Soil Penetration Resistance Research Articles

Effects of Tillage and Sowing Methods on Soil Physical Properties and Corn Plant Characters

In the northeast plains of China, the intensive utilization of agricultural soils has been a persistent issue, and finding ways to utilize soil resources efficiently and sustainably through a scientifically-driven management system has become a crucial challenge for agricultural production. Conservation tillage is a crucial technology for sustainable agriculture. Currently, plow and rotary tillage are the dominant methods used in Mollisols, but there is limited information on the effects of different conservation tillage practices in this region. The objective of this study was to investigate the short-term impact of tillage and sowing methods on soil physical properties and corn plant growth and to examine the relationship between soil physical properties and plant characteristics during various stages of growth. This study consisted of four tillage and sowing methods: plow tillage and precision seeder sowing (PTS), rotary tillage and precision seeder sowing (RTS), no-tillage and no-tillage seeder sowing (NTS), and no-tillage and precise sowing in stubble field (STS) (all four treatments involved total straw return). The results indicated that the soil penetration resistance (SPR) in the 10–40 cm soil layer under the PTS treatment was significantly lower (by 11.9% to 18%) compared to the other treatments (p < 0.05). On average, the soil moisture content in the NTS treatment was 2.7% and 1.4% higher than that of the PTS and RTS treatments. Additionally, soil temperature was 5.6% to 8.6% lower under the STS treatment compared to the other treatments during late corn growth. The RTS treatment also significantly reduced the bulk density of surface soil. High SPR impeded early crop growth but did not impact mid-crop development, while low soil temperature was one of the main factors affecting late corn growth and development as temperatures decreased. Based on the comparisons, we found that the short-term implementation of conservation tillage did not result in a significant decrease in corn yield. We believe that the short-term implementation of NTS tillage sowing practices in Mollisol regions is a feasible option.

How Much Impact Has the Cover Crop Mulch in Mitigating Soil Compaction?—A Field Study in North Italy

Soil compaction was largely studied in different scenarios with laboratory and field scale experiments, with various soil conditions and traffic intensities. However, a detailed analysis to better understand the protective role of plant residues or cover crop mulch is still required. A field test was conducted in Northeast Italy aiming to fill this gap. Rye was chosen as a winter cover crop, and growth on a controlled traffic random block experimental field. Four different cover crop mulch treatments were compared to study the effects of root systems: roller crimper, flail mower, bare soil control and harvested biomass control. Four different traffic intensities were used to evaluate the multiple passages with 0, 1, 3, 5 traffic events. During traffic events, the mean normal stress was measured. Penetration resistance was then evaluated after trafficking and soil samples were collected. The obtained results showed a 19.3% cone index increase in bare soil compared to flail mower treatment after the first traffic event, while low differences were found in harvested biomass bulk density during the first and third traffic events. Moreover, mean normal stress increased 16.5% on harvested biomass treatment compared to the flail mower. These findings highlight that the cover crop maintains a lower soil penetration resistance during compaction events, helping the subsequent field operations. Furthermore, roller crimper and flail mower cover crop termination impact soil bearing capacity differently due to different soil moisture content. However, the results showed a low contribution of cover crop mulch on mitigating soil compaction effects during the experiment.

Influence of soil compaction and moisture variation on development of sesame (sesamum indicum l.) plant in a sandy loamy soil

