Soil Ca Content Research Articles

Manure-based composts influence soil quality after lettuce (Lactuca sativa L.) production

Declining soil fertility is a major constraint for vegetable crops like lettuce in sub-Saharan Africa. With the purpose of contributing to enhancing crop yields and soil productivity, while safeguarding the environment, this study aims to assess the effect of composts made from chicken droppings (CCD) and horse dung (CHD) on soil quality after lettuce growing. The phytotoxicity of the composts was assessed by testing the germination of two varieties of lettuce (V1: Eden and V2: Blonde de Paris) with aqueous extracts of the composts at different concentrations (0, 25, 50, 75 and 100 %). For the field evaluation, treatments (C0: control without fertilizer, C1: 15 t.ha−1 of chicken droppings, C2: 15 t.ha−1 of horse dung, C3: chemical fertilizers) and varieties were distributed in a completely randomized block design with three replications. Physico-chemical soil analysis was carried out before (Ct) and after lettuce production depending on the treatments. Soil’s parameters determined included: pH, organic matter, carbon, C/N ratio, granulometry, cation exchange capacity, exchangeable bases, nitrogen, phosphorus, calcium, magnesium, sodium and potassium contents. The results of the phytotoxicity test showed that the lowest germination percentages were obtained at V1C2100%Ster+ (48.33 ± 6.01 %) and V2C2100%Ster+ (53.33 ± 6.01 %). These values were around the standard (50 %), showing that these composts were non-toxic. The results showed that overall, the composts improved soil properties, with significant increases in P and Ca content. So, soil Ca contents of C0, C1, C2 and C3 were respectively 2, 3, 2 and 2 times that of Ct. CCD and CHD can be therefore recommended for growing lettuce and maintaining soil quality.

Patterns and determinants of calcium concentrations in forest litter and different soil horizons in warm-temperate China

Calcium is an essential nutrition for the integrity and structure of plant cells, and is generally neglected because of its high abundance in temperate forest soil. To date, little is known about the changes in soil Ca and the main natural drivers in the conserved forests. Here, the concentrations of Ca in forest litter and different soil horizons (0–10, 10–20, 20–30, and 30–50 cm) from 234 forest plots were measured. Spatial variations in litter and soil Ca concentrations beneath different forest types were determined, and a structural equation model (SEM) was constructed to evaluate the causal pathways of the biotic and abiotic drivers. The results showed that litter Ca concentration beneath broadleaved forests and mixed broadleaf-conifer forests (22.62 and 19.76 mg/g, respectively) were significantly greater than that beneath the coniferous forest (15.35 mg/g). The Ca concentrations in the soil significantly increased with latitude (soil depth < 30 cm) and longitude. However, litter and soil Ca concentrations significantly declined with elevation. The basal area of the forest and soil C/N were the dominant factors regulating the concentration of Ca in litter and soil profiles, respectively. The SEM highlighted the important effects of Ca concentration in deep soil (soil depth > 20 cm) on litter Ca concentration. The basal area and soil C/N had negative and positive direct effects on Ca concentration in topsoil (soil depth < 20 cm), respectively. The precipitation and temperature in the growing season had indirect effects by affecting the soil C/N and basal area. These results collectively suggest that different forest types influence the redistribution of Ca belowground, and the process is mainly mediated by the basal area and soil C/N. The afforestation in the study area with admixture of conifers and broadleaved trees is a desirable management for the improvement of forest productivity and soil fertility.

BIOCHAR AS A POTENTIAL SOIL CONDITIONER IN SALINE PRONE COASTAL AREA OF BANGLADESH

In the coastal areas of Bangladesh, salinity restricts normal crop production and increases with the desiccation of the soil. Recently, biochar has received great attention as a soil amendment to mitigate the detrimental effects of salinity stress. In this respect, a field experiment was conducted to examine the effects of biochars on soil properties and growth of okra (Abelmoschus esculentus L.) and to identify a suitable biochar amendment for salt-affected soils in coastal areas of Bangladesh. The experiment was conducted in a randomized complete block design (RCBD) with five replications. Three types of biochar (rice straw biochar, sawdust biochar and water hyacinth biochar) were applied @ 10 t ha-1 in a silt loam soil along with the control. Results showed that biochar application to the soil enhanced plant height, leaf number, leaf area, shoot fresh weight, shoot dry weight and yield of okra as well as improving the soil quality e.g. field capacity (FC), CEC, OC, total N, available P, S, K, and Ca. The application of water hyacinth biochar improved almost all of the growth and yield attributes of okra along with most of the soil properties than that of others. The results suggest that water hyacinth biochar might be recommended as a suitable soil amendment for better crop growth and soil quality. Moreover, water hyacinth biochar had significantly (P&lt;0.001) higher surface area (205.40 m2g-1); consequently, higher capacity in salt and water adsorption which might prevent soil desiccation. Side by side, it significantly (P&lt;0.001) increased the soil Ca content which might replace Na+ in the root rhizosphere minimizing the Na+ uptake by plants. Taken together, water hyacinth biochar could also be the best choice of organic amendments to reduce the suppressing effect of salinity stress in coastal areas of Bangladesh.

