Nitrogen is the most used and least understood of all agricultural nutritional inputs. Typically, only a third of applied nitrogen is taken up by crops. However, the effect that the form of nitrogen is delivered in has a direct relation on how and which crop cells grow and develop is not widely understood, but offers great potential to increase yields.
Nitrogen can be taken up as amine (NH2), Ammonium (NH4) or nitrate (NO3), but due to conversion by soil bacteria, the vast majority of nitrogen applied to crops is taken up as nitrate.
Crops mostly take nitrogen up as nitrate, no matter what form it is applied in. This means plants mostly use their nitrogen to put on top growth. In crops like potatoes, farmers must manage conflict between applying the nitrogen the crop needs and the crops’ natural propensity to use that nitrogen to grow foliage rather than root tubers. This leads to a reduction in tuber setting and bulking of roots.
Scientists at the UK company Levity CropScience have developed LimiN, a technology that helps keep nitrogen in the amine form. SizeN is a product powered by LimiN technology that provides crops with bursts of amine nitrogen, which helps to direct growth towards root tuber development.
LimiN technology, known as SizeN in the U.S., helps crops invest more in root/tuber growth.
On root/tuber crops there is a constant battle between encouraging growth by applying nitrogen, and managing canopy growth as too much nitrogen leads to excessive vegetative growth at the expense of root/tuber growth and crop yield. Farmers must feed the crop to get growth, but growth is disproportionately allocated by the crop to the part not harvested.
This is an effect generated by nitrate exposure, as nitrates encourage production of the growth hormone auxin, which makes crops allocate growth to shoots rather than roots.