Thursday, 28 July 2011

Adding a bit of spice to the soil

What’s green, grows around 5ft in 60 days, recycles nitrogen, potassium, phosphate and organic matter to the soil, attacks herbicide-resistant weeds and kills pests?  Mustard – that’s what.

But this isn’t any type of mustard; new varieties, bred in the US, are catching on around the world as a great way of reducing nutrient loss in the autumn and reducing herbicide and pesticide use in following crops.  They not only add considerable bulk and recycle nutrients to the soil which would otherwise potentially be lost via runoff and leaching, but they can also attack weeds like blackgrass, as well as killing pests such as nematodes and slug eggs.

One Northamptonshire firm, Norman and Spicer (Agriculture) Ltd, a member of the Crest Group is nationally marketing a number of different blends of two specific mustard varieties – Pacific Gold and Idagold – at different sectors, aimed at attacking weeds in the cereals sector and nematodes, eel worm and other pests and diseases in the potato, root and vegetable sectors.

According to agronomist Mark Spicer, “Mustard blends are sown or broadcast immediately post-harvest and then left for 60 days.  At the end of this period, the crop is flailed to break it up and then incorporated with a plough or set of discs.  The compounds within the plants fumigate the soil, killing weeds and other pests, and the soil is ready for drilling or seedbed preparation after another 15 days.

“The treatment also adds significant nutrient and organic matter benefits to the soil, potentially giving the equivalent of up to 80kg N/ha and an increase of up to +2% SOM.  This, and the savings in subsequent pesticide applications, means that the use of these mustards can really stack up.  Of course, it’s not an appropriate treatment for every soil, crop or situation, but as an important tool in the ‘agricultural sustainability toolbox’ it has a great deal of potential to offer.”

Tuesday, 26 July 2011

Alarming losses of agricultural land in Egypt

A recent editorial from the Egyptian Gazette highlights the loss of valuable agricultural land due to urban expansion, a problem which has increased since the fall of the government under the Arab Spring. This blog post is a direct extract from the article, the full version of which can be read here. One feddan is apparently 0.42 hectares or 1.038 acres.

“Egypt is losing 3.5 feddans of arable land in the Nile Delta each and every hour due to urban expansion. This alarming rate should prompt harsh penalties, a close follow-up and monitoring of agricultural acreage.

“Local experts dropped another bombshell when they said that in the last three months alone building on agricultural land increased to such an extent that five feddans were lost per hour on average. If this rate were maintained, the waste of arable land would reach 43,000 feddans in one year.

“The state of chaos and the absence of adequate supervision in the wake of the January 25 revolution have encouraged profiteering and personal greed at the expense of public interest.

“Officials concerned are expected to review agricultural maps across the country to make a comparison with available areas. Plenty of vast areas have already been lost in the past decade or so due to laxity and indifference.

“It would be utterly disgraceful if a country whose ancient civilisation was based on agriculture lost its fertile land out of its own will and was forced to turn to desert reclamation for agricultural production.”

Thursday, 21 July 2011

Europeans offer solutions to beat forest and land desertification

A report on a website of the EU Commission describes how EU-funded researchers are tackling desertification in dry areas of Europe and North Africa around the Mediterranean, and also in China.  The project apparently ‘fuels the initiative of the International Year of Forests, a global platform that targets the sustainable management of the world's forests’.

The LEDDRA ('Land and ecosystem degradation and desertification: assessing the fit of responses') project is backed with almost EUR 3.1 million and is aimed at suppressing processes by which land becomes increasingly arid until no vegetation grows.  Experts say that this will bolster economic development and create jobs in rural areas.

Those behind the project have found that the areas where they’re working, which are impacted by arid and semi-arid climatic conditions and have been occupied by people for many years, show desertification processes that have reduced water and soil availability. 

The researchers say that good management will allow the recovery and conservation of both elements, but that ‘only the solid management of existing forests can ensure soil conservation and water resources’.  They also believe that forest policies should be extended to agricultural areas where there is a high loss of soil and water as a result of excessive ploughing and use of herbicides.  The team points out that using the biomass of abandoned areas and farms that respect the conservation of resources helps provide and maintain work and income for people living in these areas.

Read more here.

Monday, 18 July 2011

A story which we cannot afford to ignore

I’ve just finished reading David R. Montgomery’s Dirt: The Erosion of Civilisations.  It was an excellent read and I must credit the headline of this posting to the Financial Times’ review of the book (as featured on the book’s front cover).

Professor Montgomery goes into considerable depth about the role of soil in civilisations, ancient and modern, as well as the role of soil erosion in the decline and fall of various ancient cultures, from the Romans to the inhabitants of Easter Island.

It looks at man’s utilisation and exploitation of the soil and how he has managed and mismanaged it over the centuries, up to the present day.  The book provides clear historical detail on the development of farming systems in ancient societies but also has a very contemporary feel, referring to present-day loss of soil from agricultural land, reasons behind this and how it should be addressed. 

