Start Date: May 15, 2012
End Date: May 14, 2015
Sales of humic products have increased in recent years. These products claim to promote plant growth and increase economic yield in production agriculture, although little published research has evaluated such claims. Underlying mechanisms for improved plant growth remain unidentified: it is unknown whether they would involve improved nutrient supply or other traits of soil performance or instead whether the product would directly stimulate the plant. No information exists on whether soil type alters the field efficacy of humic products. The objectives of the proposed research are to first acquire publishable agronomic information that will demonstrate whether a micronized (i.e., super-finely ground) humic product can significantly improve corn growth in field conditions, and on two different soil types. Second, the proposed research will begin testing the hypothesis that a humic product directly alters plant growth through a hormonal-like stimulation and not indirectly through changes in soil properties. This second objective would expand on our existing collaboration with another company, which determines the field efficacy of their humic product made through the conventional alkaline extraction of lignite ore. In a farmer's field, the efficacy of the micronized product in promoting corn growth will be evaluated at two application times in replicated treatments. Crop measurements during the growing season will include leaf area, chlorophyll meter determination of nitrogen status, nutrient status in young leaves at three growth stages, plant height, total biomass and nutrient uptake at harvest, and grain yield as mapped by combine yield monitor. Measurements of plant hormones and other growth stimulant compounds will be taken at selected growth stages. Visual observations of early ear development and root growth will be collected. Post-harvest measurements of hand-picked corn plants will include 100-grain weight, cob length and mass, and stover concentrations of phenols, carbohydrates, and amino acids. All plant measurements will be repeated in two zones of the field that differ in soil properties. Soil samples will be collected at harvest and analyzed to determine basic soil properties and any beneficial or deleterious effects of the humic product.