Sunday, December 5, 2021

Managing Healthy Livestock Production and Consumption

Plants are the net producers of ecosystems. But all plants will be eaten, wither, burn, rot or in some other way be consumed. Consumers are insects, microbes, fungi, fish, animals or humans to mention the most important. The consumption of plants, the death of plants are as important for ecosystems as their lives. 

Animals are integral to all (or just most?) ecosystems and play a critical role for nutrient cycling and soil fertility. Despite this, there is a prominent narrative that portrays all livestock as inefficient, harmful or redundant. Clearly, there are many things to criticize in industrial forms of livestock production. There are also limits for how many animals can be fed with farmed crops. But the faults of conventional and industrial livestock production should not lead us to shun livestock production all together.

I have contributed a little* to a new book on sustainable livestock production with the title: Managing Healthy Livestock Production and Consumption 

By addressing gaps of knowledge and presenting scientific perspective studies of livestock’s impact on the environment and the global food supply up to 2050, this book is useful for those advocating for sustainable food systems. Existing evidence of the effects of livestock production on food quality and nutrition is reviewed. Livestock production and consumption is a highly diverse topic where current publications only include/focus a single aspect of the issues, for example, greenhouse gas emissions or health impacts, leading to a biased view of the total impact of livestock production. This book clarifies perceptions by presenting sound scientific evidence across livestock landscapes to better appreciate the ecological web of life and the social web of community related to livestock production. It has interesting case studies on:

  • Rotational grazing in the Pampa, Argentina
  • Holistic management of livestock, Zimbabwe
  • Adapting to climate change in grasslands of Inner Mongolia, China
  • Organic livestock management and climate resilience, New Zealand
  • Conservation of native vegetation and traditional camel herding in Rajasthan, India
  • Sustainability of organic dairy production in Tyrol pastures, Austria
  • Feeding spineless cactus to cattle for drought resilience, Kenya
  • Integrated organic livestock-crop production system, Thailand
  • Improving nutrient efficiency through organic management, Madagascar
  • Breeding for gastrointestinal parasite resistance in Merino sheep, Australia
  • Animals for feeding soils on biodynamic farms, Egypt


The contents of Managing Healthy Livestock Production and Consumption are

Section 1 – Introduction
1. Introduction to livestock systems
Nadia El-Hage Scialabba
 

Section 2 – Animals and health
2. Livestock food and human nutrition
Nadia El-Hage Scialabba
3. Livestock xenobiotics and zoonoses
Nadia El-Hage Scialabba
4. Healthy livestock production and consumption
Nadia El-Hage Scialabba
5. Pesticide safety in livestock products
Andre Frederick Leu
6. Continuous development of animal welfare, with a focus on organic farming
Otto Schmid and Barbara Fruh
Section 3 - Livestock Landscapes
7. Livestock and future food supply
Nadia El-Hage Scialabba
8. Pastoralism as a response to climate change and water security in Mediterranean mountains and forests
Gregory Lazarev
9. Landscape management: ecological engineering in temperate areas
Joel Salatin
10. Let them graze! Potentials of ruminant production outside the feed-food competition Florian Leiber
11. The promises of food without soil and toil
Gunnar Rundgren
12. Livestock as a tool to regenerate land
Nadia El-Hage Scialabba
Section 4 – Stories from around the world
13. Experiences of low-external-input livestock systems
Nadia El-Hage Scialabba
Improving land management through grazing strategies
Subchapter 13.1: Rotational grazing in the Pampa, Argentina
Lorena Agnelli, Oyhamburu Mariel and Delgado Caffe Jorge
Subchapter 13.2: Holistic management of livestock, Zimbabwe
Andrea Malmberg and Jody Butterfield
Subchapter 13.3: Adapting to climate change in grasslands of Inner Mongolia, China
David Kemp
Subchapter 13.4: Organic livestock management and climate resilience, New Zealand
Glenn Mead
Subchapter 13.5: Conservation of native vegetation and traditional camel herding in Rajasthan, India
Ilse Kohler-Rollefson, Hanwant Singh Rathore, and Aisha Rollefson
Subchapter 13.6: Sustainability of organic dairy production in Tyrol pastures, Austria
Wilhelm Knaus, Thomas Drapela, Roswitha Weissensteiner, Heinz Gstir, and Werner Zollitsch
Subchapter 13.7: Feeding spineless cactus to cattle for drought resilience, Kenya
Margaret Syomiti, Samuel Chirchir, John Duyu, and Dana Hoag
Subchapter 13.8: Integrated organic livestock-crop production system, Thailand
Jintana Indramagala
Subchapter 13.9: Improving nutrient efficiency through organic management, Madagascar
Paulo Salgado, Emmanuel Tillard, Stephanie Alvarez, and Philippe Lecomte
Subchapter 13.10: Breeding for gastrointestinal parasite resistance in Merino sheep, Australia
John Karlsson and Annika Karlsson
Subchapter 13.11: Animals for feeding soils on biodynamic farms, Egypt
Angela Hofmann, Helmy Abouleish, and Anne Bandel
Section 5 – Conclusions
14. Full-cost accounting for decision-making related to livestock systems
Nadia El-Hage Scialabba

