Distribution Of Soil Nutrients Research Articles

Heterogeneous distribution of soil nutrients increase intra-specific competition in the clonal plant Glechoma hederacea

Small-scale heterogeneity strongly affects plant fitness and many ecological processes, and it can significantly influence the growth of individual plants, populations and communities. Generally, clonal species achieve significantly more growth when essential resources are patchily distributed than when resources are uniformly distributed. In this study, we aim to determine the effect of spatial heterogeneity in soil resources on intraspecific competition in the clonal plant Glechoma hederacea. We report the outcomes of a greenhouse experiment where high and low densities of plants were exposed to patchy and uniform distribution of nutrients. Our results showed that patchy distribution of resources exacerbated intra-specific competition between clonal systems. We found a reduction of total mass of clonal systems growing at high-density, especially under patchy conditions. Patchy distribution of resources conduct to high concentration of resources located in small areas, and as consequence increase the competition interaction between plants. This study demonstrates that full understanding of plant–plant competitive interactions requires consideration of spatial heterogeneity in nutrient supply.

Ecosystem properties self-organize in response to a directional fog-vegetation interaction.

Feedbacks between vegetation and resource inputs can lead to the local, self-organization of ecosystem properties. In particular, feedbacks in response to directional resources (e.g., coastal fog, slope runoff) can create complex spatial patterns, such as vegetation banding. Although similar feedbacks are thought to be involved in the development of ecosystems, clear empirical examples are rare. We created a simple model of a fog-influenced, temperate rainforest in central Chile, which allows the comparison of natural banding patterns to simulations of various putative mechanisms. We show that only feedbacks between plants and fog were able to replicate the characteristic distributions of vegetation, soil water, and soil nutrients observed in field transects. Other processes, such as rainfall, were unable to match these diagnostic distributions. Furthermore, fog interception by windward trees leads to increased downwind mortality, leading to progressive extinction of the leeward edge. This pattern of ecosystem development and decay through self-organized processes illustrates, on a relatively small spatial and temporal scale, the patterns predicted for ecosystem evolution.

Geostatistical analyses of spatial distribution and origin of soil nutrients in long-term wastewater-irrigated area in Beijing, China

The purpose of this study was to investigate the current status of soil fertility in the long-term wastewater-irrigated agricultural areas of Beiyechang District in the suburb of Beijing. A total of 103 soil samples from the top 20 cm of soil layer were collected and analyzed for macro- and micronutrient elements. The mean values of these elements were: total nitrogen (TN), 0.08 ± 0.02%; available nitrogen (AN), 60.34 ± 10.08 mg/kg; available phosphorus (AP), 19.59 ± 9.75 mg/kg; available potassium (AK), 84.22 ± 19.66 mg/kg; and availabilities of trace elements (B, Cu, Fe, Mn, Mo, and Zn), 0.29 ± 0.12, 1.44 ± 0.34, 8.97 ± 2.05, 5.44 ± 0.95, 0.27 ± 0.16, 1.16 ± 0.42 mg/kg, respectively. Compared with other similar areas, the overall soil nutrient content in the study area was still at a low level after nearly 30 years of wastewater irrigation. The organic matter content of wastewater-irrigated soils has significant impact on the accumulation of nutrient elements in these soils. Geostatistical analyses suggested that the spatial distribution of TN and AP was on account of agricultural practices, such as wastewater irrigation and fertilizer use. The availability of P, Mo, Cu and Zn may be due to the joint effect of soil parent material and wastewater irrigation. The availability of K, Fe and Mn was attributed to soil parent material. A significant availability of some elements occurred around sewage outfalls in the irrigation area and water canals, where the wastewater could be easily lifted. The knowledge of spatial distribution and sources of soil nutrients in such areas is the basis for undertaking appropriate farming and irrigation activities with rationalized utilization of treated wastewater.

Soil Nutrient Distribution Affected by Nitrogen Fertilization under Conventional Tillage System

The objective of this study was to examine the effect of nitrogen-fertilization management on soil nutrient distribution at different soil depths under conventional tillage in dryland rain-fed environment. Two nitrogen (N) application methods (single application with all N applied at planting and split application with 35 kg N ha−1 applied at planting and remaining N applied at V6 growth stage) and five N rates (0, 45, 90, 135, and 180 kg N ha−1) were utilized. Increasing soil depth decreased extractable phosphorus (P), potassium (K), and calcium (Ca) contents in the soil. The nitrate (NO3)-N concentration in deeper soil was similar to the top layer as N fertilization was greater than 90 kg N ha−1. It suggests that N application should be less than 90 kg ha−1 to reduce the movement of excess N to deep soil layers and cause a potential negative impact on environment in this area.

