Soil fertility effects on carbon fluxes under two spring wheat rotations in a semiarid agroecosystem

2002 ◽  
Vol 82 (2) ◽  
pp. 155-163 ◽  
Author(s):  
D. Curtin ◽  
H. Wang ◽  
F. Selles ◽  
C. A. Campbell ◽  
R. P. Zentner

Changes in soil C storage due to management practices are important in relation to soil quality and to the broader issue of atmospheric C sequestration. Our objective was to evaluate the effects of soil fertility management on C fluxes under two spring wheat (Triticum aestivum L.) rotations in semiarid southwestern Saskatchewan, i.e., continuous wheat (Cont W) and a rotation that included summerfallow every third year (F-W-W). Continuous wheat was grown under two fertility regimes since initiation of the experiment in 1967, i.e., fertilization with N+P (no nutrient limitation) or with P only. In F-W-W there were three fertility treatments: N+ P, N only, and P only. We measured soil CO2 emissions under all fertility treatments and rotation phases during the 1995 and 1996 cropping seasons (emissions were measured at about weekly intervals between spring and freeze-up in autumn). Inputs of C in straw were measured and a root:straw ratio of 0.59 was used to estimate root C inputs. Alleviation of nutrient limitations generally had a positive effect on wheat growth (and thus on C inputs), particularly in 1995, the wetter of the 2 yr (precipitation 14% greater than average). For example, C inputs in 1995 under Cont W were estimated at 2700 kg ha-1 in the N+P treatment compared with 1500 kg ha-1 in the P only treatment. Fertility treatments had little effect on CO2 emissions; e.g., for Cont W the mean flux for the 1995 monitoring period was 2.7 mmol CO2 m-2s-1 where N + P was applied and 2.6 mmol CO2 m-2s-1 where P only was applied. Greater C inputs, but similar outputs of CO2-C for the N + P treatment vs. the systems receiving N or P only, suggest that proper fertilization resulted in a gain in soil C. However, quantifying the fertility-induced C gain is problematic because of uncertainty regarding effects of fertility on several components of the C budget, particularly root-C inputs and the contribution of rhizosphere respiration to the measured CO2 flux. Key words: Carbon sequestration, N and P fertilization, CO2 emissions, C inputs in crop residues, spring wheat, summerfallow

2016 ◽  
Vol 47 (2) ◽  
pp. 180
Author(s):  
S.A Mashi ◽  
A. Yaro

In Nigeria’s drylands, profitable crop production requires adequate soil fertility management. This study examines the effects of farmer-managed practices on soil fertility in Sabke catchment of the drylands. Seven sites under permanent cropland, fallow land, grassland, shrubland, orchard land, intercropping land and woodland distributed on four transects were selected across the catchment. At every site, five replicate soil samples were collected from 0-15cm (topsoil) and 20-30cm (subsoil) and analysed for C, N, P, Ca, Mg, K and Na. Higher topsoil values of most of the properties were observed under cropland and intercropping sites. The two cultivated plots receive annual applications of organic manure in addition to chemical fertilizer and crops residue retention while the other plots are not. Thus, improvement in soil organic matter and nutrients would be expected in soils of the area with high rate of application of manure and chemical fertilizer, and retention of crop residues


Author(s):  
Meng Na ◽  
Xiaoyang Sun ◽  
Yandong Zhang ◽  
Zhihu Sun ◽  
Johannes Rousk

AbstractSoil carbon (C) reservoirs held in forests play a significant role in the global C cycle. However, harvesting natural forests tend to lead to soil C loss, which can be countered by the establishment of plantations after clear cutting. Therefore, there is a need to determine how forest management can affect soil C sequestration. The management of stand density could provide an effective tool to control soil C sequestration, yet how stand density influences soil C remains an open question. To address this question, we investigated soil C storage in 8-year pure hybrid larch (Larix spp.) plantations with three densities (2000 trees ha−1, 3300 trees ha−1 and 4400 trees ha−1), established following the harvesting of secondary mixed natural forest. We found that soil C storage increased with higher tree density, which mainly correlated with increases of dissolved organic C as well as litter and root C input. In addition, soil respiration decreased with higher tree density during the most productive periods of warm and moist conditions. The reduced SOM decomposition suggested by lowered respiration was also corroborated with reduced levels of plant litter decomposition. The stimulated inputs and reduced exports of C from the forest floor resulted in a 40% higher soil C stock in high- compared to low-density forests within 8 years after plantation, providing effective advice for forest management to promote soil C sequestration in ecosystems.