This study determines the influence of soil compaction on shoot, root development and nutrients uptake of sesame (sesamum indicum l.) plant in a sandy loamy soil. The research was carried out in Mokwa local government of Niger state during wet season. Three soil samples of 300g weight from the top 20cm of the soil profile were taken from college farm. The initial moisture content of the soil was determined using oven-drying method. The soil samples were air dried, large clods broken and grounded. The soil samples were then mixed to obtain a homogenous mixture of the sample. The soil moisture content was then raised to varying moisture levels of 10%, 12%, and 14% exceeding the optimum moisture content of sandy loam which is 12% moisture. Each sample was subjected to five levels of compaction energy using 0,5,10,15,20 blows of a standard proctor hammer in cylindrical cores of 17cm in height and 10cm diameter in accordance with the standard proctor compaction procedure. Four holes were made in each can and four seeds were sown in each hole to be thinned into one seed per hole (four plants in each can). The depth of sowing was one cm. The seedlings were tinned to a maximum of five (5) per core at 15 days after planting. The heights (cm) of the seedling were taken with a measuring tape at 5-days interval to 20 days after planting. The experiment was laid out in randomized complete block design (RCBD). The data collected were subjected to descriptive statistical analysis, regression analysis and analysis of variance. The results from the soil physical properties analysis shows that the soil is sandy loam with sand being 76.8 % and clay as 11.2%. The bulk average density was 1.75 g/cm3. Results obtained from the study shows that compactive efforts significantly affect plant growth and development. It also shows that as compactive effort increases, the soil bulk density and penetration also increases. The effect of number of hammer blows on soil bulk density and penetration resistance was significant. The effect of excessive moisture also affects germination and plant growth. Moderate soil compaction has beneficial effect. This is due to greater water retention. In general, it appears that there is a great potential in growing sesame on sandy loam soil, if the level of compaction is maintained at moderate level, which does not impede root development and other plant requirements.

Mountain recreation impact on changes in soil penetration resistance of spruce forests

The uniqueness of the Carpathian Mountain Forest ecosystems, a large part of which belongs to nature conservation areas, attracts a significant number of visitors annually. Intensive tourist flow on popular hiking trails leads to recreational digression, topsoil compaction, development of erosion processes and deterioration of forests. The research aims to determine the impact of recreation as an external mechanical impact on soil compaction by determining the soil penetration resistance under the canopy of predominant spruce stands. For this purpose, soil penetration resistance was measured with a penetrometer along two hiking trails within the root layer of the soil at four measuring sites at different distances from the hiking trail. In general, under the canopy of a forest stand, the soil cover is not homogeneous and the obtained penetration resistance values are characterised by considerable variability. It was revealed that for the “Zelene village – Uhorski skeli rocks” hiking trail in the areas close to the path (up to 20 m) there is a significant increase in soil penetration resistance compared to remote areas: at a depth of 10 cm it doubles, at a depth of 20 cm – by 20-40%, but with further deepening, the penetration resistance level off. At the same time, for the more popular “To Mount Pip Ivan Chornohirskyi” hiking trail, in the area adjacent to the trailbed, the penetration resistance reaches 19.6 kg·cm-2 in the upper 10 cm layer, and at a depth of 30 cm, it peaks at 37.8 kg·cm-2 (over 3 MPa), which affects the root spatial distribution of spruce forests. Intensive erosion processes due to soil compaction with an increase in soil penetration resistance above 60 kg·cm-2 (~6 MPa) are observed on the trailbed. The practical significance of the results obtained, and the established patterns is to complement existing methods for assessing the degree of recreational digression in mountainous conditions and can be the basis for designing measures to regulate tourist flows and restore affected areas

Soil carbon dynamics under organic farming: Impact of tillage and cropping diversity

Ecological indicators are herculean contrivance for assessing management practices' impacts on environmental changes. Soil organic carbon (SOC) potentially regulates the agricultural sustainability. Unfortunately, the SOC has been widely degraded through unsustainable land uses and agricultural practices. Hence, the efficacy of conservation tilling and diversified cropping were assessed in terms of restoration of SOC and associated soil properties in fixed plots, which are related with farm productivity and other ecosystem services under organic production systems of the Indian Himalayas. Three tillage management were selected as treatments of the study: i) conventional tilling (CT), ii) reduced tilling (RT), and iii) Zero tilling (ZT) applied to four diversified cropping systems [CS1- maize–black gram–toria, CS2 maize–black gram–buckwheat, CS3- maize–rajmash–toria and CS4 maize–rajmash–buckwheat]. The ZT had the highest SOC content (19.58 g kg−1) as well as the C pool (25.24 Mg ha−1) at a soil depth of 0–10 cm. On the contrary, ZT had the lowest ρb (1.29 Mg m3) and soil penetration resistance (1.32 MPa) at 0–5 cm and 5–10 cm soil depth. Concerning SOC partitioning, regardless of soil depth, it had been evident that more SOC were allocated in the active pool over the passive pool. Out of the diversified cropping systems, the CS2 produced a considerably higher total carbon pool of 24.98, and 23.0 Mg ha−1 at 0–10 cm, and 10–20 cm soil depths, respectively, and active and passive C pools. Hence, abolition of tillage and cultivation of legume embedding cropping systems resulted as a sustainable management system under organic farming for SOC restoration and soil quality improvement in the Himalayan ecosystem. Thus, the study suggested that the cultivation of CS2 under ZT may be promoted for efficient land resource management planning in the study region of the Indian Himalayas.