Effects of riparian vegetation patterns on the distribution and potential loss of soil nutrients: a case study of the Wenyu River in Beijing

A riparian ecosystem is an ecological transition zone between a river channel and terrestrial ecosystems. Riparian ecosystems play a vital role in maintaining stream health and bank stabilization. The types of riparian vegetation have changed greatly because of human activities along the Wenyu River. This study examines the impact of riparian vegetation patterns on water pollution due to soil nutrient loss. Four riparian vegetation patterns from the river channel to the upland were chosen as the focus of this study: grassland, cropland, grassland-cropland, and grassland-manmade lawn. The different distributions of soil nutrients along vegetation patterns and the potential risk of nutrient loss were observed and compared. The results showed that riparian cropland has the lowest value of total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), available phosphorus (AP), and organic matter (OM), but it has the highest soil bulk density (BD). The distributions of soil TN, TP, AN, AP, and OM exhibited a declining trend from the upland toward the river channel for riparian cropland, whereas a different trend was observed for the riparian grassland. The vegetation patterns of grassland-cropland and grassland-manmade lawn show that the grassland in the lower slope has more nutrients and OM but lower soil BD than the cropland or manmade lawn in the upper slope. So, the lower-slope grassland may intercept and infiltrate surface runoff from the upland. The lower-slope grassland has higher levels of soil TN, TP, AN, and AP, and thus it may become a new source of nutrient loss. Our results suggest that the management of the riparian vegetation should be improved, particularly in densely populated areas, to control soil erosion and river pollution.

Soil nutrient content influences the abundance of soil microbes but not plant biomass at the small-scale.

Small-scale heterogeneity of abiotic and biotic factors is expected to play a crucial role in species coexistence. It is known that plants are able to concentrate their root biomass into areas with high nutrient content and also acquire nutrients via symbiotic microorganisms such as arbuscular mycorrhizal (AM) fungi. At the same time, little is known about the small-scale distribution of soil nutrients, microbes and plant biomass occurring in the same area. We examined small-scale temporal and spatial variation as well as covariation of soil nutrients, microbial biomass (using soil fatty acid biomarker content) and above- and belowground biomass of herbaceous plants in a natural herb-rich boreonemoral spruce forest. The abundance of AM fungi and bacteria decreased during the plant growing season while soil nutrient content rather increased. The abundance of all microbes studied also varied in space and was affected by soil nutrient content. In particular, the abundance of AM fungi was negatively related to soil phosphorus and positively influenced by soil nitrogen content. Neither shoot nor root biomass of herbaceous plants showed any significant relationship with variation in soil nutrient content or the abundance of soil microbes. Our study suggests that plants can compensate for low soil phosphorus concentration via interactions with soil microbes, most probably due to a more efficient symbiosis with AM fungi. This compensation results in relatively constant plant biomass despite variation in soil phosphorous content and in the abundance of AM fungi. Hence, it is crucial to consider both soil nutrient content and the abundance of soil microbes when exploring the mechanisms driving vegetation patterns.

Effects of rotational infrastructure within pasture-raised pig operations on ground cover, soil nutrient distribution, and bulk density

Interest in pasture-based pork products has increased significantly in recent years. However, nitrogen (N) losses resulting from these systems are common due to importation of feed, high stocking rates, and pig behavior. This study was conducted to evaluate soil inorganic N, soil-test phosphorus (STP), ground cover, and compaction changes as impacted by rotational shade, water, and feed structures in a pasture-raised pig operation over two 12-week pig occupations. Shade and watering structures were rotated weekly for 12 weeks within a rotational (mobile) scheme; data were compared to a stationary structure system as well as to a managed hay operation with no pigs. Soil samples were acquired from subplots and analyzed for distribution of inorganic N concentrations among main plot treatments, including nitrate (NO3), ammonium (NH4), and STP values. Soil inorganic N concentrations were higher in exterior subplot positions than in interior positions. This pattern was not maintained after a second pig group occupied the plots. Soil test phosphorus was unaffected by either pig occupation. Ground cover percentages were higher in control (hay) treatments than for pig treatments, however no difference was found between mobile and stationary structure treatments in either pig occupation. Soil compaction, as measured by soil bulk density, was found to be higher under permanent shade structure locations as compared to mobile and control treatments. Mobile and control compaction levels were not different for the second occupation, utilizing a more intensive sampling scheme, suggesting a benefit to the rotation of shade, water and feed infrastructure. The weekly rotation of infrastructure performed during both occupations was both labor intensive and time consuming. The observed lack of improvement in nutrient distribution to a rotational infrastructure may limit its utility in pastured-pig systems. However, further options are available that would allow the production of pasture-raised pigs while minimizing associated nutrient loading and pasture degradation.