Nutritional response of sugar maple seedlings to water stress under highly nitrogen‐enriched soil conditions

AbstractBackgroundTemperate forests of eastern North America will be increasingly affected by chronic atmospheric nitrogen deposition, elevated temperatures, and drought events that will expose trees to moisture‐stressed conditions in non‐nitrogen‐limited soils. Yet, little is known regarding the response of sugar maple‐dominated forests to moisture stress under non‐nitrogen‐limiting conditions.AimsThe objective of this greenhouse study was to analyze the effects of moisture stress on the nutrition and growth of sugar maple seedlings growing on base‐poor forest soils that were strongly fertilized with nitrogen.MethodsOne‐year‐old sugar maple seedlings were grown with and without water stress on soils from a sugar maple stand that had been fertilized for 15 years at a rate of 85 kg N ha−1 y−1.ResultsDecreased moisture availability decreased total, leaf, root and stem biomass, and root/stem ratio. Leaf concentrations of N, P, Ca, and Mg and root concentrations of K, Ca, and Mg were 6% to 23% significantly lower under stressed versus unstressed conditions despite no changes in N, P, K, and Mg concentrations in the soil. Only soil Ca concentration was negatively affected by the moisture stress treatment. Soil and leaf δ15N and the k‐factor (i.e., isotopic discrimination effect of 15N‐labeled sources of N between roots and soil) that was used to assess N‐use efficiency of sugar maple seedlings did not differ between water stress treatments.ConclusionsOur results indicate that decreasing root biomass of sugar maple seedlings under moisture stress in non‐nitrogen‐limiting situations would decrease their ability to take up nutrients that are necessary for growth and induce lower concentrations in leaves and roots. Expected severe drought events could substantially limit nutrient uptake capacity of sugar maple seedlings on sites that are subject to chronic atmospheric N‐deposition, which would contribute to dieback in sugar maple stands.

Geospatial patterns and geochemical compositional characteristics of molybdenum in different mediums of an urban environment

Urban areas are characterized by the presence of certain potentially toxic elements including molybdenum (Mo). Therefore, compositional data analysis combined with geospatial mapping was applied in this study to reveal the spatial distribution characteristics of Mo in courtyard surface dust (dust), soils, and river sediments (sediments), to identify potential sources of Mo, and to reveal Mo geochemical associations in different urban environmental mediums. The mean contents of Mo decreased in the following order: dust (11.9 mg/kg) – soil (5.84 mg/kg) – sediment (4.87 mg/kg). The highest maximum Mo content among the studied mediums (61.8 mg/kg) was detected in dust. It was the only investigated medium where a very high level of Mo enrichment was observed (4.4% of samples). Moreover, a significant level of enrichment predominated in dust (47% of samples) whereas in soil, moderate enrichment prevails (68.5%). A significant correlation of Mo contents was observed with Zn contents in all the studied mediums, and with Ca contents in soil and sediments. A significant negative correlation was observed only between Mo contents in dust and sampling site altitudes suggesting that high-rise buildings might play the role of geochemical barriers. Principal component analysis, k-means and hierarchical clustering showed that in the geogenic elements soil group Mo showed an affinity to be bound by Fe/Mn oxide/hydroxides whereas the Mo coprecipitation, complexation and absorption by carbonates predominated in the Mo-related soil group (geochemical compositional association of Mo, Zn, Cu, Pb, and Ca) under anthropogenic influence. For dust, the geochemical compositional association was the same, but in the geogenic-related group, Cu was the most closely associated element instead of Zn. The spatial location of the Mo-related group of samples identified by k-means clustering indicates that Mo concentrate processing plant may be a potential source of Mo introduction into the urban environment.

