Tractor Passes Research Articles

Soil compaction in progressive agricultural tractor treads

Soil compaction is one of the main problems in world agriculture. It is known that, even in soil conservation management, such as in no-till, the transit of agricultural machinery damages the soil structure, therefore, it is essential to better understand the compaction processes and ways to alleviate the problem. In soils that have traditional tillage management, just one machine pass can damage the physical structure. This research aimed to evaluate the levels of compaction as a function of different passages of an agricultural tractor, considering the hypothesis that, during agricultural operations, a machine transits several times through the same place in the crop. The experiment was carried out on plowed and harrowed agricultural soil in the state of São Paulo. Resistance to soil penetration at different depths was evaluated, and the averages were correlated as a function of the number of steps taken by the tractor. Results showed that approximately 60% of the total soil compaction occurs in the first passes of the agricultural tractor, and above five passes the increase in compaction is minimal. At depths of 20 to 30 cm, the largest RSPs were found. It is concluded that a good planning of machinery traffic is essential, because in the case of a motor-mechanized set moving out of its predestined route, the soil structure is permanently affected.

Comparative Measurement of Horizontal Penetrometry with a Focus on the Degree of Soil Compaction in Real Work Conditions

Potential soil production is closely related to the physical and mechanical properties. The aim of this paper was to evaluate the effect of different levels of soil compaction created by tractor chassis. The total area of the experimental plot was 13.22 ha. Up until 2019, a conventional tillage system had been used. The measurements were carried out with an innovative measuring device that allows for the continuous measurement of the horizontal penetrometry for comparative measurements while driving, which was designed at the Slovak University of Agriculture in Nitra. The measuring device measured the soil resistance in the tire track (On-track) and out of track (Off-track) as well as in three (50 s) sequences within one tractor pass. Three lines were chosen, where in each a pair of combinations was made. The results were subjected, in addition to graphical evaluation, to single factor ANOVA analysis. When comparing individual passes (PH1 to PH6), the statistical analysis showed that the results of the horizontal resistance measurements proved to be statistically significant (p < 0.05) with respect to the weight, number of passes, and tire underinflation. The highest compaction was caused by the first pass, while the higher weight of the tractor during the next pass had a smaller effect. Underinflating the tires ensured a reduction in compaction. Reducing the tractor tire pressure to 0.15 MPa resulted in a reduction in soil compaction of up to 16%.

Determining soil-deepener the vertical distance from blade to lower suspension point of plug

The technology of intensive treating to soil is used to harvest 2 or 3 times from watered lands. Aggregations of the car–tractor pass many times through the surface of the field as a result of it. As a result, the soil layer surface turns to small pieces of dust, and the condensation of the underground layer empowers. Apart from that, when we treat the soil with a plug in the same depth for many years, extremely condensed compensation of plug appears under the field, and it hinders the improvement of plants' roots and the being soaked process of water. After that, the rate of productivity decreases. To solve this problem, economical ways of treating the soil and protective technologies for soil are spreading worldwide. To eliminate these shortcomings, in this article, the working process is improved in the process of plowing the land. To ensure that the plug with a submersible sink to a specified depth and runs smoothly at this depth, the vertical distance from the blade of the submersible to the lower hanging point of the plug and the vertical distance of the submersible plug in the longitudinal - vertical plane the results of theoretical studies on determining the forces affecting the plug are described.

