Zai Holes

This practice of planting in small shallow holes dug during the dry season and filled with crop residue or manure was first developed in Mali and was later adopted and improved in northern Burkina Faso by farmers after the drought of the 1980’s.  This method has been successful in producing crop yield in places where soils have been so degraded that water can no longer infiltrate and topsoil has been washed or blown away.  With time, zai holes have been proven to restore organic content and productivity to soil. Termites play an important role in this process through which unproductive hardpan is turned into living, productive agricultural land. The manure attracts termites that then tunnel beneath the zai hole, this facilitates increased water infiltration.  The termites also provide another benefit; they assist in the decomposition of organic material added to the hole, making nutrients more readily available for the growing crops. 

Zai pits catch water in places where rainfall is limited.  Nutrients are concentrated and protected from high winds that threaten to blow away soils on the ground’s surface.  The simplicity of this technology allows it to be implemented with minimal resources. As a strategy for responding to climate change, farmers in parts of the Sahel are increasingly employing zai hole farming method to improve or restore agricultural productivity to degraded farmland. 

Limitations of zai crop production are important to consider, not all areas with limited rainfall and degraded soil also have “composting termites”.  Zai holes can be used in areas without these termites but productivity and infiltration may be reduced.  Digging holes is performed by hand, no technology has been designed to expedite this process, making it extremely labor intensive, 300-450 hours/ hectare. Digging in the dry season limits the time frame in which labor should be performed.  Size and position of the pits is integral to their success, proper training is necessary to ensure productivity.  Raw, organic material cannot be placed in pits, composted material is necessary for nutrients to become available to crops. 

While this method is not a panacea for the famine ridden peoples of the Sahel, it is a positive and productive component of the evolving response to land degradation in that region.  Other places around the world facing similar problems have begun to adapt zai holes to new conditions, these experiments will undoubtedly result varying degrees of success and new ideas about how to restore productivity to degraded soils and damaged ecosystems. 

http://sustainabilityquest.blogspot.com/2011/12/northeast-india-sri-to-zai-holes.html

Sand Dam

Sand Dams are an excellent method for capturing seasonal rainfall and protecting it from evaporation and contamination at a local scale. With examples of this technology being found as early as 9,000 BC, it is nearly as old as agriculture itself, and exquisitely simple.  By building a barrier in seasonal rivers with sand beds, sediment is trapped when rains feed seasonal streams and rivers. Pore space between aggregate particles holds water that is stopped by the dam.  Only 1-3% of water flowing downstream will be retained by the dam, but 25-40% of the total volume of the dam will be filled with water.  This water remains long after the rains have stopped and raises the water table in the immediate vicinity of the dam.  By extending seasonal availably of water, vegetation in the surrounding area increases, which in turn retains water in the soil and slows ground water movement.  Increased moisture content and vegetation contribute to an increase in organic soil content and improve soil fertility in degraded areas. Minor irrigation, livestock and drinking water supply can all be supported with responsible management.  

This method has been used extensively in Kenya and is being deployed in many other parts of Africa where climate change and unsustainable management practices have left agricultural land desiccated and barren.  The potential for this technology to improve soil quality in drylands is not limited to Africa although perhaps the heightened sensitivity of some African ecosystems and their cultural components have spurred the first wave of a sand dam revolution.  Drylands with seasonal watercourses containing sandy beds and shallow bedrock exist all over the globe.  As climate change continues to affect seasonal weather patterns, more sand dams will likely be built as seasonal rains in some areas decrease, or as soil degradation causes decreased in soil moisture and organic content resulting in poor crop production and general vegetative cover.  

While this approach to soil restoration and ground water retention has many positives, it must be noted that the construction of a sand dam is no small task.  In the rural farming communities where this technology is most beneficial, funding for infrastructure is often extremely limited.  Communities must therefore be well organized to provide labor and posses knowledge of surveying and construction techniques to ensure the longevity of the dam; even then, if materials are not readily available, they may prove to be prohibitively expensive.  The process of constructing a sand dam takes a years, growing deeper with each season as an additional layer of sand are deposited, increasing the volume of the sand dam reservoir. 

This technology relies on the persistence of some seasonal rain, it is therefore not likely to help improve the soils in places where land degradation from drought is worst.  However, where seasonal storm severity has increased as well as reduced precipitation in the dry season, this may be an excellent way to improve the resilience of soils through increased perennial vegetative cover.  The multitude of benefits that result from that type of change are the sort that the regeneration of degraded soils offer only if accompanied by responsible land use. 

Landscape timeline: the 90s

Thesis Statement

Thesis statement: 

I first became interested in this topic when I was in Tanzania last January, staring out he window of a Land Rover at the passing scenery. I first notices the erosion damage on the outskirts of Arusha where a Marsscape of deeply eroded gullies and channels threatened to swallow trees and buildings. The erosion was caused by a combination of overgrazing by livestock and the increasing intensity of rain events. Government policies had been instituted to protect the scant vegetation on the eroded landscape but without topsoil, little will grow and the annual rains wash away more soil every year. As a snapshot of a much larger problem this scenario has many of the major players: subsistence agriculture in the form of grazing livestock, both urban and rural land-use pressures in a developing country, both drought and increased flooding combined with ineffective government land management policies.

