Effects of direct drilling on soil conditions and root growth

1975 ◽  
Vol 8 (1_suppl) ◽  
pp. 227-232 ◽  
Author(s):  
R Scott Russell ◽  
R Q Cannell ◽  
M J Goss

Direct drilling affects the pore size distribution in the soil, the distribution of organic debris on and within the soil, and the soil structure. These changes in turn affect the development of the root system of the crop, with consequential changes on its nutrient supply and early growth.

2021 ◽  
Author(s):  
Katharina Meurer ◽  
Thomas Keller ◽  
Nicholas Jarvis

<p>The pore structure of soil is known to be dynamic at time scales ranging from seconds (e.g. compaction) to seasons (e.g. root growth, macro-faunal activity) and even decades to centuries (e.g. changes in organic matter content). Nevertheless, soil physical and hydraulic functions are generally treated as static properties in most soil-crop models. Some models account for seasonal variations in soil properties (e.g. bulk density) due to tillage loosening and post-tillage consolidation or soil sealing. However, no model can account for longer-term changes in soil structure due to biological agents and processes. The development of such a model remains a challenge due to the enormous complexity of the interactions in the soil-plant system. Here, we present a new concept for modelling soil structure evolution impacted by biological processes such as root growth and earthworm activity. In this preliminary test of the model, we compare simulations against field observations made at the Soil Structure Observatory (SSO) in Zürich, Switzerland, that was designed to provide information on soil structure recovery following a severe compaction event. In this simple application, we modelled changes in the pore size distribution in a bare soil treatment resulting from soil ingestion and egestion by earthworms and the loosening of compacted soil by casting at the soil surface. Following calibration, the model was able to reproduce the observed temporal development of total porosity, soil bulk density and pore size distribution during a four-year period following severe traffic compaction. The modelling approach presented here appears promising and could help support the development of cost-efficient strategies for sustainable soil management and the restoration of degraded soils.</p>


2020 ◽  
Author(s):  
Katharina Meurer ◽  
Thomas Keller ◽  
Nick Jarvis

<p>The pore structure of soil is known to be dynamics at time scales ranging from seconds (e.g. compaction) to seasons (e.g. root growth, macro-faunal activity) and even decades to centuries (e.g. changes in organic matter content). Nevertheless, soil physical and hydraulic functions are generally treated as static properties in most soil-crop models. Some models account for seasonal variations in soil properties (e.g. bulk density) due to tillage loosening and post-tillage consolidation or soil sealing, but none can account for longer-term changes in soil structure due to biological agents and processes. Here, we present a new concept for modelling soil structure evolution impacted by biological processes such as root growth and earthworm activity. In this preliminary test of the model, we compare simulations against field observations made at the Soil Structure Observatory (SSO) in Zürich, Switzerland, that was designed to provide information on soil structure recovery following a severe compaction event. In this simple application, we modelled changes in the pore size distribution in a bare soil treatment resulting from soil ingestion and egestion by earthworms and the loosening of compacted soil by casting at the soil surface. Following calibration, the model was able to reproduce the observed temporal development of total porosity, soil bulk density and pore size distribution during a four-year period following severe traffic compaction. The modelling approach presented here appears promising and could help support the development of cost-efficient strategies for sustainable soil management and the restoration of degraded soils.</p>


2018 ◽  
Vol 19 (12) ◽  
pp. 3888 ◽  
Author(s):  
Aurora Alaguero-Cordovilla ◽  
Francisco Gran-Gómez ◽  
Sergio Tormos-Moltó ◽  
José Pérez-Pérez

Plant roots exploit morphological plasticity to adapt and respond to different soil environments. We characterized the root system architecture of nine wild tomato species and four cultivated tomato (Solanum lycopersicum L.) varieties during early growth in a controlled environment. Additionally, the root system architecture of six near-isogenic lines from the tomato ‘Micro-Tom’ mutant collection was also studied. These lines were affected in key genes of ethylene, abscisic acid, and anthocyanin pathways. We found extensive differences between the studied lines for a number of meaningful morphological traits, such as lateral root distribution, lateral root length or adventitious root development, which might represent adaptations to local soil conditions during speciation and subsequent domestication. Taken together, our results provide a general quantitative framework for comparing root system architecture in tomato seedlings and other related species.


