Horticultural Soil Research Articles

Biogas Residue Carbonization Rather Than Biogas Residue Promoted the Yield of Pakchoi and Reduced the N2O Production Potential in Horticultural Soil

ABSTRACTBiogas residue (BR) and biogas residue‐derived biochar (BRC) are widely used as substitute for inorganic Nitrogen (N) fertilizers in vegetable production. Yet, their comparative research on vegetable production and N2O production was still lacking. Here, the pot experiment of pakchoi (Brassica chinensis) with a gradient of BR or BRC application rates (0, 30%, 60%, 100% w/w) was carried out to simulate different N fertilizer substitution rates. The results showed that the pakchoi yield had no difference between BR or BRC and control treatments; BRC had more advantages than BR in maintaining or increasing the pakchoi yield. BR and BRC could all reduce N2O production potential in vegetable soils. But BRC had a stronger ability to inhibit denitrification while BR had a stronger ability to inhibit nitrification compared with each other. The results showed that BR and BRC had different regulatory pathways for pakchoi yield and N2O production. BR regulated the pakchoi yield majorly through nitrification, but BRC majorly through denitrification. It suggested that BR and BRC could partially or completely replace inorganic fertilizers without reducing pakchoi yield. BRC combined with chemical fertilizers was a higher intelligence strategy in vegetable systems to improve pakchoi yield and N2O production compared with BR. It provided a theoretical basis for the application of BR and BRC to nutrient cycling and microbial processes in the soil‐vegetable system.

Mathematical model for predicting the yield of apple trees on rootstock 62-396

Traditionally, forecasting apple tree yields was carried out on the basis of statistics of already obtained long-term yield dynamics or based on generative formations formed on the tree. The purpose of the work is to identify the most significant soil parameters for the formation of the apple tree varieties yield on the dwarf rootstock 62-396 and to build a mathematical model for predicting fruit yield in the conditions of the Central Chernozem region of the Russian Federation. Field research was carried out in 2004-2022 in industrial apple tree plantations at the age of full fruiting in the Lipetsk (two farms) and Tambov (eight farms) regions. Seven horticultural soil types have been studied. Based on statistical analysis, a mathematical model of apple tree productivity was obtained in the form of an analytical dependence on three factors. A geometric interpretation of the regression model is given using the Mathcad symbolic mathematics system in the form of response surfaces and the corresponding level lines. Practical recommendations are given for choosing rational parameters within selected intervals of factor variation.

Draft genome of Bacillus subtilis sp. strain UAMC isolated from agricultural soil with historical use of pesticides in Argentina.

To understand microbial metabolism in horticultural soils exposed to pesticides, genome sequencing of Bacillus subtilis sp. strain UAMC was performed. A total of 7,892 genes distributed across 40 contigs were identified. Among these, those related to the degradation of endosulfan such as FMNH2 monooxygenase, or cytochrome p450 stand out.

Feeding Mars: A pilot study growing vegetables using aquaponic effluent fertiliser in simulant and analogue Martian regoliths