The Impact of Traffic-Induced Compaction on Soil Bulk Density, Soil Stress Distribution and Key Growth Indicators of Maize in North China Plain

The traffic-induced soil compaction in the field has gradually become an important constraint to sustainable agricultural development. A field experiment was conducted to acquire the stress transmitted caused by multiple passes with different types of tractors and to investigate the impact of these stresses on soil bulk density and crop growth. The experiment applied two tractors with different masses: LOVOL M904 (HC) and John Deer 280 (LC), and six different treatments of 0 (C0), 1 (C1), 3 (C3), 5 (C5), 7 (C7), and 9 (C9) tractor passes for each tractor. The results showed that at each number of passes, tractors with small axle-loads at 0–20 cm depth generated higher soil additional stress, while tractors with large axle-loads at 20–80 cm depth generated higher soil additional stress. In the 0–20 cm soil layer, when the number of continuous passes is less than 7 times, the passes of a small axle-load tractor lead to larger soil bulk density, and when the number of continuous passes is more than 7, the compaction of large axle-load tractor leads to larger soil bulk density. At depths of 20–80 cm, compaction by large axle-load tractors results in larger soil bulk density. In this study, different levels of tractor compaction inhibited key growth indicators of maize, resulting in yield reductions. The effect of different tractor load compaction on maize yield increased significantly with the number of compaction passes, with 1–5 tractor passes having no significant effect on yield and 7–9 passes producing greater yield reductions for HC. This study will provide a theoretical basis and technical support for the selection of agricultural machinery and reasonable tillage technology.

Effects of the soil compaction on root growth of cover crops in the western Amazon

The intensification of agriculture has increased the traffic of heavy machines, which can cause soil compaction, becoming a limiting factor for plant growth and development. The aim of this work was to evaluate the effects of machine traffic on soil physical attributes, root growth and dry mass production of legumes and grasses cultivated as cover. The experiment was carried in Rolim de Moura (RO). The experimental design was randomized blocks, in a split-plot scheme, with three replications. The treatments in the plots consisted of four induced soil compaction states: 0, 1, 4, 7 passes of an agricultural tractor, and in the subplots four cover crops species: Crotalaria, Stylosanthes, Millet and Palisadegrass. After two days of intense rainfall, compaction was carried out by passing the wheelsets of a New Holland-TL85E agricultural tractor, with 88hp of power, 4x2 TDA, standard tires 7.5x16 and 18.4x34, with blowing pressure of 110 kPa and 124 kPa, with a total mass of 3.16 Mg. Density, microporosity, macroporosity and total porosity were evaluated, surface area, root length and diameter and dry mass were also evaluated. During the period of full flowering of each crop, trenches were opened in each subplot for root evaluation and deformed soil and shoot dry mass samples were collected for evaluation. Significant discrepancies were observed for the physical attributes evaluated, surface area, length and root diameter of grasses in relation to legumes. After a tractor pass, there is an increase in soil density, and reductions in macroporosity and total porosity.

English

Africa is the second continent suffering from soil compaction; studies of this phenomenon must be multiplied in order to overcome this problem. Very few studies have been conducted in Tunisia to understand soil compaction, its causes and its effect on soil properties. The research was conducted on experimental field at the Higher Institute of Agronomy of Chott Mariam, Sousse, Tunisia. The main objective of this study was to evaluate the effect of different speed of tractor compaction on soil, that is, no compaction (C0), speed 1 (C2) = 4 km h-1, speed 2 (C3) = 9 km h-1 on the hydraulic and physical properties of a silt loam texture under three natural moisture conditions: H0, H1 (15 days later), and H2 (30 days later). Each test run was limited to one pass. Undisturbed soil cores were collected in the topsoil (0-10 cm), at 10-20 cm and in the subsoil (20-30 cm) below the trace of the wheel at site. Soil compaction level was determined by penetration resistance using a penetrologger. Bulk density was then determined to evaluate the impact of the two tractor frequency passages at the three moisture conditions on soil compaction. For initial soil (C0), bulk density was 1.38 Mg m-3. After the tractor pass, the highest degree of compaction was observed with tractor speed 1 (C1) which signi?cantly changed soil bulk density resulting in values of up to 1.74 Mg m-3 in the topsoil and compacted subsoil under H1, which is significantly above the critical value of 1.6 Mg m-3 for soils with clay content below 17.5%. The high degree of compaction signi?cantly affected penetration resistance of topsoil. The results demonstrate that different degrees of soil compaction under different moisture levels could greatly influence physical properties in different ways. Even under relatively low water contents, that is, below field capacity, substantial top soil compaction was induced after one tractor pass. Key words: Soil compaction, tractor speed, soil moisture, penetration resistance, bulk density.

