scholarly journals Estimations of soil fertility in physically degraded agricultural soils through selective accounting of fine earth and gravel fractions

Solid Earth ◽  
2016 ◽  
Vol 7 (3) ◽  
pp. 897-903 ◽  
Author(s):  
Mavinakoppa S. Nagaraja ◽  
Ajay Kumar Bhardwaj ◽  
G. V. Prabhakara Reddy ◽  
Chilakunda A. Srinivasamurthy ◽  
Sandeep Kumar
Keyword(s):  
Soil Fertility ◽  
Bulk Density ◽  
Agricultural Soils ◽  
Land Development ◽  
Soil Mass ◽  
Available Phosphorus ◽  
Soil Organic C ◽  
Fine Earth ◽  
Degraded Lands ◽  
Organic C

Abstract. Soil fertility and organic carbon (C) stock estimations are crucial to soil management, especially that of degraded soils, for productive agricultural use and in soil C sequestration studies. Currently, estimations based on generalized soil mass (hectare furrow basis) or bulk density are used which may be suitable for normal agricultural soils, but not for degraded soils. In this study, soil organic C, available nitrogen (N), available phosphorus (P2O5) and available potassium (K2O), and their stocks were estimated using three methods: (i) generalized soil mass (GSM, 2 million kg ha−1 furrow soil), (ii) bulk-density-based soil mass (BDSM) and (iii) the proportion of fine earth volume (FEV) method, for soils sampled from physically degraded lands in the eastern dry zone of Karnataka State in India. Comparative analyses using these methods revealed that the soil organic C, N, P2O and K2O stocks determined by using BDSM were higher than those determined by the GSM method. The soil organic C values were the lowest in the FEV method. The GSM method overestimated soil organic C, N, P2O and K2O by 9.3–72.1, 9.5–72.3, 7.1–66.6 and 9.2–72.3 %, respectively, compared to FEV-based estimations for physically degraded soils. The differences among the three methods of estimation were lower in soils with low gravel content and increased with an increase in gravel volume. There was overestimation of soil organic C and soil fertility with GSM and BDSM methods. A reassessment of methods of estimation was, therefore, attempted to provide fair estimates for land development projects in degraded lands.

scholarly journals Estimations of soil fertility in physically degraded soils through selective accounting of fine earth

2016 ◽  
Author(s):  
Mavinakoppa S. Nagaraja ◽  
Ajay Kumar Bhardwaj ◽  
G.V. Prabhakara Reddy ◽  
Chilakunda A. Srinivasamurthy ◽  
Sandeep Kumar
Keyword(s):  
Soil Fertility ◽  
Bulk Density ◽  
Land Development ◽  
Soil Mass ◽  
Available Phosphorus ◽  
Soil Organic C ◽  
Fine Earth ◽  
Degraded Lands ◽  
Available Nitrogen ◽  
Organic C

Abstract. Soil fertility and organic carbon (C) stock estimations are crucial to soil management especially that of degraded soils, for productive agricultural use and in soil C sequestration studies. Currently, estimations based on generalized soil mass (hectare-furrow basis) or bulk density (BD) basis are used which may be suitable for normal agricultural soils but not for degraded soils. We measured soil organic C, available nitrogen (N), available phosphorus (P) and available potassium (K), and estimated stocks using three methods: (i) generalized soil mass (GSM, 2 million kg ha−1 furrow soil), ii) bulk density based soil mass (BDSM) and (iii) the proportion of fine earth volume (FEV) method, for soils sampled from physically degraded lands in Eastern Dry Zone of Karnataka State in India. Comparative analyses using these methods revealed that the soil organic C, and N, P and K stocks determined by using BDSM were higher than those by GSM method. The soil organic C values were the lowest in the FEV method compared to the other two methods. The GSM method overestimated soil organic C, N, P and K by 9.3–72.1 %, 9.5–72.3 %, 7.1–66.6 % and 9.2–72.3 %, respectively, compared to FEV based estimations for physically degraded soils. The differences among the three methods of determinations were lower in soils with low gravel content and increased with increase in gravel volume. There was overestimation of soil organic C and soil fertility with GSM and BDSM methods. A reassessment of methods of estimation was, therefore, attempted to provide fair estimates for land development projects in degraded lands.