The Feeding Mars study was devised as a small, pilot proof of concept study to research the potential for using aquaponic effluents as an additive to regoliths which on Mars and the Moon are devoid of organic material and thus lacking microbes which assist in the delivery of water and nutrients to the plants via their roots. This research investigates aquaponics as a way to potentially produce fish and vegetal products in regoliths on Mars and the Moon as well as in extreme environments on Earth. In order to settle on Mars, settlers will have to grow their own food in systems that are self-perpetuating, with little or no inputs being brought from Earth once these systems have been established. This means that nutrients from the fish water can be used to grow plants in the hydroponic parts of the aquaponic system but also potentially in the Martian regoliths which are treated with effluents taken from aquaponic systems. Once production is established additional nutrients can be sourced from the arisings and waste, both from the fish (that are processed and eaten) and the plants, which can be used as compost to turn the regoliths into soil. In order to have fish in space, there is also the need for the systems to be self-sustaining in the production of fish feed. The key outcomes of the project were that all the species grown (potatoes, tomatoes, dwarf beans, carrots, lettuce, spring onions, chives and basil) indicate the potential to be grown in regoliths with the addition of aquaponic effluents. A significant result was that on the whole the plants that were grown with the addition of aquaponic effluents were greener than those grown in the horticultural soil, indicating that the nutrient supply was adequate. However, a key lesson learned is that germination and thus development of the plants grown in the Mars simulant and analogue was slower than those grown in the horticultural soil. Thus, developing nutrients in the soil before planting is necessary as it is with agriculture and horticulture practices on Earth, where manuring/fertilization occurs before planting. The consequence of this research, and the envisaged research to follow is not only for extra-terrestrial environments. The Earth has its own hostile environments, characterised with regoliths and other unproductive soils, and aquaponic water and aquaponic wastes can readily be envisaged as providing solutions to growing nutritious food in areas where agriculture is not currently viable. The research was undertaken in an exhibition gallery setting at the University of Greenwich in order to encourage public interest and dialogue, which it did.

Assessment of the humus state of hortically suitable soils Northwest Caucasus

The laying of intensive industrial gardens in Russia is carried out according to special projects, which are based on complex works that begin the selection and assessment of the soil suitability of land plots. The levels of total humus and its labile forms have been established for the main horticultural soils of the Krasnodar Territory on the basis of long-term studies. The use of these criteria makes it possible to assess the degree of cultivation or degradation processes of the soil cover of each specific garden plot. Studies have shown that, in all surveyed soils of the region, the profile distribution of humus is gradually decreasing. The most informative soil layer for assessing fertility can be considered the upper 30 cm layer. The greatest quantitative and qualitative changes of organic matter occur in this layer. Different gardening zones of the region differ in the content of total humus in the main types of soils, a decrease is observed from ordinary chernozems (northern zone) to alluvial meadow soils (river valleys of the foothill zone). The humus content in the natural cenoses of Kuban chernozems reached 5.5 %, and in heavily plowed soil up to 3.5 %, a similar situation was observed in floodplain soils, these values corresponded to 4.0 % and 2.0 %. All other types of soils occupied an intermediate position in terms of humus content.

Soil health benefits associated with urban horticulture

As the global population grows and is increasingly concentrated in urban environments, the quality of urban horticultural soils is of mounting importance. Until now, most urban horticultural soil assessments have been applied in nations and continents outside North America, and none have been conducted in Canada—an important agricultural region. Here, we present the first Canadian study to evaluate soil health in urban horticultural soil (gardens producing fruit and vegetables), benchmarked against conventional agricultural soil in surrounding rural areas (producing cereals, oilseeds, and legumes). We assessed a range of soil health indicators (total C, soil organic C [SOC], active C, CO2 evolution, wet aggregate stability [WAS], total N, autoclave citrate extractable [ACE] protein, potentially mineralizable N [PMN], and N2O production), soil fertility indicators (inorganic N, available P, and available K), and inherent soil properties (texture, electrical conductivity [EC], and pH). We found that carbon- and nitrogen-based soil attributes in urban horticultural soils were 200 % that of the agricultural soils, indicating superior soil health—which had significant implications for interpreting soil health scores. As for soil fertility, inorganic N and available K did not differ between the two systems, but available P was 400 % higher in urban horticulture than agriculture soils, indicating that management practices which build soil health might risk also building excessive soil P levels. Our findings suggest that urban horticulture soils may provide superior ecosystem services and function as a reservoir for SOC, likely due to the soil health management practices implemented by gardeners—but care should be taken to manage soil health alongside managing soil fertility. Urban horticulture soil is an ideal platform for expanding research and governance not only for food production but for valuable ecosystem services.

