Acid Sandy Soils Research Articles

Sewage sludge compost as an alternative source of phosphorus to rye in acidic sandy soil

Today, the use of chemical fertilisers is significantly determined by their production and purchase costs, which are high. In contrast, phosphorus (P) is present in sewage sludge in a form that is easy for plants to absorb. Good quality sewage sludge compost (SSC) could contain a high quantity of P, together with other macro- and microelements and organic matter. The effect of regular SSC application on soil characteristics as well as plant parameters has been studied since 2003 in Nyíregyháza in a small plot experiment. Focusing on the P in the soil-plant system, our hypothesis was that SSC covers plants’ P demand through enhancing soil P content and its plant availability in the acidic sandy soil. The effect of the SSC was examined at the doses of 0, 9, 18, and 27 t ha-1 on rye as a test crop. Some soil chemical parameters (pH, soil organic matter - SOM, ammonium lactate (AL) extractable P2O5), and the relationship between plant development (green weight, shoot length), physiological parameters (SPAD index), plant shoot P content, and soil available P content were studied. The obtained data indicated that the SOM content, pH, and available P content of the treated plots increased as a result of the long-term applied SSC compared to the control. Measurement of the relative chlorophyll content showed a strong correlation with the available P content of the soil, but surprisingly less correlation with shoot P content was found. The results of plant biomass and soil P content proved that SSC could be used as a low-cost and good source of P for plants.

Effect of soil nutrient management on soil weed seed bank dynamics across a soil fertility gradient in smallholder farms, Eastern Zimbabwe

Weed seed banks are latent biotic stress contributors to low crop production among smallholder farms. The objective of this study was to investigate effect of repeated soil nutrient amendments on weed seed bank dynamics in eastern Zimbabwe. Soil samples were taken from three farms with low, medium and high soil organic carbon (SOC) along the catena. Sampled treatments included varying combinations of compound D (7%N, 14%P, 7% K) fertiliser, cattle manure and lime. Weeds that emerged per plot were counted by species and data was tested for normality before running a linear mixed-effects model and Restricted Maximum Likelihood. Principal Component Analysis (PCA) was performed to establish the relationship between seasons, SOC, soil nutrient amendment, and emerged weeds. Significant (p < .05) species richness (Margalef index), and Shannon Weiner index were recorded in the medium (6.4g kg-1soil), high (8 g kg-1 soil) and low (< 3.9 g kg-1soil) SOC. Weed species emergence was significantly (p < .05) influenced by the level of SOC along the catena positions, representing results from the source. Emergency and abundance of weeds such as Richardia scabra, was associated with low SOC acidic sandy soils from the upper catena. However, application of nutrients (NPK+lime treatment) reduced weed species counts from 1.96±0.12 to 1.4±0.12. Cattle manure and NPK+CM treatments recorded significantly higher weed emergence, and weed biomass; compared to the control. Clearly, cattle manure treatments significantly increase the soil weed seed bank; thus, weeding intensity is likely to increase in cattle manure treated fields.

Effect of Different Herbicides on Development and Productivity of Sweet White Lupine (Lupinus albus L.)

White lupine (Lupinus albus L.) is a well-known green manure crop in Hungary, but the production of seeds can be badly impacted by weeds. The sweet white lupine ‘Nelly’ was grown on acidic sandy soil, and experimental plots were treated with different herbicides. Flumioxazin (0.06 kg ha−1), pendimethalin (5 L ha−1), dimethenamid-P (1.4 L ha−1), pethoxamid (2 L ha−1), clomazone (0.2 L ha−1), metobromuron (3 L ha−1), and metribuzin (0.55 L ha−1) were applied pre-emergence (1–2 days after sowing). Imazamox was also tested and applied post-emergence (1 L ha−1) when some basal leaves were clearly distinct (BBCH 2.3). In this paper, the weed control efficiency and the phytotoxicity of herbicides applied to lupine are examined. Vegetation index datasets were collected 12 times using a manual device and 2 times using an unmanned aerial vehicle (UAV). The phytotoxicity caused by herbicides was visually assessed on several occasions throughout the breeding season. The frequency of weed occurrence per treatment was assessed. The harvested seed yields, in kg ha−1, were analyzed after the seeds were cleaned. The herbicides metribuzin and imazamox caused extensive damage to white lupine. While pendimethalin, dimethenamid-P, pethoxamid, and clomazone were outstanding in several measured indicators, the final ranking which summarizes all the variables showed that only the pethoxamid and clomazone treatments performed better than the control. Metribuzin and imazamox were highly phytotoxic to white lupine. In the future, it would be appropriate to integrate more post-emergence active substances into trials, and the pre-emergence herbicides involved in this study should be further tested.

