Coffee cropping

Smell the coffeeMillions of people around the world wake-up each day with a cup of freshly brewed coffee and later meet their friends or do business in fashionably expensive coffee houses. Coffee is the most widely traded agricultural commodity from the tropics. Exports are worth more than $15 billion per annum and vastly more at the retail level. Worldwide, coffee consumption is increasing by about 2% every year. The industry provides work for over 100 million people worldwide, of which about 25 million are smallholder producers in developing countries. These farmers receive about 10% of the supermarket price for their coffee. The major environmental issues in coffee growing have been cited (Clay, 2004) as being:
  • Loss of habitats and effects on biodiversity

    Description

    The variety of life in all its forms, levels and combinations. Includes ecosystem diversity, species diversity, and genetic diversity (IUCN, UNEP and WWF, 1991).

    Authoritative On-line References and Resources

    http://earthtrends.wri.org/ EarthTrends is a comprehensive online database, maintained by the World Resources Institute, that focuses on environmental, social, and economic trends. Statistics on biodiversity indicators are available.
  • Soil degradation
  • Processing effects on water quality
  • Excessive use of pesticides
A major concern is that expansion in the newer major coffee growing countries has been at the expense of natural forests. However, it has been stated that: “... there is no reason to clear pristine habitat to plant coffee. With the agrochemicals available today and with improved overall production and management practices, much previously degraded land can be brought back into production.” (Clay, 2004) The non-selective

Description

A chemical product used for eliminating all types of weeds (annual and perennial grasses and broadleaved weeds).

Authoritative On-line References and Resources

http://www.weeds.iastate.edu/ An invaluable source of contemporary information about herbicides and weeds from Iowa State University.
herbicide paraquat has a key role in the quest for sustainable coffee production by controlling weeds that would otherwise seriously reduce productivity, in conjunction with other agronomic practices that protect the environment and help to reduce the overall use of pesticides.

Paraquat is an essential tool in coffee

Paraquat is a broad spectrum herbicide because its mode of action is to inhibit photosynthesis. This process is essential to plants and means that paraquat destroys all green tissue. However, although it is termed ‘non-selective’, paraquat is safe to coffee crops for several reasons. Firstly, it is immobilised on contact with the soil meaning that it cannot move to roots and be taken up into plants. You can read more about paraquat’s unique soil properties here. Secondly, it is sprayed around the coffee plants which are protected by their bark which paraquat cannot penetrate. Thirdly, even if small amounts of paraquat land on coffee leaves there is little or no damage because paraquat does not move through plants systemically like the alternative non-selective herbicide glyphosate. Paraquat is very fast acting and rainfast, unlike glyphosate. A video showing paraquat’s unsurpassed speed of action can be viewed here. Weeds sprayed in the morning will often show symptoms by the afternoon, making it easy for spray operators and plantation managers to see which areas have already been sprayed. This holds even if rain falls within 15-30 minutes, making it possible to spray for longer before rain is expected. In perennial plantation crops such as coffee, emphasis is on the management of weeds rather than their permanent removal. This is because maintaining a particular balance of weeds in the plantation flora is important for sustainability by providing habitats for predators of insect pests and minimising soil erosion

Description

Displacement of solids (soil, mud, rock and other particles) usually by the agents of currents such as, wind, water, or ice by downward or down-slope movement.

Authoritative On-line References and Resources

http://soilerosion.net/ This site brings together reliable information on soil erosion from a wide range of disciplines and sources. It aims to be the definitive internet source for those wishing to find out more about soil loss and soil conservation.
though the anchoring effect of plant roots.
Intensive use of glyphosate has caused new weed problems as species less well controlled have ‘shifted’ to become more dominant and some species have evolved biotypes which are resistant to glyphosate. Using paraquat as an alternative non-selective herbicide, with a different mode of action, is helping to avoid problems of weed shifts and resistance. Paraquat has a very robust environmental profile. It does not leach

Description

The natural process by which water soluble substances are carried downward through the soil into groundwater.
because it is extremely tightly bound to soil particles immediately on contact, so it cannot move into groundwater, or surface waters by run-off

Description

The occurrence of surplus liquid (like rain) which originates up-slope and is collected beyond the ability of the soil to absorb it. The surplus liquid then flows away over the surface to reach the nearest surface water (pond, lake, river).

Authoritative On-line References and Resources

US Geological Survey's Water Science School
. Further details of paraquat’s safety to the environment, spray operators and consumers can be found by referring to the Paraquat Fact Sheet.
You can read more about the benefits of using paraquat here.

Where does coffee come from?

What is coffee?