scholarly journals Effects of pumice mining on soil quality

Solid Earth ◽  
2016 ◽  
Vol 7 (1) ◽  
pp. 1-9 ◽  
Author(s):  
A. Cruz-Ruíz ◽  
E. Cruz-Ruíz ◽  
R. Vaca ◽  
P. Del Aguila ◽  
J. Lugo
Keyword(s):  
Bulk Density ◽  
Soil Quality ◽  
Total Nitrogen ◽  
Agricultural Soils ◽  
Microbial Biomass Carbon ◽  
Principal Component ◽  
Available Phosphorus ◽  
Total N ◽  
Organic C ◽  
Study Sites

Abstract. Mexico is the world's fourth most important maize producer; hence, there is a need to maintain soil quality for sustainable production in the upcoming years. Pumice mining is a superficial operation that modifies large areas in central Mexico. The main aim was to assess the present state of agricultural soils differing in elapsed time since pumice mining (0–15 years) in a representative area of the Calimaya region in the State of Mexico. The study sites in 0, 1, 4, 10, and 15 year old reclaimed soils were compared with an adjacent undisturbed site. Our results indicate that gravimetric moisture content, water hold capacity, bulk density, available phosphorus, total nitrogen, soil organic carbon, microbial biomass carbon and phosphatase and urease activity were greatly impacted by disturbance. A general trend of recovery towards the undisturbed condition with reclamation age was found after disturbance, the recovery of soil total N being faster than soil organic C. The soil quality indicators were selected using principal component analysis (PCA), correlations and multiple linear regressions. The first three components gathered explain 76.4 % of the total variability. The obtained results revealed that the most appropriate indicators to diagnose the quality of the soils were urease, available phosphorus and bulk density and minor total nitrogen. According to linear score analysis and the additive index, the soils showed a recuperation starting from 4 years of pumice extraction.

scholarly journals Proximal sensing for soil carbon accounting

2018 ◽  
Author(s):  
Jacqueline R. England ◽  
Raphael Armando Viscarra Rossel
Keyword(s):  
Bulk Density ◽  
Financial Incentives ◽  
Management Practices ◽  
Ghg Emissions ◽  
Carbon Accounting ◽  
Soil Organic C ◽  
Proximal Sensing ◽  
Organic C ◽  
Soil C ◽  
Cost Efficient

Abstract. Maintaining or increasing soil organic carbon (C) is important for securing food production, and for mitigating greenhouse gas (GHG) emissions, climate change and land degradation. Some land management practices in cropping, grazing, horticultural and mixed farming systems can be used to increase organic C in soil, but to assess their effectiveness, we need accurate and cost-efficient methods for measuring and monitoring the change. To determine the stock of organic C in soil, one needs measurements of soil organic C concentration, bulk density and gravel content, but using conventional laboratory-based analytical methods is expensive. Our aim here is to review the current state of proximal sensing for the development of new soil C accounting methods for emissions reporting and in emissions reduction schemes. We evaluated sensing techniques in terms of their rapidity, cost, accuracy, safety, readiness and their state of development. The most suitable technique for measuring soil organic C concentrations appears to be vis–NIR spectroscopy and for bulk density active gamma-ray attenuation. Sensors for measuring gravel have not been developed, but an interim solution with rapid wet-sieving and automated measurement appears useful. Field-deployable, multi-sensor systems are needed for cost-efficient soil C accounting. Proximal sensing can be used for soil organic C accounting, but the methods need to be standardised and procedural guidelines need to be developed to ensure proficient measurement and accurate reporting and verification. This is particularly important if the schemes use financial incentives for landholders to adopt management practices to sequester soil organic C. We list and discuss the requirements for the development of new soil C accounting methods that are based on proximal sensing, including requirements for recording, verification and auditing.

scholarly journals Effect of Land Use on Soil Quality in Afaka Forest Northern Guinea Savannah of Nigeria

