Perennial crops can reduce atmospheric carbon while delivering food and energy

Climate change and food security are two big monsters that humankind is facing, and we have to battle them together. It is urgent and timeline to look for solutions, and to implement them. I am happy to share with you some good news: We have found strong evidence showing that under proper management perennial crops are an efficient land-base climate change mitigation strategy, while also helping to deliver food security, bioproducts and bioenergy. Two mechanisms are behind the scenes: biomass accumulation and an increase in soil organic carbon. Growing perennial crops can indeed help fighting climate change and food security, if we do things properly. Perennial crops are a tool, and it ultimate depend on us, humans, to use this tool correctly.

Picture: Coffee plantation – Creative Commons

Agriculture contributes up to one third of human-induced emissions of greenhouse gases, if land use change is considered. Yet, this is the sector which has significant potential for negative emissions, that means, uptake carbon from the atmosphere and storing it in the land via sequestration in biomass and soils. Besides, agricultural and forest products be supply of feedstock for creating energy, thus not only providing us with green renewable energy but also reducing our dependence of fossil fuels.

Perennial crops are crops that are not fully harvested annually. They can be woody plants, such as fruits and nut crops (e.g., apple trees, citrus, almond, coffee), oil crops (e.g., palms) or short rotation coppices (e.g. poplar, willow). Or perennial grasses such as sugarcane, switchgrass, Miscanthus. The final end-use can be not only food or beverage, also fibre (e.g., cotton) and importantly, bioenergy (e.g., Eucalyptus, Miscanthus). Perennial crops represent 30% of the global cropland area, a notable amount. However, the positive effect of biomass storage on net GHG emissions has largely been ignored. With our studies we want to give credit and visibility to the important role that perennial crops could play, and to evidence that under proper management, can be an efficient tool to reduce atmospheric carbon while delivering food, goods and bioenergy.

To really understand the potential of perennial crops, we first studied the carbon that perennial plants can take from the atmosphere and store in their bodies. Plants use that carbon to growth. We, humans, also use minerals to growth: our bones are made with minerals. However, we obtain them from our food and not from the air, as the plants do. Plants are cleverer (or lazier, depending on how you look at it). They don’t need to go hunting, they can just take the minerals from the atmosphere. Perennial plants growth and thus accumulate carbon during their lifetime, in the shoots, leaves and branches and in the roots. They are also responsible for the increase in organic carbon in the soil, thanks to the root senescence and the incorporation of carbon from litter and other plant residues that fell in the ground, such us fruits that are rotten or little branches that break.

At this point we can see that we are on the correct track, plants take carbon dioxide from the atmosphere and store it on the land. Unfortunately, in real life things are not that simple. Besides, time also matters. The plants take carbon from the atmosphere while are alive, and then what?

 If we cut and burn a tree, for example, the carbon that was in its body goes back to the atmosphere. If all the carbon that is once stored in the plant goes back to the atmosphere in a couple of years, we have done nothing, or little. BUT if some of that carbon that the plants take from the atmosphere can be stored in the land for a long period (let´s say, a hundred years) now, we are talking.

In our work we have found interesting cases and evidence that sometimes we can accumulate carbon in the land for long. Let´s take a lemon tree as example, that is a cool perennial crop (and personally, I love lemonade). Imagine that lemon tree is growing, but then some leaves turn yellow and fall. Also, the person in charge of the field cut some branches of the plant (pruning), so the lemon tree will produce more and tastier lemons. We have some plant residues in the plantation now: leaves and branches. Depending on what we do with them, we are keeping the carbon or releasing it back in the atmosphere. For example, of we burn all this, we will put more greenhouse gasses in the atmosphere. However, if we leave the leaves on the ground, and cut and leave the branches on the ground, then the plant parts will decompose and part of the carbon that was in the plant tissues will go to the soil, and there, some carbon can be stored for a very long time. This is great, this is what we are looking for. What is the downside? Well, yes. As we have seen, life is not that easy, and the world can be complicated. In this case, those plant residues could attract pests and diseases, so we must pay attention to them. Thus, perennial crops are not magic climate change savers, we also need to do our bit and take care of them adequately. Then, they will help us.

At this point, you may have probable guessed that reducing carbon from the atmosphere is a two players process: first, we need a plant to take the carbon from the atmosphere and once the poor thing is dying, we need the soil to store the carbon there, the soil is our second player. Plants cannot store carbon for very long without soils, and soils cannot take carbon to store it without plants.

