Effect of organic and mineral fertilisers on maize nitrogen nutrition indicators and grain yield

The study examined the effect of organic and mineral fertilisers on soil nitrogen (N) supply, maize grain productivity and correlation of mid-season plant and soil indicators with grain yield and soil mineral nitrogen (N min ) at harvest.Field experiments using the short-season maize (Zea mays L.) cultivar 'Agiraxx' were conducted in 2015-2017 on a sandy loam soil in Central Lithuania.Prior to sowing, the soil was applied with 170 kg ha -1 of N as ammonium nitrate, pelletized cattle manure (PCM), pelletized poultry manure (PPM) or green waste compost (GWC), or as a combination of ammonium nitrate and organic fertilisers.The effects on soil N min , maize nitrogen nutrition index (NNI), nitrogen uptake and grain yield were investigated.Mid-season measurements of NNI and soil N min made at tasselling stage (VT) were strongly correlated (R 2 = 0.73-0.88).Sufficient maize N nutrition (NNI > 0.9) was achieved via the application of ammonium nitrate, PPM or the combination of ammonium nitrate and organic fertilisers.In these treatments at harvest N min accumulation was also significant.PCM and GWC application resulted in insufficient maize N nutrition with mid-season NNI values below 0.85.Thus, while PPM can be used as the main source of nitrogen for grain maize, PCM and GWC should be applied in combination with N min such as ammonium nitrate.