2019 ◽  
pp. 1-12
Author(s):  
H. Haruna
Keyword(s):  
Land Use ◽  
Soil Fertility ◽  
Bulk Density ◽  
Soil Quality ◽  
Negative Impact ◽  
Land Use Changes ◽  
Chemical Properties ◽  
Available Phosphorus ◽  
Cultivated Land ◽  
Soil Fertility Management

Land use changes from forest into cultivated ecosystems result in negative impact on soil structure and quality. The purpose of this study was to determine effect of land use on soil quality in Afaka forest northern guinea savannah of Nigeria. Land use systems, including natural forest and cultivated land were identified. Eighteen (18) composite disturbed and undisturbed samples were collected from depth of 0-5 and 5-10 cm for analysis of pertinent soil properties in the laboratory using grid procedure. Most physical and chemical properties show relative variations in response to land use types and geomorphic positions. Results  indicate  that the soils had  high degree of weathering potentials, low  to moderate  bulk density at 0-5cm depth values between 1.42 to 1.49 Mg m-3 in  forest and  cultivated land, bulk density of  1.34 and 1.46 1.Mg m-3at 5 -1ocm depth   for forest and  cultivated land respectively. The soil water at 0-5cm depth is from 4.20 to 2.63 cm3/cm3, while at 5-10 cm depth these values vary from 4.32 to 2.13 cm3/cm3 under forest and cultivation land use. The pH (H2O) is 6.9 to 7.16 with low electrical conductivity of 0.13 dS/m(forest) and 0.12 dS/m (cultivation). The CEC of soils is recorded as 8.60 cmol kg-1 (forest) to 8.54 cmol kg-1 (cultivated)whereas  total nitrogen content of 1.21 g kg-1 and 1.11 g kg-1 and available phosphorus of 8.78 mg kg-1 (cultivated) and 5.47 mg kg-1 (forest).. Results indicate that soil fertility parameters were moderate to low for cultivated land and at all slope positions, suggesting that soil fertility management is required in order to make agriculture sustainable on Afaka area.

Soil carbon sequestration and density distribution in a Vertosol under different farming practices

Soil Research ◽  
2004 ◽  
Vol 42 (8) ◽  
pp. 875 ◽  
Author(s):  
W. J. Wang ◽  
R. C. Dalal ◽  
P. W. Moody
Keyword(s):  
Seasonal Variations ◽  
Agricultural Soils ◽  
Cropping System ◽  
Subtropical Climate ◽  
Soil Organic C ◽  
Farming Practices ◽  
Winter Cereal ◽  
Organic C ◽  
Fallow Period

Abstract Agricultural soils play an important role in the global carbon (C) cycling and can act as a significant C sink if managed properly. The long-term (33 years) effects of no till (NT) v. conventional till (CT), stubble retention (SR) v. stubble burning (SB), and N fertiliser application (NF) v. nil N fertilisation (N0) on soil organic C sequestration, and their seasonal variations during the fallow period, were studied in a winter cereal–summer fallow cropping system under semi-arid subtropical climate in Queensland, Australia. The function of different density fractions of soil organic C in determining total organic C (TOC) dynamics and sequestration was investigated. Significant effect of NT, SR, or NF on soil organic C level was observed only in the top 10 cm soil and when they were practiced together, with the TOC contents being 1.1 to 3.4 t/ha higher under NT + NF + SR than under other treatments. There were significant seasonal fluctuations in TOC contents at different stages of the fallow period, and the lowest levels of TOC and treatment effects were observed in the late fallow period. Density fractionation of soil organic C showed that light fraction C (<1.6 g/cm3) declined rapidly during the fallow period and did not accumulate substantially in soil. TOC dynamics, either as a consequence of seasonal variations or as a long-term response to different farming practices, were predominantly controlled by the changes in the heavy fraction C (>1.6 g/cm3).