Assessing Subsoil Conditions with an ASABE Conform Vertical Penetrometer-Development and Evaluation.

Soil is the habitat for soil organisms and associated soil physical and chemical processes. The subsoil is a large reserve of water and nutrients. Soil and subsoil are thus significantly involved in the yield capacity of a site and its resilience in the case of unfavorable weather conditions. Subsoil can also retain water in drought phases and stores carbon. In times of climate change and scarcity of resources, many scientific activities involve subsoil and require sensors to assess subsoil conditions and properties. An electrically driven penetrometer with an integrated soil water content sensor could be an appropriate tool for such applications; however, such a subsoil measurement tool does not exist. One major reason for this is that, when penetrating compacted subsoil, high penetration forces (including friction) act on the penetrating thin rod (diameter 1 cm). The development of a tractor-mounted subsoil penetrometer for depths up to 2 m is described in this study. An ASABE standard cone is implemented, which can access heavy compacted layers. The rod, which includes wires for embedding an FDI moisture sensor in the cone tip, is covered by a protection tube. The penetration resistance measurement can be performed without being influenced by shaft friction. The rod, along with the sensor, is implemented in a tower that can be shifted laterally and can take probes in a single line without moving the tractor. To confirm the quality of the developed subsoil penetrometer, a suitable evaluation method is presented. Typical arable soil (loamy silt) was filled in boxes and compacted homogeneously using a hydraulic stamp so that different setups of the penetrometer could be compared and evaluated. The evaluation concludes that the distance between the free cone tip and the protection shaft should be at least 10 cm to measure the penetration resistance of soil without being influenced by the protection tube. Furthermore, the developed penetrometer has sufficient stability and precision for accessing subsoil. In field trials, the subsoil penetrometer was compared with a standard penetrometer and has proved its suitability.

How tine characteristics of subsoilers affect fuel consumption, penetration resistance and potato yield of a sandy loam soil

Subsoil compaction has become a widespread problem for modern agriculture. Subsoiling is the most common measure to try and deal with this problem. However, despite the widespread use of this type of deep tillage, its effectiveness and sustainability are not without dispute. Previous studies show a great variety of outcomes depending on soil texture, soil moisture content, weather conditions and subsequent field operations, but the effects of the wide variety in available subsoilers have remained understudied. This study evaluated the effectiveness and sustainability of three different subsoilers on a sandy loam soil with a highly compacted upper-subsoil. The tested subsoilers differed in the number of tines, and thus the spacing between them, and several other tine characteristics, like the width of the tine foot and the curvature of the tine. The choice of subsoiler showed a clear impact on soil disruption, fuel consumption and mechanical resistance after one year. Limiting subsoil disturbance by using a subsoiler with less tines seems to have the potential of slowing down recompaction, measured indirectly via penetration resistance, in the upper-subsoil. This would help reduce the frequency of subsoiling, which clearly is a high cost field operation. This experiment highlighted the importance of not over-expanding the working depth of the subsoiler. Not all available subsoilers will be able to disrupt the subsoil down to depths where compaction can regularly be found in Europe and even relatively powerful tractors will be pushed to their limits during these deep tillage operations. Even when effectively breaking open the compacted subsoil layer, no significant effects on potato (Solanum tuberosum L.) yield were observed. Most likely linked to the rather wet conditions prevailing during the tuber bulking period, reducing the potential benefit of opening up the subsoil to root exploration.

