How tillage systems and cover crops affect soil penetration resistance

Author(s):  
Felice Sartori ◽  
Ilaria Piccoli ◽  
Antonio Berti

<p>Penetration resistance (PR) is one of the most informative parameters to evaluate soil structure, being related to soil texture, compaction, and water content. PR tests are cheaper and more conservative than bulk density analyses, while potentially they can explore a deeper soil layer. On the other side PR is more sensitive to water content variation. Within this context the aim of this study is to evaluate the effects of different tillage systems and soil covers on soil strength, using PR as an indicator.</p><p>In this study, 288 PR tests were performed in the 0-80 cm profile, in an 18-plot field experiment considering three levels of tillage (conventional “CT”, minimum “MT” and no-tillage “NT”) combined with three soil covering during winter (bare soil “BS”, tillage radish “TR” and winter wheat “WW”) with two replicates. The experiment, located in northern Italy, had a homogeneous soil texture (silty loam) and it was sampled in late winter, when the gravimetric water content was equal in all the plot and along the soil profile (0.34 m<sup>3</sup>m<sup>-3</sup> on average, close to field capacity). A total of 16 tests were taken in each plot with a hand-pushed digital cone penetrometer with a base area of 2 cm<sup>2</sup> and an apex angle of 30°.</p><p>Average PR tended to increase with soil depth observing a growth from 0.25 to 1.53 MPa in the 0-15 cm layer, constant values (1.30 MPa on average) in the following 20 cm-layer, increased value up to an average of 2.87 MPa in 35-55 cm layer and reduced value (2.63 MPa on average) in the deepest layer (60-80 cm).</p><p>Considering the tilled layer (0-30 cm), PR was significantly affected by both tillage and soil covering being lower in CT (1.00 MPa) than MT and NT (1.03 MPa on average) and being lower with WW (0.98 MPa) than BS and TR (1.04 MPa on average). Similar results were registered also looking at the whole soil profile with tillage treatments ranked as follows: CT<NT<MT, while for the cover crops WW and BS (1.81 MPa on average) resulted significantly lower than TR (1.93 MPa). The 2 MPa threshold, considered a critical value for plant growth, was exceeded in the 41% of measured points in TR, 38% in WW and in 35% in BS. Most of exceeding values were collected below the tilled layer (below 30 cm depth).</p><p>These preliminary results might suggest the need to carefully monitor the soil strength during the transition period between conventional to conservation agriculture. Indeed, it seemed that tillage radish unexpectedly increased the soil PR, that instead could be mitigated in the top layer with WW. Nevertheless, crop yield was not affected by the type of winter covering, despite the high PR observed in the 30-80 cm layer with TR. This could confirm that an important cover crop function is the creation of root channels, defined as “bio-macropores”, that can be used as preferential path by subsequent crop roots even in a strongly compacted soil.</p>

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11766
Author(s):  
Mao Yang ◽  
Runya Yang ◽  
Yanni Li ◽  
Yinghua Pan ◽  
Junna Sun ◽  
...  

The aim of this study was to find a material suited for the prevention of evaporative water loss and salt accumulation in coastal saline soils. One-dimensional vertical water infiltration and phreatic evaporation experiments were conducted using a silty loam saline soil. A 3-cm-thick layer of corn straw, biochar, and peat was buried at the soil depth of 20 cm, and a 6-cm-thick layer of peat was also buried at the same soil depth for comparison. The presence of the biochar layer increased the upper soil water content, but its ability to inhibit salt accumulation was poor, leading to a high salt concentration in the surface soil. The 3-cm-thick straw and 6-cm-thick peat layers were most effective to inhibit salt accumulation, which reduced the upper soil salt concentration by 96% and 93%, respectively. However, the straw layer strongly inhibited phreatic evaporation and resulted in low water content in the upper soil layer. Compared with the straw layer, the peat layer increased the upper soil water content. Thus, burying a 6-cm-thick peat layer in the coastal saline soil is the optimal strategy to retain water in the upper soil layer and intercept salt in the deeper soil layer.


