Goat and sheep manure based vermicompost and vermi-leachate as a nutrient source in drip hydroponic tomatoes (Solanum lycopersicum) and Swiss chard (Beta vulgaris)

Introduction

Small stock animal manures have the potential to be used in arid countries to produce vermi-leachate or vermi-teas that can be effectively utilised in the hydroponic production of both leafy and fruity vegetables.

Materials & Methods

Our study evaluated the potential of sheep and goat manure vermicompost (SGMVC) as an amendment to cocopeat at varying levels, as well as sheep and goat manure vermi-leachate (SGMVL) diluted at 5%, 10%, and 20%, on crop phytotoxicity, seedling growth, and crop growth and yield.

Results

The 100% inorganic Hygrotech fertiliser and SGML showed consistently high values for relative root elongation (RRE) and germination index (GI), with values above 90% for most treatments. However, the treatments with less SGMVC incorporation showed phytotoxic effects, with cocopeat alone having the lowest GI and RRE values. However, for direct seed germination, all treatments showed germination percentages above 80% for Swiss chard and above 70% for tomato, including the cocopeat alone treatment, indicating the complementary effects of the SGMVL irrigation source. For Swiss chard, the use of 10% and 20% leachate alone resulted in a 141.8% and 137.5% lower leaf area, respectively, compared to the treatments irrigated with Hygrotech fertiliser. Similarly, for tomatoes, the use of 10% and 20% leachate alone resulted in 129.2% and 143.4% lower leaf areas, respectively, compared to the Hygrotech irrigated treatments. For Swiss chard, the application of 0% VC resulted in an overall 43% reduction in leaf yield, whereas in tomato, it resulted in an overall 44% reduction in tomato fruit yield. The increased yield under 50% VC clearly indicated increased nutrient availability and enhanced water holding capacity of the media compared to when no SGMVC was added.

Conclusion

This study showed that Swiss chard and tomato have different nutrient requirements, and the use of SGMVC should not be based on blanket recommendations from one crop. In addition, the use of reduced inorganic soluble fertilisers in combination with SGMVC has no economic benefits, as this reduced yield is almost proportional to the level of soluble fertiliser reduction.