An Investigation on Spatial Variability of Selected Soil Parameters of Landscape under Mahogany in Wet Zone of Sri Lanka

Soils show a wide variability in their macro and micronutrient contents and distribution. Thespatial distribution of soil nutrients and physical parameters can be largely attributed tophysical, chemical, and biological processes that undergo in different rates and differentintensities in different localities. The availability of nutrients and the degree of interactionbetween these nutrients and the soil ultimately influence the vegetation that grows on aparticular soil. Although past literature has investigated the spatial variability of soilparameters and correlation of soil parameters with various agricultural crops, few studieshave examined such relationships in forest plantation landscapes. GIS has emerged as avaluable tool in visualizing and understanding spatial variability of soil parameters. Such soilparameter maps of large landscapes improve our understanding of the nature and extent ofnutrient problems, as well as aid in exploring their possible relationships with various sitefactors such as slope, physical features, moisture and temperature etc.The present study examined the spatial dependency of selected soil organic matters andnutrients on a 34-acre 8-year old mixed Mahogany stand in Wet Zone of Sri Lanka. Soilparameters of pH, Total Organic Carbon, Total Nitrogen, Ammonium Chloride extractable K,Ammonium Chloride extractable Mg, Ammonium Chloride extractable Ca was analysedusing soil samples collected following a systematic grid point sampling method (50m x 50mgrid).Accordingly, data from 44 soil sampling points were analysed using geostatistics andGIS techniques. Spatial distribution maps of above soil parameters were prepared in ArcMap9.3 environment. The relationships of above soil parameters with various site specificattributes such as elevation, soil texture, proximity to drainage systems/streams werestatistically examined.Results revealed that soil parameters tested show spatial heterogeneityalong the landscape while showing correlations with selected site attributes. Implications ofthe findings in management of Mahogany forest crop are also discussed.