A perfect marriage!

The goal of our second study was to evaluate what happens in the soil after planting a perennial crop and during the perennial’s life cycle. To this end, we first had to create a global and unified dataset containing information on changes in soil carbon under perennial crops. Why that? Because such dataset did not exist before (this work of digging information form the web, colleagues, research articles, etc, is one of the most boring works of a researcher, but alas, this has to be done and anyone has to do it). It took us few months…

After those boing months of data mining, it was overly exciting to finally see a good data set. All those data were finally ready to tell us something… actually, spoiling a bit the rest of the post, I can say that the wait was worth it, even the sweat and tears! The results of our analysis were very encouraging, they did overcome my expectations (This is not quite common. All researchers have secretly high expectations about the results and most times what we see after experimenting and/or analysing the data is not that great).

Just a quick note before moving: if you want to check what is exactly the soil organic carbon and why is important, there is a small and easy post about that here ¿Why organic and why is important?

picture: creative commons

To understand the effect of perennial crops on soil carbon, we first studied what happens in the soil when you change from having a forest, or a grassland or an annual crop and then you stablish a perennial crop. The consequences of the change are limited and easy to guess: either the soil organic carbon content increases or decreases or stays the same. If the carbon concentration increases, that means that atmospheric carbon that is now stored in the soil – cool! If the soil carbon decreases is the other way around, is bad news. Some carbon that was stored in the soil is released back in the atmosphere, thus increasing the concentration of greenhouse gas emissions. And if stays the same… well, it stays the same. We are not hurting but not helping either, neither fish nor fowl.

So, what we observed? That a change from an annual to a perennial crop crops led to an average 20% increase in soil organic carbon in the upper 30 cm in 20 years. This is a lot and is indeed good news! Annual crops are crops that we plant every years, such us potatoes, tomatoes, lettuce, peas, and many other crops that are very important in our diets. Annual crops are not very friendly with the soils, but it turned that perennials aren´t doing it that badly. Why? In annual crops there are annual disturbances in the soil, such us tillage. This breaks the organic and inorganic compounds in the soil and some of the carbon that was trap in those compounds is released to the atmosphere. Same next year, and next year, next year and so on if we tillage every year before planting the annual crop. Also, in most cases annual crops requires a higher user of fertilisers, which changes bio-chemical properties in the soils and help to release carbon. On the other hand, perennial soils are not tilled in years and (maybe more importantly), perennials have bigger roots and the parts of that roots that die are directly going into the soil (well, they are already there). The roots of perennial crops pierce also deeper, so these new carbon inputs occur in a wider soil area. Besides, avoiding tillage helps the soil bacteria and other micro-organisms to develop and thrive, and those guys play a key role in creating and maintaining a good quality soil. We don´t fully know how many types or fungi and bacteria are out there, but we do know they are they essential to have good soils.

Background picture: Bacteria Spore Fungal – Free image on Pixabay

Results from the other two land changes, forest or grassland to perennial crop, the news are not that exciting: we did not obtain any robust result. A change form grassland to perennial seems to decrease the carbon and a change from forest to perennial seems to increase carbon in the first centimetres of the soil but decrease carbon at bottom layers. Those are observed trends but not supported enough with the statistics, so we can only say they may be true.

Finding that perennial crops can remove some carbon from the atmosphere was a particularly good new. And this way of removing atmospheric carbon will also deliver goods… not to mention products such as coffee or wine!

Source: creative commons

Our soil study identified the temperature as the main factor explaining changes in soil carbon: in tropical and Mediterranean areas carbon accumulation is slower than in temperate regions. This is probably because soil bacteria and microorganisms are more abundant and more active, so they eat more. As a consequence, those plant residues that could have stay in the soil are delicious dishes for our soil micro-friends instead.  They use this food for having energy, and in the process, they release carbon dioxide back to the atmosphere (then again, there´s more info about this in post about soil carbon here). Another second factor that is important to help storing carbon in the soil is the quality of the soil itself. When the soil is in good condition, it can store more carbon, because it has the structures that are needed to capture that carbon. In poor soils, without those structures, the carbon cannot be fixed. It will likely go away the next day is very windy or it rains.  