Soil Research ◽  
2012 ◽  
Vol 50 (2) ◽  
pp. 83 ◽  
Author(s):  
W. E. Cotching

Soil carbon (C) stocks were calculated for Tasmanian soil orders to 0.3 and 1.0 m depth from existing datasets. Tasmanian soils have C stocks of 49–117 Mg C/ha in the upper 0.3 m, with Ferrosols having the largest soil C stocks. Mean soil C stocks in agricultural soils were significantly lower under intensive cropping than under irrigated pasture. The range in soil C within soil orders indicates that it is critical to determine initial soil C stocks at individual sites and farms for C accounting and trading purposes, because the initial soil C content will determine if current or changed management practices are likely to result in soil C sequestration or emission. The distribution of C within the profile was significantly different between agricultural and forested land, with agricultural soils having two-thirds of their soil C in the upper 0.3 m, compared with half for forested soils. The difference in this proportion between agricultural and forested land was largest in Dermosols (0.72 v. 0.47). The total amount of soil C in a soil to 1.0 m depth may not change with a change in land use, but the distribution can and any change in soil C deeper in the profile might affect how soil C can be managed for sequestration. Tasmanian soil C stocks are significantly greater than those in mainland states of Australia, reflecting the lower mean annual temperature and higher precipitation in Tasmania, which result in less oxidation of soil organic matter.


2021 ◽  
Author(s):  
Sylvia Vetter ◽  
Michael Martin ◽  
Pete Smith

<p>Reducing greenhouse gas (GHG) emissions in to the atmosphere to limit global warming is the big challenge of the coming decades. The focus lies on negative emission technologies to remove GHGs from the atmosphere from different sectors. Agriculture produces around a quarter of all the anthropogenic GHGs globally (including land use change and afforestation). Reducing these net emissions can be achieved through techniques that increase the soil organic carbon (SOC) stocks. These techniques include improved management practices in agriculture and grassland systems, which increase the organic carbon (C) input or reduce soil disturbances. The C sequestration potential differs among soils depending on climate, soil properties and management, with the highest potential for poor soils (SOC stock farthest from saturation).</p><p>Modelling can be used to estimate the technical potential to sequester C of agricultural land under different mitigation practices for the next decades under different climate scenarios. The ECOSSE model was developed to simulate soil C dynamics and GHG emissions in mineral and organic soils. A spatial version of the model (GlobalECOSSE) was adapted to simulate agricultural soils around the world to calculate the SOC change under changing management and climate.</p><p>Practices like different tillage management, crop rotations and residue incorporation showed regional differences and the importance of adapting mitigation practices under an increased changing climate. A fast adoption of practices that increase SOC has its own challenges, as the potential to sequester C is high until the soil reached a new C equilibrium. Therefore, the potential to use soil C sequestration to reduce overall GHG emissions is limited. The results showed a high potential to sequester C until 2050 but much lower rates in the second half of the century, highlighting the importance of using soil C sequestration in the coming decades to reach net zero by 2050.</p>


2020 ◽  
Vol 43 (338) ◽  
pp. 35-41
Author(s):  
Ammal Abukari ◽  
Rahamatu Abukari

AbstractIn sub-Saharan Africa intensifying small-scale farming is essential in addressing poverty related issues in rural communities and the degradation of natural resources. Integrated Soil Fertility Management (ISFM) are the best practices used to improve the productivity of crops whilst maximizing agronomic efficiency of inputs applied and hence contributing to sustainable intensification. ISFM usually include the appropriate use of inorganic fertilizer and organic resources, good agronomic practices and appropriate use of germplasm. The survey was carried-out on the awareness of Integrated Soil Fertility Management practices in the Savelugu Municipal of Northern Ghana to study the awareness of integrated soil fertility management practices amongst farmers through the administration of questionnaires. A multistage method of sampling was used in selecting thirty (30) respondents randomly from five (5) selected communities namely Jana, Yapalsi, Diari, Nabogu and Gushie to make up a total sample size of 150 respondents. Frequency distribution and percentages were used to represent the data. Correlation analysis was used to test for the relationship between awareness, educational level and household size. The survey showed that majority of the respondents at ages between 21 and 30 years were married and majority with household size of 3 to 5 as well as primary and secondary education. Farming activities were carried-out by hand (80%). Majority of the respondents (43.3%) were informed about ISFM through demonstrations and 20% of the farmers apply inorganic fertilizer. About 85.5% of the respondents were aware of ISFM. The research also revealed that ISFM improves production and supports finances of respondents. The assessment of respondents’ perception of ISFM revealed a positive agreement of the effect of ISFM on soil health as well as improved production. In conclusion, it is thus suggested that it is needful for the involvement of the government on the adoption of ISFM via Non-Governmental Organisations (NGOs) locally and or internationally for a suitable advancement and to guarantee a sustainable environment with a world-wide corporation for improvement.