* My contribution has the title: "The promises of food without soil and
toil" and is about "farm-free" ways to produce foods. I will soon post a summary of my chapter.

Tuesday, November 16, 2021

COP26: omitting the real emission driver

Another Climate meeting has ended and little will change because the most important issues are not even on the agenda. The discussions about global warming are dominated by the transition to fossil-free energy combined with some attention to energy efficiency. Lately Direct Carbon Capture and geo-engineering has got more attention. The two factors that impacts global warming the most are hardly discussed at al.

Emissions can, according to the Kaya formula, be expressed as the product of the four factors human population, GDP per capita, energy intensity (per unit of GDP), and carbon intensity (emissions per unit of energy). Since 1960 advances in energy intensity and carbon intensity has reduced emissions per unit of GDP (e.g. a dollar) with 50%. That seems impressive, but meanwhile population has grown with 150 % and GDP per capita with almost 250%. The net result is that emissions have increased almost 300% globally (see graph).  


Even with a very rapid growth of renewables and nuclear power combined with unprecedented improvements in efficiency, it is apparent that emissions can’t be sufficiently reduced without stabilization, or a decrease of the population and the economy.  

Stabilization and ultimately shrinking populations are part of most of the IPCC scenarios, which also means one can easily see the impact thereof. None of the many scenarios include, however, a steady state or shrinking economy. In the scenario with the lowest increase of the economy, SSP3, the GDP per capita will still double to 2100. This scenario also includes increased inequality and regional rivalry, as if those where necessarily linked to each other.

The scenarios of the IPCC are not normative but are there to enlighten policy and show possible paths of development. The worst case scenario, SSP5-8,5 shows how the climate will develop if emissions continue and few countermeasures are taken. It shows a global temperature 5 centigrade higher than today. With that in mind it is very hard to understand why there are no IPCC scenarios without growth.

By omitting such scenarios, growth is no longer on the agenda. As it is apparent that renewables, nuclear power and efficiency gains will not be sufficient, direct carbon capture, carbon capture and storage as well as geo-engineering become inevitable. In this way IPCC fails its mission and give us the impression that these, untested, technologies are much more relevant and realistic than a steady state economy or de-growth. This is despite the fact that the only periods of absolute reductions in emissions are linked to economic downturns.

The main point here is not whether it is good or bad per se with degrowth or steady state, but that there are good reasons to develop scenarios without growth. As expressed by Jason Hickel and colleagues in a recent article in Nature Energy:

”Given the enormous challenge of confronting the climate crisis, and following the precautionary principle, modelers should consider a wider range of policy options in order to expand the public debate about climate mitigation, and to reflect the plurality of visions for a sustainable world. ”

*

Having said that, I think it is pertinent to address some of the arguments against having growth as a policy option, without being exhaustive.