Exploring the Combined Effects of Different Nitrogen Sources and Chabazite Zeolite-Tuff on Nitrogen Dynamics in an Acidic Sandy-Loam Soil

Volcanic tuffs rich in chabazite zeolites have been extensively examined for their potential to enhance soil properties and increase fertilizer efficiency, both in their natural state and when enriched with nitrogen (N). However, there is a scarcity of data regarding their utilization in acidic sandy soil, particularly when used alongside organic fertilizers. This paper presents the findings of a 50-day laboratory incubation study that investigated the dynamics of N pools in an acidic sandy-loam agricultural soil treated with various N sources. These sources included urea, N-enriched chabazite zeolite tuff, and pelleted composted manure applied at a rate of 170 kg N/ha. Additionally, the N sources were tested in combination with chabazite zeolite tuff mixed into the soil to assess its role as a soil conditioner. The results revealed distinct behaviours among the tested N sources, primarily impacting soil pH and N dynamics. Soil fertilized with manure exhibited slow N mineralization, whereas N-enriched zeolite displayed a more balanced behaviour concerning net NO3−-N production and NH4+-N consumption. Both N-enriched zeolite and urea temporarily altered the soil pH, resembling a “liming” effect, while pelleted manure facilitated a prolonged shift towards neutral pH values. Considering the water adsorption capacity of zeolite minerals, caution is advised when adjusting water content and employing combustion methods to measure soil organic matter in zeolite-treated soil to avoid potential inaccuracies. In summary, N-enriched chabazite zeolite tuff emerged as a valuable N source in acidic sandy-loam soil, offering a promising alternative to synthetic fertilizers and showcasing a sustainable means of N recycling.

Response of peanut to foliar application of molybdenum and seed inoculation with Bradyrhizobium spp. in Cerrado region, Brazil

The adoption of sustainable technologies that optimize biological nitrogen fixation (BNF) by peanut crops is essential to improve plant growth and ensure high grain yield potential. A study was conducted to investigate the efficiency of inoculation with Bradyrhizobium spp. and foliar application of molybdenum (Mo) in improving the productive response of peanut crop (Arachis hypogaea L., cv. IAC Tatu ST) in moderately acidic sandy soil (pH 5.0) of the Cerrado region, Brazil during two growing seasons (2016/2017 and 2017/2018). Treatments consisted of uninoculated seeds (control) and inoculated with Bradyrhizobium spp. and foliar application of Mo at five rates (0, 25, 50, 100, and 150 g Mo ha−1). These treatments were arranged in a randomized block design in split plots with four replicates. Nodulation, shoot dry matter, leaf N concentration, and peanut grain yield were significantly high in plants inoculated with Bradyrhizobium spp. in both growing seasons. The grain yield increased by 13% and 12% with the inoculation of Bradyrhizobium spp. compared with non-inoculated plants in the 2016/2017 and 2017/2018 seasons, respectively. Plants fertilized with Mo showed higher root nodulation, leaf N concentration, and shoot dry matter production than control plants in both growing seasons. However, the crop grain yield was significantly high (24%) only in the 2016/2017 season in plants fertilized with Mo. The optimal rate of foliar Mo application in peanut plants cultivated in sandy soils varies from 80 to 100 g of Mo ha−1. Due to improved root nodulation, N uptake, plant growth, and higher crop grain yield, rhizobium inoculation and foliar application of Mo are sustainable agricultural practices that should be recommended for peanut growers.

