Effects of agricultural management on Vertosols in Tasmania

Soil Research ◽  
2002 ◽  
Vol 40 (8) ◽  
pp. 1267 ◽  
Author(s):  
W. E. Cotching ◽  
J. Cooper ◽  
L. A. Sparrow ◽  
B. E. McCorkell ◽  
W. Rowley ◽  
...  

Attributes of 21 Vertosols in 2 different regions of Tasmania were assessed using field and laboratory techniques to determine differences associated with 3 local forms of agricultural management (long-term pasture, rain-fed cropping and irrigated cropping). Vertosols in the northern Midlands had better physical properties (lesser bulk density and penetration resistance, and greater porosities and water holding capacities), poorer nutrient status (lower pH, exchangeable bases, and extractable P) and better biological properties (greater organic carbon (OC), carbon fractions F1 and F3, and more worms) than south-eastern Vertosols. When adjusted for clay content, cropped sites had less soil OC than pasture sites at 0–75 mm depth. Readily oxidisable (fraction F1) carbon in the surface 75 mm was 3.6 mg/g and 6.9 mg/g under long-term pasture compared with 2.5 mg/g and 3.9 mg/g in irrigated cropped paddocks on south-eastern and Midlands sites, respectively. Soil organic carbon values were positively correlated with physical and chemical soil properties. Long-term pasture paddocks showed stronger structural development and had smaller aggregates than cropped paddocks, which had more larger clods. Vane shear strength and penetration resistance were less in rainfed cropped paddocks compared with long-term pasture but this effect was not apparent on irrigated cropped paddocks. Farmers considered that a majority of their soil attributes were healthy under all management histories but strategies for maintaining organic matter levels and minimising clod formation by tillage are essential for long-term sustainable use of these Vertosols.

Soil Research ◽  
2002 ◽  
Vol 40 (1) ◽  
pp. 65 ◽  
Author(s):  
W. E. Cotching ◽  
J. Cooper ◽  
L. A. Sparrow ◽  
B. E. McCorkell ◽  
W. Rowley

Attributes of 15 Tasmanian dermosols were assessed using field and laboratory techniques to determine changes associated with 3 typical forms of agricultural management: long-term pasture, cropping with shallow tillage using discs and tines, and cropping (including potatoes) with more rigorous and deeper tillage including deep ripping and powered implements. Soil organic carbon in the surface 75 mm was 7.0% under long-term pasture compared with 4.3% and 4.2% in cropped paddocks. Microbial biomass carbon concentrations were 217 mg/kg, 161 mg/kg, and 139 mg/kg, respectively. These differences were negatively correlated with the number of years cropped. Greater bulk densities were found in the surface layer of cropped paddocks but these were not associated with increased penetration resistance or decreased infiltration rate and are unlikely to impede root growth. Long-term pasture paddocks showed stronger structural development and had smaller clods than cropped paddocks. Vane shear strength and penetration resistance were lower in cropped paddocks than under long-term pasture. Many soil attributes showed no significant differences associated with management. Including potatoes in the rotation did not appear to affect these dermosols, which indicates a degree of robustness in these soils. clay loams, organic carbon, soil strength, aggregate stability, land management, cropping.


2003 ◽  
Vol 83 (4) ◽  
pp. 363-380 ◽  
Author(s):  
A. J. VandenBygaart ◽  
E. G. Gregorich ◽  
D. A. Angers

To fulfill commitments under the Kyoto Protocol, Canada is required to provide verifiable estimates and uncertainties for soil organic carbon (SOC) stocks, and for changes in those stocks over time. Estimates and uncertainties for agricultural soils can be derived from long-term studies that have measured differences in SOC between different management practices. We compiled published data from long-term studies in Canada to assess the effect of agricultural management on SOC. A total of 62 studies were compiled, in which the difference in SOC was determined for conversion from native land to cropland, and for different tillage, crop rotation and fertilizer management practices. There was a loss of 24 ± 6% of the SOC after native land was converted to agricultural land. No-till (NT) increased the storage of SOC in western Canada by 2.9 ± 1.3 Mg ha-1; however, in eastern Canada conversion to NT did not increase SOC. In general, the potential to store SOC when NT was adopted decreased with increasing background levels of SOC. Using no-tillage, reducing summer fallow, including hay in rotation with wheat (Triticum aestivum L.), plowing green manures into the soil, and applying N and organic fertilizers were the practices that tended to show the most consistent in creases in SOC storage. By relating treatment SOC levels to those in the control treatments, SOC stock change factors and their levels of uncertainty were derived for use in empirical models, such as the United Nations Intergovernmental Panel on Climate Change (IPCC). Guidelines model for C stock changes. However, we must be careful when attempting to extrapolate research plot data to farmers’ fields since the history of soil and crop management has a significant influence on existing and future SOC stocks. Key words: C sequestration, tillage, crop rotations, fertilizer, cropping intensity, Canada