Soil Compaction from Wheel Traffic under Three Tillage Systems

Agricultural fields are usually subjected to high amounts of traffic from field operations. The influence of traffic on sandy loam soil in three tillage systems were investigated in a field experiment. The field was located in a Canadian prairie region. In the experiment, the treatments were three tillage systems: no-tillage, disc tillage, and spring-tine tillage. Following tillage operations, field plots were trafficked with one pass of a sub-compact tractor. Soil properties were measured before and after the traffic to examine the effects of tillage systems and wheel traffic. For the effects of the tillage systems on the soil bulk density, soil shear strength, soil surface resistance, and soil cone index, the no-tillage system had higher values for all the soil properties when compared with the disc and spring-tine tillage systems. The plant (canola) population density ranged from 18.2 plants/m2 to 34.9 plants/m2, with the no-tillage having the lowest plant densities. For the effects of wheel traffic, one pass of the tractor in the disc and spring-tine tillage plots resulted in a 2.7% and 17.4% reduction in soil moisture content, respectively. After wheel traffic, the average soil shear strength for the disc and spring-tine systems were still significantly lower than the no-tilled system. Sinkages of 40 and 50 mm were observed for the spring-tine and disc tillage systems, respectively. The results of this study highlight the importance of preventing the demerits of soil compaction induced by wheel traffic after tillage operations.

A computer-based mapping approach for evaluating straight-line accuracy of autopilot tractor traversing the oil palm field terrain

Many methods have been introduced to evaluate straight-line accuracy of autopilot pilot tractor while moving across the farm field. This study presents a new alternative approach for evaluating straight-line accuracy of an autopilot tractor traversing the oil palm field terrain. A combination of mapping and spreadsheet software was utilized to develop the approach. The passes of autopilot tractor traversing the oil palm field were mapped by its embedded GPS system. The recorded tractor passes along with latitude and longitude coordinates of World Geographical System (WGS) 1984 were converted into Kertau Universal Transverse Mercator (UTM) in XY-plane of Cartesian coordinate by using mapping software. The values of converted coordinates were then exported to a spreadsheet software for computing the errors of straight-line accuracy. The new approach successfully found mean error of straight-line accuracy of ±7.78 cm of the tractor traversing the oil palm field terrain. Generally, this approach has a great potential to enrich the existing methods in the evaluation of the straight-line accuracy of autopilot tractor for field operations.

EFFECT OF TRACTOR WHEEL TRAFFIC ON SELECTED SOIL PHYSICAL PROPERTIES

The increasing use of agricultural machines in most mechanized farming fields has led to amplified soil compaction levels due to wheel traffic. Since wheel traffic is still underestimated, the main objective of this research was to determine the effect of wheel traffic on soil physical properties. This research determined the effect of wheel traffic on bulk density, soil texture, porosity, infiltration rate, hydraulic conductivity, and cone index using a field experiment at Egerton University Tatton Farm. A walking tractor was used to provide traffic loads. The experiment was conducted in a completely randomized design (CRD) with three weight applications and three traffic locations. The treatments were 1.72 kN (one tractor pass), 5.15 kN (three tractor passes) and 8.09 kN (five tractor passes) and three traffic locations, which are traffic on rows (TR), traffic between rows (TB) and traffic on the entire row (TE), replicated three times. Average moisture contents of the soil for depth ranges of 0 to 15 cm, 16 to 30 cm and 31 to 45 cm were recorded as 23%, 25% and 27%, respectively. The applied weight significantly increased bulk density and cone index but decreased infiltration rate, hydraulic conductivity and porosity. Bulk density increased by 17%, 15% and 8%, cone index increased by 44%, 10% and 7%, and porosity decreased by 25%, 23% and 36% for the three depth ranges after the three weight treatments were applied, respectively. Hydraulic conductivity decreased from 65.2 cm/day, 50.98 cm/day, and 34.05 cm/day to 13.95 cm/day, while infiltration rates decreased from 0.047 cm/min, 0.031 cm/min, and 0.018 cm/min. TE had the highest bulk density as compared to TB and TR. Analysis of variance indicated changes in weight applied, traffic location, and depth with significant effects on soil properties at a 5% level of confidence. It was concluded that wheel traffic causes soil compaction at varying levels depending on the applied weight, thus affecting the soil physical properties. This suggests that decreased and controlled wheel traffic could be a promising way to alleviate soil compaction.