1987 ◽  
Vol 38 (4) ◽  
pp. 791 ◽  
Author(s):  
KY Chan ◽  
JA Mead ◽  
WP Roberts

Poor early growth of wheat under direct drilling on a hardsetting duplex soil was studied in the light of a range of soil physical and biological properties. Two systems of direct drilling were included in the study: one with a short fallow maintained by herbicide (chemical fallow), and another in which a fallow period was absent and herbicide was applied 1 week before sowing (nil fallow). Plant measurements indicated that the poor early growth observed under both direct drilled systems, as compared to that under conventional cultivation, was not due to poor germination or poor emergence. Rather, it was shown to be a consequence of reduced growth after establishment. Weight per plant measured 64 days after sowing for the conventional, chemical and nil fallow treatments was found to be in the ratio of 3.2: 1.8 : 1.0, respectively. Soil physical measurements during the 9 weeks from sowing indicated that moisture availability was unlikely to be an important factor affecting the observed growth difference for the particular season. Much higher bulk density (1.66 versus 1.35 Mg/m3 at 50-100 mm) and vane shear strength values were found in the undisturbed soil between the drill rows in the top 100 mm of the two direct drilled treatments. Vane shear strength measured in the top 50 mm layer of the direct drilled plots was up to 2.9 times higher between the drill rows than in the drill rows. The poor vegetative growth on the chemical fallow plots was probably caused by restricted root growth in the denser and stronger 0-100 mm depth of undisturbed soil. The poor early vegetative and root growth of wheat in the nil fallow could not be fully explained by the soil physical properties, but indicated the presence of other root inhibitory factors. Our results suggest that one such factor is the presence of inhibitory Eacteria on the roots.


2020 ◽  
Author(s):  
David Nimblad Svensson ◽  
Jumpei Fukumasu ◽  
Gunnar Börjesson ◽  
John Koestel

<p>Soil porosity, pore size distribution and pore characteristics such as connectivity are important for a range of soil processes including ease of root growth and air and water transport. The pore structure is therefore an important part of soil fertility. The pore space is sensitive to management practices such as tillage, fertilization and cropping. Understanding how these practices influence the pore space is important for maintaining a good soil structure that is well aerated and has sufficient drainage. X-ray computed tomography has become a widely used method for studying the pore space as it offers the advantage of enabling soil to be studied in its undisturbed form. In this study it was used to compare the effects of crop growth, tillage and N-fertilizing with Ca(NO3)<sub>2</sub> or farm yard manure (FYM). Soil samples were taken just below the surface from the long-term experiment in Ultuna, Sweden which was started in 1956. The bare fallow, FYM and Ca(NO3)<sub>2</sub>-treatment were sampled with minimum disturbance in two column sizes with inner diameters of 22.2 and 65.5 mm. Differences in pore space morphology were quantified and compared through pore size distribution and a range of connectivity measures, including the Euler number, the critical pore diameter and Gamma connectivity. Biopores were separated from non-biopores and their volume was quantified. Soil organic carbon was determined by dry combustion. Visible porosity and pores in the 150-500 µm class were significantly larger in the FYM and Ca(NO3)<sub>2</sub>-treatment compared to the bare fallow. The porosity occupied by biopores was not found to significantly differ between treatments but the biopores were found to have the largest diameters in the FYM-treatment. Despite that the organic carbon content was 1.7 times higher in the FYM compared to the Ca(NO3)<sub>2</sub>-treatment the visible porosity was similar. This may be due to the positive effects calcium has on the soil structure. The connectivity measures indicated that the FYM-treatment had the best connected pore networks. This may be partly due to the larger biopores. Ca(NO3)<sub>2</sub> showed to be a promising alternative to increase porosity. However, as all the management practices in the long-term field study are done by hand, future studies will have to investigate if the effect is equally similar to FYM under field conditions which are subject to heavy machineries.  </p>


2021 ◽  
Author(s):  
Rumyana Karlova ◽  
Damian Boer ◽  
Scott Hayes ◽  
Christa Testerink

