Conversion from Cropping to Pasture and Graze Management - Term Paper Example

Conversion from Cropping to Pasture and Graze Management Name Institution Conversion from Cropping to Pasture and Graze Management Introduction The issue of greenhouse effect has raised quite a lot of concerns all over the world. Climatologists and other related scientists have warned against increased emission of gasses into the atmosphere. This is with regards to a lot of gases that are emitted into the atmosphere due to human activities. Australia is one of the countries that designed practical approaches that can be used to lower the content of carbon dioxide emitted into the atmosphere. The carbon soil storage is one of the approaches adopted in solving this stalemate. This is achieved through a scientific process commonly referred to as sequestration. Some of the facts surrounding the entire concept adoption are the percentage of carbon in soil and that of the atmosphere (Janzen, 2006). Scientifically, soil contains about twice the amount of carbon as compared to the atmosphere. This approach of dealing with greenhouse effect is used by employing mechanisms that can increase the carbon content in the soil. In this report, the focus is upon two methodologies which can be used to increase the carbon content storage in soil. The methodologies include conversion of cropping land into pasture and grazing management. The two methodologies require improved tactics of management of land. Notably, the potential of each of the approach in storing additional carbon is quite varied. The agricultural practices under the two methodologies define the quantity as well as the rate of carbon that the soil is capable of storing at any given time. In one way, the methodologies adopted will be used to not only store carbon found in the soil, but also absorb some of the atmospheric carbon dioxide (Chan, 2001). The process will require the transfer of the said gas into the oceanic, abiotic and geological strata. These processes are aimed at completing the natural process of reducing carbon dioxide in the atmosphere. This is because the carbon dioxide that is used to manufacture food for green plants is translated into soil organic carbon. Potential for soil carbon storage The translation of land meant for cropping to use for pasture is indeed a feasible strategy of reducing the quantity of carbon dioxide in the atmosphere for it to be stored in soil. Cropping as an agricultural process provides a leeway through which a lot of carbon is lost. This is explained by the numerous numbers of mechanical practices undertaken on such piece of land. These practices are mainly tillage in nature and they directly affect the carbon storage in the soil (Chan, 2001). While conversion of cropping land to pasture is recommended for sequestering carbon, the productivity is basically reliant on the specific practice. In overall, this practice has medium capacity to sequester carbon as compared to other agricultural practices where there is a shift. For instance, retired land has greater capacity to sequester carbon as opposed to shifting from cropping to pasture. In line with grazing management, the practice is significant in maintaining or increasing the carbon content in soil. The studies that have been carried out in line with the potential of grazing management to increase the carbon content in soil are quite varied. While the practice in itself is suitable for facilitating sequestration, allied activities have a similar effect. For instance, the activities of animal stock on the grazing fields are likely to increase the content of organic carbon in soil. This is through broken grass and other fodder content which are interfered with when animals are grazing (Conant, Paustian & Elliott, 2001). This leads to decomposition that eventually increases the content of organic carbon in soil. When grazing management is put on weighing scale with the conversion of cropping to pasture, the latter is in a better position to enhance the content of organic carbon in soil. This is simply explained through the occurrences that take place when indeed animals are grazing in the fields. For instance the urine and dung deposits have their effects on the nitrogen and also carbon content in the soil. These deposits speeds up nitrogen cycling and increases its loss via volatilization of ammonia that is generated from urine and dung. This to some extent limits carbon input into soil. Likely Storage Potential Grazing lands have been found to be one of the significant sinks of atmospheric carbon dioxide. Grazing land contains about 10% to 30% of world’s carbon soil reserves. Comparatively, the grazing land is expected to have higher content of storage capacity of the organic carbon. This is mainly determined by the high density of roots (Baker, Ochsner, Venterea & Griffis, 2007). The roots in a graze land are left intact for a long time as compared to the land that had been converted from cropping to pasture. The newly converted land requires adequate time for the roots to be fully developed deep underground. Therefore, this partly explains why the newly converted pasture land has lower capacity when it comes to storage of carbon. This is because soil tillage and other agricultural process that lead to disturbance of the soil are channels through which organic carbon is lost from the soil. In spite of the fact that the storage potential of the land in terms of tons per hectare have been in various researches, the findings are not standard. This is because sequestration rate is dependent upon many factors including soil type, climatic conditions, topography, etc. (Bronick & Lal, 2005). This makes it absolutely difficult to put a standard figure on the amount or rate of carbon sequestered under grazing land as well as that land that has been converted from cropping to pasture. Likely contribution as a GHG emission offset The main aim of carbon sequestration is to reduce the amount of GHG in the atmosphere. The grazing management practices and how they work together to affect the content of GHG emissions in the atmosphere has been researched severally. The components of GHG emissions in the atmosphere consist of mainly carbon dioxide, nitrogen gas and many other gases. The main component from the list given is carbon dioxide. From some of the studies that have been undertaken, the influence on the GHG emission is divided into two when dealing with grazing management. The first part of it is the soil state and the practices that can be undertaken upon it. On the other hand, the animals being grazed on the land are another component. While the grass and the other roots work together to provide a great deal of carbon sequestration, there is a role being performed by the animals. The excretions from animals are the main sources of ammonia and subsequently nitrogen gas. This therefore increases the level of GHG in the atmosphere (Derner, Boutton & Briske, 2006). When the entire situation is looked at marginally, the amount of carbon that is stored