石栎-青冈常绿阔叶林土壤有机碳和全氮空间变异特征

PDF HTML阅读 XML下载 导出引用 引用提醒 石栎-青冈常绿阔叶林土壤有机碳和全氮空间变异特征 DOI: 10.5846/stxb201401230170 作者: 作者单位: 中南林业科技大学生命科学与技术学院,中南林业科技大学生命科学与技术学院,中南林业科技大学生命科学与技术学院,中南林业科技大学生命科学与技术学院,中南林业科技大学生命科学与技术学院,中南林业科技大学生命科学与技术学院,中南林业科技大学生命科学与技术学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家林业局林业公益性行业专项项目（201304317）；国家自然科学基金资助项目（31170426） Spatial heterogeneity of soil organic carbon and total nitrogen concentrations in a Lithocarpus glaber-Cyclobalanopsis glauca evergreen broadleaved forest Author: Affiliation: Central South University of Forestry and Technology,Central South University of Forestry and Technology,Central South University of Forestry and Technolgy,,,, 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:在1hm2（100 m×100 m）石栎（Lithocarpus glaber）-青冈（Cyclobalanopsis glauca）常绿阔叶林内100个10 m×10 m小样方的中心位置，按0-10 cm、10-20 cm和20-30 cm土层采集土壤样品，测定土壤有机碳（C）和全氮（N）含量。基于区域化变量理论和地质统计软件（GS+ Version 9）的空间分析功能，应用地统计学的半方差函数定量研究该常绿阔叶林土壤有机C和全N的空间变异特征。结果表明：该林地土壤有机C含量平均值为18.61 g/kg，变化范围为9.53-39.40 g/kg，全N含量平均值为1.63 g/kg，变化范围为0.73-3.32 g/kg。土壤有机C半方差函数的理论模型符合球状模型，全N半方差函数的理论模型符合高斯模型。土壤有机C和全N的空间异质性主要是由结构性因素引起的，且空间自相关程度均为中等程度。分形维数反映了有机C和全N空间格局差异及尺度依赖特征，有机C分形维数较大，空间格局比全N略为复杂。采用Kriging插值方法，1hm2森林内土壤有机C和全N具有相似的空间分布格局，呈现明显的条带状和斑块状的梯度变化。土壤有机C含量与海拔、凹凸度呈负相关，但相关性不显著，与林地凋落物量呈极显著正相关。土壤全N含量与海拔、凹凸度呈显著负相关，与林地凋落物量呈正相关，反映出土壤N的淋溶特性。 Abstract:Subtropical evergreen broadleaved forests play an important role in regional carbon balance and sustainable development owing to their highest productivity, diverse ecosystem functions and complex habitat for abundant biological diversity in southern China. Spatial heterogeneity of soil nutrients in subtropical forests can provide useful information for understanding the spatial pattern of plants and for explaining to some extent, coexistence mechanism of diverse tree species. To investigate spatial variations in soil nutrients and the causes of the variations, soil samples at 0-10 cm, 10-20 cm and 20-30 cm depth were collected at the center of each 10 m×10 m quadrat within 1 hectare permanent plot of Lithocarpus glaber-Cyclobalanopsis glauca subtropical evergreen broadleaved forest. Soil organic C and total nitrogen (N) concentrations were determined for all samples. Based on regional variable theory and spatial analysis functions of GS+ Version 9, spatial heterogeneity of soil organic C and total N concentrations was examined by using semivariogram of geostatistics. The results showed that averaged soil organic C concentration was 18.61 g/kg, ranging from 9.53 to 39.40 g/kg, and the average value of total N concentration was 1.63 g/kg with a range between 0.73 and 3.32 g/kg. Theoretical semivariogram model of soil organic C approached spherical model while the best semivariogram model of total N was close to Gaussian model. The spatial variability of soil nutrient primarily resulted from the structural factors and the spatial heterogeneity degree of those indices was moderate. Fractal dimensions from log-log semivariograms quantitatively described spatial pattern differences and scale dependence of the soil organic C and total N. Fractal dimension was high for soil organic C, so soil organic C spatial structure had strong scale dependence with a complex spatial pattern. Kriging was used to analyze the spatial distribution of soil nutrients. Spatial distribution patterns of soil organic C and total N concentrations similarly revealed an apparent belt-shaped and spot massive gradient change. Within the plot, soil organic C concentration was negatively correlated with topographic factors (i.e. elevation and convexity), but the relationship was not significant. Soil organic C showed very significantly a positive relationship with litter biomass. Total soil N concentration exhibited a significant negative relationship with topographic factors, however, positive relationship was found between total soil N and litter, indicating leaching characteristics of soil N. Spatial variations in soil organic C and total N highlight the importance of vegetation and litter protection in the hilly area of subtropical China. 参考文献 相似文献 引证文献

Effect of net terrace biological bank on soil nutrients distributions along slope

网格式生物埂作为将水土保持生物措施与工程措施相结合的一种新型护坡技术, 对土壤养分特征和坡面分布规律有较大影响。本文采用野外调查和室内分析方法, 研究建设1~4年的黄花网格式生物埂对坡面土壤养分分布特点和分布规律的影响。结果表明: (1)网格式生物埂对土壤有机质含量和pH有显著改善作用, 随着建设年限的增加, 土壤pH逐渐降低, 而土壤有机质含量逐渐增大; 在不同坡位之间有机质含量表现为: 坡上>坡中>坡下, 与对照裸坡呈相反规律; (2)随着网格式生物埂建设年限的增加, 土壤全氮呈现先降低后增加的趋势, 且生物埂对于改善上坡位氮素含量效果较显著; 土壤碱解氮与全氮含量变化呈显著正相关, 且不同建设年限间生物埂土壤碱解氮含量在坡上和坡下位置差异均较显著; (3)生物埂建设1~3年, 相同年限的生物埂不同坡位的土壤全磷含量之间显著差异性规律不同, 但建设4年生物埂土壤全磷的坡面分布规律与对照完全相反, 表现为坡下>坡中>坡上, 且不同坡位差异达极显著水平(<i>P</i>=0.000); 有效磷含量随生物埂建设年限增加表现出一定的波动性, 变异系数达31.37%, 但相比对照平均值提高1.15~3.30倍, 而坡面分布随建设年限没有明显的变化规律; (4)网格式生物埂土壤全钾含量相比对照提高9.7%~28.2%, 但随着网格式生物埂建设年限的增加, 土壤全钾含量呈降低趋势; 生物埂能显著增加土壤有效钾含量, 且达到一定建设年限, 坡面不同位置土壤有效钾含量差异性显著增加。