Those are some basic clues; the process is not that easy and guessing correctly what may happen in every case is not that straightforward. But I want to show you that we do have the knowledge to manage our land properly to increase carbon, or at least not to lose it. I want to show and remark to you that good management is they key and will help us achieve not only environmental-friendly practices but also help mitigating climate change! The power is in our hands.

picture: creative commons

This article is focused on the clear benefits of perennial crops. Yet, I don’t want to finish it without an important disclaim: This is not a cornucopia. First an importantly, crops management has to be the adequate. A second key factor, which will limit the carbon storage benefits of perennial cropping system is that most perennials require quite a lot of water. Planting, for example, almond crops in arid areas will likely result in drainage of natural underwater sources. This will be disastrous for the population nearby, not to mention will result in a poor soil, which won’t have as many bacteria and will highly reduce the capacity to store carbon and nutrients. A third factor worth mentioning is that if we change a natural ecosystem into a man-made ecosystem, which is cutting down a forest to plant perennials, not only will biodiversity and present wildlife be reduced but the benefits of the natural ecosystem will be lost.  

This is the home-take message:

Perennial crops can be an effective climate change mitigation tool because they can remove greenhouse gas emissions from the atmosphere. But (there´s always a but) only if the management is correct and the plantation area is the appropriate. Mainly, if plant residues and the soil are managed properly, as we have seen before, and water scarcity is not a problem. So, perennial crops are not magic entities that will save the planet, is us, humans, who can help on this issue if we manage the crops properly. Perennial crops are a tool, but if we don´t use the tool correctly if won`t work. At the end of the day, is us who must do things properly. We can and I hope we will.

photo: Creative Commons

PS: Those articles haven’t been possible without the help and support (both scientific and personal) of my co-authors. Many thanks to them again!

You can download a pdf of this post:

Further reading: if you want to check our scientific papers, you can find them here:

Changes in soil organic carbon under perennial crops

A global, empirical, harmonised dataset of soil organic carbon changes under perennial crops

Perennial-GHG: A new generic allometric model to estimate biomass accumulation and greenhouse gas emissions in perennial food and bioenergy crops

(the first and second is open access, the later can be downloaded from my web page,

Ayudar a los bosques tropicales degradados acelera su vuelta a la normalidad

La restauración forestal activa acelera la recuperación de los bosques tropicales que han sido degradados por la acción del hombre. Este es uno de los principales resultados del estudio publicado en la revista Science esta semana, y del que me siento orgullosa de haber podido contribuir. La restauración forestal es echarle una mano a los bosques y ecosistemas naturales que han sido degradados para que vuelvan a ser sistemas completos, fuertes, con más biomasa y donde todas las especies puedan vivir a gusto: las plantas, los pájaros, los bichitos, los animales, los hongos… Hay mucha vida y naturaleza escondida dentro de un bosque, sobre todo en un bosque tropical.

Durante la restauración forestal se hacen intervenciones dentro del bosque, como por ejemplo plantar nuevos arbolitos en su interior para acelerar la regeneración natural, o cortar especies invasoras. Se pueden coger semillas de un árbol grande, cultivarlas en un invernadero, y cuando ya han crecido lo suficiente, plantarlas en el interior del bosque ¿Cómo ayuda esto? Pues en un bosque tropical en la naturaleza, la mayoría de las semillas se las comen pajaritos o bichos. De las que caen, no todas caen en un sitio del suelo donde puedan germinar, por ejemplo, si ya hay otras plantas, o en agua o rocas. De las poquitas que nacen, lo más normal es que se las coma una oruga o se pudran por un hongo. Si eres una semilla, encontrar tu sitio en el bosque no es fácil. Nosotros, los humanos, podemos ayudar a algunas de esas semillas a que no pasen tantas calamidades: las mimamos unos meses en un invernadero y cuando ya sean más grandes y se puedan valer por ellas mismas, las sembramos en el bosque (aun así, muchas se las comerán los bichos, pero es normal, también tienen derecho ellos a comer).

Regeneración natural en el suelo de un bosque tropical

Cuando un bosque ha sido degradado con el paso del tiempo, es posible que se recupere y que vuelta a tener mucha madera y biomasa en su interior. Pero eso puede tardar mucho tiempo, especialmente si ha sido muy degradado, por ejemplo, se han talado arboles de forma selectiva para sacar madera de calidad, se han abierto carreteras en medio, etc. Este estudio demuestra que, al igual que podemos hacerle daño a los bosques, también les podemos ayudar. Y eso es una noticia muy buena. La degradación y deforestación en áreas tropicales avanza muy rápido y la recuperación de los bosques es lenta. Pero si los humanos les ayudamos con buen conocimiento técnico, esa recuperación puede ser mucho más rápida.

