By Ujwala Ranade -Malvi 

Agriculture has been an integral part of civilization from times immemorial. From subsistence farming to commercial agriculture, from green revolution to gene revolution the history of agriculture has been very colorful. Coffee belongs to the Rubiaceae family of flowering plants and is a fairly new entrant on the agricultural front. It is a perfect example for this discussion as it is the beverage of choice world over, the second largest traded commodity in the world and most importantly because there are tens of thousands of people who depend of coffee for their livelihood. The majority of the coffee is cultivated in the third world developing nations that lie between the Tropic of Cancer and Tropic of Capricorn. It is these growers that need to be educated on the concepts of how to maximize their yields and quality while still increasing the health of their soils, so that growing coffee becomes a profitable endeavor for them and not just a hand to mouth livelihood.

It is a well known fact that we have very little inherent fertility left in our arable soils to produce the quantity and quality of agro-products that we need for our growing population. In the last 400 years, due to intensive agricultural practices of mono-cropping, mismanagement of fertilizer and pesticides, we have depleted our soils of nutrients that the natural processes of weathering had produced over millions and millions of years. With depleted soils of today, increasing costs of fertilizers and the global need to produce more food we will have to modify and re-evaluate our methodology of agriculture. There will have to be a shift in paradigms and we will have to put more energy and intensity into increasing the health of the soils while still churning out the yields that are so required.

What is Balanced Plant Nutrition (BPN)
Plants have evolved very intricate and close equations with mother earth for millions and millions of years. Understanding these equations and working in synch with nature is what Balanced Plant Nutrition is all about; a sustainable and progressive system of agriculture. BPN is not a revolutionary concept; it is a poorly understood one. The focus of BPN is the sustainability of the agro-system and the maximization of the genetic potential of the crop. It encompasses the basics of plant physiology, biochemistry and nutrient balancing based on crop type, soil type and stage of plant. The main aim of BPN is to work with nature to provide the plant what it needs, when it needs it in a controlled and calculated fashion. This is achieved by understanding the physiology behind a healthy coffee bush, by increasing productivity and fertility of the soil and by utilizing environment-progressive ways of growing coffee. It is important to understand that one can grow crops without fertilizers but one cannot grow crops without fertility. Hence increasing soil tilth and maximizing the genetic potential are two important goals of the BPN program.

What does the coffee bush need to thrive?
Plants are manufacturers and their physiology is an anabolic or "build-up" physiology (compare to constructing a building). Animals and humans on the other hand have "breakdown" or catabolic physiology (compare to demolition of a building). Unequivocally, plant physiology is a more complicated process and it needs raw materials in the form of 17 essential nutrients to "manufacture" food for human and animal consumption through the process of photosynthesis. These nutrients include the basic elements like carbon, hydrogen, oxygen and chlorine which are provided by nature and account for 98% of the plants needs. In the past years, the remaining 2% (which includes soil minerals like calcium, magnesium, sulphur, iron, manganese, zinc, copper, boron, molybdenum and nickel) was always present in the soils as byproducts of the inherent process of weathering.

Now, with that "insurance pool" of nutrients mined out, most of the soils across the world are depleted to a point where they are not fertile enough to sustain the growth and development of plants. The 2% may seem like a small number that can be overlooked but a plant is a living organism and it is only as strong as its weakest link! Hence the farmer/grower will have to supplement his plants with minerals and fertilizers that mother earth cannot provide at this given time.

Every perennial plant including coffee has 6 different life stages vegetative, first transition, reproductive, second transition, maturity and resting which the plant should complete efficiently in one year. Different physiological and biochemical processes are evoked in each stage of the cycle and hence the nutritional requirements of the plant also vary based on stage of the plant. For example, in the vegetative stage, the coffee bush focuses on formation of new feeder roots, lateral branches and leaves and at this stage all nutrients are required in balance. In the "first transition" stage, the plant increases in girth and starts the process of bud-differentiation. In this stage, there is a balanced need for nitrogen, phosphorus and secondary nutrients only; addition of micronutrients or potassium at this stage is unnecessary and, if applied, is a waste of money for the planter. Reproductive stage calls for a higher need of phosphorus while the maturity stage needs more potassium. The resting stage, which is post-harvest, is actually the most critical stage that sets the crop for the following year and that needs additional manipulation of the nutrient application. The point to note is that the plant cannot be given the same fertilizers throughout the year. The plant needs to be given what it needs, when it needs it, and only then plant-biochemistry can proceed uninhibited. This is one of the basic tenets of BPN.