Exploring the Root Morphological Traits of Diverse-Origin Cultivated Soybean

Root morphological traits (RMTs) profoundly influence plant growth, resilience to abiotic stresses, and yield in soybean (Glycine max). In a comprehensive study spanning two consecutive years (2021–2022), the RMTs were assessed in 216 soybean accessions from 34 diverse origins. The investigation involved randomized batches with plants cultivated in PVC pipes filled with horticultural soil and harvested at the V2 growth stage. All the germplasms exhibited significant differences (p < 0.001) in all measured traits, i.e., total root length (TRL), root volume (RV), average diameter (AD), number of tips (NT), number of forks (NF), and tertiary total length (TTL). Among the top 5% performers in TRL, which, interestingly, were exclusively of Korean origin, germplasm IT115491 displayed an impressive average TRL value of 1426.24 cm. Notably, germplasms from Serbia and Korea predominantly occupied the upper AD quantile, with IT156262 exhibiting the highest AD value of 0.57 mm. A correlation analysis showed strong positive associations of TRL with RV (r = 0.85), NT (r = 0.84), NF (r = 0.96), and TTL (r = 0.88), whereas it had a negative association with AD (r = −0.25). A principal component analysis (PCA) showed a cumulative 95% of the total variance in the data in the first three principal components (PCs). PC1 (eigenvalue = 4.64) accounted for a 77.00% variance, with TRL, RV, NF, NT, and TTL exhibiting the highest associated eigenvectors. K-means clustering was performed with three clusters. Cluster 2 contained accessions with higher AD values, whereas Cluster 3 comprised accessions with increased TRL, NT, NF, and TTL, which mostly originated from Korea. Our findings offer targeted insights for plant breeders to optimize specific root traits and enhance crop performance across diverse environmental conditions by strategically targeting these clusters. Additionally, the influence of cultivar origin on root traits warrants further investigation, with implications for future breeding programs.

Macro, meso, micro and nanoplastics in horticultural soils in Argentina: Abundance, size distribution and fragmentation mechanism

Soil contamination with plastics is a major worldwide concern. However, data on plastic pollution in horticultural soils from Latin America is scarce. Furthermore, there is limited information on the fragmentation process that plastics undergo in environmental conditions. In this study, we investigated the abundance of macro, meso, micro and nano plastics in a previously studied horticultural soil (2015) from Buenos Aires, that has not been used for any productive activity since. Although the mass of macroplastics was conserved, the number of plastic fragments per square meter increased significantly, indicating a possible natural fragmentation process. Black polyethylene (PE) mulch film was the most abundant plastic found. For this material, when considering the mass of plastic fragments per square meter, the relative abundance was, in decreasing order: macroplastics (65.1–79.1 %) > mesoplastics (15.6–24.8 %) > microplastics (5.3–12.4 %) > nanoplastics (0.1 %). However, when considering the number of plastic items per square meter, the order was: microplastics (2383–3815) > mesoplastics (1019–1076) > nanoplastics (509–550) > macroplastics (25–46). The size distribution of plastic debris was analyzed using the natural logarithm of abundance versus the square root of the mean decile area, with good linear correlations (0.7749 < R2 < 0.9785). These results provide evidence for an ongoing dynamic fragmentation process (Mott model). We hypothesize that the breakdown of plastic into smaller pieces could be explained by a random fragmentation process based on soil volume changes between natural hydration/dehydration states. These data suggest that soil under natural conditions could act as an ‘environmental plastic grinder’.