The role of coffee agroforestry on available water capacity and root length density in smallholder plantation

Abstract. Khoirunnisak A, Prijono S, Wicaksono KS. 2023. The role of coffee agroforestry on available water capacity and root length density in smallholder plantation. Biodiversitas 24: 55-61. The application of coffee agroforestry has several advantages, such as increasing the cycle of nutrients and soil organic matter as well as improving soil physical properties. However, there is still an information gap related to the interaction between coffee plants and shade plant roots. This study aimed to evaluate coffee agroforestry on available water capacity (AWC) and root length density (RLD). The research was carried out at the smallholder coffee plantation in Dampit District in four shade types (coffee-open, shaded with Musa sp., shaded with Gliricidia sp., and shaded with L. leucochepala). Soil and root samples were taken at three depths (0-20 cm, 20-40 cm, and 40-60 cm) and at two distances (near the coffee stems and between the coffee shade). The variables observed were AWC, RLD, soil organic C, soil aggregate stability, and soil penetration resistance. The result was coffee plants with shade trees increased AWC value and root density compared to coffee-open. The type of shade significantly affected RLD, where shaded with Gliricidia sp., and shaded with L. leucochepala were better than coffee-open. This indicates that there was no root competition between coffee plants and shade trees. However, shaded with Musa sp. had lower RLD than coffee-open. Soil depth had a significant effect on the AWC value and root length density of coffee plants, where the most AWC values ??and coffee root distribution were higher at a depth of 0-20 cm.

Modelling and analysis of penetration resistance of probes in cultivated soils.

At present, the measurement of tillage depth is mainly based on manual measurement, but the manual raking method results in low measurement accuracy and high labor intensity. Due to the complexity of soil, theoretical research on tillage depth is relatively scarce. In order to provide a new research direction and research idea for soil stratification, topsoil was taken as the research object of this paper. The correlation between penetration resistance and penetration depth of a probe in a cultivated soil was studied, and a mathematical model was established. There is a certain similarity between the process of spherical cavity expansion and the process of probe penetration, so we introduced the theory of spherical cavity expansion into the modeling of penetration resistance of the cultivated soil. In this paper, the spherical cavity expansion theory of unsaturated soil was used as the basis for solving the penetration resistance. And the unified strength criterion was employed as a yield condition of the soil to set a stress solution and a displacement solutionin into of the probe penetrating into the elasto-plastic zone of the cultivated soil to determine the model of expansion force. We have carried out indoor tests to revise the expansion force model. Firstly, according to the range of soil density and water content in the field, the soil densities were classified into 1.1×103kg/m3, 1.2×103kg/m3 and 1.3×103kg/m3, and the water contents were divided into 10%, 15% and 20%. In addition, the orthogonal tests were performed at different levels. The soil was put into the barrel, and the probe was inserted into the soil in the barrel at the speed of 8mm/s to determine the test values of the change of the probe penetration resistance with depth. Finally, the expansion force model was fitted with the results of the indoor test, and coefficient B was introduced to express the influence degree of density and water content on the resistance. Coefficient B was substituted into the expansion force model to obtain the penetration resistance model of the cultivated soil. Through the goodness of fit analysis of the penetration resistance model, the results show that the overall average goodness of fit of the penetration resistance modelat was up to 0.871 at different water contents and densities, which was a good fit and could present novel insights into the study relating to soil stratification theory.

