Grass versus Rocks - Green can be Green
Sustainable Landscaping Can Reduce Greenhouse Gasses
By Michael Martin Melendrez as published in GREEN LIVING magazine.
Xeriscape or Gravelscape?
At one time, cities such as Albuquerque and Las Cruces could be admired either from the air or
from the ground for their established green and shady neighborhoods. Realtors would stress the
feature of a home being in a shady and established neighborhood. Young couples could visualize
raising their children in such places, going for evening walks while pushing the baby stroller and
walking hand-in-hand. In fact, I can recall that exact scene with my parents and siblings when I
This is a segment of a more technical paper Michael Melendrez is publishing soon.
It is clear that the concept of using a process that jump starts the Pedogenesis of a soil along with the beneficial mutualism with microbe's that all plants are obligated to have will change so much of what we do in landscape design, build and maintenance. It is people like us that must share the burden of educating the public and the professionals on how important this is. The good news is that it will leave the idea of xeriscaping behind and will result in a more green, shady and sustainable landscape in our arid western cities.
It's a shame that if you look at the city of Albuquerque in the past 10 years there has been a general browning taking place as we attempt to conserve water and convert our formerly green landscapes into xeriscapes. The intent was good, but the results contradict sustainability along with the hope of leaving a smaller carbon footprint for those people living in the graveled xeriscape. These landscapes may conserve water, but are they environmentally sound?
Just think about the huge energy expenditure in mining, separating/cleaning and transporting of gravel to say nothing of spreading it and then someday cleaning it again. That is no where near a carbon neutral process and cannot be considered environmentally sound! Furthermore one of the single largest contributors to atmospheric carbon is a desert soil that is barren of vegetation.
What we really need to be doing with urban horticulture is to make an attempt to leave no ground bare or without living ground covers. This in turn will help support a terrestrial biosphere of roots, microbes and most critically the mycorrhizae that make Glomalin. It is Glomalin that we now believe can sequester more carbon from the atmosphere than can any other effort we make. Long term storage of carbon in the soil in the form of Glomalin, humus, plus living and dead organic matter can sequester huge quantities of carbon for a long time. The half life of Humus alone is measured in many decades and therefore will not be releasing this carbon anytime soon. This however requires that we jump start the missing element of plant roots with the mycorrhizal relationship because almost without exception that aspect of the constructed soils flora and fauna is missing and rarely is it provided in the plant material grown commercially.
It will not mysteriously arrive on its own in a timely manner, that is clear! See News Item below
Michael Martin Melendrez Copyright 2007
CAMDEN -- A research project underway at Rutgers University’s Camden campus could help revolutionize agriculture through the use of fungi as “biofertilizers” that reduce the farming industry’s reliance on phosphate and nitrogen fertilizers that pollute water supplies.
And more info from Soil Solutions:
What is Sustainability When It Concerns Landscaping?
By Michael Martin Melendrez
The main concept that is being discussed on the topic of global warming and global greenhouse gases are based on what is commonly called 'reducing your carbon footprint and becoming carbon neutral'. This is defined as sustainability and it's the foundation of the US Green Building Council's program. Many venues are addressing energy expenditure, recycling, pollution and a few other major categories of the topic, all with the ultimate objective of reducing the build-up of atmospheric greenhouse gases and conserving natural resources.
There is an effort going into the discussion of conserving water in Southwestern cities where water is an issue and in short supply. The real problem lies with the fact that the quantity of water that we depend on is reasonably static on a longitudinal bases, but our economy is based on growth. This leaves us with the task of constantly splitting and sharing our water supply with an ever increasing population. The first victim of this pro-growth opinion is the landscaping of our yards and neighborhoods, with the results being questionably sustainable. At one time Albuquerque and Las Cruces could be admired either from the air or from the ground with their established green and shady neighborhoods, but today we see gravel and brown yards with declining trees. Even newly planted trees soon fail because few are well adapted to growing in a ‘heatscape’ of reflective gravel. And worse yet, the most commonly planted trees in our region are native to the Midwest or East where they have adapted to high rainfall and seasonally saturated soils, something we cannot mimic here. Worse yet, is the loss of neighborhood community as the ugliest part of this landscaping is taking place in the front yards. As our front yards are included in the landscaping package by developers, or are converted for the sake of water conservation, they lose any function for neighborhood socialization. Who wants to stand around or sit in a gravel yard trying to visit with your neighbor? Neighborhood kids are not going to play kickball in the front yard like they did in my childhood days of the 60’s and 70’s. Consequently we end up living in isolation and unaware or disconnected from our neighbors.
With the carbon issue, effort is being made in what we can do as individuals to conserve energy, but little is being said about what we can do as individuals to remediate that carbon already in the atmosphere. We must be approaching this from both angles and also be thinking about how we can fix the problem or at least create closed loop energy expenditure with renewable systems. This is where xeriscaping needs to be stepped up a notch. While it may conserve water on a per capita basis, it does little to remediate atmospheric carbon via phytoremediation. Most xeriscape’s and new housing developments I’ve seen built in the past decade simply do not have enough vegetation and in particular ground covers for phytoremediation to work. Particularly when you use rock and gravel as the primary ground cover, which require huge energy expenditures to mine, clean, transport and spread onto these landscapes. Soil is a major part of this solution as the single largest potential carbon bank on earth is the soil and the humus within it. Humus is what defines topsoil and in the words of the worlds top Chemical Educators (Journal of Chemical Education, 2001, vol. 78) "Humus is a remarkable product of soil chemistry that is essential for healthy and productive soils." The half life of humus is measured in many decades and therefore will tie-up carbon for a long time as a carbon bank. But humus is made by the mutualistic association that most plants have with a beneficial group of fungi called mycorrhizae. The plant via photosynthesis sequesters carbon from the air making a high energy sugar which is then fed to the mycorrhizae that is infecting the roots of that plant. Both the plant and the mycorrhizae win in this equation because the plant is getting extra water and mineral nutrients from the mycorrhizae as a form of payment. This in turn makes the plant much more tolerant of heat, drought, dehydration, poor soils, and other hazards of life. With this mycorrhizal relationship between plant and fungus, the mycorrhizae then make a protein called Glomalin which is packed full of carbon. Glomalin is a rich source of nutritional calories and in time is converted into humus! This requires plants and lots of them, which again is a weakness of most xeriscapes that I've seen built in the west.
In order for us as individuals to have a personal roll in fixing the problem of greenhouse gases that each of us contributes to, we must utilize our private properties and landscapes. And in order for landscaping to be truly part of the concept of sustainability, the process of soil building or Pedogenesis must be primed and that will take vegetation with plentiful ground covers, shrubs and trees. Soil, humus and all the terrestrial biosphere of living and dead organic matter that’s in the soil is the single largest carbon bank on earth and that is a factor we can take advantage of. Responsible selection of native or appropriate plant material will be paramount to this process. In addition to this, priming the soils microbiology with the mutualistic fungi called mycorrhizae is a proven and extensively studied technique with over 60,000 papers of research published on the subject.
Priming the Pedogenesis of soil is what we do at Soil Secrets. We manufacture humus and produce the spores of mycorrhizae in addition to making other products used for soil conditioning and fertility. If you have interest in this process please contact us and visit our web site for more information.