Management of sugarcane harvest residues: consequences for soil carbon and nitrogen

Soil Research ◽  
2007 ◽  
Vol 45 (1) ◽  
pp. 13 ◽  
Author(s):  
Fiona A. Robertson ◽  
Peter J. Thorburn
Keyword(s):  
Microbial Biomass ◽  
Soil Fertility ◽  
Microbial Activity ◽  
Soil N ◽  
Soil Organic C ◽  
Total N ◽  
Organic C ◽  
Soil Microbial ◽  
C And N

The Australian sugar industry is moving away from the practice of burning the crop before harvest to a system of green cane trash blanketing (GCTB). Since the residues that would have been lost in the fire are returned to the soil, nutrients and organic matter may be accumulating under trash blanketing. There is a need to know if this is the case, to better manage fertiliser inputs and maintain soil fertility. The objective of this work was to determine whether conversion from a burning to a GCTB trash management system is likely to affect soil fertility in terms of C and N. Indicators of short- and long-term soil C and N cycling were measured in 5 field experiments in contrasting climatic conditions. The effects of GCTB varied among experiments. Experiments that had been running for 1–2 years (Harwood) showed no significant trash management effects. In experiments that had been running for 3–6 years (Mackay and Tully), soil organic C and total N were up to 21% greater under trash blanketing than under burning, to 0.10 or 0.25 m depth (most of this effect being in the top 50 mm). Soil microbial activity (CO2 production) and soil microbial biomass also increased under GCTB, presumably as a consequence of the improved C availability. Most of the trash C was respired by the microbial biomass and lost from the system as CO2. The stimulation of microbial activity in these relatively short-term GCTB systems was not accompanied by increased net mineralisation of soil N, probably because of the greatly increased net immobilisation of N. It was calculated that, with standard fertiliser applications, the entire trash blanket could be decomposed without compromising the supply of N to the crop. Calculations of possible long-term effects of converting from a burnt to a GCTB production system suggested that, at the sites studied, soil organic C could increase by 8–15%, total soil N could increase by 9–24%, and inorganic soil N could increase by 37 kg/ha.year, and that it would take 20–30 years for the soils to approach this new equilibrium. The results suggest that fertiliser N application should not be reduced in the first 6 years after adoption of GCTB, but small reductions may be possible in the longer term (>15 years).

Farming systems’ productivity and soil organic carbon stocks following fertilisers, no-tillage or legumes on a fertility-depleted soil in a semi-arid subtropical region

Soil Research ◽  
2018 ◽  
Vol 56 (4) ◽  
pp. 429 ◽  
Author(s):  
R. C. Dalal ◽  
W. M. Strong ◽  
E. J. Weston ◽  
J. E. Cooper ◽  
K. J. Lehane ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Grain Legume ◽  
No Tillage ◽  
Soil Organic C ◽  
Management Options ◽  
N Application ◽  
Organic C ◽  
Grain Yields ◽  
C Stocks

Depleted soil nitrogen supplies in long-term continuously cultivated soil for cereal grain cropping have resulted in reduced cereal yields, low grain proteins and hence low economic returns. This has necessitated the development of alternative management practices to sustain crop yields, as well as to restore and maintain soil fertility. In the present study we examined the comparative performance of several management options over a 12-year period, including: a 4-year rotation of grass + legume pasture followed by wheat (GL–wheat); 2-year rotations of lucerne–wheat, annual medic–wheat and chickpea–wheat; and continuous conventional tillage (CT) or no-tillage (NT), without or with fertiliser N application (0, 25 and 75 kg N ha–1 for each crop). Average wheat grain yields were highest in the chickpea–wheat rotation, followed by the NT wheat with 75 kg N ha–1; the lowest grain yields were in the CT or NT wheat treatment without fertiliser N application. Crop water use and gross margin were strongly correlated. However, there was an increasing potential for the deep leaching of nitrate-N at 75 kg N ha–1 application, as well as from the GL pasture initiated in 1987, but not from that initiated in 1986, emphasising the effect of variability in growing seasons. Soil organic C stocks increased under the 4-year GL pasture in the 0–0.1 m depth only, then decreased steadily following the cropping phase. The rotation of 4-year GL pasture followed by wheat cropping for 4–6 years may maintain initial soil organic C stock, but a shorter cropping phase is required to increase soil organic C and N stocks and soil fertility in the long term. Partial economic analysis of the treatments suggested that restoring or maintaining soil N fertility, either through legume-based pastures, grain legume and/or N fertiliser, provides long-term positive economic return.