REGRESSÃO QUADRÁTICA PARA TEORES DE ÁGUA EM FUNÇÃO DA COMPACTAÇÃO DO SOLO

REGRESSÃO QUADRÁTICA PARA TEORES DE ÁGUA EM FUNÇÃO DA COMPACTAÇÃO DO SOLO Barbara Barreto Fernandes¹; Indiamara Marasca²; Murilo³ Battistuzzi Martins; Jefferson Sandi4 e Kleber Pereira Lanças5 1 Engenheira agrônoma, Rua Luis Carlos Da Silveira, 345, Tenis Clube, 19806-370, Assis – SP, Brasil. E-mail: babarretof@hotmail.com 2 Engenheira agrônoma, Fazenda Cachoeira do Montividiu – 75915-000, Montividiu – GO, Brasil. E-mail: marasca_7@hotmail.com 3 Universidade Estadual de Mato Grosso do Sul – Unidade de Cassilândia. Rodovia MS 306 - km 6,4; 79540-000, Cassilândia, MS, Brasil. E-mail: mbm_martins@hotmail.com 4 Universidade La Salle de Lucas do Rio Verde. Av. Universitária, 1000, Parque das Emas - 78455-000, Lucas do Rio Verde, MT, Brasil. E-mail: jffsandi@gmail.com 5 Departamento de Engenharia Rural na FCA/UNESP, Av. Universitária, 3780 - Altos do Paraíso, 18610-034, Botucatu, SP, Brasil. E-mail: kp.lancas@.unesp.br 1 RESUMO O trabalho teve por objetivo avaliar a influência do teor de água na avaliação de resistência mecânica a penetração do solo, medida através do índice de cone. O experimento foi realizado na UNESP/FCA, Botucatu-SP, sendo selecionadas duas classes de solo: o Nitossolo Vermelho distroférrico e o Latossolo Vermelho. Utilizou-se o delineamento inteiramente casualizado, com os seguintes tratamentos de compactação: T0 = 0; T1 = 1; T2 = 2; T3 = 3; T4=5 e T5 = 10 passadas consecutivas de um trator agrícola. Utilizou-se um penetrômetro hidráulico-eletrônico para a amostragem da resistência mecânica do solo à penetração nas camadas de: 0,00 - 0,10; 0,10 - 0,20; 0,20 - 0,30; 0,30 - 0,40 m em quatro condições de teor de água. Com o aumento do tráfego, maior foi a compactação. Porém para o solo argiloso, a partir de uma passada do trator, os valores de resistência à penetração tiveram pouco aumento, não diferindo estatisticamente para a camada mais superficial (0-0,20 m) e para a camada de 0,20-0,40 m a partir de duas passadas. Para o solo de textura média, este comportamento foi observado a partir de uma passada para a camada mais superficial (0-0,20 m) e de cinco passadas para a camada de 0,20-0,40m. Palavras-chave: resistência do solo, umidade, agregação. FERNANDES, B. B.; MARASCA, I.; MARTINS, M. B.; SANDI, J.; LANÇAS, K. P. QUADRACTIC REGRESSION FOR WATER CONTENTS IN THE FUNCTION OF SOIL COMPACTION 2 ABSTRACT The objective of this work was to evaluate the influence of water content in the evaluation of mechanical resistance to soil penetration, measured through the cone index. The experiment was conducted at UNESP/FCA, Botucatu - SP, being selected two classes of soil: a Nitossolo Vermelho distroférrico and a Latosolo Vermelho. A completely randomized design was used, with the following compaction treatments: T0 = 0; T1 = 1; T2 = 2; T3 = 3; T4 = 5 and T5 = 10 consecutive passes of an agricultural tractor. A hydraulic-electronic penetrometer was used to sample the mechanical resistance of the soil to penetrate the layers; 0.00 – 0.10; 0.10 - 0.20; 0.20 - 0.30; 0.30 - 0.40 m in four water content conditions. With the increase in traffic, greater was the compression. However, for the clayey soil, from a tractor pass, the penetration resistance values ​​had a small increase, not differing statistically for the most superficial layer (0 - 0.20m) and for the 0.20 - 0.40 m layer from two passes. For medium textured soil, this behavior was observed from one pass to the most superficial layer (0 - 0.20 m) and five passes to the 0.20 - 0.40 m layer. Keywords: soil resistance; moisture; aggregation.