Ahora, para la restauración se necesita una estrategia técnica (muy importante, no vale cualquier cosa), y luego se necesita gente que trabaje durante años.  Y todo esto tienen un coste.

En este artículo de Science se evalúan también esos costes, con un ejemplo en la isla de Sabah (Malasia). En este bosque tropical se taló y se sacó mucha madera de calidad de forma selectiva. Para sacar esos troncos grandes, se talaban los árboles de alrededor y se abrían los caminos que fueran necesarios para sacarlos. Después de eso el bosque quedó en mal estado.

En los treinta años siguientes se han hecho actividades de restauración activa en una zona de Sabah, como plantar árboles y cortar lianas para darle más espacio para crecer a esos árboles. Y después de ese tiempo, se ha comparado esta zona de restauración activa con zonas de bosque que no se han restaurado, que se dejaron desarrollar de forma natural. En esta comparación se ha demostrado que un bosque con restauración activa tiene casi el doble de madera en su interior que un bosque al que se ha dejado recuperar solo. Esto es un montón, el proceso de recuperación que en un bosque natural puede tardar 60 años, se ha conseguido alcanzar en 30 años con restauración activa.

Volviendo al dinero ¿Cuánto cuesta eso de la restauración forestal? En este estudio en Science se quería comprobar si con el precio de los créditos de carbono que se había sugerido en la cumbre del clima de París se podrían cubrir los costes. Los árboles para crecer cogen dióxido de carbono de la atmósfera y lo usan para hacer los troncos de madera que luego los sostienen. Ese carbono que quitan de la atmosfera es un gas de efecto invernadero. Es decir, los árboles “des-contaminan”. En los últimos años se está creando un mercado de carbono. Se quiere que las empresas que contaminan tengan que pagar un precio por el dióxido de carbono que emiten, y en la cumbre de París se sugirió un precio. Pero este mercado es aún voluntario, la empresa contaminante lo paga si quiere, y si no, pues no. En este estudio calculamos si el dinero que se pagaría a ese precio por el carbono acumulado gracias a la restauración sería suficiente pagar todos los gastos que requiere dicha restauración. Y, bueno, ¿a qué conclusión se ha llegado? Que sí y no. Con el precio de mercado actual no es suficiente para una restauración completa, por desgracia, no. Pero para una restauración más sencillita, entonces sí la cubriría. Esto es mejor que nada, ayudamos un poquito al bosque y el bolsillo se lo puede permitir. Pero no ayudamos al bosque a recuperarse tanto como podría ser con sólo aumentar un poquito el precio.

Otro día escribiré una entrada en este blog sobre la compra-venta de los créditos de carbono. Este es un mercado aún voluntario, pero del que posiblemente empezaremos a oír hablar más. Y el que, sinceramente, espero sea implementado en un futuro. Me parece justo que si alguien contamina de más o más de lo necesario, se lo cobre un recargo (porque nos está metiendo porquería a todos en los pulmones y descontrolando un poco más el clima). Y ese dinero se reinvierta en mejorar los bosques o ayudar a las comunidades y personas que mantienen los bosques. Es justo, y además los árboles van a limpiar alguna de la porquería que esas industrias echan al aire.

En conclusión: este estudio nos ha enseñado que ayudando a los bosques tropicales se recuperan más fácil y crecen casi en la mitad de tiempo que si lo hicieran ellos solos. Además, que si los créditos de carbono son un poquito más caros que el precio que plantearon en la cumbre del clima de Paris, los costes estarían cubiertos. Y en el peor de los casos, una parte estaría cubierta con ese precio.

Los humanos con nuestras acciones podemos fastidiar los bosques, pero también podemos ayudarlos. Hagamos las cosas bien, ayudemos a los bosques a recuperarse, que en ese proceso ellos nos van a devolver el favor limpiando el aire, cuidando a las especies que bien ahí, dándonos sombra y lugares para pasear y respirar aire puro. En definitiva, sentirnos todos más vivos y más felices.

*El artículo original publicado en Science es: Philipson, C.D., Cutler, M.E., Brodrick, P.G., Asner, G.P., Boyd, D.S., Costa, P.M., Fiddes, J., Foody, G.M., van der Heijden, G.M., Ledo, A. and Lincoln, P.R., 2020. Active restoration accelerates the carbon recovery of human-modified tropical forests. Science, 369(6505), pp.838-841.

Se puede bajar una copia de esta entrada del blog aquí:

Dinero público, beneficio privado

¿Se debería usar el dinero público para financiar la investigación privada?