Uncovering the dark side of agriculture: How land use intensity shapes soil microbiome and increases potential plant pathogens

Soil microbiome plays a critical role in maintaining key soil processes such as litter decomposition, nutrient cycling, and plant productivity. In this study, we aimed to investigate the variability of soil chemicals, microbial diversity, and composition in seven ecosystems i.e., Fagus sylvatica and Quercus ilex forests, a Mediterranean grassland and shrubland, a vineyard, a horticultural cultivation in open field and under greenhouse, across a gradient of land-use intensity in Southern Italy. Soil chemistry included pH, organic matter, total nitrogen, and C/N ratio, and soil microbiota was characterized by high-throughput sequencing of 16S and ITS genes. Our results showed that greenhouse soils had the highest pH, while Fagus had the lowest. Horticultural, greenhouse, and grassland soils had low levels of OM and total N, while shrubland had relatively high levels of OM, total N, and C/N ratio. Fagus soils, on the other hand, had the highest levels of OM, total N, and C/N ratio. Bacterial diversity was lowest in horticultural soils, whereas fungal diversity was highest in shrubland soils. Pseudomonadota were the predominant bacteria in Fagus, grassland, and vineyard soils, while Actinomycetota dominated in Quercus, shrubland, and greenhouse soils. However, Cyanobacteria was predominant in horticultural soils. On the other hand, the Ascomycota was predominant in all ecosystems except Quercus soils, where the Basidiomycota was dominant. Our bipartite network analysis revealed that bacteria are often the same in different ecosystems while fungi tend to be specific to a particular habitat. Moreover, in agricultural ecosystems, fungal pathogens belonging to Alternaria, Fusarium, Gibellulopsis, Stemphylium, Acremonium, and Curvularia are more abundant, especially in greenhouse. The findings of this study provide important insights into the variability of soil microbial diversity and community composition in different ecosystems, highlighting the essential role of preserving natural ecosystems while managing agricultural ones, given their higher abundance of pathogens.

Patagonian Ethnopedology and Its Role in Food Security: A Case Study of Rural Communities in Arid Environments of Argentina

Local knowledge of horticultural soils was analysed from an ethnobiological perspective in a rural population of arid Patagonian, in order to gain a deeper understanding of how the farmers classify, use and value the soil. In this large but sparsely populated territory, a group of 27 participants was selected. The farmers use an ethnoclassification system that distinguishes nine different soil types according to their horticultural aptitude. The classification criteria are based on the morphological attributes of the soil and certain ethnoindicators (i.e., texture, structure, colour and plant species present). All these aspects, evaluated within the framework of local symbolic and cultural precepts, proved to be key to the management of soils with pronounced edaphic and climatic limitations in terms of farming. Recognition of local knowledge and its contribution to dealing with current socioenvironmental challenges and crises may favour the design of more sustainable farming production in communities that are socio-environmentally vulnerable, considering the populations, soil, and culture as components of a complex integrated system, and not as isolated elements.

Enantiomeric Separation and Degradation of Benoxacor Enantiomers in Horticultural Soil by Normal-Phase and Reversed-Phase High Performance Liquid Chromatography.

The separation of benoxacor enantiomers on six commercial chiral columns was investigated by high-performance liquid chromatography (HPLC) under normal-phase and reversed-phase conditions. The mobile phases included hexane/ethanol, hexane/isopropanol, acetonitrile/water, and methanol/water. The effects of the chiral stationary phases (CSPs), temperature, and mobile phase composition and ratio on the separation of benoxacor enantiomers were examined. Under normal-phase conditions, the two benoxacor enantiomers were completely separated on Chiralpak AD, Chiralpak IC, Lux Cellulose-1, and Lux Cellulose-3 columns and partially separated on a Lux Cellulose-2 column. Under reversed-phase conditions, benoxacor enantiomers were completely separated on a Lux Cellulose-3 column and partially separated on Chiralpak IC and Lux Cellulose-1 columns. Normal-phase HPLC performed better than reversed-phase HPLC for the separation of benoxacor enantiomers. As the column temperature increased from 10 °C to 4 °C, the enthalpy (ΔH) and entropy (ΔS) results indicated that the resolution was strongly affected by the temperature and that the lowest temperature did not always produce the best resolution. An optimized separation method on the Lux Cellulose-3 column was used to investigate the stability of benoxacor enantiomers in solvents and the degradation of benoxacor enantiomers in three types of horticultural soil. Benoxacor enantiomers were stable, and degradation or racemization were not observed in methanol, ethanol, isopropanol, acetonitrile, hexane, or water (pH = 4.0, 7.0, and 9.0). In three horticultural soils, the degradation rate of S-benoxacor was faster than that of R-benoxacor, resulting in soil enrichment with R-benoxacor. The results of this study will help to improve the risk assessment of enantiomer levels of benoxacor in the environment.

