<b>Spatial variability of sunn hemp under residual effect of nitrogen and water salinity

• Main Authors: Pedro Ramualyson Fernandes Sampaio, Neyton de Oliveira Miranda, José Francismar de Medeiros, Jefferson Vieira José, José Flaviano Barbosa de Lira, Joana D’arc Jales de Mendonça
• Format: Article
• Language: English
• Published: Universidade Estadual de Maringá 2015-10-01
• Series: Acta Scientiarum: Technology
• Subjects: green manuring; spatial dependence; geostatistics; sustainability.
• Online Access: http://186.233.154.254/ojs/index.php/ActaSciTechnol/article/view/27279

This work had as objectives to use the Sunn Hemp (Crotalaria juncea L.) to evaluate the residual effect in the soil of levels of water salinity and nitrogen doses, and the occurrence of spatial dependence within the experimental area. In previous years, the experimental area received six consecutive trials, which tested different levels of nitrogen and water salinity on different crops. The same experimental design was applied to this trial, that is, a randomized block design with split-plots (5 x 3), corresponding to the residual effect of water salinity and nitrogen, and four replications. The variables determined were: the plant height on six dates after the sowing, and the dry mass of the shoot, root and the whole plant. The data were firstly subjected to the variance analysis of the residual effects and to the study of spatial variability through geostatistics. The variance analysis did not show significant residual effects of the levels of salinity and nitrogen doses in the soil on the height and dry mass of Sunn Hemp. It was observed a spatial dependence, from moderate to high, in all dates, for height and dry mass of Sunn Hemp.