Effects of Tractorization and Organic Manure on Physical Properties of Sandy Loam Soil in Abeokuta, Nigeria

Soil compaction has effect on soil physical properties which could affect crop growth and yield. This study was conducted to determine the influence of incorporating organic materials and load application (tractorization) on the physical properties of sandy loamy soil in Abeokuta, Ogun State, Nigeria. Organic materials were cow dung, poultry and swine manure. Application rates of organic manures were 0 (control), 5 and 10 tonnes per hectare. Forty-five plots measuring 5 by 3 m were established in a complete randomized block experimental design with three replications making a total of 135 plots. Load application was done using an MF 435 tractor coupled with a 20-disc harrow at 0 (control), 5, 10, 15 and 20 passes. Penetration resistance, bulk density, gravimetric moisture content andporosity were determined using standard procedures. Penetrometer resistance at these passes were 392.2, 293.3, 285.0, 302.0 and 224.9 kPa respectively with significant differences between treatments (P≤0.05). Mean bulk density for the passes were 1.21, 1.26, 1.31, 1.27 and 1.29 g/cm3 respectively and bulk density increased with tractor passes. The effect of tractor passes, and manure incorporation rate did not have any significant effect on gravimetric moisture content. Poultry manure increased bulk density and penetrometer resistance on plots than swine manure and cow dung hence poultry manure at 10 t/ha can be incorporated on a sandy loam soil to enhance soil fertility and sustainability.
 Keywords: Tractorization, organic manure, sandy loam, penetration resistance, bulk density

Impact of machine traffic events on the physical quality of a minesoil after topographic reconstruction

Excessive traffic from large machines during topographic reconstruction promotes the persistent topsoil compaction in the minesoil around the world. Therefore, this study aimed to measure the impactof machine traffic events on the physical quality of a minesoil immediately after topographic reconstruction.The study was conducted in a minesoil recently constructed, on which 0.70 m of clay topsoil was placed. During topographic reconstruction, different traffic events (zero, one, three, five, eight, and twelve passes) over a 12-meter transection were simulated, totaling six treatments. Before and after traffic events soil samples were collected from the 0.00 to 0.10 and 0.10 to 0.20 m layers to evaluate bulk density, soil porosity, distribution of water-stable aggregates, preconsolidation pressure, degree of compactness, soil water retention curve, and soil penetration resistance. The minesoil restoration using topsoil with 473 g kg−1clay and 216.31 g kg−1 of soil moisture proved highly susceptible to compaction when subjected to the first machine traffic event. Bulk density, soil porosity, soil pre-consolidation pressure, and degree of compaction were highly sensitive to respond to the first machine traffic event, while the macroaggregation formed by compression machine and an increase of soil water retention was observed after twelve tractor passes. Before the topographic reconstruction operations of the minesoil, the topsoil must be subjected to a Proctor test to establish a soil moisture level to minimize the impacts of machine traffic.