A major objection to a no-growth or a degrowth scenario is that economic growth (expressed as an increase in GDP per capita) is needed to lift income for poor countries and poor people. Even if the GDP measure has its flaws as a measure of development or livelihoods there is a clear need to increase the material living standard of the world’s poor, that includes access to energy, better food, electricity and sanitation. It would be a mistake, however, to believe that global economic growth is the best pathway to ensure that. There is today already, more than enough wealth in the human civilization, it is just badly distributed. According to research by David Woodward published in the World Economic Review, with the patterns of growth  and its distribution 1998-2008 it would take 200 years to end poverty defined as incomes below $5 /day ($1,800 per year), while the average GDP would be 1 million dollars per capita. That is hardly an efficient way of poverty eradication compared to redistributional policies.

Another frequent argument against steady state or degrowth scenarios is that decoupling of energy use and emissions from GDP growth is possible and already happening. This is supposed to take place by several processes such as, efficiency gains, circular economy, sharing economy, green growth strategies, digitalization or the transformation of the economy to a service economy. I have discussed, and dismissed, those at length here. Let me also point to the intriguing analysis of Blair Fix in the article Dematerialization Through Services: Evaluating the Evidence. Globally, the service sector has increased its share of employment from 35% to 50% in less than thirty years, from 1990 to 2019.  In the same period CO2 emissions went from 21 Gt to 35 Gt.

Sunday, August 8, 2021

Nitrogen fertilizer is not a climate solution

It is often claimed from proponents of conventional farming that the use of chemical fertilizers, in particular nitrogen, is a prerequisite for binding more carbon in soils (see for instance the critique of regenerative agriculture by the World Resource Institute).

This is normally founded on two different arguments: 1) Through the use of nitrogen fertilizers total photosynthesis is increasing, thus more carbon is bound by plants. Some of this carbon is taken away from the land in the form of higher yields, but there will also be more straw, roots and residues left in the field; 2) There is a rather narrow relationship (stoichiometry) between carbon and nutrients like nitrogen and phosphorus in soil organic matter and, therefore, one have to supply concomitant quantities of those nutrients to increase carbon content.

Below, I discuss both of the arguments.

It stands beyond doubt that the supply if nitrogen fertilizers, in reasonable quantities, increases yields. It is often assumed that this also corresponds to more straw, roots and other organic matter being left in soils. This seems to be an oversimplification though. To begin with, in parallel to the increased use of fertilizers, the harvest index (the share of the above ground biomass that is the desired products, e.g. wheat kernels) of major agriculture crops has also changed a lot so that a bigger share of the carbon is allocated to the harvested crop and less to other parts of the plant. In addition, through the use of herbicides the biomass in weeds has also been substantially reduced, biomass that otherwise would contribute to soil organic matter.  


The harvest index is also influenced by management and experiments show that
increased availability of nitrogen as well as irrigation will increase the harvest index even more. Research in both Switzerland and Denmark demonstrate that in organic farming (by definition without the use of synthetic nitrogen fertilizers) a substantially higher share of the biomass is allocated to roots than in conventional farming.

This is even more important as recent research (e.g. Kätterer et al 2011 and Villarino et al 2021) show that roots and root exudates (carbon rich substances released from the roots to the soil, sometimes referred to as the liquid carbon pathway, or the microbial carbon pump) are much more important for building soil organic matter than plant litter and straw. 

