The Effect of Alfalfa Mineral Fertilization and Times of Soil Sampling on Enzymatic Activity

This study examined changes in soil enzymatic activity caused by constant mineral fertilization with NPK and diversified Fe Mo micronutrients. A field experiment was conducted a completely randomized design four replications Siedlce (central-eastern Poland) between 2012 2014. Alfalfa (Medicago sativa L.) used as the test plant. The first factor consisted of treatments: control; NPK; NPKFe1; NPKMo1; NPKFe1Mo1; NPKFe2; NPKMo2, NPKFe2Mo2. second composed time sampling (15 August 2012, 20 September 17 June 2013, July 2014). Mineral applied: N-20; P-22; K-124.5; Fe1-0.5; Mo1-0.5; Fe2-1.0; Mo2-1.0 kg ha−1. Application molybdenum (Mo2-1.0 ha−1) alfalfa fertilized optimal for obtaining beneficial nitrogenase activity. applied NPKFe1Mo1 cultivation optimized to achieve high dehydrogenases activity, alkaline phosphatase acid highest urease determined biochemical index (BCHI) fertility reached its mean value (254.9) after applying NPKFe1Mo1. BCHI indicates possibility generating yields maintaining good culture.