Utilisation of Intrinsic and Extrinsic Soil Information to Derive Soil Nutrient Management Zones for Banana Production in a Smallholder Farm

In South Africa (SA), smallholder farmers contribute significantly to food production and play an essential role in the nation’s food and nutritional security. However, there is a lack of basic understanding of the spatial variability of soil nutrients and their controlling factors in these smallholdings, which subsequently hinders their agricultural production. In this work, we assessed the spatial variability and structure of key soil nutrients required by banana fruit, identified their factors of control, and delineated management zones in a smallholder farm. We used a regular grid (50 m × 50 m) to collect a total of 27 composite samples from the 0–30 cm depth interval and analysed for soil physicochemical properties. Our classical statistics results indicated that phosphorus (P), potassium (K), calcium (Ca) and zinc (Zn) varied highly, while magnesium (Mg) and total nitrogen (TN) varied moderately across the plantation. On the other hand, geostatistics revealed that P and K were strongly spatially dependent (implying a good structure), while Mg and Zn were moderately spatially dependent (indicating a moderate structure) across the banana plantation. Soil Ca and TN contents were found to be weakly spatially dependent (meaning there was no structure) across the farm. The spatial prediction maps showed that P, Mg and Zn contents were high in the northeast part (underlain by Valsrivier) and low in the northwest part (underlain by Westleigh) of the banana plantation farm. Similarly, K and Ca were low in the northwest part (underlain by Westleigh), but they were high in the south to southwest portion (underlain by Glenrosa) of the farm. Soil TN was high in the west part (underlain by Westleigh) and low in the east-northeast part (underlain by Valsrivier) across the plantation. Three management zones (MZs) were delineated for soil P, K and Ca, while for other nutrients (Mg, Zn and TN), two MZs were delineated. The results of this study provide baseline information for site-specific management of fertilisers to supplement soil nutrients in the field to improve banana productivity.

Root architecture, root biomass and nutrient cycling in a mixed‐species agroforestry system

AbstractUnderstanding root development in soil profiles of agroforestry systems is challenging. It is uncertain to what extent the proximity of cash crops, such as cocoa and coffee, to shade trees reduces nutrient concentrations in the topsoil and whether the cash crops continue to develop fine roots in the topsoil when they are planted in close proximity to shade trees. We aimed to investigate micro‐ and macro‐nutrient concentrations in the soil profile and understand root architecture using a novel DNA metabarcoding approach in an agroforestry system where cocoa and coffee were interplanted with a shade tree, canarium. Soil and root samples were collected from (1) cocoa‐only, (2) cocoa‐canarium, (3) canarium‐only positions in a cocoa plantation, (4) coffee‐only, (5) coffee‐canarium and (6) canarium‐only positions in a coffee plantation. Proximity of shade trees did not limit nutrient concentrations for cash crops. Topsoil concentrations of total N (TN: 0.59% and 0.69%), phosphorus (P: 7.28 and 6.65 mg/kg), potassium (K: 360 and 755 mg/kg) and calcium (Ca: 1865 and 1044 mg/kg) under cocoa and coffee trees, respectively, did not differ significantly from those under the corresponding canarium trees. Soil TN, K and Ca concentrations were well above minimum required concentrations under both cocoa and coffee. DNA metabarcoding showed that canarium trees occupied deeper rooting zones (30–80 cm soil depth) than cocoa and coffee trees (0–30 cm soil depth). DNA metabarcoding demonstrated greater root colonisation of the topsoil by cocoa and coffee than canarium, suggesting that canarium had the potential to extract nutrients from deeper soil layers. Soil Ca concentrations were associated with cocoa root biomass whereas soil NO3−‐N concentrations were associated with coffee root biomass. Our study highlighted the value of selecting suitable shade trees that maintain soil nutrient concentrations for cash crops. Furthermore, DNA metabarcoding can facilitate root distribution studies in complex agroforestry systems, thus providing insights into appropriate tree‐planting designs.