Synthesis of Nanocomposite Hydrogels for Improved Water Retention in Horticultural Soil

Synthesis of Nanocomposite Hydrogels for Improved Water Retention in Horticultural Soil

Effects of application of horticultural soil amendments on decomposition, quantity, stabilisation and quality of soil carbon

Application of organic soil amendments is commonplace in horticulture to improve soil fertility. Whether this practice can also augment the soil carbon (C) pool has been of increasing interest in recent years. We used a controlled field experiment that has received annual applications of six different horticultural soil amendments for seven consecutive years. Each amendment was examined in terms of its contribution to bulk C and the distribution of C between theoretical pools, as defined by physical fractionation. Physical fractionation was combined with 13C nuclear magnetic resonance spectroscopy with cross-polarization and magic angle spinning (CPMAS NMR) analysis. Results indicated that the difference in total C concentration between treatments resulted from an increase in unprotected, free, particulate organic matter (fOM), rather than an increase in soil organic matter being occluded in aggregates or in organo-mineral complexes, and that C persisted in the fOM fraction as a result of accumulation in the alkyl C region. Unlike fresh litter or plant residues, organic amendments have undergone decomposition during the composting process (or during formation in the case of peat), in the absence of mineral soil components. This ex situ decomposition (and possible stabilization through acquired recalcitrance) could reduce the opportunity to become physically or chemically protected through association with the soil mineral phase following addition to soil. Carbon:Nitrogen (C:N) of amendment material likely influenced the rate of amendment decomposition. In addition, C:N determines the decomposition of plant litter inputs, as determined by the tea bag index.

Onychiuridae (Collembola) of Australia: a key to species with notes on their distributions and pest status

AbstractThe onychiurid fauna of Australia is revised and found to comprise six species belonging to five genera. All species are already described and are widespread in the Northern Hemisphere so they are considered to be introduced to Australia. For the most part, they are only known in Australia from agricultural and horticultural soils and home gardens as well as worm beds. A dichotomous key to the species is presented together with updated names, relevant synonymies, a brief description of each and comments on their distribution and ecology. The six species separated in the key are Protaphorura fimata (Gisin, 1952), Thalassaphorura encarpata (Denis, 1931), Thalassaphorura cryptopyga (Denis, 1931), Orthonychiurus folsomi (Schäffer, 1900), Deuteraphorura cebennaria (Gisin, 1956) and Onychiurus ambulans (Linnaeus, 1758). A seventh species is listed here but in family Tullbergiidae, Metaphorura affinis (Börner, 1902). It is included as it could be confused with the Onychiurinae in the field. In Australia and overseas, onychiurids have been associated with root damage to plants in home gardens and field crops, and we discuss their pest status using data from assessments of field crop damage in Australia. The aim of this paper is to provide an identification guide to field workers so that they can decide whether control methods are required.

AGROCHEMICAL EVALUATION OF SOILS UNDER HORTICULTURE ON THE SUITABILITY OF THEIR USAGE FOR THE MAIN AGRICULTURAL CROPS GROWING