Estoy viendo con sorpresa como esta práctica aumenta, como repetidamente aparecen anuncios de convocatorias públicas para financiar innovación dentro de empresas privadas. A la par, estoy viendo como empresas privadas se acercan a gente que hemos trabajado en el sector público para que les ayudemos a implementar ese conocimiento que hemos generado o adquirido en proyectos o propuestas que ellos van a usar en el futuro como suyos. Por supuesto, se espera que esto lo hagamos de forma altruista regalando nuestro conocimiento y tiempo, por razones que no llego a entender.

Esto me genera varios conflictos morales. Y para ser franca, no sé qué dice la legislación al respecto, si es que dice algo. A vosotros, ¿qué os parece esta práctica? ¿Se debería usar dinero público para financiar investigación privada? ¿Bajo y en qué condiciones? ¿Hasta qué punto?

foto: piqsels

Respecto a la primera aserción, se está financiado con dinero público investigación dentro de la empresa privada ¿por qué debemos darle dinero público a una empresa que lo va a usar para invertir en investigación que se va a guardar para sí misma y que posiblemente va a generarle beneficios y valor añadido a la empresa? Sin mencionar que es muy posible que se generen patentes y copyright (traducción: esto es ahora mío y me lo quedo. Paga si quieres disfrutarlo).

Con esta estrategia se ignora el hecho de que, en primer lugar, ese dinero que se les dio a una empresa a fondo perdido para investigar es dinero que sale de los impuestos de los ciudadanos, a los que se les impone esa inversión, pero luego se les cobra para usar los beneficios. Es decir, el ciudadano tiene a la vez que financiar la investigación y luego comprar el producto resultante si quiere usarlo. La empresa no invierte en investigar, pero con esa información crea un producto que patenta y comercializa, generando valor y riqueza a la empresa. El sistema suena curioso, si no más.

Las empresas generan dinero y opino yo que deberían reinvertir parte de esas ganancias en financiar sus departamentos de investigación, que van a generar futuras ganancias. Ellos se lo pueden permitir, sobre todo porque las ayudas presupuestarias van destinadas a empresas de cierta entidad (si eres autónomo, como es mi caso, olvídate de ayudas de I+D+i). Por otro lado, un investigador público no produce dinero, por contrato no puede; y si no se financia con dinero público… primero él se queda sin trabajo, segundo perdemos todos porque no generamos conocimiento.

¿Qué esto de financiar el I+D+i industrial sirve para darle innovación al sector español, que la necesita? Pues mira, sí, en eso estoy de acuerdo. ¿Qué esta es la forma más justa y eficaz de hacerlo? Pues eso ya no lo veo tan claro. Yo veo que este sistema es injusto, especialmente si pienso en España, donde la investigación pública podría ser de gran calidad gracias a la calidad y talento de muchos de sus científicos, pero se queda en mediocre por la falta de medios. Y los científicos de talento no tienen un espacio aquí, están repartidos por el mundo, donde les da un salario medio digno al menos.

Hemos visto como los bancos han sido rescatados para no caer que la quiebra (sea cual sea la definición de quiebra, yo de teoría macroeconómica no sé). Pues esto es otro tipo de “rescate” solo que esta vez las empresas no están en la quiebra, más bien, lo que quieren es aumentar sus beneficios y para eso, en lugar de invertir el dinero que han generado, se lo piden al estado. Y, ¡ojo! no un préstamo, no, a fondo perdido.

¿Hay alguna solución? Bueno, pues personalmente veo varias. Por comentar una: me gustaría ver que el desarrollo empresarial que salga de esa ayuda económica sea libre de copyright y patentes. Si entre todos se paga, parece justo que entre todos nos repartamos los beneficios.

Siendo el dinero para investigación limitado, yo estoy a favor de invertir el dinero público ¡¡y con cabeza!! en el sector público. Y, además, que ese conocimiento generado sea de libre acceso y de uso público, remarco de nuevo esto. Y es que creo que es muy importante, puesto que actualmente no es así para nada. Muchos investigadores y centros de investigación se quedan las cosas como si fueran suyas. Este acto de no compartir es más tonto (y quizás incluso egoísta) que el de las empresas, puesto que ahí nadie gana nada. Los datos, conocimiento generado y las patentes se quedan en un cajón.

Trabajemos en el I+D+i con cabeza… ¡nunca mejor dicho!

What is the soil organic carbon and why is it important?