Calcium availability affects the intrinsic water-use efficiency of temperate forest trees

Intrinsic water-use efficiency (iWUE) of trees is an important component of the Earth’s coupled carbon and water cycles. The causes and consequences of long-term changes in iWUE are, however, still poorly understood due to the complex interplay between biotic and abiotic factors. Inspired by the role calcium (Ca) plays in plant transpiration, we explore possible linkages between tree ring-derived iWUE and Ca availability in five central European forest sites that were affected by acidic air pollution. We show that increasing iWUE was directly modulated by acid air pollution in conjunction with soil Ca concentration. Responses of iWUE to rising atmospheric CO2 concentrations accelerated across sites where Ca availability decreased due to soil acidity constraints, regardless of nitrogen and phosphorus availability. The observed association between soil acidity, Ca uptake, and transpiration suggests that Ca biogeochemistry has important, yet unrecognized, implications for the plant physiological upregulation of carbon and water cycles.

Evaluation of calcium, phosphorus and soil organic matter effects on lead accumulation in Cenchrus ciliaris L. grown near a cement factory in Jazan region, Saudi Arabia

Heavy metals associated with cement production and their environmental impacts have received much attention recently. Lead (Pb) is the second most hazardous element after arsenic (As). However, information about its availability and uptake by plants in polluted soil as influenced by soil properties has shown some contradictions. We evaluated the influence of soil calcium (Ca), soil phosphorus (P), and soil organic matter (SOM) on Pb uptake by Cenchrus ciliaris L. based on distance from cement dust polluted soil near a cement factory in Jazan region, Saudi Arabia. We also evaluated the potential of Cenchrus ciliaris L. as a hyperaccumulator of Pb. Soil and plant samples were collected in triplicates from three zones based on distance from the fence of the factory: 10 – 100, 100 – 350, and 350 – 700 m. Concentrations of total Pb, total Ca, and total P in soil and plant tissues were detected using ICP-AES. SOM and other soil properties were also analyzed. Bioconcentration and translocation factors (BF&TF) of Pb were also calculated. Results showed that Pb concentration in Cenchrus ciliaris roots had a strong negative relationship with SOM (R2 = 0.93) and P concentration in soil (R2 = 0.97) but a moderate negative relationship with Ca concentration in soil (R2 = 0.69). The highest TF value was 1.87. It can be concluded that SOM, Ca, and P concentrations in soil negatively affected Pb availability and uptake by Cenchrus ciliaris. Also, based on the highest TF value, Cenchrus ciliaris could be used as a hyperaccumulator in Pb-contaminated soils.

Analysis of growth resistance mechanisms and causes in tea plants (Camellia sinensis) in high-pH regions of Northern China.

In tea plantations with high-pH (pH > 6.5) in Northern China, tea plants are prone to yellowing disease, albinism, and reductions in components that contribute to plant quality, which affect the scale and rate of tea plantation development in Northern China. To investigate the potential causes of these issues, Camellia sinensis cv. Pingyang Tezao and Camellia sinensis cv. Ruixue were planted in Shouguang city (a high-pH area, soil pH > 6.5) and Rizhao city (a normal-pH area, soil pH is 4.5-5.5), respectively; differences in growth morphology, pigment content, cell structure, quality-determining components, and element content of the two varieties in the two areas were analyzed. The results showed that tea leaves planted in Shouguang had varying degrees of yellowing disease and albinism; the pigment content in both varieties was significantly lower when planted in Shouguang compared with Rizhao. The cell structure was severely damaged and the main quality-determining components were decreased. Nitrogen (N), phosphorus (P), potassium (K), zinc (Zn), copper (Cu) and manganese (Mn) contents in the leaves of the two tea plant varieties were significantly lower when planted in Shouguang compared with those in Rizhao; the levels of these elements in Shouguang soil were significantly higher than in Rizhao soil. Calcium (Ca) contents in Shouguang soil was 9.90 times higher than that of Rizhao soil. We conclude that the soil in high-pH areas hindered tea plant uptake of N, Zn, Cu, and Mn, which had a detrimental effect on chloroplasts and reductions in chlorophyll synthesis, contributing to yellowing disease and albinism. In addition, excessive calcium (Ca) in Shouguang soil was also an important contributor to these negative effects. High-pH soil hindered tea plant uptake of P and K, resulting in reductions in tea polyphenols, amino acids, and other major quality components.