2013 ◽  
pp. 183-186
Author(s):  
Géza Tuba

he effect of reduced and conventional tillage systems on soil compaction and moisture content in two years with extreme weather conditions is introduced in this paper. The investigations were carried out in a long-term soil cultivation experiment set on a heavy textured meadow chernozem soil at the Karcag Research Institute. In 2010 the amount of precipitation during the vegetation period of winter wheat was 623.3 mm, 2.2 times higher than the 50-year average, while in 2011 this value was 188.7 mm giving only 65% of the average. The examinations were made after harvest on stubbles on 4 test plots in 5 replications in the case of each tillage system. Soil compaction was characterised by penetration resistance values, while the actual soil moisture contents were determined by gravimetry. The values of penetration resistance and soil moisture content of the cultivated soil layer were better in the case of reduced tillage under extreme precipitation conditions. It could be established that regular application of deep soil loosening is essential due to the formation of the unfavourable compact soil layer under 30 cm. Conventional tillage resulted in enhanced compaction under the depth of ploughing, the penetration resistance can reach the value of 4 MPa under wet, while even 8 MPa under dry soil status.


2018 ◽  
pp. 126-133 ◽  
Author(s):  
Nicola Silvestri ◽  
Vittoria Giannini ◽  
Daniele Antichi

The risks of soil erosion and nutrient leaching can be considered appreciable in short rotation coppices especially in the first growth phases because of the absence of any plant cover. The temporary intercropping with legumes or grasses used as cover crops can help to overcome these environmental issues. The present research work aims to evaluate the effects of the introduction of cover crops in a short rotation poplar (Populus deltoides W. Bartram ex Marshall) with two-year harvest cycle. The plantation was located in a Typic Xerofluvent, silty-loam soil of the coastal Central Italy. Two different species of cover crops, Trifolium subterraneum L. (TS) and Lolium perenne L. (LP), were compared along with an untreated control, colonised by spontaneous vegetation (CO). Several plant and soil parameters were evaluated: the above ground biomass and nutrient accumulation for the three different soil cover types, the nitrate and water content in two soil layers (0.00-0.30 and 0.30-0.60 m), the poplar yield and nutrient content in branches and leaves. TS returned to the soil about 70 kg ha–1 of nitrogen at the end of its biological cycle, thanks to the high N content (over 2%) and to the noticeable amount of dry matter produced (3.46 t ha–1 of dry matter). This value was considerably higher than those of the LP (23 kg ha–1 of N) or CO (10 kg ha–1). The different amount of nitrogen returned to the soil affected both nitrate concentration in topsoil (0.00-0.30 m) and accumulation of nitrogen in poplar organs. Concerning phosphorous, the differences among treatments were less evident and the amount of P returned to the soil ranged from 2 (CO) to 10 (TS) kg ha–1. However, the effect of soil cover type on P uptake in poplar was still appreciable. Generally, the soil water content was slightly affected by the soil cover types. Indeed, the differences between the cover crops and the control became significant only in the shallowest soil layer and over the summer season. In the first year, LP induced a significant decrease in poplar yield (10.1 t ha–1 of dry matter) in comparison with TS (14.7 t ha–1) and CO (13.4 t ha–1), whereas in the second year there were no significant differences among treatments due to the weak regrowth of cover crops. These results show how to make it feasible a long lasting coexistence between cover crops and SRC, a clever design of agro-forestry systems is therefore needed.


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2229
Author(s):  
Wenzhu Yang ◽  
Yan Jiao ◽  
Mingde Yang ◽  
Huiyang Wen ◽  
Peng Gu ◽  
...  