A coffee plantationCoffee plants are woody evergreen shrubs or small trees from several species, notably Coffea arabica and Coffea canephora which are the most economically important, producing Arabica and Robusta coffee, respectively. These coffee species have different agronomic characteristics and produce coffee beverages with distinctive brewing characteristics and tastes (Table 1). In commercial production coffee trees are pruned to shape to allow for high yields and easy harvesting.

Table 1. Characteristics of Arabica and Robusta Coffee.

  Arabica Robusta
Climate & Location    
Temperature range 15 - 24ºC 24 - 30ºC
Optimum rainfall 1500 - 2000 mm/year 2000 - 3000 mm/year
Optimum altitude 1000 - 2000 metres Under 700 metres
Plant Characteristics    
Size and form Short bushy shrub Small tree (up to 10 m tall)
Flowering time After rain Irregular
Disease resistance More susceptible More resistant
Yield Lower yielding Higher yielding
Beverage Characteristics Higher quality, lower caffeine content, lighter, more acidic Lower quality, higher caffeine content, full bodied, more bitter
  Coffee beansCoffee comes from the roasted seeds, known as ‘beans’ found in the cherry-like fruit of coffee plants. The quality of coffee is all-important and influenced by many factors including the species and where it is grown, how carefully it is harvested and how it is processed, besides how it is brewed. Another increasingly important aspect of coffee quality is the impact its production and trade has on peoples’ standard of living and the environment, ie its sustainability.

 

Where is coffee grown?

Global coffee harvested areas (FAO, 2011).Coffee is a tropical crop needing high temperatures and plentiful moisture. Major growing areas are found in Latin America and the Caribbean, Equatorial Africa, India and S. E. Asia. Arabica coffee prefers cooler, less wet conditions found in more highland regions. The main gowing areas for arabica coffee are in Latin America, Central and East Africa, India, with some grown in Indonesia. Robusta coffee is mainly found in Africa, South East Asia, and some areas of Brazil (Fig 1).

Coffee in international trade

In the past 20 years coffee production has incread from 5.6 to 8.3 million tonnes per annum with more hectares being harvested particularly in Brazil, Indonesia and Vietnam, although this growth has now stabilized (Fig.2). Figure 1.  Areas of coffee harvested in leading countries in 1996 - 2011 (FAO).In 1970, the average US consumer drank 36 gallons of coffee that year and 23 gallons of soft carbonated drinks. In 2000, these figures were 17 gallons and 53 gallons, respectively.

Sustainable coffee production

The Common Code for the Coffee Community

The Common Code for the Coffee Community has been drawn-up to provide a basis for standards of quality in the production, processing and trade of coffee in a sustainable way. It recognises quality in these processes as well as the quality of coffee products. The original steering committee included representatives from international development ministries eg GTZ (Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH) and SECO (Schweizerisches Staatssekretariat für Wirtschaft); international, regional and national industry associations; workers unions; research organisations, eg EMBRAPA, Brazil; manufacturers such as Nestlé and Tschibo; and NGOs, eg Oxfam. All members cooperate to enhance the supply and promote the demand of coffee produced under the Code’s principles of sustainable quality. Overall, the Code aims for:
  • Provision of reasonable earnings for all involved in the industry, especially producers.
  • Ensuring decent working and living conditions for farmers and their families.
  • Protection and conservation of soil, water, biodiversity and energy

Growing coffee

Ripening coffee berriesCoffee plants are grown from seed in seedbeds until they have two true leaves. Seedlings are shaded to prevent excessive water loss. After 3 months they are moved into nursery beds where they grow to 20-40 cm high before transplanting out in to the field at the start of the rainy season. First harvests are taken after bushes flower at 3-4 years old. Coffee plants produce cherry-like fruit (‘berries’) with red skins when ripe. These are harvested 7-8 months after flowering. The most expensive and labor intensive method of harvesting is to go over the crop several times picking only the ripe fruit. Alternatively, if ripening is relatively uniform, the crop may be stripped by hand or mechanically, Unripe berries are sorted later. Two beans are usually found within each fruit. ‘Green coffee’ is the extracted beans ready for roasting.

Pests and diseases

Coffee plants are attacked by many insect pests including stem borers, berry borers, aphids, green scales (eg Coccus viridis), mealybugs (eg Planococcus citri), thrips and caterpillars. The coffee leaf miner (Perileucoptera coffeella) is an important pest in Brazil. Nematodes (eg Meloidogyne incognita, Pratylencus coffeae) can be serious pests, particularly in nurseries. The most infamous disease of coffee is Coffee Rust caused by the fungus Hemileia vastatrix. This defoliating disease devastated the Brazilian crop in the 1970s and was ultimately responsible for much of the modernisation of the crop in that country. In many other countries it has caused a move towards planting the more resistant robusta species. Other diseases include Cercospora Spot (Cercospora coffeicola), Coffee Berry Disease (Colletotrichum coffeanum) and Bacterial Blight (Pseudomonas syringae pv. garcae). Damping-off diseases (Rhizoctonia spp., Fusarium spp.) can be problems in nurseries.

