Use of Shrimp Sludge as a Soil Amendment for Tomatoes Chad King, Kevin Fitzsimmons, Dennis McIntosh Environmental Research Lab University of Arizona

Purpose Determine feasibility of use of shrimp sludge from low salinity inland shrimp culture as a soil amendment. Apply sludge at disposal rates, not to meet plant requirements. Provide a use or disposal for a current waste product Reduce the potential for farm erosion, nutrient leaching/loss

Research Design Collected and dried fresh sludge from a shrimp farm in western Arizona, USA Treatments of 5, 10 and 20% sludge application by volume, 402, 805 and 1,610 g/plant Mechanically mixed shrimp sludge and potting soil mix (concrete sand, mulch, vermiculite) Randomly transplanted and arranged 28 ‘Roma’ tomato starts in a greenhouse, one plant per pot Each plant received 4 L of water daily, over four applications by drip irrigation Response measured in mass of tomatoes produced

Statistical Analysis One-way ANOVA of total mean mass of tomatoes per plant for each treatment

Shrimp Sludge Characteristics SampleTotal N % dry matter Total PO 4 -P % dry matter Total K % dry matter NO 3 -N  g/g Olsen P  g/g Soluble K  g/g EC dS/m Total N, PO 4 -P and K show total plant macronutrients NO 3 -N, Olsen P and soluble K show plant available nutrients EC provides a measurement of soil salinity

Results

Tomato Production TreatmentTomato Mass (g/plant) SEM 0% (Control)39.2 a % 402 g/plant 65.1 a % 805 g/plant b % 1,620 g/plant b 19.9 Different superscripts indicate a significant difference, p<0.05

Conclusions Applications of 10% and 20% increased plant production Suggests land application will benefit crop production while providing a disposal mechanism Large, field scale application experiment suggested to verify results Soil salinity must also be monitored, given high evaporation rates Sludge is highly variable, depending on pond management