Mapping of soil chemical attributes in pasture areas in the Cerrado of Piauí, Brazil

The low natural fertility and compaction of agricultural soils in the Cerrado are the main limitations for agricultural production. Changes in management systems are necessary to optimize the use of natural resources. The objective of this study was to map and evaluate the presence of penetration resistance and its relationship with soil chemical attributes in pasture areas in the Cerrado of Piauí. The experiment was carried out in the municipality of Corrente-PI, Brazil. The area was divided into two sub-areas of 0.5 ha each: the first is remaining vegetation and the second is pasture. Fifty soil samples were collected in the 0.00-0.20 and 0.20-0.40 m layers, with a sampling grid of 10 x 10 m. The pH in water, organic matter, calcium, magnesium, and soil penetration resistance were analyzed. The introduction of animals in the pasture area increased soil compaction by 2%. Chemical attributes, pH, organic matter, calcium and magnesium vary according to soil compaction by 2%. The native forest area has soil penetration resistance at acceptable levels (<2 MPa) and availability of nutrients at adequate levels. The maps of variability of organic matter, calcium, magnesium and penetration resistance showed the heterogeneity of the areas, allowing decisions based on specific management zones, localized application of nutrients and decompaction, and recovery of areas with inefficient management.

IMPACT OF TILLAGE PRACTICES ON PROPERTIES OF SOIL, EVAPOTRANSPIRATION AND PRODUCTIVITY OF COWPEA IN NIGERIA

<p><strong>Background</strong>: Tillage is one of the major threats to soil health which often results into soil physical degradation if not properly managed. Zero tillage is an alternative option from both economic and environmental protection of our soil resources points of view. <strong>Objective. </strong>To evaluate responses of cowpea (<em>Vigna unguiculata</em>) yield and evapotranspiration to different tillage practices.<strong> Methodology</strong>. The study was conducted in Obafemi Awolowo University, Ile-Ife Osun State, Nigeria using a replicated randomized complete block design with treatments consisting of Zero-tillage (ZT), Reduced tillage (RT), Conventional tillage + Mulch (CT + ML) and Conventional tillage (CT). <strong>Results. </strong>Soil penetration resistance (SPR) increased with the degree of soil manipulation during tillage practices. Penetration resistance (PR) across 15-30 cm in 2019 alone resulted in higher PR of 2.26 MPa for RT compared to 0.71, 0.72 and 0.79 MPa for ZT, CT + (ML and CT), respectively, approximately 218 %, 213 % and 186 % greater in RT than ZT, CT + ML and CT respectively. <strong>Implications. </strong>Cowpea production on sandy loam soil can be optimized with Zero tillage. <strong>Conclusion.</strong> Over a period of two years, ZT practice had the highest profit margin of $ 573, among the practices. </p>

Tillage-Depth Verification Based on Machine Learning Algorithms

In an analysis of the penetration resistance and tillage depth of post-tillage soil, four surface-layer discrimination methods, specifically, three machine learning algorithms—Kmeans, DBSCAN, and GMM—and a curve-fitting method, were used to analyze data collected from the cultivated and uncultivated layers. Among them, the three machine learning algorithms found the boundary between the tilled and untilled layers by analyzing which data points belonged to which layer to determine the depth of the soil in the tilled layer. The curve-fitting method interpreted the intersection among data from the fitted curves of the ploughed layer and the un-ploughed layer as the tillage depth. The three machine learning algorithms were used to process a standard data set for model evaluation. DBSCAN’s discrimination accuracy of this data set reached 0.9890 and its F1 score reached 0.9934, which were superior to those of the other two algorithms. Under standard experimental conditions, the ability of DBSCAN clustering to determine the soil depth was the best among the four discrimination methods, and the discrimination accuracy reached 90.63% when the error was 15 mm. During field-test verification, the discriminative effect of DBSCAN clustering was still the best among the four methods. However, the soil blocks encountered in the field test affected the test data, resulting in large errors in the processing results. Therefore, the combined RANSCA robust regression and DBSCAN clustering algorithm, which can eliminate interference from soil blocks in the cultivated layer and can solve the problem of large depth errors caused by soil blocks in the field, was used to process the data. After testing, when the RANSCA and DBSCAN combined method was used to process all samples in the field and the error was less than 20mm, the accuracy rate reached 82.69%. This combined method improves the applicability of discrimination methods and provides a new method of determining soil depth.

