进行定量评价。结果表明，CCA可以有效地筛选土壤肥力质量指标，有助于质量指标的科学确定；土壤肥力质量综合评价分值为稀树灌丛（0.438） > 常绿阔叶林（0.414） > 针阔混交林（-0.170） > 针叶林（-0.331）；演替初期（19 a）的植被恢复并未使土壤结构发生明显变化，土壤肥力质量是下降的；无人为干扰的3种群落类型，针叶林表现为更高的生物量积累，而天然更新的常绿阔叶林则更有利于生物多样性的增加与土壤养分的保蓄。 Abstract:Soil fertility quality assessment based on scientifically determined indicators has significant implications for the study of stand productivity and multi-objective forest management. We carried out plant census and community analysis, and compared soil physicochemical properties among forest communities in Kanghe Nature Reserve. The four community types, i.e., scrub, evergreen broadleaved forest, coniferous-broadleaved mixed forest, and coniferous forest, represented different vegetation restoration patterns originating from a selective-logging (at 12 cm diameter) event on the subtropical evergreen broadleaved forest. The main soil factors influencing tree composition and distribution were screened by Canonical Correspondence Analysis (CCA), which were subsequently used to build the minimum data set (MDS). Soil fertility quality was quantitatively assessed with Factor Analysis on MDS.The results showed that distribution of tree species was unevened. With the lowest species richness, the coniferous forest was exclusively dominated by Cunninghamia lanceolata, whereas in the most species rich evergreen broadleaved forest, codominant tree species existed. Average tree DBH (diameter at breast height) decreased successively among coniferous forest, coniferous-broadleaved mixed forest and evergreen broadleaved forest.Soils were highly acidic (pH < 5.0) and the content of AvK, ExMg, AvMn, AvZn and AvFe had no significant difference(P > 0.05)across the four forest communities. A lower canopy density due to less canopy trees resulted in the lower soil moisture content in the scrub community, which had a higher mineral element content than other vegetation patterns as a whole. Distribution of trees was closely related to soil environmental factors, but the results of CCA indicated that there was no significant correlation (Monte Carlo Test,P > 0.05) between composition and distribution of tree species and the seven soil factors, i.e., AN, ExCa, AvK, TP, ST, AP and NCP, which should be excluded when building the MDS. Therefore, the findings revealed that CCA was an effective tool for screening soil fertility quality indicators and establishing MDS by demonstrating the effect of soil fertility on plant patterns.Factor analysis was applied on MDS to assess the fertility quality and the cumulative variance explained by five principal components was 84.67%, indicating this evaluation method was reliable. The integrated soil fertility quality assessment scores for scrub, evergreen broadleaved forest, coniferous-broadleaved mixed forest, and coniferous forest were, in a descending order, 0.438, 0.414, -0.170, and -0.331, respectively. Vegetation restoration did not obviously change soil structural parameters, such as soil texture, capillary porosity, non-capillary porosity, and bulk porosity, however, soil fertility quality declined in the early succession stage (19 a). In the three community types without human disturbance, coniferous forest had the highest biomass accumulation, whereas evergreen broadleaved forest from natural regeneration was more conducive to the increase of biodiversity and soil nutrient accumulation. Site-specific indicators, including soil physicochemical factors and biological factors, should be selected in future assessment of soil fertility quality. The appropriate quantitative ecological methods could make the determination of evaluation index more scientific. 参考文献 相似文献 引证文献

Variability of above-ground litter inputs alters soil physicochemical and biological processes: a meta-analysis of litterfall-manipulation experiments

Abstract. Global change has been shown to alter the amount of above-ground litter inputs to soil greatly, which could cause substantial cascading effects on below-ground biogeochemical cycling. Despite extensive study, there is uncertainty about how changes in above-ground litter inputs affect soil carbon and nutrient turnover and transformation. Here, we conducted a meta-analysis on 70 litter-manipulation experiments in order to assess how changes in above-ground litter inputs alter soil physicochemical properties, carbon dynamics and nutrient cycles. Our results demonstrated that litter removal decreased soil respiration by 34%, microbial biomass carbon in the mineral soil by 39% and total carbon in the mineral soil by 10%, whereas litter addition increased them by 31, 26 and 10%, respectively. This suggests that greater litter inputs increase the soil carbon sink despite higher rates of carbon release and transformation. Total nitrogen and extractable inorganic nitrogen in the mineral soil decreased by 17 and 30%, respectively, under litter removal, but were not altered by litter addition. Overall, litter manipulation had a significant impact upon soil temperature and moisture, but not soil pH; litter inputs were more crucial in buffering soil temperature and moisture fluctuations in grassland than in forest. Compared to other ecosystems, tropical and subtropical forests were more sensitive to variation in litter inputs, as altered litter inputs affected the turnover and accumulation of soil carbon and nutrients more substantially over a shorter time period. Our study demonstrates that although the magnitude of responses differed greatly among ecosystems, the direction of the responses was very similar across different ecosystems. Interactions between plant productivity and below-ground biogeochemical cycling need to be taken into account to predict ecosystem responses to environmental change.

Properly Timing Foliar-applied Fertilizers Increases Efficacy: A Review and Update on Timing Foliar Nutrient Applications to Citrus and Avocado

Foliar fertilization efficiently meets the nutrient demand of tree fruit crops during periods when soil conditions (low or high temperatures, low or excess soil moisture, pH, salinity) render soil-applied fertilizers ineffective, when nutrients (e.g., phosphate, potassium, and trace elements) become fixed in the soil, and when tree nutrient demand is high. Applying nutrients directly to leaves ensures that the metabolic machinery of the tree is not compromised by low availability of an essential nutrient. It should be noted that phloem mobile nutrients applied to the foliage are translocated to all tree parts, even feeder roots. Because foliar application of fertilizers can reduce nutrient accumulation in soil, runoff water, surface water (streams, lakes, ocean), and groundwater (drinking water supply), where they contribute to salinity, eutrophication, or nitrate contamination, with negative consequences to the environment and humans, it is highly desirable to replace soil-applied fertilizers at least in part with foliar-applied fertilizers. However, not all nutrients are taken up through leaves and, even if taken up, some nutrients are not phloem mobile. In addition, although foliar fertilizer rates are typically lower than soil fertilizer rates, application can be more costly. The goal has been to time the application of foliar fertilizers to key stages of citrus (Citrus sp.) and avocado (Persea americana) tree phenology when demand for the nutrient is likely to be high and especially when soil conditions are likely to compromise nutrient uptake by roots. This approach has proven successful for increasing yield, fruit size, and grower income even when the tree is not nutrient deficient by standard leaf analysis. Winter prebloom foliar-applied low-biuret urea was previously documented to increase total yield of both navel and ‘Valencia’ oranges (Citrus sinensis). Adaptation of this treatment to ‘Nules’ Clementine mandarin (Citrus reticulata) increased the yield of commercially valuable size fruit in two experiments. Foliar application of boron or low-biuret urea to ‘Hass’ avocado trees at the “cauliflower” stage of inflorescence development increased total yield; potassium phosphite applied at this stage of tree phenology increased the yield of commercially valuable size fruit.