scholarly journals Proximal sensing for soil carbon accounting

SOIL ◽  
2018 ◽  
Vol 4 (2) ◽  
pp. 101-122 ◽  
Author(s):  
Jacqueline R. England ◽  
Raphael A. Viscarra Rossel
Keyword(s):  
Bulk Density ◽  
Financial Incentives ◽  
Management Practices ◽  
Near Infrared ◽  
Carbon Accounting ◽  
Soil Organic C ◽  
Proximal Sensing ◽  
Organic C ◽  
Soil C ◽  
Cost Efficient

Abstract. Maintaining or increasing soil organic carbon (C) is vital for securing food production and for mitigating greenhouse gas (GHG) emissions, climate change, and land degradation. Some land management practices in cropping, grazing, horticultural, and mixed farming systems can be used to increase organic C in soil, but to assess their effectiveness, we need accurate and cost-efficient methods for measuring and monitoring the change. To determine the stock of organic C in soil, one requires measurements of soil organic C concentration, bulk density, and gravel content, but using conventional laboratory-based analytical methods is expensive. Our aim here is to review the current state of proximal sensing for the development of new soil C accounting methods for emissions reporting and in emissions reduction schemes. We evaluated sensing techniques in terms of their rapidity, cost, accuracy, safety, readiness, and their state of development. The most suitable method for measuring soil organic C concentrations appears to be visible–near-infrared (vis–NIR) spectroscopy and, for bulk density, active gamma-ray attenuation. Sensors for measuring gravel have not been developed, but an interim solution with rapid wet sieving and automated measurement appears useful. Field-deployable, multi-sensor systems are needed for cost-efficient soil C accounting. Proximal sensing can be used for soil organic C accounting, but the methods need to be standardized and procedural guidelines need to be developed to ensure proficient measurement and accurate reporting and verification. These are particularly important if the schemes use financial incentives for landholders to adopt management practices to sequester soil organic C. We list and discuss requirements for developing new soil C accounting methods based on proximal sensing, including requirements for recording, verification, and auditing.

scholarly journals Calculation of organic matter and nutrients stored in soils under contrasting management regimes

1995 ◽  
Vol 75 (4) ◽  
pp. 529-538 ◽  
Author(s):  
B. H. Ellert ◽  
J. R. Bettany
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Erosion ◽  
Bulk Density ◽  
Unit Area ◽  
Soil Mass ◽  
Organic C ◽  
The Masses ◽  
Induced Changes ◽  
Gray Luvisol

Assessments of management-induced changes in soil organic matter depend on the methods used to calculate the quantities of organic C and N stored in soils. Chemical analyses in the laboratory indicate the concentrations of elements in soils, but the thickness and bulk density of the soil layers in the field must be considered to estimate the quantities of elements per unit area. Conventional methods that calculate organic matter storage as the product of concentration, bulk density and thickness do not fully account for variations in soil mass. Comparisons between the quantities of organic C, N, P and S in Gray Luvisol soils under native aspen forest and various cropping systems were hampered by differences in the mass of soil under consideration. The influence of these differences was eliminated by calculating the masses of C, N, P and S in an "equivalent soil mass" (i.e. the mass of soil in a standard or reference surface layer). Reassessment of previously published data also indicated that estimates of organic matter storage depended on soil mass. Appraisals of organic matter depletion or accumulation usually were different for comparisons among element masses in an equivalent soil mass than for comparisons among element masses in genetic horizons or in fixed sampling depths. Unless soil erosion or deposition had altered the mass of topsoil per unit area, comparisons among unequal soil masses were unjustified and erroneous. For management-induced changes in soil organic matter and nutrient storage to be assessed reliably, the masses of soil being compared must be equivalent. Key words: Soil carbon, soil nitrogen, soil phosphorus, soil sulfur, carbon cycle, carbon storage, bulk density effects, Gray Luvisol, soil erosion

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