2011 ◽  
Vol 103 (1) ◽  
pp. 234-246 ◽  
Author(s):  
H. T. Gollany ◽  
R. W. Rickman ◽  
Y. Liang ◽  
S. L. Albrecht ◽  
S. Machado ◽  
...  

ael ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 180062 ◽  
Author(s):  
Sindhu Jagadamma ◽  
Michael E. Essington ◽  
Sutie Xu ◽  
Xinhua Yin

2012 ◽  
Vol 92 (3) ◽  
pp. 419-428 ◽  
Author(s):  
X. H. Li ◽  
X. Z. Han ◽  
H. B. Li ◽  
C. Song ◽  
J. Yan ◽  
...  

Li, X. H., Han, X. Z., Li, H. B., Song, C., Yan, J. and Liang, Y. 2012. Soil chemical and biological properties affected by 21-year application of composted manure with chemical fertilizers in a Chinese Mollisol. Can. J. Soil Sci. 92: 419–428. The effects of 21-yr of application of chemical fertilizers, composted pig manure (CPM) alone, and chemical fertilizers combined with compost on soil chemical and biological properties were investigated. Soil samples (0–20cm) were collected from a long-term fertilization experiment under corn (Zea mays L.) production in 2006, prior to seeding, at the corn tasseling stage and following harvest. Fertilizer treatments were: no fertilizer (CK), nitrogen fertilizer alone (N), N + phosphorus (NP), N + P + potassium (NPK), CPM, N + CPM, N + P + CPM (NP + CPM), and N + P + K + CPM (NPK + CPM). Long-term application of N alone resulted in a reduction of soil pH by 0.38 units and reduced the available P concentration compared with CK. An increase in soil pH was seen with CPM alone and NPK + CPM. Both fertilizers sources, singly and combined, increased the total N and available N concentrations. Total P and total K concentrations were greatest with the NPK + CPM treatment. All fertilizer treatments increased the soil organic carbon (SOC), light fraction organic carbon (LFOC) and microbial biomass carbon (MBC) concentrations significantly (P < 0.05) at the tasseling stage. The NPK + CPM treatment showed the greatest increase in SOC (12%), LFOC (78%) and MBC (44%) concentrations, compared with CK. Soil enzyme activities (invertase, urease, acid and alkaline phosphatases) tended to be greater at tasseling than other sampling dates, with highest enzyme activities in the NPK + CPM treatments. These findings suggest that a long-term application of CPM combined with NPK is an efficient strategy to maintain or increase soil quality in Mollisols for sustainable agriculture.


Soil Research ◽  
2015 ◽  
Vol 53 (7) ◽  
pp. 763 ◽  
Author(s):  
Ming Li ◽  
Ming Liu ◽  
Stephen Joseph ◽  
Chun-Yu Jiang ◽  
Meng Wu ◽  
...  

Biochar has been considered to affect the transformation of soil organic carbon, soil microbial activity and diversity when applied to soil. However, the changes in chemical and biological properties of biochar itself in soil have not been fully determined. In this study, various biochar samples were obtained from three crop straws (rice, peanut and corn) and two wood chips (bamboo and pine), and incubated with an acidic paddy soil. We examined the changes of biochar water extractable organic carbon (WEOC) content and its ultraviolet (UV) absorbance at 280 nm during incubation period, and also investigated the microbial phospholipid fatty acids (PLFAs) profile of biochar after 75 days of incubation. The WEOC content of biochars decreased at the end of incubation, except for the biochar pyrolysed from bamboo chips at 400°C. An average reduction rate of 61.2% in WEOC concentration for straw biochars occurred within the first 15 days, while no significant change was observed for all biochars between day 15 and 45, and a slight increase in WEOC occurred for all biochars in the last 30 days. There was a positive relationship between biochar WEOC content and its UV absorbance properties. The microbial PLFAs concentrations of biochars varied from 15.56 to 60.35 nmol g–1, and there was a greater abundance in content and species for corn straw biochars than for the other types of biochars. General bacteria were the dominant microbial group that colonised biochar sample, while gram-positive bacterial and fungi were less in abundance. The chemical properties of fresh biochar were well correlated with total PLFAs concentrations, and significantly related to the composition of microbial community. We concluded that the WEOC component of most biochars change within such short-term application to soil, and the WEOC in combined with the pH and nutrient status of biochar, can alter the type and abundance of microorganisms that colonised biochar.