in the soil is higher than the nitrogen gas that is emitted into the atmosphere. Looking at conversion of cropping to pasture, the scenario may be slightly different. While pasturelands may have diversity in plant community, a newly converted land may present an entirely different picture. For instance, the different plants may not have been fully developed since it takes time for such progress to be achieved. One of the management practices that will play a significant role in the overall volume of GHG emission is the type, amount and frequency of fertilizer being used on such pasture. At the same time, this case involves the land that has been recently translated from cropland to pasture. This implies that there is a greater risk of overgrazing which increases soil exposure. Soil exposure directly reduces the level of carbon sequestration. Costs and Benefits of Carbon Sequestration The adoption of carbon sequestration strategies as a methodology of reducing the quantity of carbon dioxide in the atmosphere has many benefits to the society at large. Indeed this is the most reliable means of reducing GHG emissions into the atmosphere. The GHG emission is responsible for rise in global temperatures as an indication of global warming effects (Gill, Kelly, et al. 2002). The use of agricultural management practices to combat carbon dioxide in the atmosphere and facilitate carbon storage in the soils increases the level of agricultural productivity. The management practices work together to enhance productivity of the agricultural produce of choice. For instance, the several agricultural practices used for sequestration of carbon reduces nutrient loss from the soil, reduces soil erosion and increase water conservation. Those advantages are derived from practicing activities like conservation tillage. This agricultural practice has the potential of reducing the volume of fossil fuel that is utilized by various farm operations. The other practices include cover cropping and crop rotation. These improve agricultural productivity through enhancing soil structure and addition of organic matter. In spite of the benefits that have been highlighted in line with practices aimed at sequestering carbon, there are also costs that are involved. For instance, while use of nitrogen fertilizer plays a vital role in increasing organic matter of the soil, its transportation and application may have other hidden costs to the volume of carbon sequestered. This is because transportation and application may increase the level of fossil combustion which leads to increased volume of carbon dioxide emitted (Balesdent, Chenu & Balabane, 2000). Besides, carbon sequestration has an effect on other gases like nitrous oxide and methane in the atmosphere. In overall, the process of implementing carbon sequestration may lead to combustion of fossils which increases the content of carbon dioxide emitted into the atmosphere. Feasibility of the methodology The cost benefit analysis undertaken above has provided a platform upon which a feasibility analysis can be easily undertaken in order to ensure that appropriate methodology is adopted. The evaluation of the costs and benefits involved in the carbon sequestration process shows that there is a great need of ensuring carbon dioxide is absorbed from the atmosphere and stored in the soils. In other words, the costs highlighted do not exceed the benefits involved. From what has been discussed in the prior subject, the management practices involved in carbon sequestration come with overwhelming benefits (Baker, Ochsner, Venterea & Griffis, 2007). The improved agricultural productivity is very critical when carrying out this feasibility study. While the agricultural management practices involved may sound ordinary, they derived multi-dimensional benefits. The land is properly prepared to be able to sustain improved productivity for a longer period. The long term effects that such practices brought to the land are therefore worthwhile. Another factor to consider in assessing the feasibility of these methodologies is the ability of the farms to diversified activities while maintaining high performance. Therefore, this methodologies must be adopted not only with the intention of reducing carbon dioxide in the atmosphere, but also ensure increased level of agricultural productivity. Conclusion In summary, there is a lot of scientific research that has been undertaken to unravel the entire concept of carbon sequestration. This is based on the knowledge that sequestration is effective in reducing the level of carbon dioxide from the atmosphere and stores it underneath for a long period of time. While a lot of research has been done in this area, more is yet to be done. Looking at the needs at hand, there is a lot that is supposed to be done in order to ensure that the climatic changes do not turn unfavorable just on the account of human activities. Therefore, studies will help discover the most convenient means of reducing GHG emission into the atmosphere. The two methodologies that have been discussed are examples of practices that can be undertaken by farmers to facilitate carbon sequestration. The technical part in all this is the ability to understand the exact point of tradeoff when implementing mechanisms of ensuring sequestration. For instance, while use of fertilizer increases the activities of the soil that eventually increases carbon sequestration; the effect of nitrous gas into the atmosphere raises some concerns. Nevertheless, from the findings presented above, the more physical disturbance is done on the soil, the more it loses the ability to store organic carbon for a long period of time. The two methodologies present the different approaches to carbon sequestration. Grazing management seems to provide more convincing approach of carbon sequestration. This approach provides a mechanism that encourages as little disturbance to the soil as possible. The fact that root development is intact for a prolonged length of time is an indication of advanced level of soil sequestration. References Bais HP, Weir TL, Perry LG, Gilroy S, Vivanco JM. (2006). The role of root exudates in rhizosphere interactions with plants and other organisms. Annual Review of Plant Biology 57, 233-266. Baker JM, Ochsner TE, Venterea RT, Griffis TJ. (2007). Tillage and soil carbon sequestration - What do we really know? Agriculture Ecosystems & Environment 118, 1-5. Balesdent J, Chenu C, Balabane M. (2000).Relationship of soil organic matter dynamics to physical protection and tillage.Soil & Tillage Research 53, 215-230. Bronick CJ, Lal R. (2005). Soil structure and management: a review. Geoderma 124, 3-22. 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Boca Raton, FL: Lewis Publishers. Gill RA, Kelly RH, et al. (2002). Using simple environmental variables to estimate below- ground productivity in grasslands. Global Ecology and Biogeography 11, 79-86. Janzen HH (2006). The soil carbon dilemma: Shall we hoard it or use it? Soil Biology & Biochemistry 38, 419-424. Read More