Effect of Organic Manure on Soil Bio physical Properties and Dry Matter Partitioning in Cauliflower

Aims: The main aim of the study was to assess the influence of organic fertilizers on selected soil bio-physical properties and dry matter partitioning in cauliflower.
Methodology: A field experiment was conducted at Wageningen University Experimental Site, Netherlands during 2012 cropping season. The experiment was laid in a Randomized Complete Block Design (RCBD) with four replications. The treatments included N-source (dried grass clover (DGC) and lucerne pellets (LUP)) and N application rate (0, 75, 150 and 225 kg N.ha-1). Data analysis included soil structure (% granular), soil pores, earthworm population, weight and activities and crop residues. Growth (plant height and diameter) and dry matter partitioning in leaves, stems and heads were also assessed.
Results: Cauliflower amended with 150kg N.ha-1 LUP and 225kg N.ha-1 DGC had highest numbers of large (>500mg) earthworms, while the non-amended plot (control) exhibited the lowest earthworm population. Percentage granular, organic residue and earthworm activities increased with increasing organic application. The LUP manure supported earlier and higher earthworm activities, which promoted good soil structure formation, plant growth and development. Generally, LUP-amended plants produced taller plants, larger stem diameter and higher dry matter partitioning in leaf and head organs than DGC- amended plants.
Conclusion: The results implied that organic fertilizers with low C/N ratio promote early micro-organism activities with consequent early good vegetative growth and yield. Earthworm activities influence soil fertility in ways that may be of great importance to sustainable land use in naturally degraded ecosystems as well as agro-ecosystems. Findings suggest use of proper land use management practices that promote earthworm activities and sustain crop yields. Future studies will consider comprehensive cost benefit analysis to compare the economic advantages of LUP over DGC.