Technological Advances in Soil Penetration Resistance Measurement and Prediction Algorithms

Soil compaction is one of the most harmful elements affecting soil structure, limiting plant growth and agricultural productivity. It is crucial to assess the degree of soil penetration resistance to discover solutions to the harmful consequences of compaction. In order to obtain the appropriate value, using soil cone penetration requires time and labor-intensive measurements. Currently, satellite technologies, electronic measurement control systems, and computer software help to measure soil penetration resistance quickly and easily within the precision agriculture applications approach. The quantitative relationships between soil properties and the factors affecting their diversity contribute to digital soil mapping. Digital soil maps use machine learning algorithms to determine the above relationship. Algorithms include multiple linear regression (MLR), k-nearest neighbors (KNN), support vector regression (SVR), cubist, random forest (RF), and artificial neural networks (ANN). Machine learning made it possible to predict soil penetration resistance from huge sets of environmental data obtained from onboard sensors on satellites and other sources to produce digital soil maps based on classification and slope, but whose output must be verified if they are to be trusted. This review presents soil penetration resistance measurement systems, new technological developments in measurement systems, and the contribution of precision agriculture techniques and machine learning algorithms to soil penetration resistance measurement and prediction.

Effectiveness combination of leucaena compost and coconut shell biochar on reduce soil compaction and corn growth in ultisol

This study aims to identify optimal dose combinations that significantly impact reducing soil compaction in Ultisols and corn growth. The randomized block design (RBD) was utilized to conduct the study. The ameliorant materials consisted of leucaena compost and coconut shell biochar, which were divided into ten treatments and three treatments with 10 treatments & 3 group for each treatment. The treatments were combinations of coconut shell biochar leucaena compost and inorganic fertilizer. Soil physical parameters, such as soil organic matter, bulk density, porosity, and penetration resistance, were monitored during the study. The analysis was conducted using ANOVA at 95% confidence level (α = 5%). Subsequently, Duncan Multiple Range Test (DMRT) was conducted to evaluate the average effect of treatment. The result of the study indicated that Treatment of 5 tons/ha compost + 5 tons/ha biochar + ½ dose of inorganic fertilizer was able to reduce soil density compared to the control and showed a decrease in bulk density, as well as an increase in soil porosity, and a decrease in the value of soil penetration resistance. Treatment of 10 tons/ha of compost with 10 tons/ha of biochar + ½ dose of inorganic fertilizer is the best treatment for corn growth.

Fall–winter cover crops promote soil health and weed control in the southeastern clayey soils

AbstractSeven winter cover crops including grasses, legumes, and brassicas were evaluated for biomass production and effects on weed presence, stored soil water, soil health indicators, and the performance of a subsequent soybean [Glycine max (L.) Merr.] crop in the clayey soils of South Carolina during 2019–2020 and 2020–2021. A mixture of Austrian winter pea (Pisum sativum L.), rye (Secale cereale L.), crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa Roth), and oat (Avena sativa L.), a mixture of crimson clover and rye, and single rye ranked high for biomass production. Cover crops did not deplete more soil water than a fallow did (–22 to 8% difference in soil water retention, compared to fallow with or without herbicide application), controlled weeds equally well or better than herbicides (>90% reduction in weed presence, compared to herbicide control), and reduced soil penetration resistance (>40%, compared to fallow with or without herbicide application in the second season). The five‐species mixture also improved soil biological activity (>43% increase in soil respiration at cover‐crop termination, compared to that under a chemical fallow). The subsequent soybean crop's yield was never negatively affected if not improved by the above cover crops (9–173% increase, compared to that following a chemical fallow). Our results indicate the suitability of the above cover crops for the southeastern clayey soils based on biomass production, weed suppression, and improvements in soil health and the subsequent soybean crop's performance and provide the rationale for planting them rather than keeping the land under a chemical fallow.