The author spends considerable time considering how society views and treats soil – essentially as a pretty worthless and inert growing medium; something that can be exploited until it’s no longer productive, then abandoned or just topped up with synthetic fertilisers.  He argues that if we’re to survive as a society then we need to radically reconsider our attitudes – especially as soil is being lost faster than it’s being created.

The author demonstrates a keen understanding of current, strategic issues and relates these expertly to the basic, but fundamental, issue of soil.  The twin challenges of climate change and population growth are considered within the context of sustainable and resilient agricultural production.  Prof. Montgomery skilfully delivers a number of recommendations for policymakers involved with 21st century agriculture – most notably to consider better soil management as an important tool, alongside the current focus on science and technology, as mechanisms to help us deal with current and future food production problems.

The book provides a stimulating and thought-provoking read and it’s one which needs to be read by everyone with even half an interest in agricultural and environmental policy.  I’m no good as book reviewer and can’t begin to do justice to it, so your best bet is to go out and buy it.  If you’re still unconvinced, have a look at some proper reviews here, here and here.

Friday, 15 July 2011

The decline of agriculture?

A feature article on Al Jazeera's English-language website provides further arguments against the use of modern agro-chemicals due to on their impacts on soil.  This blog post is a direct extract from the article, the full version of which can be read here.

Professor Michael Bomford, a research scientist at Kentucky State University and a fellow of the Post Carbon Institute, is concerned about how our dependence on oil to feed ourselves is leading to soil depletion and degradation, as well as increasing prices.

"The farm is a very small proportion of the economy in the US and other developed countries, but it has a disproportionate impact on global change," Professor Bomford, who has a Master's of Pest Management and a PhD in Plant and Soil Sciences, told Al Jazeera.

"Clearing land for farming releases carbon into the atmosphere and that contributes to climate change.  Then by farming it, using cultivation causes soil to be lost in wind and erosion, and that topsoil took thousands of years to form.  One extreme weather event can cause us to lose thousands of years of soil."

Modern farming impacts soil by the use of nitrogen fertilizers, which are energy intensive to produce and which deplete carbon in the soil.

"This erodes the soil's ability to hold nutrients, and starts a positive feedback loop," added Professor Bomford.  "A lot of our soils now rely on irrigation rather than rainfall, which depletes groundwater reserves, and these have huge impacts on the soil."

William Ryerson, founder and president of the Population Media Center and president of the Population Institute, is also very concerned about fertilizers' impact on soil. He has questioned how, in the long run, this will impact agriculture.

"The world's agricultural systems rely substantially on increasing use of fertilizers," Ryerson told Al Jazeera.  "But now, the world's farmers are witnessing signs of a declining response curve, where the use of additional fertilizer yields little additional food product.  At the same time, fertilizers and intensive cropping lower the quality of soil.  These factors will more and more limit the possibilities of raising food production substantially and will, at a minimum, boost relative food prices and resulting hunger for many."

Carbon stored in soil allows the soil to hold nutrients and water, and losing soil contributes to climate change.  Bomford is worried about other contributing factors to climate change borne from the use of chemical fertilizers.

Friday, 8 July 2011

Dark earth: how South American and Africa farmers improved their soil

A recent article in NewScientist magazine (registration needed) helps explain the mystery of dark earths known as Terra Preta, which have been found near to ancient human settlements in the Amazon jungle.   These are fertile, dark soils found on top of the generally thin and nutrient-poor soils which are associated with tropical rainforests.

The existence of theses soils conflicts with the traditionally-held view that jungle farmers created clearings for agriculture and then moved on to new areas after a few years when the soil was depleted. But in fact, these earths suggest that there was active improvement of the soils by farmers – and similar dark earths have also been found in West Africa too.  19th century explorers in Africa reported that farmers burned wood and other vegetation beneath a layer of soil and then scattered the resulting ash over their fields.

The article states that much of what we think of as virgin and verdant rainforest is actually long-abandoned farmland, enriched by the waste created by ancient humans.

The dark soils were clearly created by humans: They are reportedly full of pottery and the charred remains of burnt wood from fires set by humans, along with organic waste from crop residues, and animal and fish bones.   Charcoal within the dark earth is a key ingredient, as it can store nutrients and help to improve moisture retention and soil drainage – the same reasons why
biochar is being investigated so much today.

Read the full article

Tuesday, 5 July 2011

We need another green revolution

A recent NewScientist opinion piece is arguably more about crops than soil, but it’s a topic which reflects on soil management nonetheless – the demand for the creation of crops which can fix atmospheric nitrogen would reduce or even negate the need for application of mineral nitrogen fertilisers.

The piece recognises the importance of the 'Haber-Bosch process' in allowing us to produce the vast quantities of nitrogen fertilisers which feed us today, and without which, many of us would not be here.

But it calls for the development of new strains of major crops which can effectively create their own fertiliser, in the same way as legumes (such as peas and clover) do, by using bacteria, living within root rhizomes, to fix atmospheric nitrogen. The challenge, the article argues, is to teach this trick to all the world's major cereals.

Read the full piece here.