The Effect of Heating on Properties of Sandy Soils

Although burning grass and crop residues is prohibited in many countries, farmers perceive it as a quick and inexpensive way to eliminate unwanted biomass. The aim of this study was to estimate the impact of heating temperature (simulation of biomass burning) on the studied properties (soil organic carbon (SOC) content, pH(H2O), water drop penetration time, WDPT, and contact angle, CA) of acidic sandy soils. Soil samples were taken from the experimental sites S1, S2, and S3 at Studienka village in the Borská nížina lowland (southwestern Slovakia). Experimental site S1 was arable land, experimental site S2 was arable land abandoned for approximately 10 years, and experimental site S3 was arable land abandoned for approximately 30 years with scattered Scots pine (Pinus sylvestris L.) trees. It was found that all the soil properties studied were strongly affected by heating. A drop in SOC was observed in all the soils for the heating temperature between 20 and 600 °C. Due to the incomplete combustion of SOC, a small (0.1–0.7%) SOC content was recorded even in soils heated to between 600 and 900 °C. An increase in pH(H2O) was observed in all the soils for the heating temperature higher than 300 °C. Soil from the experimental site S1 was wettable (WDPT < 5 s) for all of the heating temperatures. WDPT vs. heating temperature relationships for the soils from the experimental sites S2 and S3 were more complex. After a decrease in the heating temperature of 50 °C, an increase in WDPT for the heating temperature between 50 °C and 300 °C (for S3 soil) and 350 °C (for S2 soil) was registered. Finally, the WDPT dramatically dropped to 0 for the heating temperature of 350 °C (for S3 soil) and 400 °C (for S2 soil). CA started to decrease at 300 °C in all the soils and dropped to 0° for all the soils at 800 °C. CA > 0° measured in soils for the heating temperature between 400 and 800 °C, as a consequence of the small SOC contents due to the incomplete combustion of SOC, is a novelty of this study which demonstrates that CA is more sensitive to the changes in subcritical water repellency than WDPT.

Additional phosphorus intensity analysis needed to identify phosphorus requirement on acid sandy soils with high Olsen-P contents

Meeting the crops requirement for phosphorus (P) is crucial to reach the yield potential. Therefore, it is essential to determine soils´ ability to supply the crop with P to identify soils in need of P fertilization and to know where P fertilization is redundant. Thirty-two field experiments with increasing rates of mineral P fertilizers (0, 7.5, 15, 30 and 60 kg P ha−1) to spring barley were carried out from 2020 to 2022 on sandy soils developed on marine or non-marine deposits in Jutland, Denmark. Soil P extraction methods representing both intensity (P extracted with demineralized water, P-water or 0.01 M calcium chloride, P-CaCl2) and quantity tests (P extracted with 0.05 M sodium bicarbonate, Olsen-P) were evaluated by their relationship with relative yields. The examined soils had pH values between 4.6 and 6.7 and total P contents between 305 and 1309 mg P kg−1 soil. Yield increased after P fertilization on twelve soils in Northern Jutland (relative yields < 90 %). Yield responsiveness occurred in all three experimental years despite differences in precipitation and temperatures among the years. Olsen-P contents were not related to yield response, and all responsive soils had moderate or high soil P status according to the Olsen-P test (>20 mg P kg−1 soil). Contents of P-CaCl2 were significantly related to the relative yields (R2 =0.39), and slightly more of the variation in relative yields was explained by the P-CaCl2 to Olsen-P ratio (R2 =0.43). Ten of the twelve response soils were detected with the suggested critical threshold value of 0.02 for the P-CaCl2 to Olsen-P ratio. Soils responsive to P fertilization on older marine (Yoldia) and moraine deposits had higher contents of amorphous aluminium oxides determined by oxalate extraction than the non-responsive soils (+41 mmol mmol kg−1), whereas four lowland soils on younger marine (Litorina) deposits responded to P-fertilization despite low contents of oxalate extractable aluminium. We conclude that an additional P intensity test with CaCl2 extraction offered a much better identification of acid sandy soils requiring P fertilization than relying on the Olsen-P test alone.

