Improved Rice Growth Following Addition of a Humic Product in Missouri.

Rice (O. sativa L.) is a major cereal grain crop grown in the Mississippi alluvial delta of the central United States. Humic products have been shown to stimulate plant growth in some situations.  In addition to increased plant growth, nutrient uptake of minerals has been reported in some studies.  Most of the published studies have been conducted in greenhouse situations.  Little information is available on the effects of humic acids in field crops, much less is available for rice.  This two-year study investigated the effects of additions of a humic product on biomass, nutrient uptake, and grain yield for rice.  This study was conducted in two adjacent field areas, one where the P & K fertility was maintained at optimum levels, the other where the P and K levels were sub optimum.  Four rates of a humic product were compared to an untreated check. Grain yields and dry matter accumulations were improved by 5-10% with addition of humic products.  These improvements were not related to the rate of humic product addition or the P & K levels of the study area.  A similar trend was found for uptake of the major plant mineral nutrients.