Effect of Organic Manure on Nitrogen Mineralization, Nitrogen Accumulation, Nitrogen Use Efficiency and Apparent Nitrogen Recovery of Cauliflower (Braccica oleracea L., var. Botrytis)

Aims: The main aim of the study was to assess the effects of organic manure on nitrogen mineralization, uptake, use and recovery of cauliflower.
Methodology: Nitrogen is one of the major yield limiting nutrients in cauliflower production. However, organic manure is applied to supplement soil nitrogen supply to maximize dry-matter yield. A field experiment was conducted at the Droevendaal Certified Organic Research and Demonstration Site of Wageningen University, Netherlands during 2012. The experiment was laid out in a randomized complete block design with four replications. The treatments comprised of four rates (0, 75, 150 and 225kgN.ha-1) each of lucerne pellets (LUP) and dry grass clover (DGC) organic manures.
Results: Results showed that LUP amended plots exhibited highest initial N-mineralization compared to DGC and control plots. Nitrogen uptake in plant organs increased with increasing organic manure application. Nitrogen accumulation was highest in cauliflower leaf (38.28mg.kg-1), followed by the head (16.96mg.kg-1) and lowest in the stem (3.01mg.kg-1).
Conclusion: Results suggest that timely and adequate nitrogen release from organic manures is important for the success of conservation and sustainable farming systems. Findings in this study could be utilized in improving efficiency of N use in crop management rotation systems.