Improving acidic sandy soil properties for plant growth with dam reservoir sediments in the face of soaring fertiliser prices

Recent actions aimed at creating an environmentally sustainable economy, as well as very high inorganic fertiliser prices, have begun a ‘renaissance’ of alternative fertilisation. It includes utilisation of dam reservoir (DR) sediments. The aim of our study was to evaluate the agricultural value of non-toxic material to be dredged from a dam reservoir in the face of changing mineral fertiliser prices. The quality of sediments was established based on pot experiment: four different sediment dosages (5 %, 10 %, 20 %, 40 %) and three plants in rotation (maize, mustard and grass mix) were tested. Application of DR sediments into sandy soil improved its texture (depending on dose 4–31 % less sand, 50–412 % more silt and 40–70 % more clay) and sorption properties, increased pH (the soil was acidic). The content of total organic carbon increased 1.4–4.3 times, total nitrogen (N) 1.4–4.7 times, ammonium nitrogen 1.3–5.2 times, nitrate nitrogen 1.7–11.8 times, total phosphorus (P) ∼1.4 times and available phosphorus ∼2.0; most changes were statistically significant. Yield of all three plants increased significantly correspondingly to the sediment application. It shows that DR sediments might be a good alternative to chemical fertilisers. Since the catchment of the analysed reservoir is mostly agricultural, N and P compounds accumulated in sediments originated from farming. Therefore, using DR sediments as fertilisers closes the cycle of these elements; N and P compounds can be used by plants. Additionally, this alternative fertiliser is cheap – since the analysed reservoir has to be dredged, large amounts of sediments will be obtained as a ‘side-effect’ of this process. Agricultural application of this nutrient-rich material would transform sediments from waste into a resource. Recent steep increase of mineral fertilisers prices – in Poland, the prices in 2022 were 2–3 times higher than in 2018 – showed that we have to diversify fertiliser sources. Low cost, ecological sustainability and good physical and chemical properties make DR sediments, if not a substitute, a good addition to the traditional methods of agricultural fertilization.

Effects of soil amendments on soil acidity and crop yields in acidic soils: A world-wide meta-analysis

Soil amendments, including lime, biochar, industrial by-products, manure, and straw are used to alleviate soil acidification and improve crop productivity. Quantitative insight in the effect of these amendments on soil pH is limited, hampering their appropriate use. Until now, there is no comprehensive evaluation of the effects of soil amendments on soil acidity and yield, accounting for differences in soil properties. We synthesized 832 observations from 142 papers to explore the impact of these amendments on crop yield, soil pH and soil properties, focusing on acidic soils with a pH value below 6.5. Application of lime, biochar, by-products, manure, straw and combinations of them significantly increased soil pH by 15%, 12%, 15%, 13%, 5% and 17%, and increased crop yield by 29%, 57%, 50%, 55%, 9%, and 52%, respectively. The increase of soil pH was positively correlated with the increase in crop yield, but the relationship varied among crop types. The most substantial increases in soil pH and yield in response to soil amendments were found under long-term applications (>6 year) in strongly acidic (pH < 5.0) sandy soils with a low cation exchange capacity (CEC, <100 mmolc kg−1) and low soil organic matter content (SOM, <12 g kg−1). Most amendments increased soil CEC, SOM and base saturation (BS) and decreased soil bulk density (BD), but lime application increased soil BD (1%) induced by soil compaction. Soil pH and yield were positively correlated with CEC, SOM and BS, while yield declined when soils became compacted. Considering the impact of the amendments on soil pH, soil properties and crop yield as well as their costs, the addition of lime, manure and straw seem most appropriate in acidic soils with an initial pH range from <5.0, 5.0–6.0 and 6.0–6.5, respectively.

Ammonium Fertilization Enhances Nutrient Uptake, Specifically Manganese and Zinc, and Growth of Maize in Unlimed and Limed Acidic Sandy Soil

Although NH4+ fertilization is known to acidify rhizosphere and enhance nutrient uptake, the effects on a nutrient-sufficient acidic soil amended with lime are not demonstrated. Thus, the influence of NH4+ fertilization of an unlimed and limed (3 g calcium carbonate per kg soil) acidic soil on the nutrient uptake and growth of maize was studied in comparison to NH4NO3 fertilization. The pH of limed rhizosphere soil was about two units higher than that of the unlimed soil. The maize plants were grown in pots under greenhouse conditions for about two months. The results showed that the pH of the NH4+-fertilized unlimed and limed soil was 0.54 and 0.15 units lower than the NH4NO3-fertilized soil. Liming negatively affected shoot and root dry matter production, whereas the NH4+-fertilized plants produced higher dry matter than the NH4NO3-fertilized plants, with significant difference of 28% in the limed soil only. Liming decreased Fe concentration in rhizosphere soil from 99 to 69 mg kg−1 and decreased plant-available Mn the most (71%), whereas the NH4+-fertilized unlimed and limed soil had 48% and 21% higher Mn concentration than the respective NH4NO3-fertilized soils. Similarly limed rhizosphere soil had 50% lower plant-available Zn concentration than the unlimed soil, and the NH4+-fertilized soil had an 8% higher Zn concentration than the NH4NO3-fertilized unlimed soil. The liming negatively affected P, K, Mn, and Zn concentrations and contents in maize shoot to a lower degree in the NH4+-fertilized soil, whereas the positive effect of NH4+ on the nutrient concentration and contents was vigorous in the unlimed soil than the limed soil. It is concluded that NH4+ fertilization could be beneficial in enhancing nutrient uptake and growth of maize in both acidic and alkaline soils, despite the higher inherent plant-available concentrations of the nutrient in soil.