Use of quarry waste basalt rock powder as a soil remineralizer to grow soybean and maize

Production costs in Brazilian agriculture have increased with the rising prices of imported soluble fertilizers. To circumvent this import dependence, low-cost indigenous nutrient sources have been tested, including basalt rock powder (BRP). In this study, we assessed BRP and limestone effects on soil fertility, and soybean and maize dry mass (DM) accumulation. Four greenhouse pots experiments were arranged in a 2 × 4 factorial design with two soils (Clay and Sandy Clay Loam) and four doses of each material (0, 33, 66, and 99 Mg ha−1 BRP and 0, 1, 2, and 4 Mg ha−1 limestone), evaluated in two species (soybean and maize). At the end of the experiments, DM, shoot P and K concentrations, and soil pH and P, K, Ca, and Mg concentrations were assessed as a function of BRP and limestone application. Applying BRP increased DM production and improved soil fertility parameters such as pH, and Ca and P concentrations, with leaf P content also increasing. Meanwhile, limestone only triggered significant changes in pH and soil Ca content.

Arctic soil CO2 release during freeze-thaw cycles modulated by silicon and calcium

Arctic soils are the largest pool of soil organic carbon worldwide. Temperatures in the Arctic have risen faster than the global average during the last decades, decreasing annual freezing days and increasing the number of freeze-thaw cycles (temperature oscillations passing through zero degrees) per year as the temperature is expected to fluctuate more around 0 °C. At the same time, proceeding deepening of seasonal thaw may increase silicon (Si) and calcium (Ca) concentrations in the active layer of Arctic soils as the concentrations in the thawing permafrost layer might be higher depending on location. We analyzed the importance of freeze-thaw cycles for Arctic soil CO2 fluxes. Furthermore, we tested how Si (mobilizing organic C) and Ca (immobilizing organic C) interfere with the soil CO2 fluxes in the context of freeze-thaw cycles. Our results show that with each freeze-thaw cycle the CO2 fluxes from the Arctic soils decreased. Our data revealed a considerable CO2 emission below 0 °C. We also show that pronounced differences emerge in Arctic soil CO2 fluxes with Si increasing and Ca decreasing CO2 fluxes. Furthermore, we show that both Si and Ca concentrations in Arctic soils are central controls on Arctic soil CO2 release, with Si increasing Arctic soil CO2 release especially when temperatures are just below 0 °C. Our findings could provide an important constraint on soil CO2 emissions upon soil thaw, as well as on the greenhouse gas budget of high latitudes. Thus we call for work improving understanding of freeze-thaw cycles as well as the effect of Ca and Si on carbon fluxes, as well as for increased consideration of those factors in wide-scale assessments of carbon fluxes in the high latitudes.

Logistic regression analysis of relationship between severity of fruit splitting and mineral element content of Prunus salicina Lindl.

To investigate the relationship between mineral elements and the severity of fruit splitting of Prunus salicina Lindl., 15 orchards with different degrees of fruit splitting were selected and divided into mild, moderate and severe splitting wards. The correlations of the severity of fruit splitting with soil physical and chemical properties and mineral element content in leaves were analyzed by logistic regression analysis. The results revealed that when the content of soil organic matters was high, the bulk density was low and the total porosity was high, or when the calcium (Ca) content in soil and leaves was high, the fruit splitting of Prunus salicina Lindl. was milder. It is worthy of noting that the higher the manganese (Mn) content in soil and leaves, the severer the fruit splitting of Prunus salicina Lindl. Whether its pathogenic mechanism works by inhibiting Ca absorption or triggering Mn toxicity requires further research.

The Characteristics of Soil Ca and Mg Leakage in a Karst Depression

The soil leakage characteristics of depressions in karst areas should be explored by investigating their soil Ca and Mg contents. As a starting point, in a karst landform typical of Guizhou Huajiang dry valley karst watersheds, we selected surface depression and performed a field investigation, soil profile excavation, and soil sample collection. The soil samples were pretreated and taken to the laboratory for soil physical and chemical analysis. The data were processed, and the Ca and Mg contents of the soils were analyzed to determine the spatial variation characteristics of soil leakage in the depression. We found that in the depression watershed, the Ca and Mg contents in the 0–30 cm soil profile generally increased with increasing soil depth, and the Ca and Mg contents in the 30–150 cm soil profile exhibited more variability with increasing soil depth. The Ca and Mg in the soil surface profiles from the top of the slope, middle of the slope, base of the slope, bottom of the depression, and sinkhole showed obvious characteristics of a sedimentary soil leakage migration path. In combination with analyses of the soil K and N contents, the soil Ca and Mg contents can be used as an index of the likelihood of soil and water leakage in karst depressions.

Linking tree water use efficiency with calcium and precipitation.

