办事指南

Struggling crops can now get that extra help

点击量:   时间:2019-03-07 12:14:08

By Ian Sample 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’ 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’s leaves. “By looking at the reflectance of the leaves, it can tell if they’re lighter or darker green,” says Rob Starkey of Hydro Agri. This information is then used to control how much fertiliser that particular part of the field receives. “Above a certain level, you don’t get any further increase in yield—you’re just wasting money,” explains Starkey. But, the Hydro Agri fertiliser system has some shortcomings, according to Simon Blackmore of the Silsoe Research Institute in Bedfordshire. “In theory, it’s an excellent idea, but they’re oversimplifying it,