Abstract Abiotic stresses increasingly threaten existing ecological and agricultural systems across the globe. Plant roots perceive these stresses in the soil and adapt their architecture accordingly. This review provides insights into recent discoveries showing the importance of root system architecture and plasticity for the survival and development of plants under heat, cold, drought, salt, and flooding stress. In addition, we review the molecular regulation and hormonal pathways involved in controlling root system architecture plasticity, main root growth, branching and lateral root growth, root hair development and formation of adventitious roots. Several stresses affect root anatomy by causing aerenchyma formation, lignin and suberin deposition, and Casparian strip modulation. Roots can also actively grow towards favourable soil conditions and avoid environments detrimental to their development. Recent advances in understanding the cellular mechanisms behind these different root tropisms are discussed. Understanding root plasticity will be instrumental for the development of crops that are resilient in the face of abiotic stress.


1973 ◽  
Vol 7 (4) ◽  
pp. 184-189 ◽  
Author(s):  
R Q Cannell ◽  
J R Finney

The two aspects of soil conditions and root growth in reduced cultivation systems are reviewed. Generally, an uncultivated soil is characterized by increased mechanical strength, reduced porosity greater moisture, more organic matter and structural stability at the surface, more earthworms and the development of nutrient gradients. Effects on root growth are much more variable and reflect the indirect relationship that exists between bulk soil properties and root growth.


Biologia ◽  
2015 ◽  
Vol 70 (11) ◽  
Author(s):  
Kálmán Rajkai ◽  
Brigitta Tóth ◽  
Gyöngyi Barna ◽  
Hilda Hernádi ◽  
Mihály Kocsis ◽  
...  

AbstractWater storage and flow in soils are highly dependent on soil structure, which strongly determines soil porosity. However pore size distribution can be derived from soil water retention curve (SWRC). Structural characteristics of cultivated arable fields (693 soil profiles, 1773 samples) and soils covered by treated forest stands (137 soil profiles, 405 samples) were selected from the MARTHA Hungarian soil physical database, and evaluated for expressing organic matter effects on soil structure and water retention. For this purpose the normalized pore size distribution curves were determined for the selected soils, plus the modal suction (MS) corresponding to the most frequent pore size class of the soil. Skewness of soils’ pore size distribution curves are found different. The quasi-normal distribution of sandy soils are transformed into distorted in clayey soils. A general growing trend of MS with the ever finer soil texture was shown. Sandy soils have the lowest average MS values, i.e. the highest most frequent equivalent pore diameter. Silty clay and clay soil textures are characterized by the highest MS values. A slight effect of land use and organic matter content is also observable in different MS values of soils under forest vegetation (’forest’) and cultivated arable land (‘plough fields’). MS values of the two land uses were compared statistically. The results of the analyses show that certain soil group’s MS are significantly different under forest vegetation and cultivation. However this difference can be explained only partly and indirectly by the organic matter of different plant coverage in the land use types.


1992 ◽  
Vol 43 (1) ◽  
pp. 19 ◽  
Author(s):  
KY Chan ◽  
JA Mead

Root growth and distribution of wheat under different tillage practices was studied in a 4-year-old tillage experimental site at Cowra, N.S.W. Tillage affected root density as well as distribution. Up to 98 days after sowing, root length density was lower (P < 0.05) in the 0.05-0.10 m layer of the direct-drilled soil than the conventionally cultivated soil. Poor root growth found in direct-drilled soils, which was significantly related to the poor shoot growth, was not caused by soil physical conditions, viz. higher bulk density and soil strength. Rather, biological factors were involved because fumigation completely eliminated the poor shoot growth and significantly increased root length density of the direct drilled soils. Compared to a compaction treatment, roots grown under direct drilling, in addition to having lower density, also had impaired function. Under conventional cultivation, significantly lower root length density was found in the surface soil layer (0-0.05 m) and maximum root length density was found in the 0-05-0.10 m layer. Fumigation did not change the root distribution pattern. This tillage-induced difference in root distribution reflected less favourable surface soil conditions as a result of cultivation, e.g. seedbed slumping, compared to the soil under direct drilling.


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