Managed sheep grazing can improve soil quality and carbon sequestration at solar photovoltaic sites

High anthropogenic activities are constantly causing increased soil degradation and thus soil health and safety are becoming an important issue. The soil quality is deteriorating at an alarming rate in the neighborhood of smelters as a result of heavy metal deposition. Organic biowastes, also produced through anthropogenic activities, provide some solutions for remediation and management of degraded soils through their use as a substrate. Biowastes, due to their high content of organic compounds, have the potential to improve soil quality, plant productivity, and microbial activity contributing to higher humus production. Biowaste use also leads to the immobilization and stabilization of heavy metals, carbon sequestration, and release of macro and micronutrients. Increased carbon sequestration through biowaste use helps us in mitigating climate change and global warming. Soil amendment by biowaste increases soil activity and plant productivity caused by stimulation in shoot and root length, biomass production, grain yield, chlorophyll content, and decrease in oxidative stress. However, biowaste application to soils is a debatable issue due to their possible negative effect of high heavy metal concentration and risks of their accumulation in soils. Therefore, regulations for the use of biowastes as fertilizer or soil amendment must be improved and strictly employed to avoid environmental risks and the entry of potentially toxic elements into the food chain. In this review, we summarize the current knowledge on the effects of biowastes on soil remediation, plant productivity, and soil organic carbon sequestration.

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The effect of bi-culture cover crops on soil quality, carbon sequestration, and growth characteristics in apple orchards of North Western Himalayas

Agroforestry Systems ◽

10.1007/s10457-021-00687-7 ◽

2021 ◽

Author(s):

Javaid M. Dad ◽

Suheel A. Dand ◽

Nazir A. Pala

Keyword(s):

Carbon Sequestration ◽

Soil Quality ◽

Cover Crops ◽

Growth Characteristics ◽

Western Himalayas ◽

Apple Orchards ◽

North Western

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A review of the changes in soil quality and profitability accomplished by sowing rotation crops after cotton in Australian Vertosols from 1970 to 2006

Soil Research ◽

10.1071/sr07077 ◽

2008 ◽

Vol 46 (2) ◽

pp. 173 ◽

Cited By ~ 52

Author(s):

N. R. Hulugalle ◽

F. Scott

Keyword(s):

