As we begin the New Year, in our considered opinion, we need to pay importance to the impact of global warming and mitigating carbon release into the atmosphere. The coffee ecosystem holds enormous potential in building soil carbon because of the high density of a heterogenous tree population. This not only enables the Planter to build a vast reservoir of carbon storage in the form of a carbon sink but it also directly contributes to mitigating carbon release into the atmosphere. The other added advantages to the farming community are in terms of increasing soil fertility, reduced erosion, and enhanced availability of nutrients by microbial conversion of waste substrates. Hence, we have made a small beginning by addressing the soil carbon footprint in shade coffee.
In our earlier article published in November 2020, we highlighted the role of soil organic carbon and its importance in shade coffee. This article on soil carbon highlights the functional role of carbon in coffee soils.
Soil carbon is probably the most important component in soils as it affects the soil properties. Carbon as soil organic matter alters the physical, chemical, and biological properties of the soils. Soil organic matter is a primary indicator of soil quality. Improvements in soil organic matter create a more favorable environment, leading to increases in plant growth.
Soil Carbon and moisture retention
It is the carbon content of soils that largely governs their capacity to invite beneficial microbes, and beneficial insects, to access soil moisture and nutrients. It also creates a microclimate for various interactions between and among different root systems of multiple crops and forest trees and importantly regulates absorption, retention, and supply of soil moisture to support plant growth and development.
Every gram of carbon in the soil can retain up to eight grams of water.
Soil Carbon and Global warming
Scientific literature points out to the fact that healthy soils help to regulate the Earth’s climate and store more carbon than all of the world’s forests combined. A small shift in the package of practices can significantly alter the carbon pool which will have a long-term impact on global warming.
Carbon sequestering in soil has the potential to mitigate carbon footprints significantly and more importantly, it could be done an eco-friendly way, with fewer impacts to land and water. The way we nurture our coffee soils with sensible and sensitive land management and agricultural practices will go a long way in enhancing carbon storage.
Scientists are of the opinion that currently, soils remove about 25 percent of the world’s fossil fuel emissions each year. Most soil carbon is stored as permafrost and peat in Arctic areas, and in moist regions like the boreal ecosystems of Northern Eurasia and North America. Soils in hot or dry areas store less carbon.
The British pioneers advocated shade coffee with a very high tree population which used to shed their leaves during monsoon and bear fruits twice a year. As such at any given point inside the coffee ecosystem, one could find a thick layer of mulch. In fact, the method was so efficient that the recycling of nutrients was very effective and the soil system very resilient. In fact the tons of leaf litter and other organic waste on the floor of the coffee forest, made up of carbon was the basic raw material to support a healthy balance of nutrients, minerals, and soil microbial and fungal ecologies resulting in improved fertility levels of coffee soils.
Special Feature of Coffee Plantations
Another very important aspect often overlooked by the Coffee community is that the coffee Agroforestry grows in harmony with various partners inside the coffee forests. Coffee is a perennial crop, the soil system remains undisturbed for a number of years, once the plants are established. This practice is also followed in other multiple crops. We are specifically highlighting this point because scientific literature clearly points out the fact that employing farming practices that reduce disturbance of the soil (less aeration from tillage helps protect carbon), combined with practices that bring additional carbon to the soil, will allow for carbon sequestration over time. The periodic addition of organic matter which is a regular package of practice will also slow or even reverse the loss of carbon from agricultural fields, improve nutrient cycling, and reduce nutrient loss.
Gradually, the mind-set of the Planters, has shifted towards profit before sustainability and this has resulted in the indiscriminate felling of tall trees, only to be replaced by fast-growing silver oak, acacia, agarwood, mangium and acacia species.
In the past few years, more and more Planters are advocating sun-loving coffee and reducing the shade trees to maximize yields. This method of cultivation has disastrous consequences for the entire coffee ecosystem.
Ultimately, Coffee Planters may have to pay the price as a consequence of the human expansion of the greenhouse effect in terms of being responsible for accelerating global warming and releasing more carbon into the atmosphere, rather than safely storing it underground.
Anand T Pereira and Geeta N Pereira. 2009. Shade Grown Ecofriendly Indian Coffee. Volume-1.
Anand Titus Pereira & Gowda. T.K.S. 1991. Occurrence and distribution of hydrogen dependent chemolithotrophic nitrogen-fixing bacteria in the endorhizosphere of wetland rice varieties grown under different Agro-climatic Regions of Karnataka. (Eds. Dutta. S. K. and Charles Sloger. U.S.A.) In Biological Nitrogen Fixation Associated with Rice production. Oxford and I.B.H. Publishing. Co. Pvt. Ltd. India.
Brady, N.C., and R.R. Weil. 2002. The Nature and Properties of Soils, 13th edition, Prentice-Hall.
Martin Alexander. 1978. Introduction to soil microbiology. Second edition. Wiley Eastern Limited. New Delhi.
Wright, S. F. 2003. The importance of soil microorganisms in aggregate stability. Proc. North Central Extension-Industry Soil Fertility Conference. 19:93-98.
Ontl, T. A. & Schulte, L. A. (2012) Soil Carbon Storage. Nature Education Knowledge 3(10):35
Bopanna, P.T. 2011.The Romance of Indian Coffee. Prism Books ltd.
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The Carbon Cycle and Soil Organic Carbon
How should we manage our soils to increase soil carbon?