Effectiveness of narrow tyne and double-discs openers to overcome shallow compaction and improve soybean yield in long-term no-tillage soil

Compaction adversely affects the soil physical quality and crop yields in no-tillage (NT) systems. No-tillage seeders equipped with narrow tyne openers may be a cost-effective option to overcome shallow compaction in NT soil and reduce the reliance on tillage for seedbed preparation and crop establishment. This study was conducted to: (1) quantify changes in soil physical quality indicators and determine the crop response to the use of a NT seeder equipped with either narrow tyne or double-disc openers, and (2) evaluate the potential of seeding tynes to overcome shallow compaction in NT soils of southern Brazil. Soil compaction was induced by applying 0, 3, 6, and 9 tractor passes equivalent to 84 %, 89 %, 94 %, and 99 % of the degree of compactness. In each treatment, a narrow tyne opener was used for the deposition of fertilizers compared to double discs. Undisturbed soil samples were taken from the 0–0.10 and 0.10–0.20 m depths and used to measure soil bulk density, soil water and air storage capacity, and the Least Limiting Water Range (LLWR). Soil penetration resistance and soybean (Glycine max L., Merr.) yield were also measured during the 2014/2015 cropping season. Soil bulk density and soil water storage capacity increased while air storage capacity and the LLWR decreased with an increase in the degree of compactness. The use of narrow tyne openers reduced soil penetration resistance in the 0.0–0.10 m layer by up to 66 % compared with the use of discs, and increased soybean yield by an average of 600 kg ha-1 (or US$ 227 per ha). By contrast, the use of double-discs on previously compacted soil resulted in yield penalties of up to 1200 kg ha-1. Soybean yield was more strongly correlated with LLWR (r = 0.97) than with any other measured soil physical quality indicator. Overall, these results supported the hypothesis that the use of NT seeders equipped with narrow tyne openers was effective in overcoming shallow compaction in NT soil.

Response of soil macrofauna to urban park reconstruction

• Soil penetration resistance increases as a result of park reconstruction.• Soil compaction explains one-third of the variability in soil macrofauna.• The abundance of the earthworm Aporrectodea rosea increases after reconstruction.• The abundance of the earthworm A. calliginosa decreases after reconstruction.This study is based on a park in an industrial city in Ukraine. In 2019, a 2.8 ha area of the park was reconstructed. The park’s reconstruction aimed to create a comfortable environment for visitors and to improve the efficiency of ecosystem services, and thereby enhance the quality of life of citizens. The reconstruction of the park was found to cause changes in the physical properties of soils and the structure of the soil macrofauna community. The increases of soil compaction in the layers at depth 5–20 cm and the soil electrical conductivity were a consequence of technological operations during reconstruction. The park reconstruction activities can also explain 29% of the variation in the soil macrofauna community. Extracting the variation induced by the park reconstruction from the community variation induced by other causes was a major challenge. The specific changes in the community of soil macrofauna following the reconstruction of the park were revealed. The abundance of soil animal species A. rosea, A. trapezoides, H. affinis, H. rufipes, B. affinis was found to increase after the reconstruction. The earthworm A. trapezoides decreased in abundance due to the park reconstruction.

Predicting arbuscular mycorrhizal fungal colonization of soybean in farmers’ fields by using infection unit density

ABSTRACT Estimating arbuscular mycorrhizal (AM) fungal activity to colonize crop root before cultivation is prerequisite for effective utilization of their functions which enhance growth and yield of the plant especially under low fertilizer input. We have hypothesized that the infection unit (IU) density formed on test plant roots grown for short period (12 days) with soil sampled from soybean production fields would be an effective indicator to predict AM fungal colonization intensity to the plant. In order to test this hypothesis, three-year farmland survey was conducted, in which soil samples before sowing soybean and the plant root samples at third trifoliate (V3) and full bloom (R2) stage were collected from farmers’ fields in two regions in Hokkaido, Iwamizawa and Tokachi. For each sampling spot, IU density was determined by using test plants, and intensity of AM fungal colonization of soybean root was measured. Before pursuing field survey, laboratory experiments were conducted to find out proper soil storage condition that keeps IU density unchanged while handling many soil samples. Our results indicated that IU density was almost comparable to the original value after six-month storage if soil samples were kept in a refrigerator, although storing at ambient temperature significantly decreased the measurement. Air drying also had negative impact on IU density. According to the field survey, IU densities determined using field soil were positively and significantly correlated with AM fungal colonization of soybean roots at both V3 and R2 stages. Differences in climate, soil type, and style of agriculture between Iwamizawa and Tokachi seemed to have little effect on IU density-AM fungal colonization relationship. Other than IU density, soil pH and soil penetration resistance at 10 cm depth were selected as significant explanatory variables for predicting AM fungal colonization by multiple regression analysis. However, IU density was the most influential factor among three. Therefore, IU density is recognized as an effective measure to evaluate AM fungal colonizing activity in field soil.

