The Influence of Long-Term Application of Organic Manures and NPK on Barley Grain and Straw Yields and Soil Properties

Abstract

We evaluated how sixty years of regular application of mineral fertilizers (NPK), farmyard manure (FYM), poultry slurries (PS) and combination of FYM+NPK and PS+NPK influenced grain and straw yield of spring barley (Hordeum vulgare L.). The effect of fertilizer treatments on soil’s pH, soil organic carbon (Cox) and total nitrogen content (Nt) in two decades of the long-term experiment (1983–1992 and 2001–2010) was also analyzed. Long-term application of FYM and PS increased grain yield by 19 and 35%, respectively, while application of NPK, FYM+NPK and PS+NPK increased grain yield by averagely 66%. Straw yield was not affected by organic manures, only NPK, FYM+NPK and PS+NPK treatments provided significantly higher yields compared to the unfertilized Control treatment. The soil’s pH was comparable between fertilizer treatments between the years 1983–1992 and significantly differed between the years 2001–2010, especially in FYM+NPK and PS+NPK treatments. Generally, the mean pH significantly decreased from 6.42 (1983–1992) to 5.95 (2001–2010). Cox was not significantly affected by fertilizer treatment in both analyzed decades, but significantly increased from 1.44% (1983–1992) to 2.2% (2001–2010). Nt concentration was not affected by fertilizer treatment in both decades and did not change during the time. Application of NPK with or without organic manures is the best way how to achieve high production of barley grain and straw, but with organic manures and well-composed crop rotation is, according to the results, sustainable even without fertilizer inputs.