Pasture grazing intensity and presence or absence of cattle dung input and its relationships to soybean nutrition and yield in integrated crop–livestock systems under no-till

In integrated soybean–beef cattle systems, the pasture grazing intensity affects the grain crop performance in succession. In addition, the dung cattle input influences the soil nutrients distribution in the field affecting the grain crop yield. This experiment aims to evaluate the effects of winter pasture heights and cattle dung input in soybean crop performance in succession. Main soil macronutrient content, soybean plant population, dry shoot biomass, plant height, plant nutrient content, soybean yield and yield components were assessed in the 10th experimental year. The experiment was conducted in the state of Rio Grande do Sul, Southern Brazil, in a long-term integrated crop–livestock systems implemented in 2001. Treatments were arranged in a split plot design with four pasture heights (0.10, 0.20, 0.30, and 0.40m) and two levels of dung input (with or without). For all the variables analyzed, there was no interaction between pasture heights and cattle dung input (P>0.05). The pasture height management had only effect in soil P content, soybean dry biomass production, plant height and number of grains per pod. The increase in grazing intensity was associated to the rise in soybean plant height and dry mass production but was without effect on grain yield. The presence of grazing animals in the integrated soybean–beef cattle systems, and the resultant augmentation of dung input increased by 122% and 38% the availability of soil K and P, respectively in relation to the absence. Thus, the content of such nutrients in the plant were increased in 41% and 7%, respectively. The improvement in soybean nutrition increases the amount of pods per plant by 20%, and resulting in a 23% increase in soybean yield. These results indicate that cattle dung input resulting from grazing animals in the pasture phase increased soybean grain yield due to better plant nutrition. Although, the occurrence of cattle dung was very concentrated in some spots of the field and thus future studies should address strategies to improve spatial distribution of cattle dung input.

Root morphological responses to localized nutrient supply differ among crop species with contrasting root traits

Background and aims Roots have morphological plasticity to adapt to heterogeneous nutrient distribution in soil, but little is known about crop differences in root plasticity. The objective of this study was to evaluate root morphological strategies of four crop species in response to soil zones enriched with different nutrients.

Islands of Fertility: A Byproduct of Grazing?

Empirical work in arid shrubland systems has documented a distinct spatial pattern of soil nutrient distribution, with higher concentrations of nutrients under shrub canopies compared to bare ground interspaces between shrubs. This “fertile island” pattern is considered characteristic of arid ecosystems. However, recent work at a desertified shrubland site reported no island of fertility pattern for nitrogen inside a long-term grazing exclosure despite a strong fertile island pattern outside the exclosure, leading to a hypothesis that the pattern may be associated with grazing. In this paper we examine this hypothesis in two ways. First, we collected soil nitrogen data inside and outside two long-term livestock exclosures. Second, we examined published work on the fertile island pattern for nitrogen, phosphorus and carbon, and its association with livestock grazing. At the field sites, there was a strong fertile island pattern for soil nitrogen in the grazed area outside each exclosure but no fertile island pattern in the ungrazed area inside the fence. From the literature, we identified 49 studies, which represent 99 cases that examine differences in soil nutrients under and between shrubs (that is, tests of the fertile island pattern). In 92 cases, fertile islands were present for at least one of the nutrients. All cases where livestock grazing was present exhibited fertile island patterns for nitrogen and most did so for carbon and phosphorus. In contrast, fertile islands were less consistent where livestock grazing was absent; all nine cases that had been ungrazed for more than 30 years did not exhibit fertile islands for nitrogen. Our empirical data and literature review suggest that the fertile island pattern may be an artifact of grazing rather than an inherent property of arid shrublands. Further, we suggest that the grazing history of a site needs to be explicitly considered when documenting spatial patterns of soil nutrients in arid systems. This has significant implications for our understanding of soil nutrient dynamics in arid systems, the management of rangelands, and the potential for reversal of desertification.