Weed control and highbush blueberry tolerance with indaziflam on sandy soils

AbstractNorthern highbush blueberry is an important fresh market product in New Jersey where the plant was first domesticated in the early 20th century. Because of the short period for safely and timely applying postemergence (POST) herbicides, reliance on residual herbicides that provide season-long control of weeds is essential for blueberry growers to minimize the detrimental effect of weed competition on berry yield and quality and bush growth. Field studies were conducted from 2018 to 2020 in Chatsworth, New Jersey, on ‘Bluecrop’, ‘Duke’, and ‘Elliott’ blueberry cultivars growing on sandy acidic soil to evaluate weed control and crop tolerance in response to repeated annual applications of indaziflam at 73 or 146 g ai ha−1 applied in fall or spring. The efficacy of indaziflam treatments were compared to those of fall-applied dichlobenil at 3,300 g ai ha−1 or a spring-applied mix of diuron at 1,800 g ai ha−1, oryzalin at 3,360 g ai ha−1, and mesotrione at 210 g ai ha−1. Indaziflam at the currently labeled rate of 73 g ai ha−1 provided ≥85% and season-long control of horseweed, Canadian toadflax, and large crabgrass with fall applications on dormant blueberry, whereas spring applications were less effective. Whereas minor (≤8%) and transient leaf crinkling was noted in response to spring-applied indaziflam at 146 g ai ha−1, a fall application never caused leaf crinkling greater than that observed in the nontreated weedy and weed-free controls, regardless of rate. No negative effects on plant growth or fruit production were observed from indaziflam applied at 73 or 146 g ai ha−1 in fall or spring. Findings of this study suggest that indaziflam applied at 73 (1× commercial use rate) and 146 g ai ha−1 is safe to use on blueberry grown on New Jersey sandy acidic soils despite restrictions for using this herbicide on such soils.

Synergistic Effect of Multiple Metals Present at Slightly Lower Concentration than the Australian Investigation Level Can Induce Phytotoxicity

An individual trace metal present in a soil at its ecological screening value or investigation level (trigger/threshold) is expected to cause phytotoxicity. However, phytotoxicity may be induced by a mixture of multiple metals, each present at a concentration lower than the corresponding investigation level. To investigate the accumulative impact of metals present below their individual investigation levels, three successive phytotoxicity trials were conducted in a greenhouse using the triticale plant CrackerJack (Triticosecale rimpaui), a cereal crop, in a sandy acidic soil treated jointly with Cd, Cu, and Zn at various rates. Seed germination and seedling growth were monitored. The metal rates in the first two trials were either too toxic or nontoxic. In the third trial, it was found that the mixture of Cd, Cu, and Zn at rates of 2.5, 97.5, and 188 mg kg−1, respectively, did not affect seed germination, but caused a slight reduction in plant growth. Although metal concentrations used were lower than the Australian Ecological Investigation Level (Urban) for Cd, Cu, and Zn, which are 3.0, 100, and 200 mg kg−1, respectively, the reduction occurred due to synergy. It was concluded that, to enhance the usefulness of environmental investigation limits, the synergistic effects of multiple metals present at levels slightly below the established limits must be considered.

Can Organic Matter from Waste-Derived Amendments Limit Phosphorus Losses from Soil to the Aquatic Environment?

