On-Farm Evaluation of a Humic Product in Iowa (U.S.) Maize Production
The benefit to corn (Zea mays L.) production ofa humic product derived from lignite was evaluated for three years under otherwise conventional crop management in Iowa farmers fields.A liquid extract,it was applied at a rate of 3.57 L ha-1,generally as a foliar spray mixed into routine pesticide applications during early stages of crop growth.In each of three years,hand-sampled corn plants collected at physiological maturity in 30 to 35 farmers fields across Iowa showed a significant increase in grain weight with product application in 70% to 80% of the cases,covering a range of soil types and grain yield levels.Mean increases were 630-940 kg ha-l,and these were inflated,as expected,compared to a limited number of yield increases estimated by mechanical combine,typically 310-630 kg ha-1,or about 5% of normal yield levels.Grain weight increases were associated with longer,thicker,and heavier cobs and slightly larger stover biomass.Plant nutrient concentrations were not affected at harvest.In-season measurements in a few intensively monitored farmers fields associated product application with slightly taller plants,increased leaf area,earlier onset of pollination,extended grain filling,and delayed senescence,i.e.,extended duration of photosynthesis and decayed rotting of stems.Limited visual observations indicated great proliferation of roots,especially lateral roots.Ongoing data assessment will identify any environmental factors of product efficacy,an issue that to date remains unexplored in the humic product literature.Initial studies of alfalfa (Medicago sativa L.) found biomass increases with product application of 7% to 29%.A newly begun corn trial on nitrogen fertilizer response will estimate the amount of N fertilizer input that can be replaced by humic product application to save input costs and mitigate environmental degradation.The humic product increased economic yield in a large majority of cases by amounts that were agronomically modest but economically significant.Future work will expand to soybean (Glycine max (L.) Merr.) production.
Humic product Maize Grain yield
Dan C.Olk Dana L.Dinnes Chad Callaway Mike Raske
USDA-ARS,National Laboratory for Agriculture and the Environment,Ames,IA 50011,USA Innovative Crop Solutions,Radcliffe,IA,50230,USA
国际会议
the 16th Meeting of the International Humic Substances Society (第十六届国际腐殖物质学会大会(IHSS 16))
杭州
英文
589-591
2012-09-09（万方平台首次上网日期，不代表论文的发表时间）