Coffee Planters in India may be in for a rude shock after reading this article. But the focus should remain strong. And that is protecting, nurturing, and multiplying indigenous microflora that is unique to each plantation. The keyword here is indigenous, meaning originating or occurring naturally in a particular place. We are trying to highlight an important aspect, often overlooked by coffee Planters. There are a number of beneficial microorganisms that are naturally present in our coffee soils. These various types of desirable microorganisms are referred to as Beneficial Indigenous microorganisms. Indigenous Microorganisms (IMO) based Technology is one such promising technology that needs to be adopted in coffee Plantations.
Culturing and using indigenous microorganisms in our coffee gardens is an effective way to super-charge the soil microbiome. The keyword here is indigenous, meaning originating or occurring naturally in a particular place within the coffee ecosystem. These microorganisms are highly localized. In fact, from one coffee block to the adjacent block, there can exist a significant difference in the composition of microorganisms. Providing the right environment for the growth and multiplication of Indigenous microorganisms shows vast improvements in soil structure and plant health, and more importantly, the soil regains its loaminess, tilth, and structure, and the earthworms come in droves.
Based on the origin, microorganisms are categorized as, Indigenous (autochthonous) and Exogenous (allochthonous or foreign).
Improving soil health, through the multiplication of native beneficial microorganisms is the most important priority inside shade-grown coffee farms. In simple terms, it translates to the restoration of soil organic carbon as one of the principal vehicles in improving the fertility status of the soil through the increased activity of microorganisms. The basic raw material needed for microbes, namely biomass, is already available insitu and only needs to be acted upon by microbes to convert the same into energy-rich compounds beneficial to all components of the coffee forest.
Our work on indigenous soil microflora for the past thirty years provides a means of sustainability in maintaining both the ecological integrity as well as the biodiversity component in shade coffee plantations. The most important thumb rule that all farmers should understand is that no soil will support vigorous plant life unless it is teeming with billions of microbes, may it be nitrogen fixers, or phosphate solubilizers that are necessary for maintaining soil health.
The objective of writing this article is twofold. First to help coffee Planters understand that eco-friendly coffee plantations are teeming with beneficial microbes and they only need to provide a suitable micro and macro environment to express themselves. Second, to sensitize Coffee Planters, on the importance of understanding the native microflora and not disturbing the delicate balance of the coffee ecosystem by recklessly introducing foreign cultures or microorganisms from outside the coffee ecosystem. After all, the thumb rule when it comes to these microscopic microbes, is that they are ubiquitous and at the same time fastidious. More importantly, the new focus in plantation research is to shift away from fossil fuel or hydrocarbon intensive technologies towards safer and non-polluting, highly energy efficient biological systems involving a host of different microorganisms.
Indigenous microorganisms are a group of innate microorganisms that inhabit the soil and the surfaces of all living things (Rhizosphere, histosphere, endorhizosphere, rhizoplane, etc) inside and outside which have the potential to enhance productivity and release growth-promoting substances through a host of interactions either through a symbiotic association or free-living. The interactions can help in, nitrogen fixation, phosphate solubilization, mineralization, biodegradation, bioleaching, bio composting, improving soil fertility, and as well in the production of plant growth promoters and regulators. Indigenous microorganisms play an important role inside coffee plantations in by protecting the normal host from invasion by microorganisms with a greater potential for causing disease.
Biological Nitrogen Fixation
Biological nitrogen fixation occurs in a variety of bacterial species, especially in rhizobia, photosynthetic bacteria, and cyanobacteria. The process is carried out by two main types of microorganisms, known as symbiotic and non-symbiotic (Free-living).
Let’s take a classical example of biological Nitrogen Fixation with the help of nitrogen-fixing bacteria. Biological Nitrogen Fixation is efficient and is readily available to the plant for uptake. The losses are the bare minimum.
The rates of nitrogen fixation per unit area are relatively small depending on the crop and the microorganisms involved. In addition, each set of microbes requires ideal host plants in symbiotic associations or ideal soil and climatic factors for improved nitrogen fixation.
Phosphate solubilizing microbes releases growth promoters, Plant regulators, antibiotics, and Bio-control of plant diseases, which are beneficial to the entire coffee ecosystem.
The main benefit that the fungus derives is the absence of competition for nutrients from soil microorganisms. The tree in turn is benefited from increased uptake of nitrogen, phosphorus, and potassium along with water. The fungus also protects the trees from pathogens.
Mycorrhizal roots are known to break down lignin and cellulose and constantly supply nutrients to the coffee plants as well as to the surrounding biotic community. Mycorrhizal roots are known to assimilate phosphate more readily than the roots not having the fungus.
The vesicular-arbuscular mycorrhizae have so far not been cultured in the laboratory as a pure culture. These fungi are obligate symbionts. Hence mass multiplication of the fungus in pure culture forms is ruled out.
Potassium solubilizing bacteria (KSB)
Potassium solubilizing bacteria (KSB) can solubilize K-bearing minerals and convert the insoluble K to soluble forms of K available to plant uptake.
How to increase Indigenous Microflora
After weeding, Shade Lobbing all the organic matter is filled into the water trenches and allowed to decompose. It is highly advisable not to disturb the pits for a period of 5 to 6 years. These small pits act as Indigenous microflora manufacturing factories. The natural succession of an ecosystem over time alters the microbiome significantly, yet stabilizes the beneficial microorganisms.
Consequences of using Microbes from unknown sources
Using cultures or soil microbes from unknown sources will significantly alter the delicate balance of the already established soil microflora. It will result in competition and will also inhibit the physiological functions of indigenous microorganisms. Over a period of time, the introduced microbes will kill indigenous microbes and overtake their population.
It’s a well-known fact that only 40 to 60% of the fertilizer we apply actually goes to the plant, the remaining is lost to leaching, runoff, volatilization to the air or is tied up in the soil. This is why soil health is such an imperative piece of plant health.
In a vast majority of places, the damage inside shade-grown eco-friendly plantations is beyond repair. Soils are dying, and so are the indigenous microbes, due to the introduction of foreign or outsourced microorganisms from an altogether different ecosystem, not related to coffee.
We also seek the valuable guidance of the Coffee research Scientists at Balehonoor in helping the coffee Planters to isolate their own beneficial microbes and help in the multiplication and reintroduction back into respective blocks. This needs a different approach because it involves redefining the Agoclimatic regions into micro agroclimatic regions based on different parameters like soil profile, altitude, variety, and rainfall.
Solutions for a better world are found hidden in the sacred coffee mountains. Every farmer should be convinced that it is in his interest that the mountain needs to get an upper hand so as to balance nature’s resources.
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.
Booker, Karen. 2000. Fertilizers and Soil Amendments: It’s Tricky Business. Erosion Control Feature Article, September/October.
Martin Alexander. 1978. Introduction to soil microbiology. Second edition. Wiley Easter 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.