Irrigation water is limiting for crop production in arid areas and application rates of fertilizers often exceed crop requirements, resulting in high accumulation of nitrate nitrogen (NO3−-N) in the soil. Management practices play a significant role in the leaching of NO3−-N. This experiment compares the effects of traditional furrow irrigation and sprinkler fertigation on the soil NO3−-N concentration trend throughout the cropping season in potato fields in China. Two irrigation systems that were fertilized, namely by furrow (NF-FI) and sprinkler fertigation (NF-SI), and two controlling without any fertilizer (C-FI and C-SI) were tested in the same experimental site for three consecutive years. Both the NF-FI soils and NF-SI soils with three replications and fertilizer applications of 273 kg N ha−1 exhibited a different trend of NO3−-N accumulation at different depths of soil profile. However, the magnitude of NO3−-N accumulation was low in the NF-SI soil profile. In NF-SI treatments, higher NO3−-N was observed at 20–40 cm soil layer. In the NF-FI, the concentration of the highest nitrate was observed at the 40–120 cm soil layer. The concentrations of NO3−-N in the fertilized soil were higher than those of the control soil for each irrigation system. Residual levels of NO3−-N in the soil depth of 40–120 cm from NF-FI were 1.54, 3.45 and 5.28 times higher than NF-SI after harvesting potatoes from 2015 to 2017. In NF-FI treatments, apparent nitrogen loss was 234.7, 237.5 and 276.7 kg ha−1 after harvesting potatoes in 2015, 2016 and 2017. Meanwhile, apparent nitrogen loss from NF-SI treatments was only 161.9, 132.1 and 148.9 kg ha−1, which was 31.0%, 44.4% and 46.2% lower than that of NF-FI in 2015, 2016 and 2017, respectively. The risk of NO3−-N leaching below the root zone from NF-FI was higher than that from NF-SI. It has been demonstrated that sprinkler fertigation can also be used as a tool for mitigating NO3−-N accumulation and apparent nitrogen loss.


1988 ◽  
Vol 68 (4) ◽  
pp. 657-668 ◽  
Author(s):  
M. R. CARTER

Soil penetration resistance was used to characterize tillage-induced changes in soil strength, as a functon of soil depth and time, under three reduced tillage systems and a deep tillage study in loam to fine sandy loam, Podzolic and Luvisolic soils. The penetration resistance measurements quantified the depth, degree, and persistence of soil loosening, and potential soil rooting depth in regard to tillage system. Mouldboard ploughing provided a greater degree of soil loosening than chisel ploughing. The potential soil rooting depth of 33 – 36 cm under mouldboard ploughing was decreased to 26 cm under both direct drilling and shallow tillage. Use of a slant-legged subsoiler (i.e., “paraplow”) prior to direct drilling prevented the reduction in soil rooting depth. The depth of soil loosening gradually declined by 30 and 60%, over a 5-mo period, under mouldboard ploughing and the "paraplow" direct drilling system, respectively. Residual tillage effects and soil compaction after deep loosening were quantified by the penetration resistance measurements. The use of penetration resistance to rapidly screen soil depth to critical levels of soil strength demonstrated that under sequential direct drilled systems soil loosening should occur on a regular basis to maintain optimum soil structure on fine sandy loam soils. Key words: Soil strength, penetration resistance, reduced tillage, Podzolic soil, Luvisolic soil


2018 ◽  
Vol 8 (2) ◽  
pp. 221-229
Author(s):  
Edney Leandro Da Vitória ◽  
Adriano Alves Fernandes

The objective of this study was to understand the effect of the spatial variability of the soil physical attributes in areas cultivated with cassava with different soil tillage systems, using the techniques of classical statistics and geostatistics. The experiment was carried in 2013 in São Mateus - ES, Brazil, on a cohesive ultisol, with a plan relief. The preparation of the soil for transplanting were made in two adjacent areas of approximately 0.5 ha each, using up to two passes of a harrow disk or two passes of a chisel plow. The following soil physical attributes were studied 90 days after transplanting: soil density (DS), macroporosity (Macro) and microporosity (Micro), soil water content according to two preparations systems and two depth ranges. Eighty plants were randomly selected to perform the experiment. The soil physical properties resulted in spatial variability due to the strong dependence for all variables, tillage system and soil depth. The semivariograms were adjusted to the spherical and exponential models for the evaluated physical attributes. Except for water content, it was observed an increase in the range (A0) with increasing depth for both tillage systems. The soil water content presented a decrease about 23% for the harrowing and scarification systems.


2018 ◽  
Vol 46 (2) ◽  
pp. 215
Author(s):  
Yuniarti , ◽  
M. Achmad Chozin ◽  
Dwi Guntoro ◽  
Dan Kukuh Murtilaksono

