Drip Irrigation for Coffee Plantations: feasible and profitable This paper was prepared by NaanDanJain Brazil — leaders in coffee irrigation

September 2009

Introduction – Coffee Cultures Coffee culture, which up until now has remained traditional and conservative with regards to innovative technologies, is finally accepting the benefits of irrigation. Several studies clearly show how coffee productivity is severely affected by long-term water shortage, especially during the critical stages of flowering and fruit set. In the central-southern region of Brazil, the shortage of water during fruit development between October and December delays the growth of the fruit. This reduces productivity because the inferior fruit is unsuitable for marketing. The final size of the bean is entirely dependant on the amount of precipitation between weeks 10 and 17 after flowering; the period during which the bean grows fastest. In some species, such as Arabica and Robusta, there is twisting of the buds before they open. This occurs when water stress is created after small amounts of rain have prompted the initial growth. As a result of the twisting, they cannot reach the opening stage and therefore dry up. B. Sobrinho (1985) states that this twisting — unopened buds or dried flowers (stars) — is a typical phenomenon caused by high water shortage. It can result in yield loss of up to 50%.

Critical Stage: Coffee Flowering Coffee Ripening

Coffee Irrigation Increases Yield The introduction of irrigation reduces the percentage of dried flowers (stars) from 57% to less than 5%, with some percentages practically negligible (Rena / Maestri, 1987 and Thomaziello, 1999). When the productivity results of non-irrigated, irrigated and fertigated coffee were compared, there were increases of 66% and 123% in the irrigated and fertigated zones respectively (Antunes). According to Mantovani (2003), the irrigation of coffee plants is recommended for most coffee-producing regions in Brazil. The need for irrigation stems not only from the water shortage, but also from the annual mean temperatures. With temperatures below 18o C, irrigation is necessary with an annual water shortage of 150 mm. With temperatures between 18ºC and 24ºC the water shortage is more damaging. In these cases irrigation is recommended with water shortage of 100 mm. In 2003 it was estimated that 8-10% of the Brazilian coffee plantations — a total of 200,000 Ha — were already being irrigated. This irrigation took place mainly in the states of Espiritu Santo (60-65%), Minas Gerais (20-25%) and Bahía (10-15%).

Table 1. Need for irrigation in coffee plantations

Agro-climatic zones: WD (water deficit) = P – EP, where P = precipitation and EP = evaporation (soil) + transpiration (plant)

Temperatures WD/year (MM) Irrigation needs <100 (1) No irrigation <100-150 (2) Occasional irrigation <150-200 (3) Supplementary irrigation

Below 18ºC

>200 (4) Mandatory irrigation <150 (1) No irrigation <150-200 (2) Occasional irrigation <200-400 (3) Supplementary irrigation

18ºC - 24ºC

>400 (4) Mandatory irrigation

(1) WD damage* - none (2) WD damage - most years (3) WD damage - every year (4) WD damage - every year

*Damage depends highly on the phonological stage of the plants when deficit occurs

Choosing the best irrigation system

Ideally coffee plantations are irrigated with pressurized systems via sprinklers or localized irrigation. Characteristics of localized irrigation systems are:

Savings in water and energy (see Table 2) Savings in manpower Possibility of automating the system Requirement of good water quality Possibility of adapting to soil conditions Solutions for all type of topographies (self-compensating systems) Possibility of applying chemical products to the solution (fertigation)

Drip Irrigation of young coffee crops

Table 2. Power efficiency and consumption with different irrigation methods

Irrigation method Irrigation efficiency (%) Power consumption (kWh m3) Surface 40-75 0.03-0.3 Sprinkling 60-85 0.2-0.6 Localized 80-95 0.1-0.4

Source: Marouelli & Silva (1998)

Setting up an irrigation system The localized irrigation systems comprise of: water source, pumping system, filtering system, main distribution network, control heads, valves, automation, and emitters (micro-sprinklers or drippers).

Water source Water may come from wells, reservoirs or rivers. The Application Engineering Department at NaanDanJain adopts the most suitable alternative for each specific situation, bearing in mind the best cost/benefit ratio.

Pumping system Centrifugal pumps are used with electric motors (single or three-phase). Diesel or gas oil motors are used in areas with no electricity.

Filtering system The purpose of the system is to prevent clogging of the emitters. Various filtering means are used, such as sand, disks and nets. The filter must be selected according to the chemical and biological characteristics of the water being filtered.

Main network This network leads the water from the pump to the irrigated subdivisions. Steel, PVC or polyethylene tubing is used. The technical parameters (pressure and flow rate) must be observed.

Zone Control Head Located at the entrance of the subdivisions, these trestles may be configured with different components, such as anti-vacuum valves, air relief valves, basic valves (ON/OFF), and regulating valves. The valves open and close the flow, regulate the pressure in the subdivision and prevent vacuum in the network.

Dripline Zone control head Filtering system

(for 470 Ha)

Emitters

1. Driplines Various characteristics of the dripline must be considered, namely wall thickness, tube diameter, flow, spacing and self-compensating functions. The optimal combination of these factors is one of the critical factors in successful irrigation. Spacing between drippers must be selected based on the soil granulometry. Spacing of 60-85 cm is usually used, but lower spacing is required with higher sand content or rocky soil.

2. Micro-sprinklers and jets These types of emitters vary in flow rate, wetted area shape and diameter, and special features, such as self-compensating and insect-resistant mechanisms. Micro-sprinklers can be very efficient in rocky conditions and in organic plantations they assure efficient use of compost and manure.

Setting up a drip irrigation system Naan PC in coffee planatation

Automation This is performed by controllers with varying levels of sophistication. Automatic systems are more precise and save manpower.

Fertilizer injector The fertilizer injector is chosen according to the specific project. System pressure, flow rate and fertilizer demand are considered, together with the availability of electrical power and economical aspects of primary and operational costs.

Venturi injectors Proportional dosing, water-driven pumps (Tefen) Pressure-operated, water-driven pumps (Amiad) Stainless steel centrifugal pumps Automatic fertigation machines

Summary – Coffee Expertise NaanDanJain's expertise in the design and implementation of drip-irrigation projects in coffee plantations is evident in the 10,000 Ha of coffee plantations in Brazil. The projects vary in size (between 10-1000 Ha) and the topographical and weather conditions are diverse. Despite this, individual solutions have been provided for each project. NaanDanJain irrigation projects result in an immediate increase in productivity. Whereas production only reaches 1500 kg/Ha of dry green coffee beans without irrigation, 6000-7000 kg/Ha is achieved when irrigation systems have been implemented

6-7 ton/ha with irrigation Mechanical harvest

Contacts In Brazil: Eng. Alfredo Mendes, Rua Biazo Vincentin No. 260, Bairro Cidade Jardim, P.O. Box 175, Leme SP – CEP 13614-330, Brazil T: 55-19-3571.4646 F: 55-19-3554.1588 M: 55-19-8122.5401 E: alfredo@naandan.com.br Worldwide: Visit our website - http://www.naandanjain.com