Response of seasonal variation in soil detachment capacity to straw incorporation in sloping farmland on the Loess Plateau

AbstractSoil detachment capacity by rill flow (Dc) is sensitive to changes in topsoil properties generated by crop straw incorporation. In the present study, we investigated the effect of crop straw incorporation on the seasonal variation in Dc, the knowledge regarding which is limited currently, and identified the key influencing factors. Three typical crop straw types (wheat, soybean, and maize) were selected for this study. Soil samples incorporated with crop straw and without crop straw were collected over 375 days (from October 1, 2020 to October 10, 2021) and were subjected to a hydraulic flume (length, 4.0 m; width, 0.2 m) to determine Dc. The topsoil properties soil bulk density (BD), soil cohesion (Coh), soil penetration resistance (PR), soil organic matter content (SOM), mean weight diameter (MWD), and straw decomposition rate (SDR) were measured to explain the seasonal variation in Dc. The results showed that crop straw incorporation effectively reduced Dc, and the Dc for the soil incorporated with straw decreased by 25.92%–38.76% compared with that without straw incorporation. Dc exhibited a significant decreasing trend over time, and the Dc at the end stage decreased by 83.00%–88.31%, compared with the initial stage. Seasonal variation in Dc was significantly correlated with BD, Coh, PR, SOM, MWD, and SDR. The measured Dc decreased with BD and Coh as a power function and with SOM and MWD as an exponential function. The influence of straw incorporation on Dc is time‐dependent and can be divided into short‐term and long‐term effects. Natural soil consolidation gradually masked the effect of straw residue with the decomposition of the incorporated straw. The comprehensive response of seasonal variation in Dc to straw incorporation was described by a power combination equation (Dc = 1.23 τ1.65 BD−2.63 Coh−1.33 SOM−0.70; R2 = 0.96). Thus, the seasonal variations in Dc with straw incorporation were mainly controlled by the changes in soil properties triggered by the decomposition of incorporated straw and natural soil consolidation. The results of this study provided a scientific reference for soil erosion prediction and control in sloping farmlands.

Effects of Second-Season Crops on Soybean Cultivation in Compacted Soil in Brazilian Cerrado

In no-tillage systems, soil compaction has caused negative impacts on crop productivity and soil quality. The objective of this study was to evaluate the soil physical quality after different crops of the second season: maize, sorghum, and millet in compacted and uncompacted soils, in addition to evaluating the performance of soybean in succession in Rhodic Ferralsol under no-tillage (NT) in the Brazilian Cerrado biome. A field experiment was conducted during the second season of 2019 and the first season of 2019/20 in Rio Verde, Brazil. The experimental design used randomized blocks in a 3 × 2 factorial scheme, with six replications. The first factor corresponded to the cultivation of maize, sorghum, and millet; the second factor was the cultivation of these crops in compacted and uncompacted soils. The physical properties of the soils in the 0–0.1 and 0.1–0.2 m depth layers were evaluated after the second season of cultivation, in addition to the agronomic characteristics of the soybean cultivated in succession. The results indicate that the compaction influenced the soil physical quality, mainly in the 0.1–0.2 m layer, reflecting a decrease in the performance of the soybean crop (i.e., the plant height, number of pods per plant, and grain yield). The use of the second-season crop of millet improved the soil physical properties of penetration resistance and macroporosity and improved the water/air relation. The use of millet provided a reduction of up to 20% in the soil penetration resistance. About 10% more soybean was produced after cultivation in succession to millet compared to maize and sorghum.