This article reveals the results of research on the agrochemical composition of soils released from horticulture (Apple orchard) for the effectiveness of their usage in growing crops in field crop rotation. The research was conducted on Gray forest soils in the central part of Vinnytsia region in the forest-steppe of the Right Bank. The subject of research is agro-ecological indicators of soils that have been released from horticulture of varying degrees of intensity. It was found that in soils used for intensive horticulture nitrogen content of easily hydrolyzed, exchangeable potassium and humus was lower on 37.1, 23.7, 2.9 %, and mobile phosphorus, soil pH, metabolic calcium and metabolic magnesium on the contrary higher on 71.8, 12.8, 19.8 and 8.0 %, respectively, compared to the soils used for extensive horticulture. There is also a certain difference between mobile compounds of chemical metals in the soils under horticulture. The content of boron, molybdenum, cobalt and iron in the soils used for intensive horticulture was lower on 50.0, 32.8, 2.5 and 62.5 % compared to the soils of extensive horticultural lands. The concentration of sulfur was 8.0 % higher in intensive horticultural soils compared to the extensive ones. Characterizing the content of heavy metals-toxicants in soils used for intensive horticulture, it should be noted that the content of cadmium, lead, copper and mercury was higher on 4.0, 6.1, 9.5 and 6.6 %, and zinc is twice lower compared to the soils in extensive horticulture. Analysis of soils released from horticulture of varying degrees of intensity showed that the content of basic plant nutrients needs to be replenished, taking into account the growing need for basic nutrients in soils from phosphorus, potassium to nitrogen. When converting soils used for horticulture into arable land, it is necessary to take into account the measures that maximize the accumulation of soil nitrogen, in particular the cultivation of legumes. On these soils, it is not advisable to immediately grow nitrogen-loving crops, such as corn, winter wheat and sunflower, in the cultivation of which a high amount of this element is removed from the soil to form an optimal harvest. The practical significance of the results is that they will enable them to develop concrete proposals for reducing soil contamination by restoring soil fertility and improving the quality of plant material from cereals grown under exempted horticulture conditions.

Interactions between nitrogen release from organic fertilisers and organic horticultural soils

Mushroom compost has been one of the most commonly used fertilisers in organic greenhouse vegetable production in Iceland. However, mushroom compost contains conventional chicken manure. Therefore, the use of this fertiliser is prohibited in organic horticulture. In search of alternative nutrient resources, nine different substitutes for mushroom compost (plant compost, four composted animal manures, fishmeal, white clover residues, coarse meal of faba beans, ‘Pioner complete 6-1-3®’) were tested on two soils differing in organic matter in a pot experiment. Dry matter yield (DM) and the apparent N utilisation with the model plant perennial ryegrass was quantified in five cuts throughout 131 days. Both the DM yield and the apparent N utilisation was influenced by the fertiliser, the soil and their interaction. The N release of the tested alternative organic fertiliser resources was described by the N content and C:N ratio of the fertilisers, but was also affected by the soil. It was concluded that the composted animal manures provided an N release equal to mushroom compost and could therefore act as substitutes.

Soil response to root-knot nematode management with wine vinasse in a solarised horticultural soil under glasshouse conditions

Summary The increasing interest in agroecological practices and the current consideration of agrarian soils as a sustainable resource are driving the development of new strategies to manage soil parasites and diseases. The application of organic matter from different sources to reduce plant parasites contributes to circular economy by applying by-products as soil organic amendments that reduce wastes. Wine vinasse (WV) is a by-product generated to obtain alcohol from wine by physical methods in distilleries. The aim of this study was to determine the potential of WV and its combination with animal manure (WV+M) as soil biodisinfestation products. For this, it was compared with a plastic-covered control to distinguish the biodisinfestation from solarisation effect. The crops tested consisted of a tomato-Swiss chard rotation under glasshouse conditions. Their effects on Meloidogyne incognita, soil fertility, nematode community and crop yield were assessed. The results obtained after two seasons showed a reduction of M. incognita galling in the root system of both crops. The immediate effect after the treatment application was a reduction in the abundance of nematodes and changes in the nematode-based indices that affected all plots, including the control, most likely related to the tillage effect for the treatments application and the plastic cover. Soil fertility was improved by the application of WV (NO3−, Bioav. P) and WV+M (C, Ntotal, K), which reduced herbivore nematode metabolic footprints and enhanced bacterivore footprints. Our results indicate that the combination WV+M was effective reducing M. incognita infection, and improved crop yield. Use of by-products such as WV is a helpful tool for managing horticultural soils.