When introducing innovative waste-derived amendments, their potential impact on soil retention capacity towards phosphorus (P) should be accounted for to limit its losses and thus water eutrophication. The study was aimed at evaluating P sorption properties of organic waste-derived amendments conifer woodchip biochar (BIO) and brown coal waste (BCW), and assessing their impact on P sorption properties in soil five years after their application in terms of limiting P losses from soils to the water sources. In batch tests samples of amendments and sandy acid soil (Haplic Luvisol) were exposed for 24 h to balancing solutions with a different P content, respectively 0–80 mg P L−1 for amendments and 0–20 mg P L−1 for soil. Three treatments were studied: (1) conifer woodchip biochar (BIO, (2) brown coal waste (BCW) and (0) soil without amendment (control). Organic amendments were applied to soil at a rate equivalent of 10.2 t C ha−1 once at the start of the trial and they amounted to 24.2 t ha−1 for BCW and 12.8 t ha−1 for BIO. Based on the results of the bath tests and the Langmuir and Freundlich equations, sorption parameters of P were determined for BIO, BCW and the soil after their application. The maximum sorption capacities (Smax) of BIO and BCW were 832.3 and 250.4 mg kg−1, respectively, and were controlled mainly by the organic surfaces of their structures. Within the range of concentrations used in the balancing solutions (5–20 mg P L−1), sorption of P was generally higher in unfertilized soil compared to soil amended with BCW and BIO. The application of BIO significantly (p &lt; 0.05) decreased the Smax (17%), while BCW decreased the bonding energy of P (k) by 15% compared to the untreated soil. The content of dissolved P increased significantly in the case of both BCW and BIO applications, which may indicate an increase in soil susceptibility to P losses. However, the effectiveness of these amendments in limiting P losses with the use of other doses and in different soil and climatic conditions cannot be excluded. Further research is recommended to better understand the effect of biochar feedstock and temperature of its production on P retention/losses in various types of soils.

Phosphorus critical levels in soil and grapevine leaves for South Brazil vineyards: A Bayesian approach

In South Brazil, grapevines (Vitis vinifera L.) have been grown in acid sandy soils, increasing phosphorus (P) need for fertilization. However, current fertilizer guidelines for growers are based on Vitis labrusca grown in clay soils. Therefore, there is a clear need to provide new recommendations on fertilization in vineyards. This study aimed to: (i) establish critical levels (CL) for P in the soil and grape leaves at flowering and veraison growth stages; and (ii) propose P maximum technical efficiency (MTE) rates for white and red grapevines grown in sandy soils based on a Bayesian approach. The study was carried out in sandy soil in South Brazil, with six P fertilization rates (0, 10, 20, 40, 60, and 100 kg P2O5 ha−1) applied annually from 2011 to 2015. Grape yield, P concentration in both soil and leaves (at flowering and veraison), and grape composition were measured during three growing seasons (2016, 2017, and 2018). The CL of P in the soil was 37 mg dm−3. This study is the first to propose CL for grapevine leaves at flowering (1.63 g kg−1) and at veraison for white (1.12 g kg−1) and red (1.38 g kg−1) grapevine cultivars in Brazil. Lastly, we proposed MTE rates for ‘Chardonnay’ (42 kg P2O5 ha−1) and ‘Pinot Noir’ (66 kg P2O5 ha−1). This new information provides foundational knowledge to reduce the rate of P fertilization up to 60 % for ‘Chardonnay’ vineyards. The utilization of this Bayesian approach has relevant implications for defining the optimal P management to be applied to vineyards around the globe.

Preservation of microscopic fur, feather, and bast fibers in the Mesolithic ochre grave of Majoonsuo, Eastern Finland.

The study of animal and plant fibers related to grave furnishing, garments, and grave goods in thousands-of-year-old burials provides new insights into these funerary practices. Their preservation presupposes favorable conditions, where bacterial and fungal activity is at a minimum, as in anaerobic, wet, salty, arid, or frozen environments. The extreme acidic-soil environments (i.e., podzols) of Finland pose a challenge when it comes to studying funerary deposits, as human remains are rarely found. However, its potential to preserve microparticles allows us to approach the funerary event from a totally different point of view. Here, we present the first multiproxy analyses of a Mesolithic deposit from Finland. A red-ochre burial of a child found in Majoonsuo is studied by analyzing 1) microscopic fibers, 2) fatty acids, and 3) physical-chemical (CIELab color, pH, grain size) properties of 60 soil samples and associated materials. The microscopic fibers evidenced the remains of waterfowl downy feathers, a falcon feather fragment, canid and small rodent hairs as well as bast fibers. These could have been used in furnishing the grave and as ornaments or clothes. Canid hairs could belong to a dog inhumation, or more likely to canid fur used as grave good/clothes. Samples with microparticles have more long-chain and unsaturated fatty acids, although animal species identification was not possible. Soil properties indicate that the burial was made in the local soil, adding homogeneous red ochre and removing the coarser material; no bioturbation was found. The highly acidic sandy soil, together with a slight increase in finer particles when ochre is abundant, probably resulted in micro-scale, anoxic conditions that prevented bacterial attack. This study reveals the first animal hairs and feathers from a Finnish Mesolithic funerary context, and provides clues about how their preservation was possible.