ABSTRACT<br /><br />Cover crops have the same role as biomulches to maintain soil moisture and reduce the evaporation of soil water. The objective of research was to compare Arachis pintoi versus other cover crops as biomulch in immature oil palm plantations. The study was conducted in the Field of Education and Research Palm IPB-Cargill, Jonggol, Bogor starting in December 2014 until May 2015. The experiment was designed according to a randomized block design with four replications. The treatments were cover crop species (biomulch) i.e. no biomulch/natural vegetation, Arachis pintoi Karp. &amp; Greg., Centrosema pubescens Benth., Calopogonium mucunoides L. and Pueraria javanica Benth. Planting materials used were cutings of A. pintoi and seed of C. pubescens, C. mucunoides and P. javanica. The planting material were planted in plots 9 m x 3 m and plot for biomass 1 m x 1 m. The results showed that the A. pintoi was not significantly different from other biomulches for ground covering and capability to hold water. Soil water content in the treatment of A. pintoi biomulch was not different from other biomulch treatments.<br /><br />Keywords: biomass production, cover ground, soil depth, soil water content<br /><br /><em><br /></em><em></em>


Author(s):  
Liting Zhang ◽  
Shujun Sun ◽  
Mengqi Lin ◽  
Kaijun Feng ◽  
Yue Zhang ◽  
...  

The water content is a crucial factor in evaluating the causes of Benggang collapse. The soil–water characteristic curve (SWCC) is an important parameter for the quantitative study of soil water content. However, limited research has been carried out on the SWCCs of the Benggang soil profile. We studied two typical collapsing gullies in southeast China and conducted desorption experiments using a pressure plate extractor to analyze the SWCCs of the undisturbed soils of collapsing walls. The results show large variations in the SWCCs for different soil horizons of a collapsing wall that can be accurately fitted by the van Genuchten (VG) model (NSE≥0.90). With increasing soil depth, the a and θs parameters of the VG model first decrease and then increase, red soil layer had the highest a and θs (the average value of 0.046 and 0.369, respectively), whereas the n parameter of the VG model exhibits the opposite trend, sand soil layer had the highest n (the average value of 1.563). The θr parameter of the VG model decreases with increasing soil depth, red soil layer had the highest θr (the average value of 0.194). The red soil layer has the highest water-holding capacity, whereas the sandy soil and detritus layers have lower water-holding capacities. The SWCCs are related to the soil material composition, particle composition and porosity. The gravel content and the particle morphology (the aspect ratio, sphericity, and specific surface area) are also the significant influence factors for the SWCC that cannot be neglected. The difference among the SWCCs for the soil profiles of collapsing walls can be used to explain the mechanism for the collapse of collapsing wall. The results of this study provide a theoretical basis for understanding the process of the collapse of collapsing wall in Benggang in southeast China.


2006 ◽  
Vol 49 (4) ◽  
pp. 875-882 ◽  
Author(s):  
J. Bueno ◽  
C. Amiama ◽  
J. L. Hernanz ◽  
J. M. Pereira

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1844 ◽  
Author(s):  
Francisco Del Toro-Guerrero ◽  
Enrique Vivoni ◽  
Thomas Kretzschmar ◽  
Stephen Bullock Runquist ◽  
Rogelio Vázquez-González

In this research, we examined temporal variations in soil water content (θ), infiltration patterns, and potential recharge at three sites with different mountain block positions in a semiarid Mediterranean climate in Baja California, Mexico: two located on opposing aspects (south- (SFS) and north-facing slopes (NFS)) and one located in a flat valley. At each site, we measured daily θ between 0.1 and 1 m depths from May 2014 to September 2016 in four hydrological seasons: wet season (winter), dry season (summer) and two transition seasons. The temporal evolution of θ and soil water storage (SWS) shows a strong variability that is associated mainly with high precipitation (P) pulses and soil profile depth at hillslope sites. Results shows that during high-intensity P events sites with opposing aspects reveal an increase of θ at the soil–bedrock interface suggesting lateral subsurface fluxes, while vertical soil infiltration decreases noticeably, signifying the production of surface runoff. We found that the dry soil conditions are reset annually at hillslope sites, and water is not available until the next wet season. Potential recharge occurred only in the winter season with P events greater than 50 mm/month at the SFS site and greater than 120 mm/month at the NFS site, indicating that soil depth and lack of vegetation cover play a critical role in the transport water towards the soil–bedrock interface. We also calculate that, on average, around 9.5% (~34.5 mm) of the accumulated precipitation may contribute to the recharge of the aquifer at the hillslope sites. Information about θ in a mountain block is essential for describing the dynamics and movement of water into the thin soil profile and its relation to potential groundwater recharge.


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