Abundance, diversity, and distribution of plant-parasitic nematodes in horticultural soils under different management systems in a tomato-producing area in Argentina

Summary Monitoring the diversity and structure of plant-parasitic nematode (PPN) communities together with developing appropriate control strategies can reduce the occurrence of these pathogens and other plant pests in horticultural crops. In this context a study of the abundance, frequency, diversity and distribution of PPN in horticultural soils under glasshouse conditions from the Green Belt of La Plata, Buenos Aires, Argentina, under different management systems was undertaken. Soil samples were collected from three horticultural areas with different tomato crop managements: agroecological crop (AC); organic crop with Brassicaceae soil amendments (OC); intensive conventional crop treated with methyl bromide (MeBr) (IC). The parameters evaluated were: nematode genera richness (G); Shannon-Wiener diversity index () (Hutcheson’s t-test was applied for this index); equitability index (E); abundance; and frequency of genera. ANOSIM and SIMPER statistical analyses were performed to find significant differences between the nematode assemblages from the different sites. A total of 14 genera of PPN were identified among the three crop sites. Members of the feeding habits categories ectoparasites, semi-endoparasites, migratory endoparasites and sedentary endoparasites were observed. Statistical analysis enabled us to characterise each site based on the composition of the nematode assemblages. Helicotylenchus, Tylenchus and Nacobbus were the most frequent and abundant genera. AC and OC showed similar values of richness and diversity; the crop treated with MeBr (IC) showed the lowest diversity of PPN.

Effects of Repeated Application of Organic Soil Amendments on Horticultural Soil Physicochemical Properties, Nitrogen Budget and Yield

Application of organic amendments to soil is commonplace in domestic gardening. However, a vast array of materials could be labelled as ‘compost’ by retailers and suppliers. We investigated six different amendments currently used, or available for use, in horticulture: composted bark, composted bracken, spent mushroom compost, composted horse manure, garden waste compost (at two different application rates), and peat. Using a controlled field experiment, we examined the physicochemical differences between the amendments, the subsequent effects on soil characteristics, and resultant yield and biometrics of Lavatera trimiestris. Amended soils resulted in a significantly different multivariate soil environment and N budget when compared to the unamended control. However, the effect on yield and plant biometrics (number of flowers, plant height, etc.) depended on the amendment used. Application of garden compost resulted in up to a five-fold increase in yield. However, there was no significant difference in yields in soils amended with composted bark or peat, when compared to the unamended control. This has implications, as there is increasing pressure to remove peat from products available to domestic gardeners. The variability in the different amendments investigated in our research, in addition to the variable effects on plant growth parameters, suggests that repeated use of a single amendment may not be best practise for gardeners.

Forms of Copper in the Aspect of Anthropogenic Changes in the Profiles of Horticultural Soils in the Cities of South-Eastern Poland

The aim of the research was to show the changes taking place in soils as a result of the influence of anthropogenic factors in the form of intensive horticulture and pollution within the city. It was made on the basis of the distribution of individual fractions as well as available and total Cu forms in the profiles of garden soils located at houses and in the family allotment gardens in six cities in south-eastern Poland. The research took into account the granulometric composition according to which the cities were divided into two groups. The pollution assessment was based on the concentration indicator, Igeo, and indicators taking into account the forms available for plants: Cav/Ct and BF. There was no copper contamination with regard to legislation act and Igeo. The role of organic matter as an important component in copper in the humus horizons of soils in long-term horticultural cultivation has been considered. The content of all forms of copper was higher in humus horizon which also indicated the anthropogenic changes. Among the two groups of soils, a greater impact of the treatments used in horticulture on those made of sands was found in relation to the silty ones.