1989 ◽  
Vol 69 (1) ◽  
pp. 39-47 ◽  
Author(s):  
A. NDAYEGAMIYE ◽  
D. CÔTÉ

Chemical and biological properties were evaluated in 1987 on an acidic silty loam soil following a long-term field study established in 1978 and cultivated with silage corn. Treatments included a control, solid cattle manure (20, 40 and 60 Mg ha−1 FYM) and pig slurry (60, 120 m3 ha−1 SLU) applied every 2 yr and annually, respectively. No fertilizer was applied. The results of this study have shown that neither treatment significantly affected soil pH values, total-N contents and C:N ratios compared to the control. The cation exchange capacity (CEC) of the soil was significantly higher with FYM treatment than with control or SLU application. The highest rates of FYM and SLU have also increased (P < 0.05) soil organic carbon, microbial activity and potentially mineralizable nitrogen. The soil microflora populations (bacteria, fungi, actinomycetes, ammonifiers and nitrifiers) were greatly improved by both treatments. There were no significant differences in organic matter content or the relative amount of humic and fulvic acids between FYM and SLU plots. In spite of these results, FYM application (40 and 60 Mg ha−1) did affect more significantly the distribution of organic carbon in HA and the E4/E6 quotients than SLU additions. Humic acids extracted from SLU amended soils had a lower C content and lower E4/E6 ratios than humic acids from FYM soils. Long-term SLU application did not contribute to decreased organic matter content, CEC and humic acids yield, probably because of optimal organic residues returned to the soil by the corn crops. The FYM application generally improved soil chemical and biological properties. For a sustainable soil productivity, long-term SLU application should then be avoided in rotation in which small amounts of plant residues are returned, especially on soils with low organic matter contents. Key words: Organic matter, microbial activity, nitrogen mineralization potential, CEC, solid cattle manure, pig slurry


Soil Research ◽  
2017 ◽  
Vol 55 (3) ◽  
pp. 245
Author(s):  
T. T. Mukasa Mugerwa ◽  
P. A. McGee

Levels of organic carbon within agricultural soils in Australia continue to decline predominantly due to intensive cultivation. Such practices place sustainable use of agricultural soils at risk. The aim of the present study was to test whether selected melanised endophytic fungi could enhance organic carbon in an experimental soil. In a compartmental pot study, 20 melanised endophytic fungi significantly increased carbon in an aggregated carbon-rich Alfisol over 14 weeks, with increases of up to 17% measured. Two of these fungi increased organic carbon within microaggregates. This study demonstrates that some melanised endophytic fungi have the potential to increase levels of organic carbon within an experimental soil. Melanin, a polyaromatic compound present within the cell walls of melanised endophytic fungi, may have contributed towards increases in organic carbon, particularly if protected within soil aggregates. Deposition of aromatic carbon within aggregates would leave this carbon less susceptible to oxidation and contribute towards long-term carbon storage in soils.


Soil Research ◽  
2002 ◽  
Vol 40 (1) ◽  
pp. 45 ◽  
Author(s):  
W. E. Cotching ◽  
J. Cooper ◽  
L. A. Sparrow ◽  
B. E. McCorkell ◽  
W. Rowley

Attributes of 15 Tasmanian sandy tenosols were assessed using field and laboratory techniques to determine differences under 3 typical forms of agricultural management: long-term pasture, cropping with shallow tillage using discs and tines, and cropping (including potatoes) with more rigorous and deeper tillage including deep ripping and powered implements. Soil organic carbon in the surface 75 mm was 2.6&percnt; under long-term pasture compared with 1.1&percnt; in rigorously tilled cropping paddocks. Readily oxidisable carbon concentrations were 2.3 mg&sol;g and 1.0 mg&sol;g, respectively. These differences were negatively correlated with the number of years cropped, which we viewed with concern. Infiltration rate was greater and shear strength less in cropped paddocks compared with long-term pasture. Dry bulk density was greater and total porosity and macroporosity were less in rigorously tilled paddocks. Subsoil compaction was apparent in paddocks which had grown potatoes. Cropping was not clearly associated with smaller or less stable aggregates. A survey of farmers' perceptions found that they identified more healthy than unhealthy soil attributes under all management histories. Significant negative correlations were found between the number of unhealthy attributes identified in a farmer survey and laboratory-determined water-stable aggregates and mean weight diameter of dry soil aggregates. The effects of cropping are not associated with a broad range of degraded soil attributes on these Tasmanian tenosols. tenosols, sandy soils, organic carbon, soil strength, aggregate stability, land management, cropping.


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