Potential ammonia volatilization from 39 different novel biobased fertilizers on the European market – A laboratory study using 5 European soils

Current political focus on promoting circular economy in the European Union drives great interest in developing and using more biobased fertilizers (BBFs, most often waste or residue-derived). Many studies have been published on environmental emissions, including ammonia (NH3) volatilization from manures, but there have only been a few such studies on BBFs. Ammonia volatilization from agriculture poses a risk to the environment and human health, causing pollution in natural ecosystems when deposited and formation of fine particulate matter (PMx). Furthermore, NH3 volatilization results in removal of plant-available N from agricultural systems, constituting an economic loss for farmers.The aim of this laboratory study was to determine the potential NH3 volatilization from 39 different BBFs commercially available on the European market. In addition, this study aimed to investigate the effect of incorporation, application rate, soil type, and soil moisture content on potential NH3 volatilization in order to derive suggestions for the optimal field application conditions. Results showed a great variation between BBFs in potential NH3 volatilization, both in terms of their temporal pattern of volatilization and amount of NH3 volatilized. The potential NH3 volatilization varied from 0% of applied total N (olive oil compost) to 64% of applied total N (manure and crop digestate) during a 27- or 44-day incubation period. Characteristics of BBFs (pH, NH4+-N, NO3−-N, DM, C:N) and their interaction with time could explain 89% of the variation in accumulated potential NH3 volatilization. Incorporation of BBFs into an acidic sandy soil effectively reduced potential NH3 volatilization by 37%–96% compared to surface application of BBFs. Potential NH3 volatilization was not significantly affected by differences in application rate or soil moisture content, but varied between five different soils (with different clay and organic matter content), with the highest NH3 volatilization potential from the acidic sandy soil.

Depth profile of colloidal iron in the pore water of an Albic Podzol

AbstractIron (Fe) colloids dominate the soil solution Fe and these colloids potentially act as vectors for nutrients and contaminants in soil. The question remains which factors, that is, gradients in soil chemical characteristics with depth or physical processes, cause vertical mobilisation and immobilisation of Fe colloids in soils. This question was addressed by characterising the change in concentration, size and composition of Fe colloids in a podzol profile and by relating these changes to soil properties along the profile. Pore waters were analysed with Flow Field Flow Fractionation (FlFFF‐UV‐ICP‐MS) to overcome the artefacts typically obtained when using filtration for fractionation. Pore water was obtained by centrifugation of field moist samples taken from an Albic Podzol. The samples were taken within a depth of 110 cm, at eight depths corresponding to different horizons. The pore water Fe concentration increased with depth and peaked at 66 μM in the E horizon just above the Bh horizon, beyond which, it sharply decreased to only 9 μM. The pore water Fe concentration correlated strongly with dissolved organic carbon (DOC). The high‐resolution size fractionation analysis with FlFFF suggested that the Fe colloids (&lt;100 nm) in the pore water not only consisted of Fe‐organic carbon (OC) complexes, but also of mineral Fe colloids associated with organic matter (OM), as indicated by the colloid size (&gt;5 nm) and by the relatively large Fe/OC ratio that exceeds the complexation capacity of natural OM. The smallest mineral Fe colloids dominated in the Ah1 horizon, while the larger mineral colloids increased with increasing depth, explaining the rise in total Fe towards the Bh horizon. This suggests that Fe complexation with OM and stabilisation of mineral Fe colloids with OM explain colloidal Fe in the pore water. The adsorption of the OM at the top of the Bs horizons is likely the primary mechanism of DOC retention in the Bh horizon. Below this depth, the concentration of DOC was very low, resulting in low Fe concentration in the pore water. The colloids (&lt;100 nm) are considerably smaller than the soil pore size distribution and increase in size with depth, which suggests that straining was not a significant mechanism for colloid retention. This study demonstrates that OM plays a key role in the transport of Fe colloids in acid sandy soil.Highlights Depth profile of pore water Fe in a podzol is studied to investigate colloid migration processes Pore water colloids are characterised by Flow Field Flow Fractionation Fe colloids consist of complexes with OM and mainly larger mineral colloids Natural OM plays a key role in the transport of Fe colloids in acid sandy soil

