Effect of Soil Urease Inhibitors on Germination, Growth, and Yield of Plants

Abstract

Based on the results of a laboratory experiment in which KC1 addition to urea reduced the volatile N losses as ammonia [for example combination of 1 part of urea with 1 part of KC1 (by weight) applied in solution on samples of a loamy sand soil reduced the NH3 losses from 24.0 to 4.5%], Rappaport and Axley (1984) initiated field experiments on 3 by 15 m plots installed on a silt loam soil in Maryland. The solution containing only urea (8.4 g N/m2) and that containing both urea and KC1 (at urea/KC1 weight ratio of 1:1) were applied 2 days after planting of maize. KCI added with urea significantly (p=0.05) increased maize yield over urea alone from 768 to 881 g/m2. But when KCI was added 10 days after urea addition, no yield increase was recorded.