Nowadays, we often hear about carbon. Most of the comments and news talk about carbon dioxide in the atmosphere, which is a greenhouse gas that increases the global temperature and creates climate change. Well, while this may be partly true, the big picture is not like that. Carbon is essential to life, and we can find carbon not only in the atmosphere, but also in the soils, all living beings, and dissolved in the water.

Most of the carbon that we can find on Earth is fixed, as in the rocks. However, some other carbon is circulating around, in the ecosystems. See this example: a farmer plants a lettuce seed, which takes carbon from the atmosphere to growth and being a growth-up lettuce. After, we ate that lettuce in our salad, and the carbon is now in our bodies. A beautiful sunny day we decide to go for a walk in the forest, and while there, some of our hear gets stuck on a tree branch so we cut it and leave it there. The hear falls, now the carbon is on the ground. Some blows with the wind and falls in a nearby stream. The carbon is now in the soil and the water. This is a delicatessen for a worm passing by, which eats it and then burps of satisfaction like a baby. The carbon is now back in the atmosphere. We have completed a cycle of the carbon cycle. And so forth.

Carbon molecule (creative commons)

Carbon is needed to create life, essential to keep the natural Earth cycles working and to build ecosystems. The carbon is a molecule, is not a good or a bad boy. If I have to pick a role, I will go for the good one. Just, we cannot leave it alone unsupervised or will run wild and will mess up.

 I want to write a detailed post about the soil carbon cycle to share with you all, but I am afraid that day has still not yet arrived. For now, you can read this comment on soil organic carbon. Why organic? To tell it apart from the mineral carbon, the one that form the rocks. The mineral carbon is considered unchangeable and irremovable. Actually, it could stop being part of the rock and break free, but that may happen in a million of years thus we consider it unchangeable from our human scale perspective. On the other hand, the organic carbon can move, and it is in fact the one that circulates in the carbon cycle.

The organic carbon is part of the organic matter that fells on the ground and is also found in the soil aggregates (such us clays). It can be there for days or up to a couple of centuries. This organic carbon goes into the soil when some parts of living things die, split for the main body of the individual, and fall. Those are mainly plant parts, for example, litter from the trees or roots from a daisy flower.

When those ex-living parts arrive in the soil, they start to decompose. What does this mean? Bacteria and soil micro-fauna use those plant residues to feed themselves. They use that food to growth and generate energy, as we humans do. During those processes, the tiny micro-organisms will excrete gases that contain carbon molecules, such as carbon monoxide or methane. This will be the case for about 80-90% of the carbon that goes in the soil. So, that carbon goes back to the atmosphere in the form of a gas in a short period of time. This is what we call decomposition, which is no more complicated than soil micro-organisms eating plant parts and putting back in the atmosphere some components in the form of a gas.

Yet, there is still a 10-20% of the carbon that can stay in the soil for a longer period. Some of that carbon may go away soon, for example on a stream when it rains. But some other will stay, and the way that carbon will remain in the soil is by sticking itself to other soil components, mostly clays. The clay, apart from being useful to create a vase for mother´s day, is a key component of the soil. The clay is formed by small lumps that stick to each other, and if we put some water, they agglutinate more (as happens with the vases).

Soil aggregates at microscope (nasa.gob)

In general, if the soil is not in good condition, it is quite likely that not much carbon can be stored. A good soil is a soil with minerals, bacteria, fungi, other micro-flora and micro-fauna, well-aerated and where water can move through.  This soil is dark, sometimes almost black and when it rains it smells good.

The thirstier for carbon a soil is, the more carbon will hold back. That may be the case after years of crop cultivation. Those crops have taken minerals from the soil, and now the soil is hungry. If after cultivation the area is restored, for example by planting trees, that soil is going to soak up carbon during the first ten or twenty years. During this time, communities of soil bacteria will be developing, and the soil will turn darker. Once that soil has achieved its maximum capacity to absorb carbon, it will retain less carbon as the one it took after being converted into a forest. But that soil will keep the carbon very well, safe, and for longer. The soil of a forest is going to store more soil organic carbon than the soil of a cultivated field.

In conclusion, having soil organic carbon in the soil is essential to have a healthy soil, thus plants can growth, forests can be strong, and crops will give good quality fruits. Besides, all this carbon that is buried underneath is not in the atmosphere. So, if we manage to keep that carbon hidden under our feet, we will be reducing the quantity of greenhouse gas in the atmosphere and will be sowing our seeds for a greener planet.