Are the yield of sunflower and Paiaguas palisadegrass biomass influenced by soil physical quality?

Soil compaction affects physical soil properties, which in turn influence crop growth, development and yield. The present study tested the hypothesis that the yield of sunflower achenes and Paiaguas palisadegrass biomass are influenced by soil physical properties. The effects of compaction were measured by the least limiting water range (LLWR), and its relationship with crop yield were studied. The experiment was conducted in the Rio Verde municipality, south-western Goias State, Brazil, on a Latossolo Vermelho Acriférrico típico (Typic Haplustox) soil and in accordance with a randomized complete block design, in which the treatments consisted of compaction levels established by zero, two, 10, and 30 passes of an agricultural tractor (with four replicates each). In the subplots, sunflower and Paiaguas palisadegrass were grown as monocropping and intercropping systems. The following indicators of soil physical quality were determined: bulk density (Bd), the LLWR, the Bd/alert bulk density of the LLWR (Bdalert) ratio, and the Bd/critical bulk density of the LLWR (Bdc) ratio. The correlations of these indicators with crop yield were calculated to define critical resistance values specific to each crop. The LLWR adequately described the physical quality of the soil resulting from compaction and was significantly correlated with crop yield. The relationship between sunflower and Paiaguas palisadegrass yield was modelled by a second-order equation featuring Bd and the Bd/Bdalert ratio (R2 = 0.77, ** and 0.74 **, respectively), with the greatest yield recorded when the Bd/Bdalert ratio was 1.0. Sunflower cultivation was extremely sensitive to soil compaction: when sunflower was grown as a monoculture or intercropped with palisadegrass, its yield decreased by 50 % or 80 %, respectively. However, the Paiaguas palisadegrass yield was influenced little by soil compaction. The limiting penetration resistance values for sunflower and Paiaguas palisadegrass were 1.5 MPa and 4.2 MPa, respectively.

Effect of subsoil compaction on rooting behavior and yields of wheat

Soil compactions are widely dispersed in the world but tend to be the most prevalent, where heavy machinery is used in agriculture. The increasing use of heavy machinery is the primary cause of soil and subsoil compaction. The impact of subsoil compaction on root growth and yield of wheat (Triticum aestivum L) were evaluated during 2006 and 2007. Sub-soil compactions were created by three normal loads, i.e. 4.40, 6.40 and 8.40 kg and four number of passes of tractor, i.e. 1, 6, 11 and 16. The field was divided into 39 plots including a control plot, i.e. no passes of the tractor. The size of each plot was 400 square meter. A factorial randomized block design was followed in laying out the experiment and care was taken that all the 13 treatments and their replications are included in field experiments. It was observed that for all the compaction treatments in the field experiment on the wheat crop, 51–61% of wheat roots were confined in 0–15 cm, 17–20% in 15–30 cm and the rest 22–28% is below 30 cm soil layer. Sub-soil compaction reduced the wheat crop yields to a maximum of 23%. A statistical model is developed to predict crop yield considering the root length density of the crop. Average root diameters increased with the increase of the sub-soil compaction level. In sub-soil zone, average root diameter decreased with the increase of sub-soil compaction level.

