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Watering
crops 'correctly' and accurately is becoming more and more
important as one has to be aware of not only increasing yields,
but improving quality, reducing wastage of water and hence
fertilisers and all the 'green' issues of the day.
Farming
is under considerable pressure, not only in the UK but, throughout
the world. With increased understanding we are able to help
achieve all of these issues, but it is only by increasing
'profit' that farmers will survive. Therefore, if a grower
can increase yield and quality by 10%, he could double his
profit per acre.
Water
advisers have tried using most sorts of measuring equipment
including 'Spades', Neutron Probes,
Tensiometers, TDRs and FDRs, computer models and capacitance
probes. All of them are better than doing nothing. But,
it is understanding what they tell us that is important.
Firstly
one has to understand the aims of the crop in question. For
what is it being grown?
-
Potatoes - chips, crisps, bakers, baby scrapers, salads,
starch, prepacking etc
-
Lettuce - hard hearted, small size for supermarkets -larger
'fluffy' etc
- Strawberries
-taste, shelf life, yield, quality etc.
Identifying
the limiting deficit has always been the way to look at needs
of the crop and then watering to keep above it. But, what
we are able to 'see' with contnuous monitoring equipment such
as the EnviroSCAN is that each
layer of soil (it measures in 10cms, so we work with this)
has a 'full' point and a 'refill' point. Some layers may have
plenty of water and others have run out. In some crops this
does not seem to matter as the crop just takes water from
a different layer to compensate. But experience shows that
this is not the case in most crops that areirrigated in the
UK.
If
the water demand is high then it is probably important that
all the roots are able to contribute to the needs of the plant.
If only some are working this will also have an effect on
the nutrient uptake.
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