Photo Credit: Rodale Institute

An article recently published in the Journal of Agronomy Research assessed a wide range of organic mulch and fertilizers on the production of shallots in nutrient-poor and water-limited soils. The study found the combination of rice straw and composted cow manure achieved the best results with improved soil water content and increased shallot yield, beating out plastic mulch and leaf-based compost. The study first applied a range of organic mulches including rice straw, coconut husk, silver-black plastic mulch and a control of no mulch. Then organic fertilizer was added in the form of either composted cow manure, leaf compost, or a control of no fertilizer. The winning combination was rice straw and cow manure. This combination altered important physical conditions of the soil by lowering the soil temperature from 96.8 F degrees to 86.0 F degrees and raising soil moisture from 7% to 37%. These conditions more than doubled shallot yield from 1.7 tons/acre to 4.1 tons/acre.