Solutions for soil fertility management to overcome the challenges of the Mediterranean organic agriculture: tomato plant case study

Abstract

Regulation of organic farming allows the use of a limited range of fertilisers and soil amendments to meet nutritional needs of the plants. Before advocating alternative strategies for fertility management, performance should be evaluated. An open field experiment was conducted to study the effects of different fertilisation scenarios on tomato (Solanum lycopersicum Mill, cv. San Marzano) production and soil chemical properties. Fertilisation scenarios were based on combinations of amendments (composts and biochar) with organic and/or mineral fertilisers to balance plant nutrient requirements. Amendments were produced from agricultural and food-industry wastes available in the region. Most of the soil parameters did not vary by the end of experiment; only available phosphorus slightly increased in the treatments where organic fertilisers were applied. All treatments significantly increased yields over control and biochar alone. Different compost types showed promising results for tomato production and quality, whereas biochar did not. The study demonstrated that recycling of nutrients from on-farm or food-industry wastes might be a good strategy to increase productivity and sustainability of Mediterranean organic agriculture when integrated fertility management is adapted. However, more studies are needed to evaluate their effect in long-term experiments.