Water use efficiency (WUE) is a key physiological trait in studying plant carbon and water relations. However, the determinants of WUE across a large geographical scale are not always clear, limiting our capacity to predict WUE in response to future global climate change. We propose that tree WUE is influenced by calcium (Ca) availability and precipitation. In addition, although it is well-known that transpiration is the major driving force for passive nutrient uptake, the linkage between these two processes has not been well-established. Because Ca uptake is an apoplastic and passive process that purely relies on transpiration, and there is no translocation once assimilated, we further developed a theoretical model to quantify the relationship between tree Ca accumulation and WUE using soil-to-plant calcium ratio (SCa/BCa) and tree WUE derived from δ13C. We tested our theoretical model and predicted relationships using three common tree species across their native habitats in Northern China, spanning 2300km and a controlled greenhouse experiment with soil Ca concentrations manipulated. We found that tree WUE was negatively related to precipitation of the growing season (GSP) and positively with soil Ca. A multiple regression model and a path analysis suggested a higher contribution of soil Ca to WUE than GSP. As predicted by our theoretical model, we found a positive relationship between WUE and SCa/BCa across their distribution ranges in all three tree species and in the controlled experiment for one selected species. This relationship suggests a tight coupling between water and Ca uptake and the potential use of SCa/BCa to indicate WUE. A negative relationship between SCa/BCa and GSP also suggests a possible decrease in tree Ca accumulation efficiency in a drier future in Northern China.

Formulasi Limbah Cangkang Telur Ayam Ras Dengan Kompos Limbah Pasar untuk Peningkatan Hasil Sawi Hijau (Brassica juncea L.)

The formulation of chicken eggshell waste with market waste compost to increase the yield of green mustard (Brassica juncea L.). Aims to find the best and environmentally friendly organic fertilizer formula to increase the yield of green mustard and improve some soil chemical properties. This research is a pot experiment in a greenhouse, using a simple randomized block design consisting of 7 combinations. Fertilizer formulas that were tried were: F0 (without treatment), F1 = (100 kg of shell + 10 tonnes of compost), F2 = (200 kg of shell + 8 tonnes of compost), F3 = (300 kg of shell + 6 tonnes of compost), F4 = (400 kg of shell + 4 tons of compost), F5 = (500 kg of shells + 2 tons of compost), F6 = (600 kg of shells + 0 tons of compost), and each treatment was repeated 4 times. The parameters observed included: maximum plant height (cm), fresh plant weight at harvest, oven dry plant weight, soil pH, C-organic content, CEC and soil Ca content at harvest. The data were analyzed statistically, tested for variance. If the effect of the treatment had significant, then continued with the 5 % Duncans test. The results of this study indicate that the treatment has a significant effect on plant height growth, fresh weight and oven dry weight of plants, as well as changes in soil chemical properties such as: C-organic, soil CEC, and soil Ca content. The fresh plant weight was obtained in treatment F2 (9.55 g), followed by F3 (9.37 g), and F1 (9.18 g) per pot. While the highest CEC was obtained in the F2 treatment (36.31 me 100 g-1) with a soil Ca content of 7.52 me 100 g-1. The best fertilizer formula from this study was found in the F2 treatment.

Status of Essential Elements in Soil and Grain of Organically Produced Maize, Spelt, and Soybean

Organic agriculture offers many benefits through the increased nutritional quality of produced crops, agro-ecosystem preservation, and climate change mitigation. The development of an efficient nutrient management strategy in low-input systems, such as organic agriculture, which supports soil fertility and essential nutrients absorption by crops, is continually exploring. Thus, a study with maize–spelt–soybean rotation during a 5-year period in organic production was established to evaluate the variability in soil organic matter (SOM) and the status of available elements: N, P, K, Ca, Mg, Fe, Cu, Mn, Zn, and Si from the soil, as well as grain yield (GY) and the content of protein, P, K, Ca, Mg, Fe, Cu, Mn, Zn, and Si concentration in the grain of spelt, maize, and soybean. Significant variations in mineral elements in the soil, GY, and grain composition were detected. Spelt achieved the highest average GY, while soybean grain was the richest in a majority of examined nutrients. The soil Ca content was important for GY, while the protein level in grain was generally tied to the Mn level in the soil. It was recognized that soil–crop crosstalk is an important strategy for macro- and micro-nutrients management in the soil and grain of organically produced spelt, maize, and soybean. While a reduction in the GY and protein concentration in grain was present over time, it was established that a low-input system under dry-farming conditions supports nutrient availability and accumulation in grain, under semi-arid agro-ecological conditions of central Serbia.