Effects of Ecological Projects on Grassland Soil Physicochemical Properties in Three-River Headwater

The depth variations of soil physicochemical properties in the degraded native grasslands and the artificially restored grasslands were studied in the Three-river headwater areas of Qinghai-Tibetan plateau, China. The results showed: (1) With the increase of the gradient of restoration years, soil water content, total chemical properties, total potassium, phosphorus, available phosphorus and potassium were increased thereafter in the artificial grasslands. (2) With the increase of grassland degradation gradient, soil water content was gradually reduced, and the total N, K, the organic matter didnt gradually reduced also. (3) Both restoration years and degradation degree didnt influence the nutrient distribution in soil. (4) The organic matter, total N and K of degraded grassland were increased by artificial grassland construction. Therefore, artificial grassland construction canbe used as an effective measure of ecological projects in the Three-river headwater area.

Application of GIS Technique in the Distribution of Nutrients in Tropical Arable Land: A Case Study of Longjiang Farm, Hainan Island

Exploring the distribution of soil pH and nutrients are significant to the sustainable development of tropical agricultural growth. Taking Longjiang Farm in Hainan province as the research plot, and exploring the distribution characteristics of soil nutrients in study area by applying the GIS spatial analysis tools. The results indicated that the soil is acidic and the contents of soil nutrients are varied significantly in research area. The spatial distributions of available Ca, available Mg, available Cu and available Zn were mainly determined by the distributions of soil parent materials. The contents of soil organic matters and total N are escalated gradually from north to south in study area. The spatial analysis tools can be applied to explore the distribution of soil nutrients in areas, which is significant to the regional agricultural planning.

Long-term effect of different soil management systems and winter crops on soil acidity and vertical distribution of nutrients in a Brazilian Oxisol

“Strategies” to sustain crop productivity by reducing the fertilizer and lime demands must be developed. The use of plant species that use more efficiently the soil nutrients and tillage systems that provide nutrients accumulation in more labile forms are prerequisites for sustainable agroecosystems. This study aimed to evaluate the long period effect of cultivating different winter species under different soil management systems on vertical distribution of soil nutrients and the soil acidity distribution in soil profile. The experiment was established in 1986 with six winter treatments (blue lupine, hairy vetch, oat, radish, wheat and fallow) under conventional tillage (CT) and no-tillage (NT) in a very clayey Rhodic Hapludox in Southern Brazil. As a result of 19 years of no soil disturbance, soil chemical attributes related to soil acidity and the availability of P and K were more favorable to crops growth up to 10cm in the soil under no-tillage than in the conventional tillage. On other hand, lime applications in low doses on the soil surface were not efficient in neutralizing the aluminum toxicity below 10cm depth. It shows that repeated use of lime on the soil surface under NT system can be a viable alternative strategy only when soil acidity and aluminum toxicity in subsurface has been previously eliminated using the adequate amount of lime and incorporating it into the arable layer. Moreover, in the conventional tillage system P and K availability were higher below 10cm depth compared to the no-tillage system. Even after 19 years of no soil disturbance in the NT system the available P content below 10cm soil layer was lower than the optimal content of available P recommended to cash crops. The reduced surface K application over time was sufficient to gain adequate crop yields and to maintain the optimal content of soil available K in both soil management systems. The effects of soil management systems were predominant on the soil acidity attributes, and no effects of winter cover crops were observed on soil acidity attributes. Black oat and blue lupine were more efficient in P cycling, increasing the soil available P content especially in the surface soil under NT. The lower amount of biomass produced over time when no cover crops were used in the winter period resulted in lower P and K availability in the soil, showing the important role of growing winter species to maintain soil fertility.

The effects of earthworms, botanical diversity and fertiliser type on the vertical distribution of soil nutrients and plant nutrient acquisition

The application of phosphorus (P)-based fertiliser to agricultural soils can result in a skewed vertical distribution of P down the soil profile, since the element tends to accumulate at the soil surface. Such accumulation can have detrimental effects on the environment, as the erosion of surface soil can facilitate the transfer of large quantities of P out of the field into water bodies. Earthworm and plant communities are intricately linked to vertical nutrient distributions in soil, with both communities either facilitating or negating the incorporation of nutrients into the soil matrix. This study aimed to investigate the effect of earthworm presence, plant community structure and fertiliser type to affect the distribution of nutrients in experimental mesocosms; with particular emphasis on the vertical distribution of P. Mesocosms were designed to simulate a soil which has a high P concentration at the surface compared to further down the soil profile. It was hypothesised that the presence of earthworms would facilitate the incorporation of P into the soil matrix and the presence of a more botanically diversity community would assimilate a greater quantity of soil nutrients. After 1 year, mesocosms were deconstructed into five depth ranges, and the distribution of nutrients were modelled and analysed. Results indicated that the presence of earthworms did redistribute soil nutrients from the surface into the matrix beneath. This redistribution was apparent from a reduction in nutrient concentrations in the 0–1 cm depth range. The presence of a more botanically diverse community not only assimilated greater soil nutrient concentrations, but also promoted a less even vertical distribution of soil nutrients, demonstrating the importance of soil biota and plant diversity in the redistribution of soil nutrients.

