Faithin Omaha eBook Collection

Download or read book Evaluation of Two Procedures for Screening Legume Green Manures as Nitrogen Sources to Succeeding Corn written by Jorge Ovidio Quintana and published by . This book was released on 1987 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: As alternatives to the time consuming crop response studies, two screening procedures were proposed to estimate the potential of different legumes to supply nitrogen: a) a field procedure based on measurements of inorganic nitrogen accumulated in bare fallow soil after incorporating the legumes; and b) a laboratory procedure based on inorganic nitrogen released during aerobic incubation of soil samples from plots incorporated with legumes. The field procedure was tested on an irrigated experiment (dry season 1986). The legumes used, mucuna (Mucuna aterrima Merr.), jack beans (Canavalia ensiformes (L.), crotolaria (Crotolaria paulina Schrank) and zornia (Zornia latifolia Sm), were grown in the experimental site during the previous wet season and then incorporated in plots kept fallow or planted to corn (Zea mays L.) after incorporation. Inorganic nitrogen accumulated in fallow soil was correlated with both nitrogen content in corn aboveground dry matter (r=0.99, p=0.002) and nitroten in corn aboveground plus the residual inorganic nitrogen in cropped soil (r=0.99, p.=o.001). The results showed that the accumulation of inorganic nitrogen in fallow soil incorporated with legumes can be useful to estimate their potential to supply nitrogen for succeeding non-legume crops. The laboratory procedure was evaluated by comparing inorganic nitrogen released during aerobic incubation (35°C of soil samples (0.0-0.15) with corn yield parameters. Soil samples from the present and previous field experiments receibed different pre-incubation and incubation treatments. Soil samples incubated soon after being taken from the field gave the best correlations. The results of one (1) week incubation of samples oven dried at 50°C (the most covenient incubation procedure) were correlated (r=0.92, p=0.03) with N-uptake of corn in 1986. Therefore, the incubation procedure represents an alternative for estimating the nitrogen supplying potential of legumes.