Page 6 - Vol.40-No.2 issue

CROP PROTECTION

FERTIGATION FOR FRESH

VEGETABLES PART 1: THE

SYSTEM AND ITS ADVANTAGES

common irrigation system used for ferti- can thus be applied on a daily, weekly, or
gation although not because it is easy to less frequent basis as necessary depending
carry out. Indeed drip irrigation either used on the overall nutrient management plan
on its own or to also apply soluble nutrients for the crop.
by fertigation is the most demanding in When nutrients are applied in this way
terms of knowledge and expertise. and shortly before they are needed the
There are many good reasons to harness opportunities for loss of nutrients from the
DR. TERRY MABBETT the power of drip irrigation for conveying root zone are greatly reduced, and especial-
nutrients to growing crops but main one ly important in high rainfall locations and for
Fertigation is a well-chosen and high- is typically using less than half the wa- nutrients like nitrate that leach very readily.
ly appropriate name perfectly describing ter consumed by overhead and furrow Compared to the more traditional methods
systems in which fertilizer is conveyed, irrigation. Indeed drip irrigation efficiency of applying fertiliser throughout the year,
applied and provided to agricultural and exceeds 90 per cent whereas a sprinkler and which require tractors or heavy foot
horticultural crops as soluble nutrients in system will struggle to achieve a 60 per traffic, fertigation will minimize potential
the irrigation water. In other words ferti- cent efficiency of water use. for and risk of soil compaction as well as
gation is the practice of applying fertiliser The exceptionally high efficiency afforded being less restricted by weather condi-
to a crop via the irrigation system. by drip irrigation is down to water soaking tions. Fertigation is equally advantageous
Fertigation has become an increasingly into the soil before it can evaporate or run for both greenhouse growing of vegetables
popular choice for farmers and growers off. And because water is only applied to the and outdoor vegetable cropping systems.
facing reduced water supplies due to cli- area where it is required (near the crop and Fertigation encapsulated
mate change and other factors. These in- in the root zone) rather than being splashed In summary, fertigation features the
clude implementation of regulations to re- and spread over the entire field. And in drier application of irrigation water and crop
duce the environmental impact in the face climates where an increasing amount of fertiliser within a single integrated system.
of increasing fertiliser run-off from fields the world’s vegetable production is now Fertigation is used most frequently with
and into rivers and other water sources. taking place, application of irrigation water drip irrigation systems because combin-
Such issues together with both practical to the crop zone rather than the entire field ing pressurised irrigation systems (such as
and economic advantages will continue to mitigates against weed growth between drip or advanced sprinkler systems) offers
make fertigation an increasingly attractive the rows of crops plants. some important advantages for vegetable
dual irrigation and fertilisation system. An additional advantage offered by drip farmers and growers, the most notable of
Why use drip irrigation for irrigation is a reduction in water contact which are:
with aerial parts of the crop including
fertigation? leaves, stems, and fruit. This will minimise •A reduction in or the elimination of me-
Any system of irrigation can be used the extent and duration of wet crop-sur- chanical fertiliser application, thus dispens-
to apply soluble fertilizer but in practice face conditions that will invariably favour ing with inherently high costs.
and for reasons of accuracy and economy infection by fungal and bacterial pathogens •Capacity to automate both the appli-
the system used in fresh market vegetable with resulting disease development. Last cation of irrigation water and nutrients
production is drip irrigation, also known as but not least, vegetable growers plagued •Ability to exert more exact control over
micro irrigation or trickle irrigation. These with variable water resources will benefit the application of irrigation water and nu-
are also perfect names to describe what is from the lower pressures (8–10 psi at the trients throughout the life of a crop
essentially the slow and measured appli- drip line) required for the operation of a •Opportunities to synchronise the ap-
cation of water and targeted directly on drip irrigation system. A well-maintained plication of nutrients with specific growth
the soil around the crop and therefore at and effective drip irrigation system is a and development stages of the crop.
the root zone. Drip irrigation is the most must for successful fertigation.
Fertigation for all crops
and seasons
Drip irrigation is the vehicle for nutrient
delivery but what about fertigation in its
entirety? Fertiliser delivered as nutrients in
water soluble form are immediately availa-
ble for plant uptake and utilisation. This, in
turn, allows farmers and growers to exert
more control over nutrient availability to
the crop and the key factor which maxim-
Sweet capsium pepper is widely grown ises the efficient use of fertilizers. Nutrients Tomato and aubergine both respond
under fertigation (Picture credit Omex) well to fertigation (Picture credit Omex)
4 Vol. 40 No. 2 Circle 4 on enquiry card