Container production of tomato with food by‐product compost and mineral fines
Agricultural applications are sought for by-products from agricultural, municipal, and industrial operations. Incorporation into media for container production of crops is a suggested use of organic and mineral by-products. Composted food by-products generated by grocery stores and restaurants and mineral fines from the aggregate industry were assessed in the formulation of media for tomato (Lycopersicon esculentum Mill.) production in containers. The basic medium was compost and perlite (2 compost: 1 perlite, v:v). This medium was mixed with basalt fines or glacial moraine fines added separately at 60 or 120 g L-1. Nitrogen (N) fertilizer was added weekly to the media except for one treatment that included the basic medium without N. Incorporation of mineral fines into the food by-product compost produced an early stimulation of vegetative growth, but did not affect fruiting of tomatoes significantly; however, fruiting was heavy in the containers to which N was added, with an average of nearly 23 kg of total fruits per plant. Extractable (acidified sodium acetate solution) calcium (Ca) and manganese (Mn) from the media increased, but other nutrients were unaffected by additions of basalt or glacial fines. In all media, extractable nitrate and potassium (K) were almost depleted during the experiment; phosphorus (P) was moderately depleted, whereas extractable Ca, magnesium (Mg), iron (Fe), zinc (Zn), and copper (Cu) were slightly lower or unchanged during the experiment. Tissue analyses showed that leaf concentrations of N, K, Mn, and Zn were below the range needed for wellnourished plants whereas Ca exceeded concentrations necessary for adequate nutrition. Tissue concentrations of P and Mg were sufficient for proper plant nutrition. Although fertilization with N and K, were necessary to sustain optimum yields, formulations of food by-product compost and mineral fines were excellent media for container production of tomato.