Carbon Sequestration ◽

Organic Carbon ◽

Soil Quality ◽

Soil Structure ◽

Crop Rotations ◽

Soil Biodiversity ◽

Physical Quality ◽

Soil Physical Quality ◽

Rotation Crops ◽

Rotation Crop

In agricultural systems, soil quality is thought of in terms of productive land that can maintain or increase farm profitability, as well as conserving soil resources so that future farming generations can make a living. Management practices which can modify soil quality include tillage systems and crop rotations. A major proportion of Australian cotton (Gossypium hirsutum L.) is grown on Vertosols (~75%), of which almost 80% is irrigated. These soils have high clay contents (40–80 g/100 g) and strong shrink–swell capacities, but are frequently sodic at depth and prone to deterioration in soil physical quality if incorrectly managed. Due to extensive yield losses caused by widespread deterioration of soil structure and declining fertility associated with tillage, trafficking, and picking under wet conditions during the middle and late 1970s, a major research program was initiated with the objective of developing soil management systems which could improve cotton yields while concurrently ameliorating and maintaining soil structure and fertility. An outcome of this research was the identification of cotton–winter crop sequences sown in a 1 : 1 rotation as being able to sustain lint yields while at the same time maintaining soil physical quality and minimising fertility decline. Consequently, today, a large proportion (~75%) of Australian cotton is grown in rotation with winter cereals such as wheat (Triticum aestivum L.), or legumes such as faba bean (Vicia faba L.). A second phase of research on cotton rotations in Vertosols was initiated during the early 1990s with the main objective of identifying sustainable cotton–rotation crop sequences; viz. crop sequences which maintained and improved soil quality, minimised disease incidence, facilitated soil organic carbon sequestration, and maximised economic returns and cotton water use efficiency in the major commercial cotton-growing regions of Australia. The objective of this review was to summarise the key findings of both these phases of Australian research with respect to soil quality and profitability, and identify future areas of for research. Wheat rotation crops under irrigated and dryland conditions and in a range of climates where cotton is grown can improve soil quality indicators such as subsoil structure, salinity, and sodicity under irrigated and dryland conditions, while leguminous crops can increase available nitrogen by fixing atmospheric nitrogen, and by reducing N volatilisation and leaching losses. Soil organic carbon in most locations has decreased with time, although the rate of decrease may be reduced by sowing crop sequences that return about 2 kg/m2.crop cycle of residues to the soil, minimising tillage and optimising N inputs. Although the beneficial effects of soil biodiversity on quality of soil are claimed to be many, except for a few studies on soil macrofauna such as ants, conclusive field-based evidence to demonstrate this has not been forthcoming with respect to cotton rotations. In general, lowest average lint yields per hectare were with cotton monoculture. The cotton–wheat systems generally returned higher average gross margins/ML irrigation water than cotton monoculture and other rotation crops. This indicates that where irrigation water, rather than land, is the limiting resource, cotton–wheat systems would be more profitable. Recently, the addition of vetch (Vicia villosa Roth.) to the cotton–wheat system has further improved average cotton yields and profitability. Profitability of cotton–wheat sequences varies with the relative price of cotton to wheat. In comparison with cotton monoculture, cotton–rotation crop sequences may be more resilient to price increases in fuel and fertiliser due to lower overall input costs. The profitability of cotton–rotation crop sequences such as cotton–wheat, where cotton is not sown in the same field every year, is more resilient to fluctuations in the price of cotton lint, fuel and nitrogen fertiliser. This review identified several issues with respect to cotton–rotation crop sequences where knowledge is lacking or very limited. These are: research into ‘new’ crop rotations; comparative soil quality effects of managing rotation crop stubble; machinery attachments for managing rotation crop stubble in situ in permanent bed systems; the minimum amount of crop stubble which needs to be returned per cropping cycle to increase SOC levels from present values; the relative efficacy of C3 and C4 rotation crops in relation to carbon sequestration; the interactions between soil biodiversity and soil physical and chemical quality indicators, and cotton yields; and the effects of sowing rotation crops after cotton on farm and cotton industry economic indicators such as the economic incentives for adopting new cotton rotations, farm level impacts of research and extension investments, and industry- and community/catchment-wide economic modelling of the impact of cotton research and extension activities.

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Comparative evaluation of growth performance and soil quality of two age sequences of Gmelina arborea plantation in University of Port Harcourt, Nigeria

Journal of Applied Sciences and Environmental Management ◽

10.4314/jasem.v24i10.9 ◽

2020 ◽

Vol 24 (10) ◽

pp. 1767-1773

Author(s):

E.F. Akhabue ◽

U.D. Chima ◽

F.S. Eguakun

Keyword(s):

Carbon Sequestration ◽

Growth Performance ◽

Soil Quality ◽

Tree Growth ◽

Exchange Capacity ◽

Available Phosphorus ◽

Gmelina Arborea ◽

Port Harcourt ◽

Significant Difference

This study was conducted in 2019 to compare the growth performance and soil quality of two agesequences of Gmelina arborea plantation within the premises of the University of Port Harcourt, Nigeria. Data were collected from two stands of G. arborea established in 2011 and 2015. Growth performance was evaluated based on tree growth variables and above-ground carbon stored. Tree growth variables estimated were total height (TH), diameter at breast height (DBH), crown height (CH), crown diameter (CD) and merchantable height (MH). Topsoil (0 – 30 cm) samples collected from the two sites were analyzed for particle size distribution, organic carbon (OC), total nitrogen (TN), available phosphorus (Av.P), exchangeable bases (Mg, Ca, K and Na), exchangeable acidity (Al+ H+), effective cation exchange capacity (ECEC), base saturation (BS), pH, Manganese (Mn), Iron (Fe), Copper (Cu) and Zinc (Zn). The above-ground biomass (AGB) and carbon stock (CS) were also determined. T-test was used to test for significant difference in the measured parameters between the two age-sequences of G. arborea. Higher values for TH, DBH, CS and MH were recorded for the older stand although the differences between the two age-sequences were not significantly different (p ≥ 0.05). The AGB and CS per hectare were higher for the older than the younger G. arborea stand (302.27 m3 ha-1 and 151.52 m3 ha-1, respectively). Higher values for silt, clay, Ca, Mg, Al+ H+, ECEC, BS, Mn, Fe and Zn were also recorded for the older stand. However, the observed differences were only significant (p < 0.05) for clay, pH, Av.P, Mn and Fe. The study revealed that although soil properties, tree growth as well as carbon sequestration capacity of G. arborea stand improved/increased with age, the differences were mainly not statistically significant (p ≥ 0.05) between the two (eight and four years) age-sequences. Keywords: Gmelina arborea, age sequence, soil quality, carbon sequestration

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