Predicting habitat suitability for the endangered species Hedysarum criniferum Boiss. using a fuzzy model in the semi-arid zone in Iran

The present study explored the habitat suitability for an endangered species, Hedysarum criniferum, in Iran using fuzzy logic. We measured 24 environmental variables including soil, climate, and physiographic variables of eight natural habitats of H. criniferum as the predictive variables and the percent cover of the species as the response variable. The most important environmental factors influencing species distribution and the species response curves were determined by principal component analysis (PCA) and the generalized linear model, respectively. The tolerance range and the optimal growth point of the studied species with respect to the environmental factors were specified, the ranges were divided into 11 classes by fuzzy value, and the fuzzy functions of the environmental factors were calculated. The species habitats were classified by the developed fuzzy model. Three regions with no H. criniferum occurrence were selected to determine their fuzzy suitability. The success in germination and shoot growth length of H. criniferum were used as the metrics of the habitat suitability in these regions. Based on the PCA, H. criniferum occurrence was most strongly affected by soil Mg, K, and Ca content, soil pH, wind speed, annual minimum temperature, slope, and altitude. The results revealed that the seedling length and germination percentage in the site with the fuzzy suitability of 0.6 differed from those in the two other sites with the fuzzy suitability of 0.5 and 0.3 significantly. The method used in this study can be employed in predicting optimal habitats for other endangered species in different ecosystems.

Removal of invasive Scotch broom increases its negative effects on soil chemistry and plant communities

Recovery of ecosystem properties following removal of invasive plants likely varies with characteristics of the plant and the relative soil quality at a given site. These factors may influence the occurrence of soil legacies and secondary invasions, hindering the effectiveness of restoration strategies. We assessed the potential for ecosystem recovery following removal of N-fixing Scotch broom for 4years at two sites that contrasted strongly in soil quality in western Washington and Oregon, USA. Comparisons were made among plots, where Scotch broom was never present (uninvaded), retained, or removed. Scotch broom removal increased PAR and soil temperature but had limited effects on soil moisture. Concentrations of soilCa, Mg, K, and P were significantly lower with Scotch broom removal, with the effect being most pronounced at the low-quality site. NMS ordinations indicated that the treatments differed in vegetation composition, with limited recovery following broom removal. Non-native and native species varied inversely in their abundance responses, where non-native species abundance was greatest in the removal treatment, intermediate in the retained treatment, and lowest in the uninvaded treatment, indicating occurrence of a secondary invasion following removal. As with the soil response, effects were more pronounced at the low-quality site. Our findings indicate that Scotch broom removal exacerbates negative effects on soil chemistry and plant communities, with little evidence of recovery over our study period. These findings highlight the importance of controlling Scotch broom invasions immediately after the species establishes, especially on low-quality sites that are more susceptible to Scotch broom invasion.

Liming and biochar on sorghum growth and Arenosol chemical properties in the Semiarid environment

ABSTRACT: This research evaluated the effect of liming (with and without) and biochar (with and without) on sorghum cv. BRS Ponta Negra growth and Arenosol chemical properties in the Semiarid environment. The experimental design was in randomized blocks, with treatments in a 2x2 factorial scheme, corresponding to the application or not of lime (0 and 2.5 t ha-1) and biochar (0 and 12.5 t ha-1). Biochar was produced from cashew branches. The experiment was conducted in 16 m² plots where the forage sorghum cultivar BRS Ponta Negra was cultivated. The soil chemical characteristics, the production attributes, and the structural characteristics of the sorghum cultivar studied were evaluated. There was no interaction between factors. The use of biochar increased the pH and Ca and P contents in the soil and contributed to increasing the panicle mass (2.51 t ha-1 of DM). Lime application affected the soil Ca content as the dose of 2.5 t ha-1 resulted in higher values of culm diameter (15.25 mm), panicle mass, and culm mass (2.63 and 7.50 t ha-1 of DM, respectively). Therefore, these results allowed to outline strategies for the use of limestone and biochar for forage production in semiarid environments in sandy soils. Because, these materials improve some chemical attributes of the soil and the production of forage sorghum. It is noteworthy that edophoclimatic conditions can change the response patterns observed in this research. Therefore, research in other regions is essential.