Effect of horn shaving and horn core powder fertilizers on the dynamics of mineral nitrogen in the soil of organic farm

Research on the effect of horn shavings and horn core powder fertilizers, produced from cattle horn waste, on mineral nitrogen and its forms in soil layers of 0–30 and 30–60 cm was carried out in 2008–2010 on the farm of organic production in the Centre of Agroecology at Aleksandras Stulginskis University in Kazliskės village, Kaunas region. Organic winter wheat was grown for this research. Before sowing and in the stage of tillering organic winter wheat was treated with fertilizers of horn shavings and horn core powder, which resolved in the period of autumn–spring and spring–summer. During the period of winter wheat tillering (BBCH 21–23) and at the end of vegetation in the period of complete maturity (BBCH 89) soil layer of 0–30 cm contained an increased amount of nitrogenous compounds. Intensity of degradation was different in different years as it depended on meteorological conditions during the period of winter wheat vegetation. In the event of warm and humid weather more compounds of mineral nitrogen were formed and this increase due to fertilization was essential. Leaching of nitrogen compounds into the deeper layer of 30–60 cm was different in different years and depended on the meteorological conditions during the vegetation period of winter wheat. In the event of higher weather temperature and more humid air during vegetation period of winter wheat horn shavings and horn core powder significantly increased amount of nitrogen compounds in this soil layer. Additional treatment of winter wheat in tillering stage (BBCH 21–23) with different rates of horn shavings increased the amount of mineral nitrogen compounds in soil, though this amount was different in different years. In 2008–2009 strong correlation between horn shavings rates and the amount of nitrate nitrogen in 0–30 cm layer of soil was found, while correlation with the amount of ammonium and mineral nitrogen was found to be very strong. Meanwhile in 2009–2010 no correlation between nitrate nitrogen and fertilizer rates was determined, while correlation with amounts of ammonium and mineral nitrogen was weak. In 2008–2009 in the deeper layer of 30–60 cm correlation between horn shaving rates and nitrate nitrogen was found to be weak, while correlation with amounts of ammonium and mineral nitrogen was found to be moderate. In 2009–2010 correlation between fertilizer rates and forms of mineral nitrogen was found to be weak.