快猫短视频

A SMART fertiliser spreader that works out exactly how much each square metre
of a field needs will help farmers to achieve higher yields, say its
developers.

The quality of soil in a field can vary tremendously, so some areas produce a
better yield than others. At the moment, most farmers rely on maps of previous
years鈥� yields to work out how much fertiliser each patch needs.

One of the main reasons why crops fail to flourish uniformly is that they are
not getting enough nitrogen. Plants need nitrogen to produce chlorophyll, so
nitrogen-deficient plants are a light shade of green while healthy plants have a
darker hue.

Agricultural engineers at Hydro Agri in Gainsborough, Lincolnshire, have now
developed optical sensors that can be mounted on a tractor. One sensor measures
the ambient light while the other measures the light that is reflected off the
crop鈥檚 leaves. 鈥淏y looking at the reflectance of the leaves, it can tell if
they鈥檙e lighter or darker green,鈥� says Rob Starkey of Hydro Agri. This
information is then used to control how much fertiliser that particular part of
the field receives. 鈥淎bove a certain level, you don鈥檛 get any further increase
in yield鈥攜ou鈥檙e just wasting money,鈥� explains Starkey.

But, the Hydro Agri fertiliser system has some shortcomings, according to
Simon Blackmore of the Silsoe Research Institute in Bedfordshire. 鈥淚n theory,
it鈥檚 an excellent idea, but they鈥檙e oversimplifying it,鈥� he says. 鈥淥ther factors
like trace mineral deficiencies and waterlogging can also influence how much
chlorophyll crops produce.鈥