Root and shoot growth in safflower as affected by soil compaction

Soil compaction, induced by no-tillage practices, can negatively impact soil properties important for plant growth. Compacted soils can restrict root growth depth, resulting in reduced crop yield. Although safflower (Carthamus tinctorius) has a deep root system, yield may still be affected by soil compaction. Therefore, this study aimed to evaluate safflower root and shoot growth when submitted to soil compaction in an Oxisol soil under controlled (greenhouse) and field conditions. Five soil bulk density measures were performed in a greenhouse (1.1, 1.2, 1.3, 1.4 and 1.5 Mg m–3). Four compaction levels (established by the number of passes of a farm tractor: 0, 1, 3, and 5 passes consecutively) were performed to evaluate the effect of soil compaction in the field. Root and shoot growth were measured after harvesting the plants. Safflower root growth was reduced when soil compaction increased from 1.1 to 1.5 Mg m–3 under controlled (greenhouse) conditions. In field conditions, we observed a decrease in root length, and fresh and dry matter in roots and shoots of safflower as the soil compaction increased to 5P (1.28 Mg m–3). The results of our study suggest safflower root and shoot growth can be impacted by soil compaction which could affect crop yield.

Quantifying Soil Compaction in Persimmon Orchards Using ISUM (Improved Stock Unearthing Method) and Core Sampling Methods

Agricultural activities induce micro-topographical changes, soil compaction and structural changes due to soil cultivation, which directly affect ecosystem services. However, little is known about how these soil structural changes occur during and after the planting of orchards, and which key factors and processes play a major role in soil compaction due to cultivation works. This study evaluates the improved stock unearthing method (ISUM) as a low-cost and precise alternative to the tedious and costly traditional core sampling method, to characterize the changes in soil compaction in a representative persimmon orchard in Eastern Spain. To achieve this goal, firstly, in the field, undisturbed soil samples using metallic core rings (in January 2016 and 2019) were collected at different soil depths between 45 paired-trees, and topographic variations were determined following the protocol established by ISUM (January 2019). Our results show that soil bulk density (Bd) increases with depth and in the inter-row area, due to the effect of tractor passes and human trampling. The bulk density values of the top surface layers (0–12 cm) showed the lowest soil accumulation, but the highest temporal and spatial variability. Soil consolidation within three years after planting as calculated using the core samples was 12 mm, whereas when calculated with ISUM, it was 14 mm. The quality of the results with ISUM was better than with the traditional core method, due to the higher amount of sampling points. The ISUM is a promising method to measure soil compaction, but it is restricted to the land where soil erosion does not take place, or where soil erosion is measured to establish a balance of soil redistribution. Another positive contribution of ISUM is that it requires 24 h of technician work to acquire the data, whereas the core method requires 272 h. Our research is the first approach to use ISUM to quantify soil compaction and will contribute to applying innovative and low-cost monitoring methods to agricultural land and conserving ecosystem services.

Effects of Tractor Passes on Hydrological and Soil Erosion Processes in Tilled and Grassed Vineyards

Soil erosion is affected by rainfall temporal patterns and intensity variability. In vineyards, machine traffic is implemented with particular intensity from late spring to harvest, and it is responsible for soil compaction, which likely affects soil hydraulic properties, runoff, and soil erosion. Additionally, the hydraulic and physical properties of soil are highly influenced by vineyards’ inter-rows soil management. The effects on soil compaction and both hydrological and erosional processes of machine traffic were investigated on a sloping vineyard with different inter-row soil managements (tillage and permanent grass cover) in the Alto Monferrato area (Piedmont, NW Italy). During the investigation (November 2016–October 2018), soil water content, rainfall, runoff, and soil erosion were continuously monitored. Field-saturated hydraulic conductivity, soil penetration resistance, and bulk density were recorded periodically in portions of inter-rows affected and not affected by the machine traffic. Very different yearly precipitation characterized the observed period, leading to higher bulk density and lower infiltration rates in the wetter year, especially in the tilled vineyard, whereas soil penetration resistance was generally higher in the grassed plot and in drier conditions. In the wet year, management with grass cover considerably reduced runoff (−76%) and soil loss (−83%) compared to tillage and in the dry season. Those results highlight the need to limit the tractor traffic, in order to reduce negative effects due to soil compaction, especially in tilled inter-rows.