Influence of Site-specific Nutrient Management and Nutrient Omission on Yield Augmentation of Maize (Zea mays) in an Acid Soil

A field experiment was carried out during the Kharif seasons of 2016 and 2017 on a strongly acidic sandy soil (pH- 5.01 and organic carbon - 4.8 g kg-1) of Sambalpur district in Odisha, India to study the influence of site-specific nutrient management (SSNM) and nutrient omission technique on the productivity of ‘Mahyco-Hybrid 3845 S’ maize under eight treatment combinations consisting of SSNM, three nutrient omissions, one organic, another organic and inorganic amelioration and absolute control. SSNM treated plot showed the highest biomass production (10.9 t ha-1) whereas omission of all NPK resulted in 50.4 % less biomass production. All the major nutrient concentrations i.e., N, P and K were found lowest in their respective omission treatment. It was observed that lime treatment showed the highest Ca content in biomass whereas the lowest in N omitted treatment. Integration of organic alone, with inorganic amelioration and organic-inorganic combination with deficient nutrient resulted in the highest uptake of N, P and K as compared to 100% NPK. SSNM practices improved the soil fertility status and raised the net income and B: C ratio.

MODELLING THE EFFECT OF WOOD AND MAIZE COB-DERIVED BIOCHAR APPLICATION ON SOIL DYNAMICS AND MAIZE GROWTH FOR SUSTAINABLE AGRICULTURE

Intensive agriculture has degraded global agricultural land and resulted in a food crisis. The application of biochar in agricultural soil has been proven effective at improving soil quality and increasing crop yield. This study aims to develop a simulation and investigate the effect of wood-derived biochar (WBC) and maize cob-derived biochar (MBC) at different application rates on soil pH, soil cation exchange capacity (CEC), soil organic carbon (SOC) and the productivity of the maize cropping system. The prediction regarding the effect of biochar on soil pH was the most accurate of all the parameters studied. The simulation was good at predicting the change of properties in calcareous clay soil for both WBC and MBC, as well as WBC in acidic, sandy soil. The results demonstrated that amendments to both WBC and MBC successfully improved the soil pH, SOC and CEC. The effect was more significant when higher biochar application rates were applied. The biochar amendment enhanced the properties of acidic sandy soil more significantly as compared to calcareous clay soil. Overall, WBC and MBC are potential green fertilisers capable of enhancing soil quality for the sustainable development in agriculture.

Acute Ecotoxicological Effects of Bauxite Residue Addition on Mortality and Motion-frequency of Dendrobaena veneta and Enchytraeus albidus (Annelida) in Three Types of Soils

The bauxite residue is produced in high amounts all over the world. This industrial waste is a possible soil-amendment material. Although the material has been produced in high amounts, it is not frequently reused. We investigated its ecotoxicological effects on two annelid species: Dendrobaena veneta and Enchytraeus albidus. Two forms of bauxite residue (BR: S – untreated; G – dried, filter pressed, and gypsum neutralized) and three natural soils (NH: Nagyhörcsök, NY: Nyírlugos, OB: Őrbottyán) were examined. To determine the safe concentration of bauxite residue in soil on the short, acute mortality and sublethal behavioral tests (peristaltic motion-frequency) were performed. The bauxite residue addition (&lt;5/10%) raised the pH and water holding capacity level of soils. Both types of the bauxite residue increased the motion-frequency of the worms. The untreated type had an acute mortality effect (&gt;25%). Both species refused the soils containing both bauxite residue types at higher concentrations (&gt;10%). Slight bauxite residue addition may improve the life circumstances of annelids in acidic sandy soils because of the potential rise of the pH level and water holding capacity.