There are many review articles and meta-analyses published on the topic and they come to varying conclusions. Poeplau concludes that there is a general positive relationship between the use of nitrogen fertilizers and soil carbon in grassland, but there are also research showing the opposite, e.g Sochorova 2016. A synthesis of Bolinder et al (2020) claims that 1 kg of N can increase soil C with 1 kg compared to plots which are totally unfertilized. They conclude, however, that this is not a linear relationship, i.e. there is higher effect with low nitrogen supply than with a high supply. They also say that to compare with plots that are not fertilized at all has limited practical value as farmers, in the absence of chemical fertilizers, will try to supply nitrogen in other ways, such as with biological nitrogen fixation or use of organic amendments. They point out that many other methods than increased use of fertilizer to increase soil carbon is much more important. Another synthesis from 2021 concurs.  Therein, Alexandra Tiefenbacher and colleagues show that adding N can work both ways depending on conditions. It can stimulate the decomposition of organic matter and thus reduce the carbon stock, but it can also increase primary production and thereby the supply of carbon.

Based on the research above it seems quite clear that use of N fertilizer is no shortcut to soil carbon sequestration and that its effects are uncertain, and in any case very small. If we lift our perspective this should be apparent already from the fact that most soils have been losing carbon all throughout the era of increased use of nitrogen fertilizer. On a systems level, use of nitrogen fertilizers is clearly not a pathway to increased soil organic matter.

*

Let’s now look at the other argument. Do you have to supply a certain amount of nitrogen to increase the carbon stocks in soils? This is based on the observation that a C:N ratio of around 10 is a benchmark for organic matter in soils, i.e. for each kg of carbon there is 100 gram of nitrogen. In a very simplistic way this is interpreted into that in order to increase soil carbon stocks with, say, 1 ton we need to supply 100 kg of nitrogen.  

But while these relations indeed have some value one can’t draw the arguments thus far. The C:N ratio differs a lot between different types of organic matter and even within the organic matter itself. In plants it vary the most while the range is narrower for microorganisms. Recent research has shown that dead microorganisms make up a substantial part of the soil organic matter. But the micro life will also adapt itself to soil conditions such as the availability of nitrogen. Fungi has typically more than two times higher C:N ratio than bacteria for instance. Also within a certain group of organisms species thrive under different conditions. A high C:N ratio will stimulate bacteria which preserve nitrogen (and reduces emissions of nitrous oxide) while N- fertilization will favor the opposite.

Again, if we look through a wider lens we can see that organic soils have almost 5 times higher C:N ration than mineral soils and that there is also a marked difference between arable soils and grasslands. In addition the C:N ratio changes with soil depth. Summing up, the stoichiometric argument for nitrogen fertilizers is weak.

Both arguments are based on a static view of agriculture systems. If you start with the prevailing agriculture system, which is adapted to the regular supply of nitrogen, and just cut out nitrogen fertilizer, you will get all kinds of problems, of which reduced yields is the dominating one. But farmers will respond to changed conditions by changing management, crop and variety selection and crop-livestock integration. It is therefore not really possible, or at least not meaningful to discuss one component of an agriculture system within the framework of ceteris paribus, all else being equal.

In addition, already today, nitrogen use efficiency in the agriculture system is low and more than half of the nitrogen supply is lost in the fields. There is no research showing that increased use of nitrogen fertilizers would be a good pathway for increasing soil carbon stocks. Even with the assumed carbon storage efficiency of nitrogen fertilizer of one to one (or even slightly better) it would still be a “climate loss” to increase soil carbon through the use of nitrogen fertilizer because the whole life cycle emissions (in the range of 10 kg CO2e) from 1 kg of N surpasses the climate value of 1 kg of C (which is 3.66 kg CO2). Few, if any, of the proponents of nitrogen fertilizers as an important factor for carbon sequestration, are actually suggesting that nitrogen should be supplied in higher rates to cater for that. The effect on yields will still determine nitrogen supply.

 

The nitrogen argument for carbon sequestration could, therefore, be seen as a distraction or possibly a method of diverting focus away from the substantial greenhouse gas emissions associated with their production, transportation and use.

Nitrogen fertilizers are not just a technicality, it is a major building block in the industrial, global and capitalist agriculture system. As such they both drive and enable the increasing metabolic rift between human society and the ecosystem that sustains it. It is hard, but definitively possible to feed the global population without them, but it will need changes in the food system and in society at large.