Correlation between agrotechnical properties of selected soil types and corresponding GPR response

In this study, we investigated the relationship between ground-penetrating radar (GPR) response and agriculture properties of soil with a view to understanding how the constraint of soil degradation may influence the properties. GPR field data measurements were made at a location with soil types, properties, and disturbances caused by tractor movement. The data were processed, and empirical equations relating soil physical properties and material properties of soil media were considered for the analysis of the field data. The results showed a change in the reflection coefficient and increase in the GPR wave velocity when comparing the records of the initial parts of the GPR records, lasting about 2.5 ns, of the signal response of soil subjected to compaction as a result of 10 tractor passes, with those obtained prior to movement of the tractor. The summation of the absolute value of GPR wave amplitude in the analyzed results clearly shows that the amplitude of the signal corresponding to the compressed ground is twice and even three times smaller than the amplitude recorded before the tractor runs. The results prompted the design of a relatively simple method for tracking changes in soil properties based on the results of GPR measurements, which show that zones subjected to direct tire pressure are easy to delineate and are not limited to the part that is directly under the tire, but extend about 0.5 m. It thus shows that there is a relationship between the penetration resistance induced by a change in porosity and changes in the coefficient of reflectivity and the velocity of radar waves.

Apparent Gains, Hidden Costs: Examining Adoption Drivers, Yield, and Profitability Outcomes of Rotavator Tillage in Wheat Systems in Nepal.

The ‘high speed’ rotavator is used for shallow tillage to create a fine tilth and incorporate crop residues, often with a single tractor pass. Rotavator tillage has spread quickly in many parts of South Asia, despite short‐term experimental trials suggesting deteriorating soil quality and crop yield penalties. Evidence of rotavator impacts on farmer fields across soil gradients and time is largely absent. From a farm household survey conducted among wheat farmers in Nepal, we estimate wheat yield and profitability outcomes for rotavator adopters and non‐adopters using propensity score matching. We find that rotavator adoption leads to inferior outcomes, despite significant cost savings for land preparation (US$ 11–15 per hectare). With rotavator adoption, farmers lose about 284–309 kg of wheat grain and about US$ 93–101 of profits on average per hectare per season, and these penalties increase with longer‐term use of the technology. Adoption of rotavator appears to be driven by the cost and time savings for land preparation. Against this backdrop, new policy and extension efforts are required that discourage rotavator use and favour more sustainable tillage technologies.

Effect of Soil Compaction and Bulk Density on the Growth and Yield of Soybean (Glycine max) on Sandy Clay Loam Soil of the Semi-arid Region of Northern Nigeria as Influenced by Tractor Wheel Traffic

Soil compaction from farm machinery is an environmental problem. The effect of compaction on plant growth and yield depends on the crop grown and the environmental conditions that crop encounters. The effect of compaction from tractor traffic on soybean (Glycine max), variety TGX1448-2E, on a sandy clay loam soil in the semi-arid region of northern Nigeria was investigated for two growing seasons, 2015 and 2016. A randomized complete block design of the field of plots with treatments of 0,5,10, 15 and 20 passes of a tractor MF 390 was used. Each treatment was replicated three times. The soil bulk density, penetration resistance and soil moisture content for each applied load were measured and the yield from each treatment was determined. Agronomic treatments were kept the same for all plots in both 2015 and 2016. Results showed increased soil bulk density, penetration resistance and soil moisture content with increased tractor passes. Highest grain yield was obtained at 5 tractor passes with a mean bulk density of 1.76 Mgm,-3 penetration resistance 1.70 MPa and moisture content 13.37% with a mean yield of 2568 kgha-1 and lowest was obtained from 20 tractor passes were 340 kgha-1. Statistical models were used to predict yield as a function of bulk density, penetration resistance, moisture content, contact pressure, and a number of tractor traffic passes. Grain yield with respect to moisture content gave the best yield prediction (r2 = 0.94).