Weed management

A large number of annual and perennial weeds

Description

Weeds that return year after year. Some die back in the winter but their roots remain alive and shoots reappear in spring; some don't die back and grow in size and stature the next season.

Authoritative On-line References and Resources

The International Weed Science Society represents individual associations around the world.
infest coffee plantations. Tropical climates with ample sunshine, heat and moisture mean that weeds thrive and may compete with crops for space, water and nutrients, and shade the crop plants, especially when they are young.
Traditionally, and in poorer farming communities, coffee is weeded by hand hoeing or slashing with machetes. This is labor intensive and time consuming, and, therefore, can limit opportunities for other activities, including education. Effective use of herbicides can very significantly reduce the resources needed to control weeds. The most commonly used herbicides include paraquat and glyphosate which have no activity in the soil, and the class of herbicides known as ‘residuals’ which remain active in the soil and prevent the germination of weed seeds. However, the inappropriate use of herbicides can lead to two particular problems, weed shifts and soil erosion.

Weed shifts

Intensive use of the systemic non-selective herbicide glyphosate and residuals has led to changes in plantation weed flora (‘weed shifts’) as species more tolerant to their particular modes of action become more dominant. ‘Soft’ weeds, typically prostrate annual grasses

Description

The leaves are "narrow" as opposed to the "broad" leaves of broadleaved weeds. Also called 'monocots' having one seed leaf opposed to 'dicots' having two seed leaves.

Authoritative On-line References and Resources

The International Weed Science Society represents individual associations around the world. 
which are easily controlled, are replaced by re-invasion of cleared land by more aggressive ‘noxious’ weeds which reduce crop yields. These ‘noxious’ species are typically creeping and climbing annual and perennial broad-leaved species, eg Borreria spp., Ipomoea spp. and Commelina spp. They compete with the coffee crop and make spray operations, fertilizer application and harvesting difficult.
Using paraquat, however, can help to maintain a balanced flora which precludes the dominance of aggressive species. Paraquat only removes the top growth of well established weeds, and does not affect the germination of new seedlings allowing vegetation to re-establish after 1-2 months. A controlled presence of soft weeds maintains the balance of the weed flora and prevents weed shifts to noxious species simply because bare ground for them to colonise is less available. The presence of non-competitive vegetative cover also provides habitats to encourage biodiversity. The wildlife encouraged will include predators of insect pests which would otherwise have to be controlled chemically.

Soil Erosion

Extended periods of bare soil left by using glyphosate and residual herbicides leads to problems with soil erosion which can be severe where coffee is grown on steeply sloping land. The use of herbicides to produce weed-free fields on the slopes of coffee farms, particularly those at high elevations, is one of the major causes of soil exposure and erosion.” (Clay, 2004) The first coffee in Brazil was planted in rows perpendicular to hillsides causing much erosion. Losses of up to 4.4 tonnes of soil per hectare each year were recorded. Moving to planting crop rows following contours reduced soil erosion and water run-off by around 25%, but it is still a problem when heavy rains fall on bare ground. Establishing grass strips between coffee rows has been found to reduce soil losses to 0.2 tonne/ha and rainfall run-off by 90% (May et al. 1993). Paraquat can be safely sprayed to manage the weed flora along the crop rows between the grass strips without fear of damaging the coffee bushes. It is immobile in soil and cannot move to the roots and up into the shoots. Bark cannot be penetrated by paraquat meaning that it can be sprayed right up to the base of the bushes. Even if paraquat drifts on to coffee leaves there is little or no damage because paraquat does not move through plants systemically like glyphosate.

References & Resources

Coffee Associations

International Coffee Organisation

Sustainable coffee growing and crop protection

The Coffee Guide Coffee Research US National Information System for the Regional IPM Centers Clifford M.N. and Willson K.C. (Editors) - Coffee; botany, biochemistry and production of beans and beverage. London, Croom Helm, 1985

Soil erosion

May, P H et al. (1993). Coffee and cocoa production and processing in Brazil. Geneva: UN Conference on Trade and Development. UNCTAD/COM/17. 27 August 1993 Clay, J A (2004).  World Agriculture and the Environment: a commodity-by-commodity guide to impacts and practices. Island Press. ISBN No. 1-55963- 370-0