A recent study that analyzed the effectiveness of a natural-based fertilizer on tomato plants found a 10 percent increase by weight of fruit output on treated plants compared to untreated plants.

Pacific Ag Research of San Luis Obispo, Calif., recently conducted an independent growth study to compare the effects of using a natural-based fertilizer on tomato plants to the same plants with no added fertilizer.

The product used was Organic Series Formula 4-3-3 by Aggrand and the plants tested were hand-transplanted early girl tomatoes.

The fertilized tomato plants yielded 10 percent more, by weight, of marketable tomatoes than the untreated plots. According to the manufacturer, continued use of the product would increase bacterial activity in the soil, leading to stronger, healthier plants. The amount of bacterial activity in soil is determined by measuring the carbon dioxide produced by microorganisms. Higher levels indicate more bacterial activity, and so, more potential nutrients becoming available to the plants.

The study was conducted in Arroyo Grande, Calif., on irrigated sandy clay loam soil. The fertilizer was diluted with water and applied with backpack and tow-behind sprayers.

The manufacturer offers a line of natural-based products intended to be an alternative to the chemical fertilizers on the market.