Spatial Distribution of Soil Organic Matter and Nutrients in the Pear Orchard Under Clean and Sod Cultivation Models

The soil organic matter and nutrients are fundamental for the sustainability of pear production, but little is known about the spatial distribution of soil organic matter and nutrients in a pear orchard. With the soil of the pear (cv. Dangshansu on P. betulifolia Bunge. rootstock) orchard under clean and sod cultivation models as test materials, the experiment was conducted to evaluate spatial variability of soil organic matter (SOM), total nitrogen (STN), total phosphorus (STP), total potassium (STK), available nitrogen (SAN), and available potassium (SAK) in and between rows at different soil depths (0–60 cm). The SOM, STN, STP, STK, SAN and SAK of the different soil layers under the two tillage models were different in the vertical direction. The SOM, STN, STP and SAN in the 0–20 cm soil layer were higher than those in the 20–40 and 40–60 cm soil layers. The STK of 40–60 cm soil layer was higher than that in the 0–20 and 20–40 cm soil layers. The STK increased with the depth of soil in the vertical direction in the clean cultivated pear orchard. Variability of the SOM, STN, STP, STK, SAN and SAK of sample sites in between rows of the same soil layer was found in the pear orchard soil in the horizontal direction under clean and sod cultivation management systems, except that STK of all sites did not show the difference in identical soil layers in the pear orchard under clean cultivation. The sod cultivation model improved the SOM, STN, and STK in the 0–20 cm soil layer in the pear orchard, and the three components increased by 12.8, 12.7 and 7.3% compared to clean cultivation, respectively. The results can be applicable to plan collection of orchard soil samples, assess orchard soil quality, and improve orchard soil management practices.

Tree species and earthworm effects on soil nutrient distribution and turnover in a northeastern United States common garden

Differences in soil nutrients beneath different tree species are often attributed to the impacts of species-level patterns of nutrient uptake and litter chemistry. However, in naturally established forests it is difficult to isolate tree species' influence on soil development from differences in underlying soil properties that can affect tree species establishment. To discern the impacts of tree species on soil properties, we investigated how Norway spruce (Picea abies (L.) H. Karst.), red oak (Quercus rubra L.), and sugar maple (Acer saccharum Marshall) influence the distribution of carbon, nitrogen, and calcium in a 67-year-old common garden. We expected these species would produce foliar litter with contrasting chemistry, resulting in corresponding variation in organic matter (OM) turnover and nutrient accumulation in soils. Instead, we found that forest floor mean residence time correlated negatively with earthworm density and did not correlate with any measurement of litter chemistry. Red oak exhibited the fastest OM turnover and highest earthworm densities and Norway spruce showed the greatest OM accumulation and fewest earthworms. These findings suggest that future changes in earthworm invasion and forest tree species composition may have strong implications for ecosystem nutrient cycling and retention.

Study on Spatial Distribution of Soil Nutrients and Comprehensive Evaluation of Nutrients in Low Mountain-Hilly Region of Sichuan Province, China

It is generally accepted that to overuse fertilize can led to cause fertilize resource waste, increase agriculture production cost, reducing the quality of agricultural products, and cause agricultural non-point source pollution. Determining soil nutrient distribution is critical to identify sites which are at risk of N, P and K nutrition loading. In order to know the soil nutrition spatial distribution and to determine agricultural rational fertilization, a total of 98 soil samples from the plow layer (0-20 cm) were collected in low mountain-hilly region of Sichuan Province, China. Spatial variability and distribution of soil organic matter (SOM), total N (TN), available nitrogen (AN), available phosphorus (AP) and available potassium (AK) in agricultural soils were studied using geographic information system (GIS) software. And the analytical hierarchy process (AHP) was used to determine the weight of indexes by using quantitative analysis.