2018 ◽  
Vol 115 (11) ◽  
pp. 2776-2781 ◽  
Author(s):  
Lucas E. Nave ◽  
Grant M. Domke ◽  
Kathryn L. Hofmeister ◽  
Umakant Mishra ◽  
Charles H. Perry ◽  
...  

Soils are Earth’s largest terrestrial carbon (C) pool, and their responsiveness to land use and management make them appealing targets for strategies to enhance C sequestration. Numerous studies have identified practices that increase soil C, but their inferences are often based on limited data extrapolated over large areas. Here, we combine 15,000 observations from two national-level databases with remote sensing information to address the impacts of reforestation on the sequestration of C in topsoils (uppermost mineral soil horizons). We quantify C stocks in cultivated, reforesting, and natural forest topsoils; rates of C accumulation in reforesting topsoils; and their contribution to the US forest C sink. Our results indicate that reforestation increases topsoil C storage, and that reforesting lands, currently occupying >500,000 km2 in the United States, will sequester a cumulative 1.3–2.1 Pg C within a century (13–21 Tg C·y−1). Annually, these C gains constitute 10% of the US forest sector C sink and offset 1% of all US greenhouse gas emissions.


2013 ◽  
Vol 1 ◽  
pp. 1-9 ◽  
Author(s):  
BP Tripathi ◽  
JE Jones

The middle mountain region of Nepal, which occupies some 30% of the total land, is the homeland of 45% of the total population, with agriculture being the main source of their livelihoods. Hill farming is primarily based on organic manure with livestock, forest and crops being major components of an integrated system. The aim of this study is to develop and promote improved methods for research and development organizations to identify cost-effective and appropriate soil fertility management strategies through; providing an improved understanding of the biophysical and socio-economic factors affecting the adaptability of sustainable soil management strategies in hillside systems, developing methodologies for evaluating soil fertility technologies and management systems for differently resource farmers in different farming systems, and strengthening the capability of local professionals in collaborating institutions to provide useful information to farmers. The work is placing emphasis on promoting cost-effective methods of soil fertility management, building on farmers' own knowledge and systems. Participatory techniques have been used for gaining a better understanding of fertility indicators, trends and existing soil management practices during 2000/01 in the western hills of Nepal. Farmers are now concerned that increasing amounts of chemical fertilizer at increasingly higher cost have to be applied, soils are becoming “harder” and production is declining. As a result farmers in four agro-ecological zones opted to either test methods for “improving” the quality of farm yard manure (FYM), or “improve” crop residue management. Early results show that through covering the FYM with black plastic sheets, yield increases of over 30% can be achieved. The use of participatory farm management techniques is providing a basis for local NGOs and farmers to evaluate their own experiments and develop soil fertility technologies and systems for their environments.DOI: http://dx.doi.org/10.3126/ajn.v1i0.7536 Agronomy Journal of Nepal (Agron JN) Vol. 1: 2010 pp.1-9


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1349
Author(s):  
John Havlin ◽  
Ron Heiniger

Increasing crop productivity per unit of land area to meet future food and fiber demand increases both soil nutrient removal and the importance of replenishing soil fertility through efficient nutrient management practices. Significant progress in enhancing nutrient-use efficiency in production agriculture requires improved estimates of plant-available nutrients in the root zone, enhanced crop response to applied nutrients, and reduced offsite nutrient transport. This special issue, Soil Fertility Management for Better Crop Production, presents 15 manuscripts that advance our knowledge of interrelated soil, plant, and management factors important to increasing the nutrient availability and crop recovery of applied nutrients.


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