Plant nutrition & next-generation fertilizers

The group grew out of work on the mineral nutrition of wheat, above all on how nitrogen supply changes the uptake, translocation and remobilization of zinc and iron. That physiology is still the foundation: we follow nutrients through the plant with nutrient solution and soil experiments, isotope labelling and tissue analysis, and we test how micronutrient supply and foliar feeding affect yield and grain quality.

The applied side is fertilizer development. In the LignoNANO platform project (TÜBİTAK 1004) we work on controlled-release urea, boron and iron fertilizers built from micro- and nanostructures, and in the TÜBİTAK 2244 industry PhD programme with GÜBRETAŞ we develop biotechnological fertilizers and biostimulants for sustainable agriculture. A third strand looks at fertilizer use efficiency: getting the same yield from less input.

What we have found

Our early studies on durum and bread wheat showed that a better nitrogen status raises the zinc and iron concentrations of the grain, including the endosperm that ends up in white flour, by increasing root uptake and the remobilization of both elements from leaves into the grain. In soybean, nickel reserves in the seed and externally supplied nickel improved growth and the use of urea nitrogen. More recently, in pot trials with bread wheat, a urea-loaded biodegradable superabsorbent polymer raised nitrogen use efficiency 2.6-fold under terminal drought and protected grain yield under leaching; the release rate of urea, not the water-holding capacity of the polymer, decided the outcome. The publications listed below carry the details.