There are many different projects world wide working to combat soil degradation in the face of climate change.  Land degradation also has a great diversity of causes; overuse, contamination, and processes associated with climate change, nearly all causes of major land degradation are the result of human activity. I am most interested in those regeneration approaches with the potential for proliferation in highly compromised conditions; places where resources are scarce and the possibility of external assistance is low. Anthropogenic causes of soil degradation are due in large part to poor management. If the vast number of subsistence farmers throughout the world can be mobilized to engage in the work of regenerating soils, the problem of soil degradation may be alleviated in a wide range of landscapes. Major challenges that the the field faces are numerous, most striking and immediately apparent is climate change. However, coupled with climate change is population growth which has placed increased pressures on the land. The lack of access to technology is a major stumbling block for many potential solutions, the technologies employed to create successful agriculture in Israel cannot be employed in Rwanda or Inner Mongolia, these impoverished regions affected by the twin threats of overgrazing and drought.

New processes are emerging to combat and degradation. Specialists in agronomic scientists and remote, rural farmers along with countless others are all working on this problem. Encouraging the growth of vegetation and drought tolerance may be one small piece of the solution in places experiencing reduced rainfall. The development of improved polices on land management may also help in places where compaction and overuse have caused land degradation.  Nothing can be achieved however without the participation of and benefit to the people who are currently most affected by the global land degradation crisis.

Thesis Abstract

How can degraded soils be regenerated to protect to facilitate ecological health and continued human habitation in places of declining biotic diversity and ecosystem performance. Through a survey of case studies, reviewing different conditions that lead to soil degradation, I will look specifically at the patterns of human land use that negatively impact soil quality, the processes that exacerbate these impacts and the mitigation approaches that are being enacted and proposed in order to understand how different mitigation approaches function and assess their potential for success.

The problem of soil degradation carries with it significant global socio-political and environmental consequences. The lives of millions of people, the fates countless species and habitats as well as the trajectory of global climate change are all dependent on the success of these efforts to restore degraded soils.

Desertification of the Gobi in Mongolia

Reading summaries

Kelly McCracken

Design Research

September 25, 2012

Reading summary:

Judith Butler, What is Critique? An Essay in Foucault's Virtue

In this essay Butler looks at critique and evaluates the way it has been discussed by Foucault along with and a number of other theorists. Butler exposes the shared concerns of Williams and Adorno that criticism should not be reduced to simple judgment; Adorno is quoted to illustrate this point; “danger...of judging intellectual phenomena in a subsumptive, uninformed and administrative manner and assimilating them into the prevailing constellations of power which the intellect ought to expose.” By asking the question “What is critique?” Focault challenges the practice and simultaneously performs within it and in doing so takes a position on critique itself. This statement brings Butler to Habermas and the problem of normatively impoverished critique where she asserts that in Focault's writing can be found a normatively enriched critique where “...poiesis itself is central to the politics of desubjugation”.

Foucault's attempts to define critique as a thing can only exist in a state of hetrogneity, that is critique requires an object and that the goal of critique on objects is “to bring into relief the very framework of evaluation itself.” The paradoxical nature of critique that looks out to reflect it's inner structure is challenging and Butler reminds the reader “critique is a practice that requires a certain amount of patience in the same way that reading, according to Nietzsche, required that we act a bit more like cows than humans and learn the art of slow rumination.” Only when there is an idea that exists outside the normative structure can critique be applied to identify it; as Butler puts it, “the tear in the fabric of our epistemological web” is the place from which critique forms.

Foucault connects critique to virtue, as a by recognizing the critical attitude as a critical relation to the normative, which Butler describes as a “specific stylization of morality.” Butler clarifies the concept of morality; “ Moral experience has to do with a self-transformation prompted by a form of knowledge that is foreign to one’s own.” The understanding of an object is limited to the prevailing ontological domain, Foucault's example of austerity is used as an example of this idea. The act of austerity as a self-production is not a denial of pleasure but is a certain “practice of pleasure in the context of moral experience.” The connection Foucault makes between virtue and critique is challenging to reconcile, Butler seeks to extrapolate the nuance of his position by clarifying what it is not, a call for anarchy. In recognizing relationship between the present normative state, ontology and epistemology, Butler sees a threat to liberty. “Who can I become in such a world where the meanings and limits of the subject are set out in advance for me? By what norms am I constrained as I begin to ask what I may become? And what happens when I begin to become that for which there is no place within the given regime of truth?” This liberty is another way to describe the virtue Foucault discusses.

The process of rationalization as the governmentializing of ontology results in the relationship between rationalization and power. “Power sets the limits to what a subject can “be,” beyond which it no longer “is,” .... But power seeks to constrain the subject through the force of coercion, and the resistance to coercion consists in the stylization of the self at the limits of established being.” The stylization of the self is a way of self forming, if this poiese occurs “in disobidence to the principles by which one is formed” then the self is formed virtuously and in this process, desubjugated.   

Reading summary:

Marc Treib, Being Critical

Trieb begins his essay with a discussion of the studio critique, its practice, process and goals. He clarifies that the goal of criticism is not to judge so much as to assists the student in expanding his or her thinking, developing a set of skills most useful to their future success; the ability to meet goals, the ability to speak publicly and understand which ideas are best conveyed through drawings and which are best communicated with words. Listening is also a valuable component of critique for the student as they hear the perspectives and values of different judges reacting to the work of their peers. He enumerates the uses of a design education with 3 items; the experience of the instructors, learning how to learn, and the ability to be self-critical.

Critical thinking is the most important component of academic experience according to Trieb. For landscape architects and designers, this critical evaluation needs to extend to evaluating one's experience of the world, in order create meaningful designs. He uses the various works as a vehicle for asserting his own perspectives on landscape design as a discipline and the primacy of theory in guiding all creative work. In critically addressing issues related to number of major works of landscape architecture, he describes his own process of critical evaluation and the shifting theoretical awarenesses that have facilitated changes in his values. In closing, Trieb reinforces the the absolute necessity of critical thinking for designers and the importance of imagination to better understand the way the places designers create will be received and used.